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TP-Link_Archer-XR500v/EN7526G_3.18Kernel_SDK/apps/public/net-snmp-5.3.1/snmplib/snmpusm.c
Matheus Sampaio Queiroga aaca98136a
Add gpl
2024-07-22 01:58:46 -03:00

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/* Portions of this file are subject to the following copyright(s). See
* the Net-SNMP's COPYING file for more details and other copyrights
* that may apply:
*/
/*
* Portions of this file are copyrighted by:
* Copyright © 2003 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms specified in the COPYING file
* distributed with the Net-SNMP package.
*/
/*
* snmpusm.c
*
* Routines to manipulate a information about a "user" as
* defined by the SNMP-USER-BASED-SM-MIB MIB.
*
* All functions usm_set_usmStateReference_*() return 0 on success, -1
* otherwise.
*
* !! Tab stops set to 4 in some parts of this file. !!
* (Designated on a per function.)
*/
#include <net-snmp/net-snmp-config.h>
#include <sys/types.h>
#if HAVE_WINSOCK_H
#include <winsock.h>
#endif
#include <stdio.h>
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#if TIME_WITH_SYS_TIME
# ifdef WIN32
# include <sys/timeb.h>
# else
# include <sys/time.h>
# endif
# include <time.h>
#else
# if HAVE_SYS_TIME_H
# include <sys/time.h>
# else
# include <time.h>
# endif
#endif
#if HAVE_STRING_H
#include <string.h>
#else
#include <strings.h>
#endif
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#if HAVE_DMALLOC_H
#include <dmalloc.h>
#endif
#include <net-snmp/types.h>
#include <net-snmp/output_api.h>
#include <net-snmp/config_api.h>
#include <net-snmp/utilities.h>
#include <net-snmp/library/asn1.h>
#include <net-snmp/library/snmp_api.h>
#include <net-snmp/library/callback.h>
#include <net-snmp/library/tools.h>
#include <net-snmp/library/keytools.h>
#include <net-snmp/library/snmpv3.h>
#include <net-snmp/library/lcd_time.h>
#include <net-snmp/library/scapi.h>
#include <net-snmp/library/callback.h>
#include <net-snmp/library/snmp_secmod.h>
#include <net-snmp/library/snmpusm.h>
oid usmNoAuthProtocol[10] = { 1, 3, 6, 1, 6, 3, 10, 1, 1, 1 };
#ifndef DISABLE_MD5
oid usmHMACMD5AuthProtocol[10] =
{ 1, 3, 6, 1, 6, 3, 10, 1, 1, 2 };
#endif
oid usmHMACSHA1AuthProtocol[10] =
{ 1, 3, 6, 1, 6, 3, 10, 1, 1, 3 };
oid usmNoPrivProtocol[10] = { 1, 3, 6, 1, 6, 3, 10, 1, 2, 1 };
#ifndef DISABLE_DES
oid usmDESPrivProtocol[10] = { 1, 3, 6, 1, 6, 3, 10, 1, 2, 2 };
#endif
oid usmAESPrivProtocol[10] = { 1, 3, 6, 1, 6, 3, 10, 1, 2, 4 };
/* backwards compat */
oid *usmAES128PrivProtocol = usmAESPrivProtocol;
static u_int dummy_etime, dummy_eboot; /* For ISENGINEKNOWN(). */
/*
* Globals.
*/
static u_int salt_integer;
#ifdef HAVE_AES
static u_int salt_integer64_1, salt_integer64_2;
#endif
/*
* 1/2 of seed for the salt. Cf. RFC2274, Sect 8.1.1.1.
*/
static struct usmUser *noNameUser = NULL;
/*
* Local storage (LCD) of the default user list.
*/
static struct usmUser *userList = NULL;
/*
* Prototypes
*/
int
usm_check_secLevel_vs_protocols(int level,
const oid * authProtocol,
u_int authProtocolLen,
const oid * privProtocol,
u_int privProtocolLen);
int
usm_calc_offsets(size_t globalDataLen,
int secLevel, size_t secEngineIDLen,
size_t secNameLen, size_t scopedPduLen,
u_long engineboots, long engine_time,
size_t * theTotalLength,
size_t * authParamsOffset,
size_t * privParamsOffset,
size_t * dataOffset, size_t * datalen,
size_t * msgAuthParmLen,
size_t * msgPrivParmLen, size_t * otstlen,
size_t * seq_len, size_t * msgSecParmLen);
/*
* Set a given field of the secStateRef.
*
* Allocate <len> bytes for type <type> pointed to by ref-><field>.
* Then copy in <item> and record its length in ref-><field_len>.
*
* Return 0 on success, -1 otherwise.
*/
#define MAKE_ENTRY( type, item, len, field, field_len ) \
{ \
if (ref == NULL) \
return -1; \
if (ref->field != NULL) { \
SNMP_ZERO(ref->field, ref->field_len); \
SNMP_FREE(ref->field); \
} \
ref->field_len = 0; \
if (len == 0 || item == NULL) { \
return 0; \
} \
if ((ref->field = (type*) malloc (len * sizeof(type))) == NULL) \
{ \
return -1; \
} \
\
memcpy (ref->field, item, len * sizeof(type)); \
ref->field_len = len; \
\
return 0; \
}
struct usmStateReference *
usm_malloc_usmStateReference(void)
{
struct usmStateReference *retval = (struct usmStateReference *)
calloc(1, sizeof(struct usmStateReference));
return retval;
} /* end usm_malloc_usmStateReference() */
void
usm_free_usmStateReference(void *old)
{
struct usmStateReference *old_ref = (struct usmStateReference *) old;
if (old_ref) {
SNMP_FREE(old_ref->usr_name);
SNMP_FREE(old_ref->usr_engine_id);
SNMP_FREE(old_ref->usr_auth_protocol);
SNMP_FREE(old_ref->usr_priv_protocol);
if (old_ref->usr_auth_key) {
SNMP_ZERO(old_ref->usr_auth_key, old_ref->usr_auth_key_length);
SNMP_FREE(old_ref->usr_auth_key);
}
if (old_ref->usr_priv_key) {
SNMP_ZERO(old_ref->usr_priv_key, old_ref->usr_priv_key_length);
SNMP_FREE(old_ref->usr_priv_key);
}
SNMP_ZERO(old_ref, sizeof(*old_ref));
SNMP_FREE(old_ref);
}
} /* end usm_free_usmStateReference() */
struct usmUser *
usm_get_userList(void)
{
return userList;
}
int
usm_set_usmStateReference_name(struct usmStateReference *ref,
char *name, size_t name_len)
{
MAKE_ENTRY(char, name, name_len, usr_name, usr_name_length);
}
int
usm_set_usmStateReference_engine_id(struct usmStateReference *ref,
u_char * engine_id,
size_t engine_id_len)
{
MAKE_ENTRY(u_char, engine_id, engine_id_len,
usr_engine_id, usr_engine_id_length);
}
int
usm_set_usmStateReference_auth_protocol(struct usmStateReference *ref,
oid * auth_protocol,
size_t auth_protocol_len)
{
MAKE_ENTRY(oid, auth_protocol, auth_protocol_len,
usr_auth_protocol, usr_auth_protocol_length);
}
int
usm_set_usmStateReference_auth_key(struct usmStateReference *ref,
u_char * auth_key, size_t auth_key_len)
{
MAKE_ENTRY(u_char, auth_key, auth_key_len,
usr_auth_key, usr_auth_key_length);
}
int
usm_set_usmStateReference_priv_protocol(struct usmStateReference *ref,
oid * priv_protocol,
size_t priv_protocol_len)
{
MAKE_ENTRY(oid, priv_protocol, priv_protocol_len,
usr_priv_protocol, usr_priv_protocol_length);
}
int
usm_set_usmStateReference_priv_key(struct usmStateReference *ref,
u_char * priv_key, size_t priv_key_len)
{
MAKE_ENTRY(u_char, priv_key, priv_key_len,
usr_priv_key, usr_priv_key_length);
}
int
usm_set_usmStateReference_sec_level(struct usmStateReference *ref,
int sec_level)
{
if (ref == NULL)
return -1;
ref->usr_sec_level = sec_level;
return 0;
}
#ifdef SNMP_TESTING_CODE
/*******************************************************************-o-******
* emergency_print
*
* Parameters:
* *field
* length
*
* This is a print routine that is solely included so that it can be
* used in gdb. Don't use it as a function, it will be pulled before
* a real release of the code.
*
* tab stop 4
*
* XXX fflush() only works on FreeBSD; core dumps on Sun OS's
*/
void
emergency_print(u_char * field, u_int length)
{
int iindex;
int start = 0;
int stop = 25;
while (start < stop) {
for (iindex = start; iindex < stop; iindex++)
printf("%02X ", field[iindex]);
printf("\n");
start = stop;
stop = stop + 25 < length ? stop + 25 : length;
}
fflush(0);
} /* end emergency_print() */
#endif /* SNMP_TESTING_CODE */
/*******************************************************************-o-******
* asn_predict_int_length
*
* Parameters:
* type (UNUSED)
* number
* len
*
* Returns:
* Number of bytes necessary to store the ASN.1 encoded value of 'number'.
*
*
* This gives the number of bytes that the ASN.1 encoder (in asn1.c) will
* use to encode a particular integer value.
*
* Returns the length of the integer -- NOT THE HEADER!
*
* Do this the same way as asn_build_int()...
*/
int
asn_predict_int_length(int type, long number, size_t len)
{
register u_long mask;
if (len != sizeof(long))
return -1;
mask = ((u_long) 0x1FF) << ((8 * (sizeof(long) - 1)) - 1);
/*
* mask is 0xFF800000 on a big-endian machine
*/
while ((((number & mask) == 0) || ((number & mask) == mask))
&& len > 1) {
len--;
number <<= 8;
}
return len;
} /* end asn_predict_length() */
/*******************************************************************-o-******
* asn_predict_length
*
* Parameters:
* type
* *ptr
* u_char_len
*
* Returns:
* Length in bytes: 1 + <n> + <u_char_len>, where
*
* 1 For the ASN.1 type.
* <n> # of bytes to store length of data.
* <u_char_len> Length of data associated with ASN.1 type.
*
* This gives the number of bytes that the ASN.1 encoder (in asn1.c) will
* use to encode a particular integer value. This is as broken as the
* currently used encoder.
*
* XXX How is <n> chosen, exactly??
*/
int
asn_predict_length(int type, u_char * ptr, size_t u_char_len)
{
if (type & ASN_SEQUENCE)
return 1 + 3 + u_char_len;
if (type & ASN_INTEGER) {
u_long value;
memcpy(&value, ptr, u_char_len);
u_char_len = asn_predict_int_length(type, value, u_char_len);
}
if (u_char_len < 0x80)
return 1 + 1 + u_char_len;
else if (u_char_len < 0xFF)
return 1 + 2 + u_char_len;
else
return 1 + 3 + u_char_len;
} /* end asn_predict_length() */
/*******************************************************************-o-******
* usm_calc_offsets
*
* Parameters:
* (See list below...)
*
* Returns:
* 0 On success,
* -1 Otherwise.
*
*
* This routine calculates the offsets into an outgoing message buffer
* for the necessary values. The outgoing buffer will generically
* look like this:
*
* SNMPv3 Message
* SEQ len[11]
* INT len version
* Header
* SEQ len
* INT len MsgID
* INT len msgMaxSize
* OST len msgFlags (OST = OCTET STRING)
* INT len msgSecurityModel
* MsgSecurityParameters
* [1] OST len[2]
* SEQ len[3]
* OST len msgAuthoritativeEngineID
* INT len msgAuthoritativeEngineBoots
* INT len msgAuthoritativeEngineTime
* OST len msgUserName
* OST len[4] [5] msgAuthenticationParameters
* OST len[6] [7] msgPrivacyParameters
* MsgData
* [8] OST len[9] [10] encryptedPDU
* or
* [8,10] SEQUENCE len[9] scopedPDU
* [12]
*
* The bracketed points will be needed to be identified ([x] is an index
* value, len[x] means a length value). Here is a semantic guide to them:
*
* [1] = globalDataLen (input)
* [2] = otstlen
* [3] = seq_len
* [4] = msgAuthParmLen (may be 0 or 12)
* [5] = authParamsOffset
* [6] = msgPrivParmLen (may be 0 or 8)
* [7] = privParamsOffset
* [8] = globalDataLen + msgSecParmLen
* [9] = datalen
* [10] = dataOffset
* [11] = theTotalLength - the length of the header itself
* [12] = theTotalLength
*/
int
usm_calc_offsets(size_t globalDataLen, /* SNMPv3Message + HeaderData */
int secLevel, size_t secEngineIDLen, size_t secNameLen, size_t scopedPduLen, /* An BER encoded sequence. */
u_long engineboots, /* XXX (asn1.c works in long, not int.) */
long engine_time, /* XXX (asn1.c works in long, not int.) */
size_t * theTotalLength, /* globalDataLen + msgSecurityP. + msgData */
size_t * authParamsOffset, /* Distance to auth bytes. */
size_t * privParamsOffset, /* Distance to priv bytes. */
size_t * dataOffset, /* Distance to scopedPdu SEQ -or- the
* crypted (data) portion of msgData. */
size_t * datalen, /* Size of msgData OCTET STRING encoding. */
size_t * msgAuthParmLen, /* Size of msgAuthenticationParameters. */
size_t * msgPrivParmLen, /* Size of msgPrivacyParameters. */
size_t * otstlen, /* Size of msgSecurityP. O.S. encoding. */
size_t * seq_len, /* Size of msgSecurityP. SEQ data. */
size_t * msgSecParmLen)
{ /* Size of msgSecurityP. SEQ. */
int engIDlen, /* Sizes of OCTET STRING and SEQ encodings */
engBtlen, /* for fields within */
engTmlen, /* msgSecurityParameters portion of */
namelen, /* SNMPv3Message. */
authlen, privlen;
/*
* If doing authentication, msgAuthParmLen = 12 else msgAuthParmLen = 0.
* If doing encryption, msgPrivParmLen = 8 else msgPrivParmLen = 0.
*/
*msgAuthParmLen = (secLevel == SNMP_SEC_LEVEL_AUTHNOPRIV
|| secLevel == SNMP_SEC_LEVEL_AUTHPRIV) ? 12 : 0;
*msgPrivParmLen = (secLevel == SNMP_SEC_LEVEL_AUTHPRIV) ? 8 : 0;
/*
* Calculate lengths.
