libsql/libsql-ffi/bundled/sqlean/crypto/sha1.c

// Originally from the sha1 SQLite exension, Public Domain
// https://sqlite.org/src/file/ext/misc/sha1.c
// Modified by Anton Zhiyanov, https://github.com/nalgeon/sqlean/, MIT License

#include <assert.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>

#include "crypto/sha1.h"

#define SHA_ROT(x, l, r) ((x) << (l) | (x) >> (r))
#define rol(x, k) SHA_ROT(x, k, 32 - (k))
#define ror(x, k) SHA_ROT(x, 32 - (k), k)

#define blk0le(i) (block[i] = (ror(block[i], 8) & 0xFF00FF00) | (rol(block[i], 8) & 0x00FF00FF))
#define blk0be(i) block[i]
#define blk(i)       \
    (block[i & 15] = \
         rol(block[(i + 13) & 15] ^ block[(i + 8) & 15] ^ block[(i + 2) & 15] ^ block[i & 15], 1))

/*
 * (R0+R1), R2, R3, R4 are the different operations (rounds) used in SHA1
 *
 * Rl0() for little-endian and Rb0() for big-endian.  Endianness is
 * determined at run-time.
 */
#define Rl0(v, w, x, y, z, i)                                      \
    z += ((w & (x ^ y)) ^ y) + blk0le(i) + 0x5A827999 + rol(v, 5); \
    w = ror(w, 2);
#define Rb0(v, w, x, y, z, i)                                      \
    z += ((w & (x ^ y)) ^ y) + blk0be(i) + 0x5A827999 + rol(v, 5); \
    w = ror(w, 2);
#define R1(v, w, x, y, z, i)                                    \
    z += ((w & (x ^ y)) ^ y) + blk(i) + 0x5A827999 + rol(v, 5); \
    w = ror(w, 2);
#define R2(v, w, x, y, z, i)                            \
    z += (w ^ x ^ y) + blk(i) + 0x6ED9EBA1 + rol(v, 5); \
    w = ror(w, 2);
#define R3(v, w, x, y, z, i)                                          \
    z += (((w | x) & y) | (w & x)) + blk(i) + 0x8F1BBCDC + rol(v, 5); \
    w = ror(w, 2);
#define R4(v, w, x, y, z, i)                            \
    z += (w ^ x ^ y) + blk(i) + 0xCA62C1D6 + rol(v, 5); \
    w = ror(w, 2);

/*
 * Hash a single 512-bit block. This is the core of the algorithm.
 */
void SHA1Transform(unsigned int state[5], const unsigned char buffer[64]) {
    unsigned int qq[5]; /* a, b, c, d, e; */
    static int one = 1;
    unsigned int block[16];
    memcpy(block, buffer, 64);
    memcpy(qq, state, 5 * sizeof(unsigned int));

#define a qq[0]
#define b qq[1]
#define c qq[2]
#define d qq[3]
#define e qq[4]

    /* Copy ctx->state[] to working vars */
    /*
  a = state[0];
  b = state[1];
  c = state[2];
  d = state[3];
  e = state[4];
  */