*/
if ((engIDlen = asn_predict_length(ASN_OCTET_STR,
0, secEngineIDLen)) == -1) {
return -1;
}
if ((engBtlen = asn_predict_length(ASN_INTEGER,
(u_char *) & engineboots,
sizeof(long))) == -1) {
return -1;
}
if ((engTmlen = asn_predict_length(ASN_INTEGER,
(u_char *) & engine_time,
sizeof(long))) == -1) {
return -1;
}
if ((namelen = asn_predict_length(ASN_OCTET_STR, 0, secNameLen)) == -1) {
return -1;
}
if ((authlen = asn_predict_length(ASN_OCTET_STR,
0, *msgAuthParmLen)) == -1) {
return -1;
}
if ((privlen = asn_predict_length(ASN_OCTET_STR,
0, *msgPrivParmLen)) == -1) {
return -1;
}
*seq_len =
engIDlen + engBtlen + engTmlen + namelen + authlen + privlen;
if ((*otstlen = asn_predict_length(ASN_SEQUENCE, 0, *seq_len)) == -1) {
return -1;
}
if ((*msgSecParmLen = asn_predict_length(ASN_OCTET_STR,
0, *otstlen)) == -1) {
return -1;
}
*authParamsOffset = globalDataLen + +(*msgSecParmLen - *seq_len)
+ engIDlen + engBtlen + engTmlen + namelen
+ (authlen - *msgAuthParmLen);
*privParamsOffset = *authParamsOffset + *msgAuthParmLen
+ (privlen - *msgPrivParmLen);
/*
* Compute the size of the plaintext. Round up to account for cipher
* block size, if necessary.
*
* XXX This is hardwired for 1DES... If scopedPduLen is already
* a multiple of 8, then *add* 8 more; otherwise, round up
* to the next multiple of 8.
*
* FIX Calculation of encrypted portion of msgData and consequent
* setting and sanity checking of theTotalLength, et al. should
* occur *after* encryption has taken place.
*/
if (secLevel == SNMP_SEC_LEVEL_AUTHPRIV) {
scopedPduLen = ROUNDUP8(scopedPduLen);
if ((*datalen =
asn_predict_length(ASN_OCTET_STR, 0, scopedPduLen)) == -1) {
return -1;
}
} else {
*datalen = scopedPduLen;
}
*dataOffset = globalDataLen + *msgSecParmLen +
(*datalen - scopedPduLen);
*theTotalLength = globalDataLen + *msgSecParmLen + *datalen;
return 0;
} /* end usm_calc_offsets() */
#ifndef DISABLE_DES
/*******************************************************************-o-******
* usm_set_salt
*
* Parameters:
* *iv (O) Buffer to contain IV.
* *iv_length (O) Length of iv.
* *priv_salt (I) Salt portion of private key.
* priv_salt_length (I) Length of priv_salt.
* *msgSalt (I/O) Pointer salt portion of outgoing msg buffer.
*
* Returns:
* 0 On success,
* -1 Otherwise.
*
* Determine the initialization vector for the DES-CBC encryption.
* (Cf. RFC 2274, 8.1.1.1.)
*
* iv is defined as the concatenation of engineBoots and the
* salt integer.
* The salt integer is incremented.
* The resulting salt is copied into the msgSalt buffer.
* The result of the concatenation is then XORed with the salt
* portion of the private key (last 8 bytes).
* The IV result is returned individually for further use.
*/
int
usm_set_salt(u_char * iv,
size_t * iv_length,
u_char * priv_salt, size_t priv_salt_length, u_char * msgSalt)
{
size_t propersize_salt = BYTESIZE(USM_DES_SALT_LENGTH);
int net_boots;
int net_salt_int;
/*
* net_* should be encoded in network byte order. XXX Why?
*/
int iindex;
/*
* Sanity check.
*/
if (!iv || !iv_length || !priv_salt || (*iv_length != propersize_salt)
|| (priv_salt_length < propersize_salt)) {
return -1;
}
net_boots = htonl(snmpv3_local_snmpEngineBoots());
net_salt_int = htonl(salt_integer);
salt_integer += 1;
memcpy(iv, &net_boots, propersize_salt / 2);
memcpy(iv + (propersize_salt / 2), &net_salt_int, propersize_salt / 2);
if (msgSalt)
memcpy(msgSalt, iv, propersize_salt);
/*
* Turn the salt into an IV: XOR <boots, salt_int> with salt
* portion of priv_key.
*/
for (iindex = 0; iindex < (int) propersize_salt; iindex++)
iv[iindex] ^= priv_salt[iindex];
return 0;
} /* end usm_set_salt() */
#endif
#ifdef HAVE_AES
/*******************************************************************-o-******
* usm_set_aes_iv
*
* Parameters:
* *iv (O) Buffer to contain IV.
* *iv_length (O) Length of iv.
* net_boots (I) the network byte order of the authEng boots val
* net_time (I) the network byte order of the authEng time val
* *salt (O) A buffer for the outgoing salt (= 8 bytes of iv)
*
* Returns:
* 0 On success,
* -1 Otherwise.
*
* Determine the initialization vector for AES encryption.
* (draft-blumenthal-aes-usm-03.txt, 3.1.2.2)
*
* iv is defined as the concatenation of engineBoots, engineTime
and a 64 bit salt-integer.
* The 64 bit salt integer is incremented.
* The resulting salt is copied into the salt buffer.
* The IV result is returned individually for further use.
*/
int
usm_set_aes_iv(u_char * iv,
size_t * iv_length,
u_int net_boots,
u_int net_time,
u_char * salt)
{
/*
* net_* should be encoded in network byte order.
*/
int net_salt_int1, net_salt_int2;
#define PROPER_AES_IV_SIZE 64
/*
* Sanity check.
*/
if (!iv || !iv_length) {
return -1;
}
net_salt_int1 = htonl(salt_integer64_1);
net_salt_int2 = htonl(salt_integer64_2);
if ((salt_integer64_2 += 1) == 0)
salt_integer64_2 += 1;
/* XXX: warning: hard coded proper lengths */
memcpy(iv, &net_boots, 4);
memcpy(iv+4, &net_time, 4);
memcpy(iv+8, &net_salt_int1, 4);
memcpy(iv+12, &net_salt_int2, 4);
memcpy(salt, iv+8, 8); /* only copy the needed portion */
return 0;
} /* end usm_set_salt() */
#endif /* HAVE_AES */
int
usm_secmod_generate_out_msg(struct snmp_secmod_outgoing_params *parms)
{
if (!parms)
return SNMPERR_GENERR;
return usm_generate_out_msg(parms->msgProcModel,
parms->globalData, parms->globalDataLen,
parms->maxMsgSize, parms->secModel,
parms->secEngineID, parms->secEngineIDLen,
parms->secName, parms->secNameLen,
parms->secLevel,
parms->scopedPdu, parms->scopedPduLen,
parms->secStateRef,
parms->secParams, parms->secParamsLen,
parms->wholeMsg, parms->wholeMsgLen);
}
/*******************************************************************-o-******
* usm_generate_out_msg
*
* Parameters:
* (See list below...)
*
* Returns:
* SNMPERR_SUCCESS On success.
* SNMPERR_USM_AUTHENTICATIONFAILURE
* SNMPERR_USM_ENCRYPTIONERROR
* SNMPERR_USM_GENERICERROR
* SNMPERR_USM_UNKNOWNSECURITYNAME
* SNMPERR_USM_GENERICERROR
* SNMPERR_USM_UNSUPPORTEDSECURITYLEVEL
*
*
* Generates an outgoing message.
*
* XXX Beware of misnomers!
*/
int
usm_generate_out_msg(int msgProcModel, /* (UNUSED) */
u_char * globalData, /* IN */
/*
* Pointer to msg header data will point to the beginning
* * of the entire packet buffer to be transmitted on wire,
* * memory will be contiguous with secParams, typically
* * this pointer will be passed back as beginning of
* * wholeMsg below. asn seq. length is updated w/ new length.
* *
* * While this points to a buffer that should be big enough
* * for the whole message, only the first two parts
* * of the message are completed, namely SNMPv3Message and
* * HeaderData. globalDataLen (next parameter) represents
* * the length of these two completed parts.
*/
size_t globalDataLen, /* IN - Length of msg header data. */
int maxMsgSize, /* (UNUSED) */
int secModel, /* (UNUSED) */
u_char * secEngineID, /* IN - Pointer snmpEngineID. */
size_t secEngineIDLen, /* IN - SnmpEngineID length. */
char *secName, /* IN - Pointer to securityName. */
size_t secNameLen, /* IN - SecurityName length. */
int secLevel, /* IN - AuthNoPriv, authPriv etc. */
u_char * scopedPdu, /* IN */
/*
* Pointer to scopedPdu will be encrypted by USM if needed
* * and written to packet buffer immediately following
* * securityParameters, entire msg will be authenticated by
* * USM if needed.
*/
size_t scopedPduLen, /* IN - scopedPdu length. */
void *secStateRef, /* IN */
/*
* secStateRef, pointer to cached info provided only for
* * Response, otherwise NULL.
*/
u_char * secParams, /* OUT */
/*
* BER encoded securityParameters pointer to offset within
* * packet buffer where secParams should be written, the
* * entire BER encoded OCTET STRING (including header) is
* * written here by USM secParams = globalData +
* * globalDataLen.
*/
size_t * secParamsLen, /* IN/OUT - Len available, len returned. */
u_char ** wholeMsg, /* OUT */
/*
* Complete authenticated/encrypted message - typically
* * the pointer to start of packet buffer provided in
* * globalData is returned here, could also be a separate
* * buffer.
*/
size_t * wholeMsgLen)
{ /* IN/OUT - Len available, len returned. */
size_t otstlen;
size_t seq_len;
size_t msgAuthParmLen;
size_t msgPrivParmLen;
size_t msgSecParmLen;
size_t authParamsOffset;
size_t privParamsOffset;
size_t datalen;
size_t dataOffset;
size_t theTotalLength;
u_char *ptr;
size_t ptr_len;
size_t remaining;
size_t offSet;
u_int boots_uint;
u_int time_uint;
long boots_long;
long time_long;
/*
* Indirection because secStateRef values override parameters.
*
* None of these are to be free'd - they are either pointing to
* what's in the secStateRef or to something either in the
* actual prarmeter list or the user list.
*/
char *theName = NULL;
u_int theNameLength = 0;
u_char *theEngineID = NULL;
u_int theEngineIDLength = 0;
u_char *theAuthKey = NULL;
u_int theAuthKeyLength = 0;
const oid *theAuthProtocol = NULL;
u_int theAuthProtocolLength = 0;
u_char *thePrivKey = NULL;
u_int thePrivKeyLength = 0;
const oid *thePrivProtocol = NULL;
u_int thePrivProtocolLength = 0;
int theSecLevel = 0; /* No defined const for bad
* value (other then err).
*/
DEBUGMSGTL(("usm", "USM processing has begun.\n"));
if (secStateRef != NULL) {
/*
* To hush the compiler for now. XXX
*/
struct usmStateReference *ref
= (struct usmStateReference *) secStateRef;
theName = ref->usr_name;
theNameLength = ref->usr_name_length;
theEngineID = ref->usr_engine_id;
theEngineIDLength = ref->usr_engine_id_length;
if (!theEngineIDLength) {
theEngineID = secEngineID;
theEngineIDLength = secEngineIDLen;
}
theAuthProtocol = ref->usr_auth_protocol;
theAuthProtocolLength = ref->usr_auth_protocol_length;
theAuthKey = ref->usr_auth_key;
theAuthKeyLength = ref->usr_auth_key_length;
thePrivProtocol = ref->usr_priv_protocol;
thePrivProtocolLength = ref->usr_priv_protocol_length;
thePrivKey = ref->usr_priv_key;
thePrivKeyLength = ref->usr_priv_key_length;
theSecLevel = ref->usr_sec_level;
}
/*
* Identify the user record.
*/
else {
struct usmUser *user;
/*
* we do allow an unknown user name for
* unauthenticated requests.
*/
if ((user = usm_get_user(secEngineID, secEngineIDLen, secName))
== NULL && secLevel != SNMP_SEC_LEVEL_NOAUTH) {
DEBUGMSGTL(("usm", "Unknown User(%s)\n", secName));
usm_free_usmStateReference(secStateRef);
return SNMPERR_USM_UNKNOWNSECURITYNAME;
}
theName = secName;
theNameLength = secNameLen;
theEngineID = secEngineID;
theSecLevel = secLevel;
theEngineIDLength = secEngineIDLen;
if (user) {
theAuthProtocol = user->authProtocol;
theAuthProtocolLength = user->authProtocolLen;
theAuthKey = user->authKey;
theAuthKeyLength = user->authKeyLen;
thePrivProtocol = user->privProtocol;
thePrivProtocolLength = user->privProtocolLen;
thePrivKey = user->privKey;
thePrivKeyLength = user->privKeyLen;
} else {
/*
* unknown users can not do authentication (obviously)
*/
theAuthProtocol = usmNoAuthProtocol;
theAuthProtocolLength =
sizeof(usmNoAuthProtocol) / sizeof(oid);
theAuthKey = NULL;
theAuthKeyLength = 0;
thePrivProtocol = usmNoPrivProtocol;
thePrivProtocolLength =
sizeof(usmNoPrivProtocol) / sizeof(oid);
thePrivKey = NULL;
thePrivKeyLength = 0;
}
} /* endif -- secStateRef==NULL */
/*
* From here to the end of the function, avoid reference to
* secName, secEngineID, secLevel, and associated lengths.
*/
/*
* Check to see if the user can use the requested sec services.
*/
if (usm_check_secLevel_vs_protocols(theSecLevel,
theAuthProtocol,
theAuthProtocolLength,
thePrivProtocol,
thePrivProtocolLength) == 1) {
DEBUGMSGTL(("usm", "Unsupported Security Level (%d)\n",
theSecLevel));
usm_free_usmStateReference(secStateRef);
return SNMPERR_USM_UNSUPPORTEDSECURITYLEVEL;
}
/*
* Retrieve the engine information.
*
* XXX No error is declared in the EoP when sending messages to
* unknown engines, processing continues w/ boots/time == (0,0).
*/
if (get_enginetime(theEngineID, theEngineIDLength,
&boots_uint, &time_uint, FALSE) == -1) {
DEBUGMSGTL(("usm", "%s\n", "Failed to find engine data."));
}
boots_long = boots_uint;
time_long = time_uint;
/*
* Set up the Offsets.
*/
if (usm_calc_offsets(globalDataLen, theSecLevel, theEngineIDLength,
theNameLength, scopedPduLen, boots_long,
time_long, &theTotalLength, &authParamsOffset,
&privParamsOffset, &dataOffset, &datalen,
&msgAuthParmLen, &msgPrivParmLen, &otstlen,
&seq_len, &msgSecParmLen) == -1) {
DEBUGMSGTL(("usm", "Failed calculating offsets.\n"));
usm_free_usmStateReference(secStateRef);
return SNMPERR_USM_GENERICERROR;
}
/*
* So, we have the offsets for the three parts that need to be
* determined, and an overall length. Now we need to make
* sure all of this would fit in the outgoing buffer, and
* whether or not we need to make a new buffer, etc.
*/
/*
* Set wholeMsg as a pointer to globalData. Sanity check for
* the proper size.
*
* Mark workspace in the message with bytes of all 1's to make it
* easier to find mistakes in raw message dumps.
*/
ptr = *wholeMsg = globalData;
if (theTotalLength > *wholeMsgLen) {
DEBUGMSGTL(("usm", "Message won't fit in buffer.\n"));
usm_free_usmStateReference(secStateRef);
return SNMPERR_USM_GENERICERROR;
}
ptr_len = *wholeMsgLen = theTotalLength;
#ifdef SNMP_TESTING_CODE
memset(&ptr[globalDataLen], 0xFF, theTotalLength - globalDataLen);
#endif /* SNMP_TESTING_CODE */
/*
* Do the encryption.
*/
if (theSecLevel == SNMP_SEC_LEVEL_AUTHPRIV) {
size_t encrypted_length = theTotalLength - dataOffset;
size_t salt_length = BYTESIZE(USM_MAX_SALT_LENGTH);
u_char salt[BYTESIZE(USM_MAX_SALT_LENGTH)];
/*
* XXX Hardwired to seek into a 1DES private key!
*/
#ifdef HAVE_AES
if (ISTRANSFORM(thePrivProtocol, AESPriv)) {
if (!thePrivKey ||
usm_set_aes_iv(salt, &salt_length,
htonl(boots_uint), htonl(time_uint),
&ptr[privParamsOffset]) == -1) {
DEBUGMSGTL(("usm", "Can't set AES iv.\n"));
usm_free_usmStateReference(secStateRef);
return SNMPERR_USM_GENERICERROR;
}
}
#endif
#ifndef DISABLE_DES
if (ISTRANSFORM(thePrivProtocol, DESPriv)) {
if (!thePrivKey ||
(usm_set_salt(salt, &salt_length,
thePrivKey + 8, thePrivKeyLength - 8,
&ptr[privParamsOffset])
== -1)) {
DEBUGMSGTL(("usm", "Can't set DES-CBC salt.\n"));
usm_free_usmStateReference(secStateRef);
return SNMPERR_USM_GENERICERROR;
}
}
#endif
if (sc_encrypt(thePrivProtocol, thePrivProtocolLength,
thePrivKey, thePrivKeyLength,
salt, salt_length,
scopedPdu, scopedPduLen,
&ptr[dataOffset], &encrypted_length)
!= SNMP_ERR_NOERROR) {
DEBUGMSGTL(("usm", "encryption error.\n"));
usm_free_usmStateReference(secStateRef);
return SNMPERR_USM_ENCRYPTIONERROR;
}
#ifdef SNMP_TESTING_CODE
if (debug_is_token_registered("usm/dump") == SNMPERR_SUCCESS) {
dump_chunk("usm/dump", "This data was encrypted:",
scopedPdu, scopedPduLen);
dump_chunk("usm/dump", "salt + Encrypted form:",
salt, salt_length);
dump_chunk("usm/dump", NULL,
&ptr[dataOffset], encrypted_length);
dump_chunk("usm/dump", "*wholeMsg:",
*wholeMsg, theTotalLength);
}
#endif
ptr = *wholeMsg;
ptr_len = *wholeMsgLen = theTotalLength;
/*
* XXX Sanity check for salt length should be moved up
* under usm_calc_offsets() or tossed.
*/
if ((encrypted_length != (theTotalLength - dataOffset))
|| (salt_length != msgPrivParmLen)) {
DEBUGMSGTL(("usm", "encryption length error.\n"));
usm_free_usmStateReference(secStateRef);
return SNMPERR_USM_ENCRYPTIONERROR;
}
DEBUGMSGTL(("usm", "Encryption successful.\n"));
}
/*
* No encryption for you!
*/
else {
memcpy(&ptr[dataOffset], scopedPdu, scopedPduLen);
}
/*
* Start filling in the other fields (in prep for authentication).
*
* offSet is an octet string header, which is different from all
* the other headers.
*/
remaining = ptr_len - globalDataLen;
offSet = ptr_len - remaining;
asn_build_header(&ptr[offSet], &remaining,
(u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE |
ASN_OCTET_STR), otstlen);
offSet = ptr_len - remaining;
asn_build_sequence(&ptr[offSet], &remaining,
(u_char) (ASN_SEQUENCE | ASN_CONSTRUCTOR), seq_len);
offSet = ptr_len - remaining;
DEBUGDUMPHEADER("send", "msgAuthoritativeEngineID");
asn_build_string(&ptr[offSet], &remaining,
(u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE |
ASN_OCTET_STR), theEngineID,
theEngineIDLength);
DEBUGINDENTLESS();
offSet = ptr_len - remaining;
DEBUGDUMPHEADER("send", "msgAuthoritativeEngineBoots");
asn_build_int(&ptr[offSet], &remaining,
(u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_INTEGER),
&boots_long, sizeof(long));
DEBUGINDENTLESS();
offSet = ptr_len - remaining;
DEBUGDUMPHEADER("send", "msgAuthoritativeEngineTime");
asn_build_int(&ptr[offSet], &remaining,
(u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_INTEGER),
&time_long, sizeof(long));
DEBUGINDENTLESS();
offSet = ptr_len - remaining;
DEBUGDUMPHEADER("send", "msgUserName");
asn_build_string(&ptr[offSet], &remaining,
(u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE |
ASN_OCTET_STR), (u_char *) theName,
theNameLength);
DEBUGINDENTLESS();
/*
* Note: if there is no authentication being done,
* msgAuthParmLen is 0, and there is no effect (other than
* inserting a zero-length header) of the following
* statements.
*/
offSet = ptr_len - remaining;
asn_build_header(&ptr[offSet],
&remaining,
(u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE |
ASN_OCTET_STR), msgAuthParmLen);
if (theSecLevel == SNMP_SEC_LEVEL_AUTHNOPRIV
|| theSecLevel == SNMP_SEC_LEVEL_AUTHPRIV) {
offSet = ptr_len - remaining;
memset(&ptr[offSet], 0, msgAuthParmLen);
}
remaining -= msgAuthParmLen;
/*
* Note: if there is no encryption being done, msgPrivParmLen
* is 0, and there is no effect (other than inserting a
* zero-length header) of the following statements.
*/
offSet = ptr_len - remaining;
asn_build_header(&ptr[offSet],
&remaining,
(u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE |
ASN_OCTET_STR), msgPrivParmLen);
remaining -= msgPrivParmLen; /* Skipping the IV already there. */
/*
* For privacy, need to add the octet string header for it.
*/
if (theSecLevel == SNMP_SEC_LEVEL_AUTHPRIV) {
offSet = ptr_len - remaining;
asn_build_header(&ptr[offSet],
&remaining,
(u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE |
ASN_OCTET_STR),
theTotalLength - dataOffset);
}
/*
* Adjust overall length and store it as the first SEQ length
* of the SNMPv3Message.
*
* FIX 4 is a magic number!
*/
remaining = theTotalLength;
asn_build_sequence(ptr, &remaining,
(u_char) (ASN_SEQUENCE | ASN_CONSTRUCTOR),
theTotalLength - 4);
/*
* Now, time to consider / do authentication.
*/
if (theSecLevel == SNMP_SEC_LEVEL_AUTHNOPRIV
|| theSecLevel == SNMP_SEC_LEVEL_AUTHPRIV) {
size_t temp_sig_len = msgAuthParmLen;
u_char *temp_sig = (u_char *) malloc(temp_sig_len);
if (temp_sig == NULL) {
DEBUGMSGTL(("usm", "Out of memory.\n"));
usm_free_usmStateReference(secStateRef);
return SNMPERR_USM_GENERICERROR;
}
if (sc_generate_keyed_hash(theAuthProtocol, theAuthProtocolLength,
theAuthKey, theAuthKeyLength,
ptr, ptr_len, temp_sig, &temp_sig_len)
!= SNMP_ERR_NOERROR) {
/*
* FIX temp_sig_len defined?!
*/
SNMP_ZERO(temp_sig, temp_sig_len);
SNMP_FREE(temp_sig);
DEBUGMSGTL(("usm", "Signing failed.\n"));
usm_free_usmStateReference(secStateRef);
return SNMPERR_USM_AUTHENTICATIONFAILURE;
}
if (temp_sig_len != msgAuthParmLen) {
SNMP_ZERO(temp_sig, temp_sig_len);
SNMP_FREE(temp_sig);
DEBUGMSGTL(("usm", "Signing lengths failed.\n"));
usm_free_usmStateReference(secStateRef);
return SNMPERR_USM_AUTHENTICATIONFAILURE;
}
memcpy(&ptr[authParamsOffset], temp_sig, msgAuthParmLen);
SNMP_ZERO(temp_sig, temp_sig_len);
SNMP_FREE(temp_sig);
}
/*
* endif -- create keyed hash
*/
usm_free_usmStateReference(secStateRef);
DEBUGMSGTL(("usm", "USM processing completed.\n"));
return SNMPERR_SUCCESS;
} /* end usm_generate_out_msg() */
#ifdef USE_REVERSE_ASNENCODING
int
usm_secmod_rgenerate_out_msg(struct snmp_secmod_outgoing_params *parms)
{
if (!parms)
return SNMPERR_GENERR;
return usm_rgenerate_out_msg(parms->msgProcModel,
parms->globalData, parms->globalDataLen,
parms->maxMsgSize, parms->secModel,
parms->secEngineID, parms->secEngineIDLen,
parms->secName, parms->secNameLen,
parms->secLevel,
parms->scopedPdu, parms->scopedPduLen,
parms->secStateRef,
parms->wholeMsg, parms->wholeMsgLen,
parms->wholeMsgOffset);
}
int
usm_rgenerate_out_msg(int msgProcModel, /* (UNUSED) */
u_char * globalData, /* IN */
/*
* points at the msgGlobalData, which is of length given by next
* parameter.
*/
size_t globalDataLen, /* IN - Length of msg header data. */
int maxMsgSize, /* (UNUSED) */
int secModel, /* (UNUSED) */
u_char * secEngineID, /* IN - Pointer snmpEngineID. */
size_t secEngineIDLen, /* IN - SnmpEngineID length. */
char *secName, /* IN - Pointer to securityName. */
size_t secNameLen, /* IN - SecurityName length. */
int secLevel, /* IN - AuthNoPriv, authPriv etc. */
u_char * scopedPdu, /* IN */
/*
* Pointer to scopedPdu will be encrypted by USM if needed
* * and written to packet buffer immediately following
* * securityParameters, entire msg will be authenticated by
* * USM if needed.
*/
size_t scopedPduLen, /* IN - scopedPdu length. */
void *secStateRef, /* IN */
/*
* secStateRef, pointer to cached info provided only for
* * Response, otherwise NULL.
*/
u_char ** wholeMsg, /* IN/OUT */
/*
* Points at the pointer to the packet buffer, which might get extended
* if necessary via realloc().
*/
size_t * wholeMsgLen, /* IN/OUT */
/*
* Length of the entire packet buffer, **not** the length of the
* packet.
*/
size_t * offset /* IN/OUT */
/*
* Offset from the end of the packet buffer to the start of the packet,
* also known as the packet length.
*/
)
{
size_t msgAuthParmLen = 0;
#ifdef SNMP_TESTING_CODE
size_t theTotalLength;
#endif
u_int boots_uint;
u_int time_uint;
long boots_long;
long time_long;
/*
* Indirection because secStateRef values override parameters.
*
* None of these are to be free'd - they are either pointing to
* what's in the secStateRef or to something either in the
* actual parameter list or the user list.
*/
char *theName = NULL;
u_int theNameLength = 0;
u_char *theEngineID = NULL;
u_int theEngineIDLength = 0;
u_char *theAuthKey = NULL;
u_int theAuthKeyLength = 0;
const oid *theAuthProtocol = NULL;
u_int theAuthProtocolLength = 0;
u_char *thePrivKey = NULL;
u_int thePrivKeyLength = 0;
const oid *thePrivProtocol = NULL;
u_int thePrivProtocolLength = 0;
int theSecLevel = 0; /* No defined const for bad
* value (other then err). */
size_t salt_length = 0, save_salt_length = 0, save_salt_offset = 0;
u_char salt[BYTESIZE(USM_MAX_SALT_LENGTH)];
u_char authParams[USM_MAX_AUTHSIZE];
u_char iv[BYTESIZE(USM_MAX_SALT_LENGTH)];
size_t sp_offset = 0, mac_offset = 0;
int rc = 0;
DEBUGMSGTL(("usm", "USM processing has begun (offset %d)\n", *offset));
if (secStateRef != NULL) {
/*
* To hush the compiler for now. XXX
*/
struct usmStateReference *ref
= (struct usmStateReference *) secStateRef;
theName = ref->usr_name;
theNameLength = ref->usr_name_length;
theEngineID = ref->usr_engine_id;
theEngineIDLength = ref->usr_engine_id_length;
if (!theEngineIDLength) {
theEngineID = secEngineID;
theEngineIDLength = secEngineIDLen;
}
theAuthProtocol = ref->usr_auth_protocol;
theAuthProtocolLength = ref->usr_auth_protocol_length;
theAuthKey = ref->usr_auth_key;
theAuthKeyLength = ref->usr_auth_key_length;
thePrivProtocol = ref->usr_priv_protocol;
thePrivProtocolLength = ref->usr_priv_protocol_length;
thePrivKey = ref->usr_priv_key;
thePrivKeyLength = ref->usr_priv_key_length;
theSecLevel = ref->usr_sec_level;
}
/*
* * Identify the user record.
*/
else {
struct usmUser *user;
/*
* we do allow an unknown user name for
* unauthenticated requests.