    /* 4 rounds of 20 operations each. Loop unrolled. */
    if (1 == *(unsigned char*)&one) {
        Rl0(a, b, c, d, e, 0);
        Rl0(e, a, b, c, d, 1);
        Rl0(d, e, a, b, c, 2);
        Rl0(c, d, e, a, b, 3);
        Rl0(b, c, d, e, a, 4);
        Rl0(a, b, c, d, e, 5);
        Rl0(e, a, b, c, d, 6);
        Rl0(d, e, a, b, c, 7);
        Rl0(c, d, e, a, b, 8);
        Rl0(b, c, d, e, a, 9);
        Rl0(a, b, c, d, e, 10);
        Rl0(e, a, b, c, d, 11);
        Rl0(d, e, a, b, c, 12);
        Rl0(c, d, e, a, b, 13);
        Rl0(b, c, d, e, a, 14);
        Rl0(a, b, c, d, e, 15);
    } else {
        Rb0(a, b, c, d, e, 0);
        Rb0(e, a, b, c, d, 1);
        Rb0(d, e, a, b, c, 2);
        Rb0(c, d, e, a, b, 3);
        Rb0(b, c, d, e, a, 4);
        Rb0(a, b, c, d, e, 5);
        Rb0(e, a, b, c, d, 6);
        Rb0(d, e, a, b, c, 7);
        Rb0(c, d, e, a, b, 8);
        Rb0(b, c, d, e, a, 9);
        Rb0(a, b, c, d, e, 10);
        Rb0(e, a, b, c, d, 11);
        Rb0(d, e, a, b, c, 12);
        Rb0(c, d, e, a, b, 13);
        Rb0(b, c, d, e, a, 14);
        Rb0(a, b, c, d, e, 15);
    }
    R1(e, a, b, c, d, 16);
    R1(d, e, a, b, c, 17);
    R1(c, d, e, a, b, 18);
    R1(b, c, d, e, a, 19);
    R2(a, b, c, d, e, 20);
    R2(e, a, b, c, d, 21);
    R2(d, e, a, b, c, 22);
    R2(c, d, e, a, b, 23);
    R2(b, c, d, e, a, 24);
    R2(a, b, c, d, e, 25);
    R2(e, a, b, c, d, 26);
    R2(d, e, a, b, c, 27);
    R2(c, d, e, a, b, 28);
    R2(b, c, d, e, a, 29);
    R2(a, b, c, d, e, 30);
    R2(e, a, b, c, d, 31);
    R2(d, e, a, b, c, 32);
    R2(c, d, e, a, b, 33);
    R2(b, c, d, e, a, 34);
    R2(a, b, c, d, e, 35);
    R2(e, a, b, c, d, 36);
    R2(d, e, a, b, c, 37);
    R2(c, d, e, a, b, 38);
    R2(b, c, d, e, a, 39);
    R3(a, b, c, d, e, 40);
    R3(e, a, b, c, d, 41);
    R3(d, e, a, b, c, 42);
    R3(c, d, e, a, b, 43);
    R3(b, c, d, e, a, 44);
    R3(a, b, c, d, e, 45);
    R3(e, a, b, c, d, 46);
    R3(d, e, a, b, c, 47);
    R3(c, d, e, a, b, 48);
    R3(b, c, d, e, a, 49);
    R3(a, b, c, d, e, 50);
    R3(e, a, b, c, d, 51);
    R3(d, e, a, b, c, 52);
    R3(c, d, e, a, b, 53);
    R3(b, c, d, e, a, 54);
    R3(a, b, c, d, e, 55);
    R3(e, a, b, c, d, 56);
    R3(d, e, a, b, c, 57);
    R3(c, d, e, a, b, 58);
    R3(b, c, d, e, a, 59);
    R4(a, b, c, d, e, 60);
    R4(e, a, b, c, d, 61);
    R4(d, e, a, b, c, 62);
    R4(c, d, e, a, b, 63);
    R4(b, c, d, e, a, 64);
    R4(a, b, c, d, e, 65);
    R4(e, a, b, c, d, 66);
    R4(d, e, a, b, c, 67);
    R4(c, d, e, a, b, 68);
    R4(b, c, d, e, a, 69);
    R4(a, b, c, d, e, 70);
    R4(e, a, b, c, d, 71);
    R4(d, e, a, b, c, 72);
    R4(c, d, e, a, b, 73);
    R4(b, c, d, e, a, 74);
    R4(a, b, c, d, e, 75);
    R4(e, a, b, c, d, 76);
    R4(d, e, a, b, c, 77);
    R4(c, d, e, a, b, 78);
    R4(b, c, d, e, a, 79);

    /* Add the working vars back into context.state[] */
    state[0] += a;
    state[1] += b;
    state[2] += c;
    state[3] += d;
    state[4] += e;

#undef a
#undef b
#undef c
#undef d
#undef e
}

/* Initialize a SHA1 context */
void* sha1_init() {
    /* SHA1 initialization constants */
    SHA1Context* ctx;
    ctx = malloc(sizeof(SHA1Context));
    ctx->state[0] = 0x67452301;
    ctx->state[1] = 0xEFCDAB89;
    ctx->state[2] = 0x98BADCFE;
    ctx->state[3] = 0x10325476;
    ctx->state[4] = 0xC3D2E1F0;
    ctx->count[0] = ctx->count[1] = 0;
    return ctx;
}

/* Add new content to the SHA1 hash */
void sha1_update(SHA1Context* ctx, const unsigned char* data, size_t len) {
    unsigned int i, j;

    j = ctx->count[0];
    if ((ctx->count[0] += len << 3) < j) {
        ctx->count[1] += (len >> 29) + 1;
    }
    j = (j >> 3) & 63;
    if ((j + len) > 63) {
        (void)memcpy(&ctx->buffer[j], data, (i = 64 - j));
        SHA1Transform(ctx->state, ctx->buffer);
        for (; i + 63 < len; i += 64) {
            SHA1Transform(ctx->state, &data[i]);
        }
        j = 0;
    } else {
        i = 0;
    }
    (void)memcpy(&ctx->buffer[j], &data[i], len - i);
}

int sha1_final(SHA1Context* ctx, unsigned char hash[]) {
    unsigned int i;
    unsigned char finalcount[8];

    for (i = 0; i < 8; i++) {
        finalcount[i] = (unsigned char)((ctx->count[(i >= 4 ? 0 : 1)] >> ((3 - (i & 3)) * 8)) &
                                        255); /* Endian independent */
    }
    sha1_update(ctx, (const unsigned char*)"\200", 1);
    while ((ctx->count[0] & 504) != 448) {
        sha1_update(ctx, (const unsigned char*)"\0", 1);
    }
    sha1_update(ctx, finalcount, 8); /* Should cause a SHA1Transform() */
    for (i = 0; i < 20; i++) {
        hash[i] = (unsigned char)((ctx->state[i >> 2] >> ((3 - (i & 3)) * 8)) & 255);
    }
    free(ctx);
    return SHA1_BLOCK_SIZE;
}