*/
if ((user = usm_get_user(secEngineID, secEngineIDLen, secName))
== NULL && secLevel != SNMP_SEC_LEVEL_NOAUTH) {
DEBUGMSGTL(("usm", "Unknown User\n"));
usm_free_usmStateReference(secStateRef);
return SNMPERR_USM_UNKNOWNSECURITYNAME;
}
theName = secName;
theNameLength = secNameLen;
theEngineID = secEngineID;
theSecLevel = secLevel;
theEngineIDLength = secEngineIDLen;
if (user) {
theAuthProtocol = user->authProtocol;
theAuthProtocolLength = user->authProtocolLen;
theAuthKey = user->authKey;
theAuthKeyLength = user->authKeyLen;
thePrivProtocol = user->privProtocol;
thePrivProtocolLength = user->privProtocolLen;
thePrivKey = user->privKey;
thePrivKeyLength = user->privKeyLen;
} else {
/*
* unknown users can not do authentication (obviously)
*/
theAuthProtocol = usmNoAuthProtocol;
theAuthProtocolLength =
sizeof(usmNoAuthProtocol) / sizeof(oid);
theAuthKey = NULL;
theAuthKeyLength = 0;
thePrivProtocol = usmNoPrivProtocol;
thePrivProtocolLength =
sizeof(usmNoPrivProtocol) / sizeof(oid);
thePrivKey = NULL;
thePrivKeyLength = 0;
}
} /* endif -- secStateRef==NULL */
/*
* From here to the end of the function, avoid reference to
* secName, secEngineID, secLevel, and associated lengths.
*/
/*
* Check to see if the user can use the requested sec services.
*/
if (usm_check_secLevel_vs_protocols(theSecLevel,
theAuthProtocol,
theAuthProtocolLength,
thePrivProtocol,
thePrivProtocolLength) == 1) {
DEBUGMSGTL(("usm", "Unsupported Security Level or type (%d)\n",
theSecLevel));
usm_free_usmStateReference(secStateRef);
return SNMPERR_USM_UNSUPPORTEDSECURITYLEVEL;
}
/*
* * Retrieve the engine information.
* *
* * XXX No error is declared in the EoP when sending messages to
* * unknown engines, processing continues w/ boots/time == (0,0).
*/
if (get_enginetime(theEngineID, theEngineIDLength,
&boots_uint, &time_uint, FALSE) == -1) {
DEBUGMSGTL(("usm", "%s\n", "Failed to find engine data."));
}
boots_long = boots_uint;
time_long = time_uint;
if (theSecLevel == SNMP_SEC_LEVEL_AUTHPRIV) {
/*
* Initially assume that the ciphertext will end up the same size as
* the plaintext plus some padding. Really sc_encrypt ought to be able
* to grow this for us, a la asn_realloc_rbuild_<type> functions, but
* this will do for now.
*/
u_char *ciphertext = NULL;
size_t ciphertextlen = scopedPduLen + 64;
if ((ciphertext = (u_char *) malloc(ciphertextlen)) == NULL) {
DEBUGMSGTL(("usm",
"couldn't malloc %d bytes for encrypted PDU\n",
ciphertextlen));
usm_free_usmStateReference(secStateRef);
return SNMPERR_MALLOC;
}
/*
* XXX Hardwired to seek into a 1DES private key!
*/
#ifdef HAVE_AES
if (ISTRANSFORM(thePrivProtocol, AESPriv)) {
salt_length = BYTESIZE(USM_AES_SALT_LENGTH);
save_salt_length = BYTESIZE(USM_AES_SALT_LENGTH)/2;
save_salt_offset = 0;
if (!thePrivKey ||
usm_set_aes_iv(salt, &salt_length,
htonl(boots_uint), htonl(time_uint),
iv) == -1) {
DEBUGMSGTL(("usm", "Can't set AES iv.\n"));
usm_free_usmStateReference(secStateRef);
SNMP_FREE(ciphertext);
return SNMPERR_USM_GENERICERROR;
}
}
#endif
#ifndef DISABLE_DES
if (ISTRANSFORM(thePrivProtocol, DESPriv)) {
salt_length = BYTESIZE(USM_DES_SALT_LENGTH);
save_salt_length = BYTESIZE(USM_DES_SALT_LENGTH);
save_salt_offset = 0;
if (!thePrivKey || (usm_set_salt(salt, &salt_length,
thePrivKey + 8,
thePrivKeyLength - 8,
iv) == -1)) {
DEBUGMSGTL(("usm", "Can't set DES-CBC salt.\n"));
usm_free_usmStateReference(secStateRef);
SNMP_FREE(ciphertext);
return SNMPERR_USM_GENERICERROR;
}
}
#endif
#ifdef SNMP_TESTING_CODE
if (debug_is_token_registered("usm/dump") == SNMPERR_SUCCESS) {
dump_chunk("usm/dump", "This data was encrypted:",
scopedPdu, scopedPduLen);
}
#endif
if (sc_encrypt(thePrivProtocol, thePrivProtocolLength,
thePrivKey, thePrivKeyLength,
salt, salt_length,
scopedPdu, scopedPduLen,
ciphertext, &ciphertextlen) != SNMP_ERR_NOERROR) {
DEBUGMSGTL(("usm", "encryption error.\n"));
usm_free_usmStateReference(secStateRef);
SNMP_FREE(ciphertext);
return SNMPERR_USM_ENCRYPTIONERROR;
}
/*
* Write the encrypted scopedPdu back into the packet buffer.
*/
#ifdef SNMP_TESTING_CODE
theTotalLength = *wholeMsgLen;
#endif
*offset = 0;
rc = asn_realloc_rbuild_string(wholeMsg, wholeMsgLen, offset, 1,
(u_char) (ASN_UNIVERSAL |
ASN_PRIMITIVE |
ASN_OCTET_STR),
ciphertext, ciphertextlen);
#ifdef SNMP_TESTING_CODE
if (debug_is_token_registered("usm/dump") == SNMPERR_SUCCESS) {
dump_chunk("usm/dump", "salt + Encrypted form: ", salt,
salt_length);
dump_chunk("usm/dump", "wholeMsg:",
(*wholeMsg + *wholeMsgLen - *offset), *offset);
}
#endif
DEBUGMSGTL(("usm", "Encryption successful.\n"));
SNMP_FREE(ciphertext);
} else {
/*
* theSecLevel != SNMP_SEC_LEVEL_AUTHPRIV
*/
}
/*
* Start encoding the msgSecurityParameters.
*/
sp_offset = *offset;
DEBUGDUMPHEADER("send", "msgPrivacyParameters");
/*
* msgPrivacyParameters (warning: assumes DES salt).
*/
rc = asn_realloc_rbuild_string(wholeMsg, wholeMsgLen, offset, 1,
(u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE
| ASN_OCTET_STR),
iv,
save_salt_length);
DEBUGINDENTLESS();
if (rc == 0) {
DEBUGMSGTL(("usm", "building privParams failed.\n"));
usm_free_usmStateReference(secStateRef);
return SNMPERR_TOO_LONG;
}
DEBUGDUMPHEADER("send", "msgAuthenticationParameters");
/*
* msgAuthenticationParameters (warnings assumes 0x00 by 12).
*/
if (theSecLevel == SNMP_SEC_LEVEL_AUTHNOPRIV
|| theSecLevel == SNMP_SEC_LEVEL_AUTHPRIV) {
memset(authParams, 0, USM_MD5_AND_SHA_AUTH_LEN);
msgAuthParmLen = USM_MD5_AND_SHA_AUTH_LEN;
}
rc = asn_realloc_rbuild_string(wholeMsg, wholeMsgLen, offset, 1,
(u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE
| ASN_OCTET_STR), authParams,
msgAuthParmLen);
DEBUGINDENTLESS();
if (rc == 0) {
DEBUGMSGTL(("usm", "building authParams failed.\n"));
usm_free_usmStateReference(secStateRef);
return SNMPERR_TOO_LONG;
}
/*
* Remember where to put the actual HMAC we calculate later on. An
* encoded OCTET STRING of length USM_MD5_AND_SHA_AUTH_LEN has an ASN.1
* header of length 2, hence the fudge factor.
*/
mac_offset = *offset - 2;
/*
* msgUserName.
*/
DEBUGDUMPHEADER("send", "msgUserName");
rc = asn_realloc_rbuild_string(wholeMsg, wholeMsgLen, offset, 1,
(u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE
| ASN_OCTET_STR),
(u_char *) theName, theNameLength);
DEBUGINDENTLESS();
if (rc == 0) {
DEBUGMSGTL(("usm", "building authParams failed.\n"));
usm_free_usmStateReference(secStateRef);
return SNMPERR_TOO_LONG;
}
/*
* msgAuthoritativeEngineTime.
*/
DEBUGDUMPHEADER("send", "msgAuthoritativeEngineTime");
rc = asn_realloc_rbuild_int(wholeMsg, wholeMsgLen, offset, 1,
(u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE |
ASN_INTEGER), &time_long,
sizeof(long));
DEBUGINDENTLESS();
if (rc == 0) {
DEBUGMSGTL(("usm",
"building msgAuthoritativeEngineTime failed.\n"));
usm_free_usmStateReference(secStateRef);
return SNMPERR_TOO_LONG;
}
/*
* msgAuthoritativeEngineBoots.
*/
DEBUGDUMPHEADER("send", "msgAuthoritativeEngineBoots");
rc = asn_realloc_rbuild_int(wholeMsg, wholeMsgLen, offset, 1,
(u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE |
ASN_INTEGER), &boots_long,
sizeof(long));
DEBUGINDENTLESS();
if (rc == 0) {
DEBUGMSGTL(("usm",
"building msgAuthoritativeEngineBoots failed.\n"));
usm_free_usmStateReference(secStateRef);
return SNMPERR_TOO_LONG;
}
DEBUGDUMPHEADER("send", "msgAuthoritativeEngineID");
rc = asn_realloc_rbuild_string(wholeMsg, wholeMsgLen, offset, 1,
(u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE
| ASN_OCTET_STR), theEngineID,
theEngineIDLength);
DEBUGINDENTLESS();
if (rc == 0) {
DEBUGMSGTL(("usm", "building msgAuthoritativeEngineID failed.\n"));
usm_free_usmStateReference(secStateRef);
return SNMPERR_TOO_LONG;
}
/*
* USM msgSecurityParameters sequence header
*/
rc = asn_realloc_rbuild_sequence(wholeMsg, wholeMsgLen, offset, 1,
(u_char) (ASN_SEQUENCE |
ASN_CONSTRUCTOR),
*offset - sp_offset);
if (rc == 0) {
DEBUGMSGTL(("usm", "building usm security parameters failed.\n"));
usm_free_usmStateReference(secStateRef);
return SNMPERR_TOO_LONG;
}
/*
* msgSecurityParameters OCTET STRING wrapper.
*/
rc = asn_realloc_rbuild_header(wholeMsg, wholeMsgLen, offset, 1,
(u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE
| ASN_OCTET_STR),
*offset - sp_offset);
if (rc == 0) {
DEBUGMSGTL(("usm", "building msgSecurityParameters failed.\n"));
usm_free_usmStateReference(secStateRef);
return SNMPERR_TOO_LONG;
}
/*
* Copy in the msgGlobalData and msgVersion.
*/
while ((*wholeMsgLen - *offset) < globalDataLen) {
if (!asn_realloc(wholeMsg, wholeMsgLen)) {
DEBUGMSGTL(("usm", "building global data failed.\n"));
usm_free_usmStateReference(secStateRef);
return SNMPERR_TOO_LONG;
}
}
*offset += globalDataLen;
memcpy(*wholeMsg + *wholeMsgLen - *offset, globalData, globalDataLen);
/*
* Total packet sequence.
*/
rc = asn_realloc_rbuild_sequence(wholeMsg, wholeMsgLen, offset, 1,
(u_char) (ASN_SEQUENCE |
ASN_CONSTRUCTOR), *offset);
if (rc == 0) {
DEBUGMSGTL(("usm", "building master packet sequence failed.\n"));
usm_free_usmStateReference(secStateRef);
return SNMPERR_TOO_LONG;
}
/*
* Now consider / do authentication.
*/
if (theSecLevel == SNMP_SEC_LEVEL_AUTHNOPRIV ||
theSecLevel == SNMP_SEC_LEVEL_AUTHPRIV) {
size_t temp_sig_len = msgAuthParmLen;
u_char *temp_sig = (u_char *) malloc(temp_sig_len);
u_char *proto_msg = *wholeMsg + *wholeMsgLen - *offset;
size_t proto_msg_len = *offset;
if (temp_sig == NULL) {
DEBUGMSGTL(("usm", "Out of memory.\n"));
usm_free_usmStateReference(secStateRef);
return SNMPERR_USM_GENERICERROR;
}
if (sc_generate_keyed_hash(theAuthProtocol, theAuthProtocolLength,
theAuthKey, theAuthKeyLength,
proto_msg, proto_msg_len,
temp_sig, &temp_sig_len)
!= SNMP_ERR_NOERROR) {
SNMP_FREE(temp_sig);
DEBUGMSGTL(("usm", "Signing failed.\n"));
usm_free_usmStateReference(secStateRef);
return SNMPERR_USM_AUTHENTICATIONFAILURE;
}
if (temp_sig_len != msgAuthParmLen) {
SNMP_FREE(temp_sig);
DEBUGMSGTL(("usm", "Signing lengths failed.\n"));
usm_free_usmStateReference(secStateRef);
return SNMPERR_USM_AUTHENTICATIONFAILURE;
}
memcpy(*wholeMsg + *wholeMsgLen - mac_offset, temp_sig,
msgAuthParmLen);
SNMP_FREE(temp_sig);
}
/*
* endif -- create keyed hash
*/
usm_free_usmStateReference(secStateRef);
DEBUGMSGTL(("usm", "USM processing completed.\n"));
return SNMPERR_SUCCESS;
} /* end usm_rgenerate_out_msg() */
#endif /* */
/*******************************************************************-o-******
* usm_parse_security_parameters
*
* Parameters:
* (See list below...)
*
* Returns:
* 0 On success,
* -1 Otherwise.
*
* tab stop 4
*
* Extracts values from the security header and data portions of the
* incoming buffer.
*/
int
usm_parse_security_parameters(u_char * secParams,
size_t remaining,
u_char * secEngineID,
size_t * secEngineIDLen,
u_int * boots_uint,
u_int * time_uint,
char *secName,
size_t * secNameLen,
u_char * signature,
size_t * signature_length,
u_char * salt,
size_t * salt_length, u_char ** data_ptr)
{
u_char *parse_ptr = secParams;
u_char *value_ptr;
u_char *next_ptr;
u_char type_value;
size_t octet_string_length = remaining;
size_t sequence_length;
size_t remaining_bytes;
long boots_long;
long time_long;
u_int origNameLen;
/*
* Eat the first octet header.
*/
if ((value_ptr = asn_parse_sequence(parse_ptr, &octet_string_length,
&type_value,
(ASN_UNIVERSAL | ASN_PRIMITIVE |
ASN_OCTET_STR),
"usm first octet")) == NULL) {
/*
* RETURN parse error
*/ return -1;
}
/*
* Eat the sequence header.
*/
parse_ptr = value_ptr;
sequence_length = octet_string_length;
if ((value_ptr = asn_parse_sequence(parse_ptr, &sequence_length,
&type_value,
(ASN_SEQUENCE | ASN_CONSTRUCTOR),
"usm sequence")) == NULL) {
/*
* RETURN parse error
*/ return -1;
}
/*
* Retrieve the engineID.
*/
parse_ptr = value_ptr;
remaining_bytes = sequence_length;
DEBUGDUMPHEADER("recv", "msgAuthoritativeEngineID");
if ((next_ptr
= asn_parse_string(parse_ptr, &remaining_bytes, &type_value,
secEngineID, secEngineIDLen)) == NULL) {
DEBUGINDENTLESS();
/*
* RETURN parse error
*/ return -1;
}
DEBUGINDENTLESS();
if (type_value !=
(u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_OCTET_STR)) {
/*
* RETURN parse error
*/ return -1;
}
/*
* Retrieve the engine boots, notice switch in the way next_ptr and
* remaining_bytes are used (to accomodate the asn code).
*/
DEBUGDUMPHEADER("recv", "msgAuthoritativeEngineBoots");
if ((next_ptr = asn_parse_int(next_ptr, &remaining_bytes, &type_value,
&boots_long, sizeof(long))) == NULL) {
DEBUGINDENTLESS();
/*
* RETURN parse error
*/ return -1;
}
DEBUGINDENTLESS();
if (type_value !=
(u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_INTEGER)) {
DEBUGINDENTLESS();
/*
* RETURN parse error
*/ return -1;
}
*boots_uint = (u_int) boots_long;
/*
* Retrieve the time value.
*/
DEBUGDUMPHEADER("recv", "msgAuthoritativeEngineTime");
if ((next_ptr = asn_parse_int(next_ptr, &remaining_bytes, &type_value,
&time_long, sizeof(long))) == NULL) {
/*
* RETURN parse error
*/ return -1;
}
DEBUGINDENTLESS();
if (type_value !=
(u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_INTEGER)) {
/*
* RETURN parse error
*/ return -1;
}
*time_uint = (u_int) time_long;
if (*boots_uint > ENGINEBOOT_MAX || *time_uint > ENGINETIME_MAX) {
return -1;
}
/*
* Retrieve the secName.
*/
origNameLen = *secNameLen;
DEBUGDUMPHEADER("recv", "msgUserName");
if ((next_ptr
= asn_parse_string(next_ptr, &remaining_bytes, &type_value,
(u_char *) secName, secNameLen)) == NULL) {
DEBUGINDENTLESS();
/*
* RETURN parse error
*/ return -1;
}
DEBUGINDENTLESS();
/*
* FIX -- doesn't this also indicate a buffer overrun?
*/
if ((int) origNameLen < *secNameLen + 1) {
/*
* RETURN parse error, but it's really a parameter error
*/
return -1;
}
if (*secNameLen > 32) {
/*
* This is a USM-specific limitation over and above the above
* limitation (which will probably default to the length of an
* SnmpAdminString, i.e. 255). See RFC 2574, sec. 2.4.
*/
return -1;
}
secName[*secNameLen] = '\0';
if (type_value !=
(u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_OCTET_STR)) {
/*
* RETURN parse error
*/ return -1;
}
/*
* Retrieve the signature and blank it if there.
*/
DEBUGDUMPHEADER("recv", "msgAuthenticationParameters");
if ((next_ptr
= asn_parse_string(next_ptr, &remaining_bytes, &type_value,
signature, signature_length)) == NULL) {
DEBUGINDENTLESS();
/*
* RETURN parse error
*/ return -1;
}
DEBUGINDENTLESS();
if (type_value !=
(u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_OCTET_STR)) {
/*
* RETURN parse error
*/ return -1;
}
if (*signature_length != 0) { /* Blanking for authentication step later */
memset(next_ptr - (u_long) * signature_length,
0, *signature_length);
}
/*
* Retrieve the salt.
*
* Note that the next ptr is where the data section starts.
*/
DEBUGDUMPHEADER("recv", "msgPrivacyParameters");
if ((*data_ptr
= asn_parse_string(next_ptr, &remaining_bytes, &type_value,
salt, salt_length)) == NULL) {
DEBUGINDENTLESS();
/*
* RETURN parse error
*/ return -2;
}
DEBUGINDENTLESS();
if (type_value !=
(u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_OCTET_STR)) {
/*
* RETURN parse error
*/ return -2;
}
return 0;
} /* end usm_parse_security_parameters() */
/*******************************************************************-o-******
* usm_check_and_update_timeliness
*
* Parameters:
* *secEngineID
* secEngineIDen
* boots_uint
* time_uint
* *error
*
* Returns:
* 0 On success,
* -1 Otherwise.
*
*
* Performs the incoming timeliness checking and setting.
*/
int
usm_check_and_update_timeliness(u_char * secEngineID,
size_t secEngineIDLen,
u_int boots_uint,
u_int time_uint, int *error)
{
u_char myID[USM_MAX_ID_LENGTH];
u_long myIDLength =
snmpv3_get_engineID(myID, USM_MAX_ID_LENGTH);
u_int myBoots;
u_int myTime;
if ((myIDLength > USM_MAX_ID_LENGTH) || (myIDLength == 0)) {
/*
* We're probably already screwed...buffer overwrite. XXX?
*/
DEBUGMSGTL(("usm", "Buffer overflow.\n"));
*error = SNMPERR_USM_GENERICERROR;
return -1;
}
myBoots = snmpv3_local_snmpEngineBoots();
myTime = snmpv3_local_snmpEngineTime();
/*
* IF the time involved is local
* Make sure message is inside the time window
* ELSE
* IF boots is higher or boots is the same and time is higher
* remember this new data
* ELSE
* IF !(boots same and time within USM_TIME_WINDOW secs)
* Message is too old
* ELSE
* Message is ok, but don't take time
* ENDIF
* ENDIF
* ENDIF
*/
/*
* This is a local reference.
*/
if ((int) secEngineIDLen == myIDLength
&& memcmp(secEngineID, myID, myIDLength) == 0) {
u_int time_difference = myTime > time_uint ?
myTime - time_uint : time_uint - myTime;
if (boots_uint == ENGINEBOOT_MAX
|| boots_uint != myBoots
|| time_difference > USM_TIME_WINDOW) {
if (snmp_increment_statistic(STAT_USMSTATSNOTINTIMEWINDOWS) ==
0) {
DEBUGMSGTL(("usm", "%s\n",
"Failed to increment statistic."));
}
DEBUGMSGTL(("usm",
"boot_uint %u myBoots %u time_diff %u => not in time window\n",
boots_uint, myBoots, time_difference));
*error = SNMPERR_USM_NOTINTIMEWINDOW;
return -1;
}
*error = SNMPERR_SUCCESS;
return 0;
}
/*
* This is a remote reference.
*/
else {
u_int theirBoots, theirTime, theirLastTime;
u_int time_difference;
if (get_enginetime_ex(secEngineID, secEngineIDLen,
&theirBoots, &theirTime,
&theirLastTime, TRUE)
!= SNMPERR_SUCCESS) {
DEBUGMSGTL(("usm", "%s\n",
"Failed to get remote engine's times."));
*error = SNMPERR_USM_GENERICERROR;
return -1;
}
time_difference = theirTime > time_uint ?
theirTime - time_uint : time_uint - theirTime;
/*
* XXX Contrary to the pseudocode:
* See if boots is invalid first.
*/
if (theirBoots == ENGINEBOOT_MAX || theirBoots > boots_uint) {
DEBUGMSGTL(("usm", "%s\n", "Remote boot count invalid."));
*error = SNMPERR_USM_NOTINTIMEWINDOW;
return -1;
}
/*
* Boots is ok, see if the boots is the same but the time
* is old.
*/
if (theirBoots == boots_uint && time_uint < theirLastTime) {
if (time_difference > USM_TIME_WINDOW) {
DEBUGMSGTL(("usm", "%s\n", "Message too old."));
*error = SNMPERR_USM_NOTINTIMEWINDOW;
return -1;
}
else { /* Old, but acceptable */
*error = SNMPERR_SUCCESS;
return 0;
}
}
/*
* Message is ok, either boots has been advanced, or
* time is greater than before with the same boots.
*/
if (set_enginetime(secEngineID, secEngineIDLen,
boots_uint, time_uint, TRUE)
!= SNMPERR_SUCCESS) {
DEBUGMSGTL(("usm", "%s\n",
"Failed updating remote boot/time."));
*error = SNMPERR_USM_GENERICERROR;
return -1;
}
*error = SNMPERR_SUCCESS;
return 0; /* Fresh message and time updated */
} /* endif -- local or remote time reference. */
} /* end usm_check_and_update_timeliness() */
int
usm_secmod_process_in_msg(struct snmp_secmod_incoming_params *parms)
{
if (!parms)
return SNMPERR_GENERR;
return usm_process_in_msg(parms->msgProcModel,
parms->maxMsgSize,
parms->secParams,
parms->secModel,
parms->secLevel,
parms->wholeMsg,
parms->wholeMsgLen,
parms->secEngineID,
parms->secEngineIDLen,
parms->secName,
parms->secNameLen,
parms->scopedPdu,
parms->scopedPduLen,
parms->maxSizeResponse,
parms->secStateRef,
parms->sess, parms->msg_flags);
}
/*******************************************************************-o-******
* usm_process_in_msg
*
* Parameters:
* (See list below...)
*
* Returns:
* SNMPERR_SUCCESS On success.
* SNMPERR_USM_AUTHENTICATIONFAILURE
* SNMPERR_USM_DECRYPTIONERROR
* SNMPERR_USM_GENERICERROR
* SNMPERR_USM_PARSEERROR
* SNMPERR_USM_UNKNOWNENGINEID
* SNMPERR_USM_PARSEERROR
* SNMPERR_USM_UNKNOWNSECURITYNAME
* SNMPERR_USM_UNSUPPORTEDSECURITYLEVEL
*
*
* ASSUMES size of decrypt_buf will always be >= size of encrypted sPDU.
*
* FIX Memory leaks if secStateRef is allocated and a return occurs
* without cleaning up. May contain secrets...
*/
int
usm_process_in_msg(int msgProcModel, /* (UNUSED) */
size_t maxMsgSize, /* IN - Used to calc maxSizeResponse. */
u_char * secParams, /* IN - BER encoded securityParameters. */
int secModel, /* (UNUSED) */
int secLevel, /* IN - AuthNoPriv, authPriv etc. */
u_char * wholeMsg, /* IN - Original v3 message. */
size_t wholeMsgLen, /* IN - Msg length. */
u_char * secEngineID, /* OUT - Pointer snmpEngineID. */
size_t * secEngineIDLen, /* IN/OUT - Len available, len returned. */
/*
* NOTE: Memory provided by caller.
*/
char *secName, /* OUT - Pointer to securityName. */
size_t * secNameLen, /* IN/OUT - Len available, len returned. */
u_char ** scopedPdu, /* OUT - Pointer to plaintext scopedPdu. */
size_t * scopedPduLen, /* IN/OUT - Len available, len returned. */
size_t * maxSizeResponse, /* OUT - Max size of Response PDU. */
void **secStateRf, /* OUT - Ref to security state. */
netsnmp_session * sess, /* IN - session which got the message */
u_char msg_flags)
{ /* IN - v3 Message flags. */
size_t remaining = wholeMsgLen - (u_int)
((u_long) * secParams - (u_long) * wholeMsg);
u_int boots_uint;
u_int time_uint;
#ifdef HAVE_AES
u_int net_boots, net_time;
#endif
u_char signature[BYTESIZE(USM_MAX_KEYEDHASH_LENGTH)];
size_t signature_length = BYTESIZE(USM_MAX_KEYEDHASH_LENGTH);
u_char salt[BYTESIZE(USM_MAX_SALT_LENGTH)];
size_t salt_length = BYTESIZE(USM_MAX_SALT_LENGTH);
u_char iv[BYTESIZE(USM_MAX_SALT_LENGTH)];
u_int iv_length = BYTESIZE(USM_MAX_SALT_LENGTH);
u_char *data_ptr;
u_char *value_ptr;
u_char type_value;
u_char *end_of_overhead = NULL;
int error;
int i, rc = 0;
struct usmStateReference **secStateRef =
(struct usmStateReference **) secStateRf;
struct usmUser *user;
DEBUGMSGTL(("usm", "USM processing begun...\n"));
if (secStateRef) {
usm_free_usmStateReference(*secStateRef);
*secStateRef = usm_malloc_usmStateReference();
if (*secStateRef == NULL) {
DEBUGMSGTL(("usm", "Out of memory.\n"));
return SNMPERR_USM_GENERICERROR;
}
}
/*
* Make sure the *secParms is an OCTET STRING.
* Extract the user name, engine ID, and security level.
*/
if ((rc = usm_parse_security_parameters(secParams, remaining,
secEngineID, secEngineIDLen,
&boots_uint, &time_uint,
secName, secNameLen,
signature, &signature_length,
salt, &salt_length,
&data_ptr)) < 0) {
DEBUGMSGTL(("usm", "Parsing failed (rc %d).\n", rc));
if (rc == -2) {
/*
* This indicates a decryptionError.
*/
if (snmp_increment_statistic(STAT_USMSTATSDECRYPTIONERRORS) ==
0) {
DEBUGMSGTL(("usm", "%s\n",
"Failed to increment statistic."));
}
return SNMPERR_USM_DECRYPTIONERROR;
}
if (snmp_increment_statistic(STAT_SNMPINASNPARSEERRS) == 0) {
DEBUGMSGTL(("usm", "%s\n", "Failed to increment statistic."));
}
return SNMPERR_USM_PARSEERROR;
}
/*
* RFC 2574 section 8.3.2
* 1) If the privParameters field is not an 8-octet OCTET STRING,
* then an error indication (decryptionError) is returned to the
* calling module.
*/
if ((secLevel == SNMP_SEC_LEVEL_AUTHPRIV) && (salt_length != 8)) {
if (snmp_increment_statistic(STAT_USMSTATSDECRYPTIONERRORS) ==
0) {
DEBUGMSGTL(("usm", "%s\n", "Failed increment statistic."));
}
return SNMPERR_USM_DECRYPTIONERROR;
}
if (secLevel != SNMP_SEC_LEVEL_AUTHPRIV) {
/*
* pull these out now so reports can use them
*/
*scopedPdu = data_ptr;
*scopedPduLen = wholeMsgLen - (data_ptr - wholeMsg);
end_of_overhead = data_ptr;
}
if (secStateRef) {
/*
* Cache the name, engine ID, and security level,
* * per step 2 (section 3.2)
*/
if (usm_set_usmStateReference_name
(*secStateRef, secName, *secNameLen) == -1) {
DEBUGMSGTL(("usm", "%s\n", "Couldn't cache name."));
return SNMPERR_USM_GENERICERROR;
}
if (usm_set_usmStateReference_engine_id
(*secStateRef, secEngineID, *secEngineIDLen) == -1) {
DEBUGMSGTL(("usm", "%s\n", "Couldn't cache engine id."));
return SNMPERR_USM_GENERICERROR;
}
if (usm_set_usmStateReference_sec_level(*secStateRef, secLevel) ==
-1) {
DEBUGMSGTL(("usm", "%s\n", "Couldn't cache security level."));
return SNMPERR_USM_GENERICERROR;
}
}
/*
* Locate the engine ID record.
* If it is unknown, then either create one or note this as an error.
*/
if ((sess && (sess->isAuthoritative == SNMP_SESS_AUTHORITATIVE ||
(sess->isAuthoritative == SNMP_SESS_UNKNOWNAUTH &&
(msg_flags & SNMP_MSG_FLAG_RPRT_BIT)))) ||
(!sess && (msg_flags & SNMP_MSG_FLAG_RPRT_BIT))) {
if (ISENGINEKNOWN(secEngineID, *secEngineIDLen) == FALSE) {
DEBUGMSGTL(("usm", "Unknown Engine ID.\n"));
if (snmp_increment_statistic(STAT_USMSTATSUNKNOWNENGINEIDS) ==
0) {
DEBUGMSGTL(("usm", "%s\n",
"Failed to increment statistic."));
}
return SNMPERR_USM_UNKNOWNENGINEID;
}
} else {
if (ENSURE_ENGINE_RECORD(secEngineID, *secEngineIDLen)
!= SNMPERR_SUCCESS) {
DEBUGMSGTL(("usm", "%s\n", "Couldn't ensure engine record."));
return SNMPERR_USM_GENERICERROR;
}
}
/*
* Locate the User record.
* If the user/engine ID is unknown, report this as an error.
*/
if ((user = usm_get_user_from_list(secEngineID, *secEngineIDLen,
secName, userList,
(((sess && sess->isAuthoritative ==
SNMP_SESS_AUTHORITATIVE) ||
(!sess)) ? 0 : 1)))
== NULL) {
DEBUGMSGTL(("usm", "Unknown User(%s)\n", secName));
if (snmp_increment_statistic(STAT_USMSTATSUNKNOWNUSERNAMES) == 0) {
DEBUGMSGTL(("usm", "%s\n", "Failed to increment statistic."));
}
return SNMPERR_USM_UNKNOWNSECURITYNAME;
}
/*
* Make sure the security level is appropriate.
*/
if (usm_check_secLevel(secLevel, user) == 1) {
DEBUGMSGTL(("usm", "Unsupported Security Level (%d).\n",
secLevel));
if (snmp_increment_statistic
(STAT_USMSTATSUNSUPPORTEDSECLEVELS) == 0) {
DEBUGMSGTL(("usm", "%s\n", "Failed to increment statistic."));
}
return SNMPERR_USM_UNSUPPORTEDSECURITYLEVEL;
}
/*
* Check the authentication credentials of the message.
*/
if (secLevel == SNMP_SEC_LEVEL_AUTHNOPRIV
|| secLevel == SNMP_SEC_LEVEL_AUTHPRIV) {
if (sc_check_keyed_hash(user->authProtocol, user->authProtocolLen,
user->authKey, user->authKeyLen,
wholeMsg, wholeMsgLen,
signature, signature_length)
!= SNMP_ERR_NOERROR) {
DEBUGMSGTL(("usm", "Verification failed.\n"));
if (snmp_increment_statistic(STAT_USMSTATSWRONGDIGESTS) == 0) {
DEBUGMSGTL(("usm", "%s\n",
"Failed to increment statistic."));
}
snmp_log(LOG_WARNING, "Authentication failed for %s\n",
user->name);
return SNMPERR_USM_AUTHENTICATIONFAILURE;
}
DEBUGMSGTL(("usm", "Verification succeeded.\n"));
}
/*
* Steps 10-11 user is already set - relocated before timeliness
* check in case it fails - still save user data for response.
*
* Cache the keys and protocol oids, per step 11 (s3.2).
*/
if (secStateRef) {
if (usm_set_usmStateReference_auth_protocol(*secStateRef,
user->authProtocol,
user->
authProtocolLen) ==
-1) {
DEBUGMSGTL(("usm", "%s\n",
"Couldn't cache authentication protocol."));
return SNMPERR_USM_GENERICERROR;
}
if (usm_set_usmStateReference_auth_key(*secStateRef,
user->authKey,
user->authKeyLen) == -1) {
DEBUGMSGTL(("usm", "%s\n",
"Couldn't cache authentication key."));
return SNMPERR_USM_GENERICERROR;
}
if (usm_set_usmStateReference_priv_protocol(*secStateRef,
user->privProtocol,
user->
privProtocolLen) ==
-1) {
DEBUGMSGTL(("usm", "%s\n",
"Couldn't cache privacy protocol."));
return SNMPERR_USM_GENERICERROR;
}
if (usm_set_usmStateReference_priv_key(*secStateRef,
user->privKey,
user->privKeyLen) == -1) {
DEBUGMSGTL(("usm", "%s\n", "Couldn't cache privacy key."));
return SNMPERR_USM_GENERICERROR;
}
}
/*
* Perform the timeliness/time manager functions.
*/
if (secLevel == SNMP_SEC_LEVEL_AUTHNOPRIV
|| secLevel == SNMP_SEC_LEVEL_AUTHPRIV) {
if (usm_check_and_update_timeliness(secEngineID, *secEngineIDLen,
boots_uint, time_uint,
&error) == -1) {
return error;
}
}
#ifdef LCD_TIME_SYNC_OPT
/*
* Cache the unauthenticated time to use in case we don't have
* anything better - this guess will be no worse than (0,0)
* that we normally use.
*/
else {
set_enginetime(secEngineID, *secEngineIDLen,
boots_uint, time_uint, FALSE);
}
#endif /* LCD_TIME_SYNC_OPT */
/*
* If needed, decrypt the scoped PDU.
*/
if (secLevel == SNMP_SEC_LEVEL_AUTHPRIV) {
remaining = wholeMsgLen - (data_ptr - wholeMsg);
if ((value_ptr = asn_parse_sequence(data_ptr, &remaining,
&type_value,
(ASN_UNIVERSAL | ASN_PRIMITIVE
| ASN_OCTET_STR),
"encrypted sPDU")) == NULL) {
DEBUGMSGTL(("usm", "%s\n",
"Failed while parsing encrypted sPDU."));
if (snmp_increment_statistic(STAT_SNMPINASNPARSEERRS) == 0) {
DEBUGMSGTL(("usm", "%s\n", "Failed increment statistic."));
}
usm_free_usmStateReference(*secStateRef);
*secStateRef = NULL;
return SNMPERR_USM_PARSEERROR;
}
#ifndef DISABLE_DES
if (ISTRANSFORM(user->privProtocol, DESPriv)) {
/*
* From RFC2574:
*
* "Before decryption, the encrypted data length is verified.
* If the length of the OCTET STRING to be decrypted is not
* an integral multiple of 8 octets, the decryption process
* is halted and an appropriate exception noted."
*/
if (remaining % 8 != 0) {
DEBUGMSGTL(("usm",
"Ciphertext is %lu bytes, not an integer multiple of 8 (rem %d)\n",
remaining, remaining % 8));
if (snmp_increment_statistic(STAT_USMSTATSDECRYPTIONERRORS) ==
0) {
DEBUGMSGTL(("usm", "%s\n", "Failed increment statistic."));
}
usm_free_usmStateReference(*secStateRef);
*secStateRef = NULL;
return SNMPERR_USM_DECRYPTIONERROR;
}
end_of_overhead = value_ptr;
/*
* XOR the salt with the last (iv_length) bytes
* of the priv_key to obtain the IV.
*/
iv_length = BYTESIZE(USM_DES_SALT_LENGTH);
for (i = 0; i < (int) iv_length; i++)
iv[i] = salt[i] ^ user->privKey[iv_length + i];
}
#endif
#ifdef HAVE_AES
if (ISTRANSFORM(user->privProtocol, AESPriv)) {
iv_length = BYTESIZE(USM_AES_SALT_LENGTH);
net_boots = ntohl(boots_uint);
net_time = ntohl(time_uint);
memcpy(iv, &net_boots, 4);
memcpy(iv+4, &net_time, 4);
memcpy(iv+8, salt, salt_length);
}
#endif
if (sc_decrypt(user->privProtocol, user->privProtocolLen,
user->privKey, user->privKeyLen,
iv, iv_length,
value_ptr, remaining, *scopedPdu, scopedPduLen)
!= SNMP_ERR_NOERROR) {
DEBUGMSGTL(("usm", "%s\n", "Failed decryption."));
if (snmp_increment_statistic
(STAT_USMSTATSDECRYPTIONERRORS) == 0) {
DEBUGMSGTL(("usm", "%s\n", "Failed increment statistic."));
}
return SNMPERR_USM_DECRYPTIONERROR;
}
#ifdef SNMP_TESTING_CODE
if (debug_is_token_registered("usm/dump") == SNMPERR_SUCCESS) {
dump_chunk("usm/dump", "Cypher Text", value_ptr, remaining);
dump_chunk("usm/dump", "salt + Encrypted form:",
salt, salt_length);
dump_chunk("usm/dump", "IV + Encrypted form:", iv, iv_length);
dump_chunk("usm/dump", "Decrypted chunk:",
*scopedPdu, *scopedPduLen);
}
#endif
}
/*
* sPDU is plaintext.
*/
else {
*scopedPdu = data_ptr;
*scopedPduLen = wholeMsgLen - (data_ptr - wholeMsg);
end_of_overhead = data_ptr;
} /* endif -- PDU decryption */
/*
* Calculate the biggest sPDU for the response (i.e., whole - ovrhd).
*
* FIX Correct?
*/
*maxSizeResponse = maxMsgSize - (int)
((u_long) end_of_overhead - (u_long) wholeMsg);
DEBUGMSGTL(("usm", "USM processing completed.\n"));
return SNMPERR_SUCCESS;
} /* end usm_process_in_msg() */
void
usm_handle_report(void *sessp,
netsnmp_transport *transport, netsnmp_session *session,
int result, netsnmp_pdu *pdu)
{
/*
* handle reportable errors
*/
/* this will get in our way */
usm_free_usmStateReference(pdu->securityStateRef);
pdu->securityStateRef = NULL;
switch (result) {
case SNMPERR_USM_AUTHENTICATIONFAILURE:
{
int res = session->s_snmp_errno;
session->s_snmp_errno = result;
if (session->callback) {
session->callback(NETSNMP_CALLBACK_OP_RECEIVED_MESSAGE,
session, pdu->reqid, pdu,
session->callback_magic);
}
session->s_snmp_errno = res;
}
case SNMPERR_USM_UNKNOWNENGINEID:
case SNMPERR_USM_UNKNOWNSECURITYNAME:
case SNMPERR_USM_UNSUPPORTEDSECURITYLEVEL:
case SNMPERR_USM_NOTINTIMEWINDOW:
case SNMPERR_USM_DECRYPTIONERROR:
if (SNMP_CMD_CONFIRMED(pdu->command) ||
(pdu->command == 0
&& (pdu->flags & SNMP_MSG_FLAG_RPRT_BIT))) {
netsnmp_pdu *pdu2;
int flags = pdu->flags;
pdu->flags |= UCD_MSG_FLAG_FORCE_PDU_COPY;
pdu2 = snmp_clone_pdu(pdu);
pdu->flags = pdu2->flags = flags;
snmpv3_make_report(pdu2, result);
if (0 == snmp_sess_send(sessp, pdu2)) {
snmp_free_pdu(pdu2);
/*
* TODO: indicate error
*/
}
}
break;
}
}
void
init_usm(void)
{
struct snmp_secmod_def *def;
DEBUGMSGTL(("init_usm", "unit_usm: %d %d\n", usmNoPrivProtocol[0],
usmNoPrivProtocol[1]));
sc_init(); /* initalize scapi code */
/*
* register ourselves as a security service
*/
def = SNMP_MALLOC_STRUCT(snmp_secmod_def);
/*
* XXX: def->init_sess_secmod move stuff from snmp_api.c
*/
def->encode_reverse = usm_secmod_rgenerate_out_msg;
def->encode_forward = usm_secmod_generate_out_msg;
def->decode = usm_secmod_process_in_msg;
def->pdu_free_state_ref = usm_free_usmStateReference;
def->handle_report = usm_handle_report;
register_sec_mod(USM_SEC_MODEL_NUMBER, "usm", def);
snmp_register_callback(SNMP_CALLBACK_LIBRARY,
SNMP_CALLBACK_POST_PREMIB_READ_CONFIG,
init_usm_post_config, NULL);
snmp_register_callback(SNMP_CALLBACK_LIBRARY,
SNMP_CALLBACK_SHUTDOWN,
deinit_usm_post_config, NULL);
snmp_register_callback(SNMP_CALLBACK_LIBRARY,
SNMP_CALLBACK_SHUTDOWN,
free_engineID, NULL);
}
void
init_usm_conf(const char *app)
{
register_config_handler(app, "usmUser",
usm_parse_config_usmUser, NULL, NULL);
register_config_handler(app, "createUser",
usm_parse_create_usmUser, NULL,
"username (MD5|SHA) passphrase [DES [passphrase]]");
/*
* we need to be called back later
*/
snmp_register_callback(SNMP_CALLBACK_LIBRARY, SNMP_CALLBACK_STORE_DATA,
usm_store_users, NULL);
}
/*
* initializations for the USM.
*
* Should be called after the (engineid) configuration files have been read.
*
* Set "arbitrary" portion of salt to a random number.
*/
int
init_usm_post_config(int majorid, int minorid, void *serverarg,
void *clientarg)
{
size_t salt_integer_len = sizeof(salt_integer);
if (sc_random((u_char *) & salt_integer, &salt_integer_len) !=
SNMPERR_SUCCESS) {
DEBUGMSGTL(("usm", "sc_random() failed: using time() as salt.\n"));
salt_integer = (u_int) time(NULL);
}
#ifdef HAVE_AES
salt_integer_len = sizeof (salt_integer64_1);
if (sc_random((u_char *) & salt_integer64_1, &salt_integer_len) !=
SNMPERR_SUCCESS) {
DEBUGMSGTL(("usm", "sc_random() failed: using time() as aes1 salt.\n"));
salt_integer64_1 = (u_int) time(NULL);
}
salt_integer_len = sizeof (salt_integer64_1);
if (sc_random((u_char *) & salt_integer64_2, &salt_integer_len) !=
SNMPERR_SUCCESS) {
DEBUGMSGTL(("usm", "sc_random() failed: using time() as aes2 salt.\n"));
salt_integer64_2 = (u_int) time(NULL);
}
#endif
#ifndef DISABLE_MD5
noNameUser = usm_create_initial_user("", usmHMACMD5AuthProtocol,
USM_LENGTH_OID_TRANSFORM,
#ifndef DISABLE_DES
usmDESPrivProtocol,
#else
usmAESPrivProtocol,
#endif
USM_LENGTH_OID_TRANSFORM);
#else
noNameUser = usm_create_initial_user("", usmHMACSHA1AuthProtocol,
USM_LENGTH_OID_TRANSFORM,
#ifndef DISABLE_DES
usmDESPrivProtocol,
#else
usmAESPrivProtocol,
#endif
USM_LENGTH_OID_TRANSFORM);
#endif
if ( noNameUser ) {
SNMP_FREE(noNameUser->engineID);
noNameUser->engineIDLen = 0;
}
return SNMPERR_SUCCESS;
} /* end init_usm_post_config() */
int
deinit_usm_post_config(int majorid, int minorid, void *serverarg,
void *clientarg)
{
if (usm_free_user(noNameUser) != NULL) {
DEBUGMSGTL(("deinit_usm_post_config", "could not free initial user\n"));
return SNMPERR_GENERR;
}
noNameUser = NULL;
DEBUGMSGTL(("deinit_usm_post_config", "initial user removed\n"));
return SNMPERR_SUCCESS;
} /* end deinit_usm_post_config() */
void
clear_user_list(void)
{
struct usmUser *tmp = userList, *next = NULL;
while (tmp != NULL) {
next = tmp->next;
usm_free_user(tmp);
tmp = next;
}
userList = NULL;
}
/*******************************************************************-o-******
* usm_check_secLevel
*
* Parameters:
* level
* *user
*
* Returns:
* 0 On success,
* -1 Otherwise.
*
* Checks that a given security level is valid for a given user.
*/
int
usm_check_secLevel(int level, struct usmUser *user)
{
if (user->userStatus != RS_ACTIVE)
return -1;
DEBUGMSGTL(("comparex", "Comparing: %d %d ", usmNoPrivProtocol[0],
usmNoPrivProtocol[1]));
DEBUGMSGOID(("comparex", usmNoPrivProtocol,
sizeof(usmNoPrivProtocol) / sizeof(oid)));
DEBUGMSG(("comparex", "\n"));
if (level == SNMP_SEC_LEVEL_AUTHPRIV
&& (netsnmp_oid_equals(user->privProtocol, user->privProtocolLen,
usmNoPrivProtocol,
sizeof(usmNoPrivProtocol) / sizeof(oid)) ==
0)) {
DEBUGMSGTL(("usm", "Level: %d\n", level));
DEBUGMSGTL(("usm", "User (%s) Auth Protocol: ", user->name));
DEBUGMSGOID(("usm", user->authProtocol, user->authProtocolLen));
DEBUGMSG(("usm", ", User Priv Protocol: "));
DEBUGMSGOID(("usm", user->privProtocol, user->privProtocolLen));
DEBUGMSG(("usm", "\n"));
return 1;
}
if ((level == SNMP_SEC_LEVEL_AUTHPRIV
|| level == SNMP_SEC_LEVEL_AUTHNOPRIV)
&&
(netsnmp_oid_equals
(user->authProtocol, user->authProtocolLen, usmNoAuthProtocol,
sizeof(usmNoAuthProtocol) / sizeof(oid)) == 0)) {
DEBUGMSGTL(("usm", "Level: %d\n", level));
DEBUGMSGTL(("usm", "User (%s) Auth Protocol: ", user->name));
DEBUGMSGOID(("usm", user->authProtocol, user->authProtocolLen));
DEBUGMSG(("usm", ", User Priv Protocol: "));
DEBUGMSGOID(("usm", user->privProtocol, user->privProtocolLen));
DEBUGMSG(("usm", "\n"));
return 1;
}
return 0;
} /* end usm_check_secLevel() */
/*******************************************************************-o-******
* usm_check_secLevel_vs_protocols
*
* Parameters:
* level
* *authProtocol
* authProtocolLen
* *privProtocol
* privProtocolLen
*
* Returns:
* 0 On success,
* 1 Otherwise.
*
* Same as above but with explicitly named transform types instead of taking
* from the usmUser structure.
*/
int
usm_check_secLevel_vs_protocols(int level,
const oid * authProtocol,
u_int authProtocolLen,
const oid * privProtocol,
u_int privProtocolLen)
{
if (level == SNMP_SEC_LEVEL_AUTHPRIV
&&
(netsnmp_oid_equals
(privProtocol, privProtocolLen, usmNoPrivProtocol,
sizeof(usmNoPrivProtocol) / sizeof(oid)) == 0)) {
DEBUGMSGTL(("usm", "Level: %d\n", level));
DEBUGMSGTL(("usm", "Auth Protocol: "));
DEBUGMSGOID(("usm", authProtocol, authProtocolLen));
DEBUGMSG(("usm", ", Priv Protocol: "));
DEBUGMSGOID(("usm", privProtocol, privProtocolLen));
DEBUGMSG(("usm", "\n"));
return 1;
}
if ((level == SNMP_SEC_LEVEL_AUTHPRIV
|| level == SNMP_SEC_LEVEL_AUTHNOPRIV)
&&
(netsnmp_oid_equals
(authProtocol, authProtocolLen, usmNoAuthProtocol,
sizeof(usmNoAuthProtocol) / sizeof(oid)) == 0)) {
DEBUGMSGTL(("usm", "Level: %d\n", level));
DEBUGMSGTL(("usm", "Auth Protocol: "));
DEBUGMSGOID(("usm", authProtocol, authProtocolLen));
DEBUGMSG(("usm", ", Priv Protocol: "));
DEBUGMSGOID(("usm", privProtocol, privProtocolLen));
DEBUGMSG(("usm", "\n"));
return 1;
}
return 0;
} /* end usm_check_secLevel_vs_protocols() */
/*
* usm_get_user(): Returns a user from userList based on the engineID,
* engineIDLen and name of the requested user.
*/
struct usmUser *
usm_get_user(u_char * engineID, size_t engineIDLen, char *name)
{
DEBUGMSGTL(("usm", "getting user %s\n", name));
return usm_get_user_from_list(engineID, engineIDLen, name, userList,
1);
}
struct usmUser *
usm_get_user_from_list(u_char * engineID, size_t engineIDLen,
char *name, struct usmUser *puserList,
int use_default)
{
struct usmUser *ptr;
char noName[] = "";
if (name == NULL)
name = noName;
for (ptr = puserList; ptr != NULL; ptr = ptr->next) {
if (ptr->name && !strcmp(ptr->name, name)) {
DEBUGMSGTL(("usm", "match on user %s\n", ptr->name));
if (ptr->engineIDLen == engineIDLen &&
((ptr->engineID == NULL && engineID == NULL) ||
(ptr->engineID != NULL && engineID != NULL &&
memcmp(ptr->engineID, engineID, engineIDLen) == 0)))
return ptr;
DEBUGMSGTL(("usm", "no match on engineID ("));
DEBUGMSGHEX(("usm", engineID, engineIDLen));
DEBUGMSG(("usm", ")\n"));
}
}
/*
* return "" user used to facilitate engineID discovery
*/
if (use_default && !strcmp(name, ""))
return noNameUser;
return NULL;
}
/*
* usm_add_user(): Add's a user to the userList, sorted by the
* engineIDLength then the engineID then the name length then the name
* to facilitate getNext calls on a usmUser table which is indexed by
* these values.
*
* Note: userList must not be NULL (obviously), as thats a rather trivial
* addition and is left to the API user.
*
* returns the head of the list (which could change due to this add).
*/
struct usmUser *
usm_add_user(struct usmUser *user)
{
struct usmUser *uptr;
uptr = usm_add_user_to_list(user, userList);
if (uptr != NULL)
userList = uptr;
return uptr;
}
struct usmUser *
usm_add_user_to_list(struct usmUser *user, struct usmUser *puserList)
{
struct usmUser *nptr, *pptr, *optr;
/*
* loop through puserList till we find the proper, sorted place to
* insert the new user
*/
/* XXX - how to handle a NULL user->name ?? */
/* XXX - similarly for a NULL nptr->name ?? */
for (nptr = puserList, pptr = NULL; nptr != NULL;
pptr = nptr, nptr = nptr->next) {
if (nptr->engineIDLen > user->engineIDLen)
break;
if (user->engineID == NULL && nptr->engineID != NULL)
break;
if (nptr->engineIDLen == user->engineIDLen &&
(nptr->engineID != NULL && user->engineID != NULL &&
memcmp(nptr->engineID, user->engineID,
user->engineIDLen) > 0))
break;
if (!(nptr->engineID == NULL && user->engineID != NULL)) {
if (nptr->engineIDLen == user->engineIDLen &&
((nptr->engineID == NULL && user->engineID == NULL) ||
memcmp(nptr->engineID, user->engineID,
user->engineIDLen) == 0)
&& strlen(nptr->name) > strlen(user->name))
break;
if (nptr->engineIDLen == user->engineIDLen &&
((nptr->engineID == NULL && user->engineID == NULL) ||
memcmp(nptr->engineID, user->engineID,
user->engineIDLen) == 0)
&& strlen(nptr->name) == strlen(user->name)
&& strcmp(nptr->name, user->name) > 0)
break;
if (nptr->engineIDLen == user->engineIDLen &&
((nptr->engineID == NULL && user->engineID == NULL) ||
memcmp(nptr->engineID, user->engineID,
user->engineIDLen) == 0)
&& strlen(nptr->name) == strlen(user->name)
&& strcmp(nptr->name, user->name) == 0) {
/*
* the user is an exact match of a previous entry.
* Credentials may be different, though, so remove
* the old entry (and add the new one)!
*/
if (pptr) { /* change prev's next pointer */
pptr->next = nptr->next;
}
if (nptr->next) { /* change next's prev pointer */
nptr->next->prev = pptr;
}
optr = nptr;
nptr = optr->next; /* add new user at this position */
/* free the old user */
optr->next=NULL;
optr->prev=NULL;
usm_free_user(optr);
break; /* new user will be added below */
}
}
}
/*
* nptr should now point to the user that we need to add ourselves
* in front of, and pptr should be our new 'prev'.
*/
/*
* change our pointers
*/
user->prev = pptr;
user->next = nptr;
/*
* change the next's prev pointer
*/
if (user->next)
user->next->prev = user;
/*
* change the prev's next pointer
*/
if (user->prev)
user->prev->next = user;
/*
* rewind to the head of the list and return it (since the new head
* could be us, we need to notify the above routine who the head now is.
*/
for (pptr = user; pptr->prev != NULL; pptr = pptr->prev);
return pptr;
}
/*
* usm_remove_user(): finds and removes a user from a list
*/
struct usmUser *
usm_remove_user(struct usmUser *user)
{
return usm_remove_user_from_list(user, &userList);
}
struct usmUser *
usm_remove_user_from_list(struct usmUser *user,
struct usmUser **ppuserList)
{
struct usmUser *nptr, *pptr;
/*
* NULL pointers aren't allowed
*/
if (ppuserList == NULL)
return NULL;
if (*ppuserList == NULL)
return NULL;
/*
* find the user in the list
*/
for (nptr = *ppuserList, pptr = NULL; nptr != NULL;
pptr = nptr, nptr = nptr->next) {
if (nptr == user)
break;
}
if (nptr) {
/*
* remove the user from the linked list
*/
if (pptr) {
pptr->next = nptr->next;
}
if (nptr->next) {
nptr->next->prev = pptr;
}
} else {
/*
* user didn't exist
*/
return NULL;
}
if (nptr == *ppuserList) /* we're the head of the list, need to change
* * the head to the next user */
*ppuserList = nptr->next;
return *ppuserList;
} /* end usm_remove_user_from_list() */
/*
* usm_free_user(): calls free() on all needed parts of struct usmUser and
* the user himself.
*
* Note: This should *not* be called on an object in a list (IE,
* remove it from the list first, and set next and prev to NULL), but
* will try to reconnect the list pieces again if it is called this
* way. If called on the head of the list, the entire list will be
* lost.
*/
struct usmUser *
usm_free_user(struct usmUser *user)
{
if (user == NULL)
return NULL;
SNMP_FREE(user->engineID);
SNMP_FREE(user->name);
SNMP_FREE(user->secName);
SNMP_FREE(user->cloneFrom);
SNMP_FREE(user->userPublicString);
SNMP_FREE(user->authProtocol);
SNMP_FREE(user->privProtocol);
if (user->authKey != NULL) {
SNMP_ZERO(user->authKey, user->authKeyLen);
SNMP_FREE(user->authKey);
}
if (user->privKey != NULL) {
SNMP_ZERO(user->privKey, user->privKeyLen);
SNMP_FREE(user->privKey);
}
/*
* FIX Why not put this check *first?*
*/
if (user->prev != NULL) { /* ack, this shouldn't happen */
user->prev->next = user->next;
}
if (user->next != NULL) {
user->next->prev = user->prev;
if (user->prev != NULL) /* ack this is really bad, because it means
* * we'll loose the head of some structure tree */
DEBUGMSGTL(("usm",
"Severe: Asked to free the head of a usmUser tree somewhere."));
}
SNMP_ZERO(user, sizeof(*user));
SNMP_FREE(user);
return NULL; /* for convenience to returns from calling functions */
} /* end usm_free_user() */
/*
* take a given user and clone the security info into another
*/
struct usmUser *
usm_cloneFrom_user(struct usmUser *from, struct usmUser *to)
{
/*
* copy the authProtocol oid row pointer
*/
SNMP_FREE(to->authProtocol);
if ((to->authProtocol =
snmp_duplicate_objid(from->authProtocol,
from->authProtocolLen)) != NULL)
to->authProtocolLen = from->authProtocolLen;
else
to->authProtocolLen = 0;
/*
* copy the authKey
*/
SNMP_FREE(to->authKey);
if (from->authKeyLen > 0 &&
(to->authKey = (u_char *) malloc(from->authKeyLen))
!= NULL) {
to->authKeyLen = from->authKeyLen;
memcpy(to->authKey, from->authKey, to->authKeyLen);
} else {
to->authKey = NULL;
to->authKeyLen = 0;
}
/*
* copy the privProtocol oid row pointer
*/
SNMP_FREE(to->privProtocol);
if ((to->privProtocol =
snmp_duplicate_objid(from->privProtocol,
from->privProtocolLen)) != NULL)
to->privProtocolLen = from->privProtocolLen;
else
to->privProtocolLen = 0;
/*
* copy the privKey
*/
SNMP_FREE(to->privKey);
if (from->privKeyLen > 0 &&
(to->privKey = (u_char *) malloc(from->privKeyLen))
!= NULL) {
to->privKeyLen = from->privKeyLen;
memcpy(to->privKey, from->privKey, to->privKeyLen);
} else {
to->privKey = NULL;
to->privKeyLen = 0;
}
return to;
}
/*
* usm_create_user(void):
* create a default empty user, instantiating only the auth/priv
* protocols to noAuth and noPriv OID pointers
*/
struct usmUser *
usm_create_user(void)
{
struct usmUser *newUser;
/*
* create the new user
*/
newUser = (struct usmUser *) calloc(1, sizeof(struct usmUser));
if (newUser == NULL)
return NULL;
/*
* fill the auth/priv protocols
*/
if ((newUser->authProtocol =
snmp_duplicate_objid(usmNoAuthProtocol,
sizeof(usmNoAuthProtocol) / sizeof(oid))) ==
NULL)
return usm_free_user(newUser);
newUser->authProtocolLen = sizeof(usmNoAuthProtocol) / sizeof(oid);
if ((newUser->privProtocol =
snmp_duplicate_objid(usmNoPrivProtocol,
sizeof(usmNoPrivProtocol) / sizeof(oid))) ==
NULL)
return usm_free_user(newUser);
newUser->privProtocolLen = sizeof(usmNoPrivProtocol) / sizeof(oid);
/*
* set the storage type to nonvolatile, and the status to ACTIVE
*/
newUser->userStorageType = ST_NONVOLATILE;
newUser->userStatus = RS_ACTIVE;
return newUser;
} /* end usm_clone_user() */
/*
* usm_create_initial_user(void):
* creates an initial user, filled with the defaults defined in the
* USM document.
*/
struct usmUser *
usm_create_initial_user(const char *name,
const oid * authProtocol, size_t authProtocolLen,
const oid * privProtocol, size_t privProtocolLen)
{
struct usmUser *newUser = usm_create_user();
if (newUser == NULL)
return NULL;
if ((newUser->name = strdup(name)) == NULL)
return usm_free_user(newUser);
if ((newUser->secName = strdup(name)) == NULL)
return usm_free_user(newUser);
if ((newUser->engineID =
snmpv3_generate_engineID(&newUser->engineIDLen)) == NULL)
return usm_free_user(newUser);
if ((newUser->cloneFrom = (oid *) malloc(sizeof(oid) * 2)) == NULL)
return usm_free_user(newUser);
newUser->cloneFrom[0] = 0;
newUser->cloneFrom[1] = 0;
newUser->cloneFromLen = 2;
SNMP_FREE(newUser->privProtocol);
if ((newUser->privProtocol = snmp_duplicate_objid(privProtocol,
privProtocolLen)) ==
NULL) {
return usm_free_user(newUser);
}
newUser->privProtocolLen = privProtocolLen;
SNMP_FREE(newUser->authProtocol);
if ((newUser->authProtocol = snmp_duplicate_objid(authProtocol,
authProtocolLen)) ==
NULL) {
return usm_free_user(newUser);
}
newUser->authProtocolLen = authProtocolLen;
newUser->userStatus = RS_ACTIVE;
newUser->userStorageType = ST_READONLY;
return newUser;
}
/*
* this is a callback that can store all known users based on a
* previously registered application ID
*/
int
usm_store_users(int majorID, int minorID, void *serverarg, void *clientarg)
{
/*
* figure out our application name
*/
char *appname = (char *) clientarg;
if (appname == NULL) {
appname = netsnmp_ds_get_string(NETSNMP_DS_LIBRARY_ID,
NETSNMP_DS_LIB_APPTYPE);
}
/*
* save the user base
*/
usm_save_users("usmUser", appname);
/*
* never fails
*/
return SNMPERR_SUCCESS;
}
/*
* usm_save_users(): saves a list of users to the persistent cache
*/
void
usm_save_users(const char *token, const char *type)
{
usm_save_users_from_list(userList, token, type);
}
void
usm_save_users_from_list(struct usmUser *puserList, const char *token,
const char *type)
{
struct usmUser *uptr;
for (uptr = puserList; uptr != NULL; uptr = uptr->next) {
if (uptr->userStorageType == ST_NONVOLATILE)
usm_save_user(uptr, token, type);
}
}
/*
* usm_save_user(): saves a user to the persistent cache
*/
void
usm_save_user(struct usmUser *user, const char *token, const char *type)
{
char line[4096];
char *cptr;
memset(line, 0, sizeof(line));
sprintf(line, "%s %d %d ", token, user->userStatus,
user->userStorageType);
cptr = &line[strlen(line)]; /* the NULL */
cptr =
read_config_save_octet_string(cptr, user->engineID,
user->engineIDLen);
*cptr++ = ' ';
cptr = read_config_save_octet_string(cptr, (u_char *) user->name,
(user->name == NULL) ? 0 :
strlen(user->name) + 1);
*cptr++ = ' ';
cptr = read_config_save_octet_string(cptr, (u_char *) user->secName,
(user->secName == NULL) ? 0 :
strlen(user->secName) + 1);
*cptr++ = ' ';
cptr =
read_config_save_objid(cptr, user->cloneFrom, user->cloneFromLen);
*cptr++ = ' ';
cptr = read_config_save_objid(cptr, user->authProtocol,
user->authProtocolLen);
*cptr++ = ' ';
cptr =
read_config_save_octet_string(cptr, user->authKey,
user->authKeyLen);
*cptr++ = ' ';
cptr = read_config_save_objid(cptr, user->privProtocol,
user->privProtocolLen);
*cptr++ = ' ';
cptr =
read_config_save_octet_string(cptr, user->privKey,
user->privKeyLen);
*cptr++ = ' ';
cptr = read_config_save_octet_string(cptr, user->userPublicString,
(user->userPublicString ==
NULL) ? 0 : strlen((char *)
user->
userPublicString)
+ 1);
read_config_store(type, line);
}
/*
* usm_parse_user(): reads in a line containing a saved user profile
* and returns a pointer to a newly created struct usmUser.
*/
struct usmUser *
usm_read_user(char *line)
{
struct usmUser *user;
size_t len;
size_t expected_privKeyLen = 0;
user = usm_create_user();
if (user == NULL)
return NULL;
user->userStatus = atoi(line);
line = skip_token(line);
user->userStorageType = atoi(line);
line = skip_token(line);
line = read_config_read_octet_string(line, &user->engineID,
&user->engineIDLen);
/*
* set the lcd entry for this engineID to the minimum boots/time
* values so that its a known engineid and won't return a report pdu.
* This is mostly important when receiving v3 traps so that the usm
* will at least continue processing them.
*/
set_enginetime(user->engineID, user->engineIDLen, 1, 0, 0);
line = read_config_read_octet_string(line, (u_char **) & user->name,
&len);
line = read_config_read_octet_string(line, (u_char **) & user->secName,
&len);
SNMP_FREE(user->cloneFrom);
user->cloneFromLen = 0;
line =
read_config_read_objid(line, &user->cloneFrom,
&user->cloneFromLen);
SNMP_FREE(user->authProtocol);
user->authProtocolLen = 0;
line = read_config_read_objid(line, &user->authProtocol,
&user->authProtocolLen);
line = read_config_read_octet_string(line, &user->authKey,
&user->authKeyLen);
SNMP_FREE(user->privProtocol);
user->privProtocolLen = 0;
line = read_config_read_objid(line, &user->privProtocol,
&user->privProtocolLen);
line = read_config_read_octet_string(line, &user->privKey,
&user->privKeyLen);
#ifndef DISABLE_DES
if (ISTRANSFORM(user->privProtocol, DESPriv)) {
/* DES uses a 128 bit key, 64 bits of which is a salt */
expected_privKeyLen = 16;
}
#endif
#ifdef HAVE_AES
if (ISTRANSFORM(user->privProtocol, AESPriv)) {
expected_privKeyLen = 16;
}
#endif
/* For backwards compatibility */
if (user->privKeyLen > expected_privKeyLen) {
user->privKeyLen = expected_privKeyLen;
}
line = read_config_read_octet_string(line, &user->userPublicString,
&len);
return user;
}
/*
* snmpd.conf parsing routines
*/
void
usm_parse_config_usmUser(const char *token, char *line)
{
struct usmUser *uptr;
uptr = usm_read_user(line);
usm_add_user(uptr);
}
/*******************************************************************-o-******
* usm_set_password
*
* Parameters:
* *token
* *line
*
*
* format: userSetAuthPass secname engineIDLen engineID pass
* or: userSetPrivPass secname engineIDLen engineID pass
* or: userSetAuthKey secname engineIDLen engineID KuLen Ku
* or: userSetPrivKey secname engineIDLen engineID KuLen Ku
* or: userSetAuthLocalKey secname engineIDLen engineID KulLen Kul
* or: userSetPrivLocalKey secname engineIDLen engineID KulLen Kul
*
* type is: 1=passphrase; 2=Ku; 3=Kul.
*
*
* ASSUMES Passwords are null-terminated printable strings.
*/
void
usm_set_password(const char *token, char *line)
{
char *cp;
char nameBuf[SNMP_MAXBUF];
u_char *engineID;
size_t engineIDLen;
struct usmUser *user;
cp = copy_nword(line, nameBuf, sizeof(nameBuf));
if (cp == NULL) {
config_perror("invalid name specifier");
return;
}
DEBUGMSGTL(("usm", "comparing: %s and %s\n", cp, WILDCARDSTRING));
if (strncmp(cp, WILDCARDSTRING, strlen(WILDCARDSTRING)) == 0) {
/*
* match against all engineIDs we know about
*/
cp = skip_token(cp);
for (user = userList; user != NULL; user = user->next) {
if (user->secName && strcmp(user->secName, nameBuf) == 0) {
usm_set_user_password(user, token, cp);
}
}
} else {
cp = read_config_read_octet_string(cp, &engineID, &engineIDLen);
if (cp == NULL) {
config_perror("invalid engineID specifier");
return;
}
user = usm_get_user(engineID, engineIDLen, nameBuf);
if (user == NULL) {
config_perror("not a valid user/engineID pair");
return;
}
usm_set_user_password(user, token, cp);
}
}
/*
* uses the rest of LINE to configure USER's password of type TOKEN
*/
void
usm_set_user_password(struct usmUser *user, const char *token, char *line)
{
char *cp = line;
u_char *engineID = user->engineID;
size_t engineIDLen = user->engineIDLen;
u_char **key;
size_t *keyLen;
u_char userKey[SNMP_MAXBUF_SMALL];
size_t userKeyLen = SNMP_MAXBUF_SMALL;
u_char *userKeyP = userKey;
int type, ret;
/*
* Retrieve the "old" key and set the key type.
*/
if (!token) {
return;
} else if (strcmp(token, "userSetAuthPass") == 0) {
key = &user->authKey;
keyLen = &user->authKeyLen;
type = 0;
} else if (strcmp(token, "userSetPrivPass") == 0) {
key = &user->privKey;
keyLen = &user->privKeyLen;
type = 0;
} else if (strcmp(token, "userSetAuthKey") == 0) {
key = &user->authKey;
keyLen = &user->authKeyLen;
type = 1;
} else if (strcmp(token, "userSetPrivKey") == 0) {
key = &user->privKey;
keyLen = &user->privKeyLen;
type = 1;
} else if (strcmp(token, "userSetAuthLocalKey") == 0) {
key = &user->authKey;
keyLen = &user->authKeyLen;
type = 2;
} else if (strcmp(token, "userSetPrivLocalKey") == 0) {
key = &user->privKey;
keyLen = &user->privKeyLen;
type = 2;
} else {
/*
* no old key, or token was not recognized
*/
return;
}
if (*key) {
/*
* (destroy and) free the old key
*/
memset(*key, 0, *keyLen);
SNMP_FREE(*key);
}
if (type == 0) {
/*
* convert the password into a key
*/
if (cp == NULL) {
config_perror("missing user password");
return;
}
ret = generate_Ku(user->authProtocol, user->authProtocolLen,
(u_char *) cp, strlen(cp), userKey, &userKeyLen);
if (ret != SNMPERR_SUCCESS) {
config_perror("setting key failed (in sc_genKu())");
return;
}
} else if (type == 1) {
cp = read_config_read_octet_string(cp, &userKeyP, &userKeyLen);
if (cp == NULL) {
config_perror("invalid user key");
return;
}
}
if (type < 2) {
*key = (u_char *) malloc(SNMP_MAXBUF_SMALL);
*keyLen = SNMP_MAXBUF_SMALL;
ret = generate_kul(user->authProtocol, user->authProtocolLen,
engineID, engineIDLen,
userKey, userKeyLen, *key, keyLen);
if (ret != SNMPERR_SUCCESS) {
config_perror("setting key failed (in generate_kul())");
return;
}
/*
* (destroy and) free the old key
*/
memset(userKey, 0, sizeof(userKey));
} else {
/*
* the key is given, copy it in
*/
cp = read_config_read_octet_string(cp, key, keyLen);
if (cp == NULL) {
config_perror("invalid localized user key");
return;
}
}
} /* end usm_set_password() */
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