diff options
Diffstat (limited to 'src/sha256.c')
| -rw-r--r-- | src/sha256.c | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/src/sha256.c b/src/sha256.c new file mode 100644 index 0000000..e5ba5dd --- /dev/null +++ b/src/sha256.c @@ -0,0 +1,167 @@ +/* + * SHA256 + * + * The author (Brad Conte) has released this file "into the public domain free + * of any restrictions". This file is unchanged except for some style + * clean-up and argument order for sha256_hash (feh). + */ + +#include <stdint.h> +#include <string.h> +#include "sha256.h" + +// DBL_INT_ADD treats two unsigned ints a and b as one 64-bit integer and adds c to it + +#define DBL_INT_ADD(a,b,c) if (a > 0xffffffff - (c)) ++b; a += c; +#define ROTLEFT(a,b) (((a) << (b)) | ((a) >> (32-(b)))) +#define ROTRIGHT(a,b) (((a) >> (b)) | ((a) << (32-(b)))) + +#define CH(x,y,z) (((x) & (y)) ^ (~(x) & (z))) +#define MAJ(x,y,z) (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z))) +#define EP0(x) (ROTRIGHT(x,2) ^ ROTRIGHT(x,13) ^ ROTRIGHT(x,22)) +#define EP1(x) (ROTRIGHT(x,6) ^ ROTRIGHT(x,11) ^ ROTRIGHT(x,25)) +#define SIG0(x) (ROTRIGHT(x,7) ^ ROTRIGHT(x,18) ^ ((x) >> 3)) +#define SIG1(x) (ROTRIGHT(x,17) ^ ROTRIGHT(x,19) ^ ((x) >> 10)) + +uint32_t k[64] = +{ + 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, + 0x923f82a4, 0xab1c5ed5, 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, + 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, 0xe49b69c1, 0xefbe4786, + 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da, + 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, + 0x06ca6351, 0x14292967, 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, + 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 0xa2bfe8a1, 0xa81a664b, + 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070, + 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, + 0x5b9cca4f, 0x682e6ff3, 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, + 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2 +}; + +static void sha256_transform(sha256_ctx *ctx, uint8_t *data) +{ + uint32_t a, b, c, d, e, f, g, h, i, j, t1, t2, m[64]; + + for (i = 0, j = 0; i < 16; ++i, j += 4) + m[i] = (data[j] << 24) | (data[j+1] << 16) | (data[j+2] << 8) | (data[j+3]); + for (; i < 64; ++i) + m[i] = SIG1(m[i-2]) + m[i-7] + SIG0(m[i-15]) + m[i-16]; + + a = ctx->state[0]; + b = ctx->state[1]; + c = ctx->state[2]; + d = ctx->state[3]; + e = ctx->state[4]; + f = ctx->state[5]; + g = ctx->state[6]; + h = ctx->state[7]; + + for (i = 0; i < 64; ++i) { + t1 = h + EP1(e) + CH(e,f,g) + k[i] + m[i]; + t2 = EP0(a) + MAJ(a,b,c); + h = g; + g = f; + f = e; + e = d + t1; + d = c; + c = b; + b = a; + a = t1 + t2; + } + + ctx->state[0] += a; + ctx->state[1] += b; + ctx->state[2] += c; + ctx->state[3] += d; + ctx->state[4] += e; + ctx->state[5] += f; + ctx->state[6] += g; + ctx->state[7] += h; +} + +static void sha256_init(sha256_ctx *ctx) +{ + ctx->datalen = 0; + ctx->bitlen[0] = 0; + ctx->bitlen[1] = 0; + ctx->state[0] = 0x6a09e667; + ctx->state[1] = 0xbb67ae85; + ctx->state[2] = 0x3c6ef372; + ctx->state[3] = 0xa54ff53a; + ctx->state[4] = 0x510e527f; + ctx->state[5] = 0x9b05688c; + ctx->state[6] = 0x1f83d9ab; + ctx->state[7] = 0x5be0cd19; +} + +static void sha256_update(sha256_ctx *ctx, uint8_t *data, uint32_t len) +{ + uint32_t i; + + for (i=0; i < len; ++i) { + ctx->data[ctx->datalen] = data[i]; + ctx->datalen++; + if (ctx->datalen == 64) { + sha256_transform(ctx,ctx->data); + DBL_INT_ADD(ctx->bitlen[0],ctx->bitlen[1],512); + ctx->datalen = 0; + } + } +} + +static void sha256_final(uint8_t *hash,sha256_ctx *ctx) +{ + uint32_t i; + + i = ctx->datalen; + +// Pad whatever data is left in the buffer. + + if (ctx->datalen < 56) { + ctx->data[i++] = 0x80; + while (i < 56) + ctx->data[i++] = 0x00; + } + else { + ctx->data[i++] = 0x80; + while (i < 64) + ctx->data[i++] = 0x00; + sha256_transform(ctx,ctx->data); + memset(ctx->data,0,56); + } + +// Append to the padding the total message's length in bits and transform. + + DBL_INT_ADD(ctx->bitlen[0],ctx->bitlen[1],ctx->datalen * 8); + ctx->data[63] = ctx->bitlen[0]; + ctx->data[62] = ctx->bitlen[0] >> 8; + ctx->data[61] = ctx->bitlen[0] >> 16; + ctx->data[60] = ctx->bitlen[0] >> 24; + ctx->data[59] = ctx->bitlen[1]; + ctx->data[58] = ctx->bitlen[1] >> 8; + ctx->data[57] = ctx->bitlen[1] >> 16; + ctx->data[56] = ctx->bitlen[1] >> 24; + sha256_transform(ctx,ctx->data); + +// Since this implementation uses little endian byte ordering and SHA uses +// big endian, reverse all the bytes when copying the final state to the output hash. + + for (i = 0; i < 4; ++i) { + hash[i] = (ctx->state[0] >> (24-i*8)) & 0x000000ff; + hash[i+4] = (ctx->state[1] >> (24-i*8)) & 0x000000ff; + hash[i+8] = (ctx->state[2] >> (24-i*8)) & 0x000000ff; + hash[i+12] = (ctx->state[3] >> (24-i*8)) & 0x000000ff; + hash[i+16] = (ctx->state[4] >> (24-i*8)) & 0x000000ff; + hash[i+20] = (ctx->state[5] >> (24-i*8)) & 0x000000ff; + hash[i+24] = (ctx->state[6] >> (24-i*8)) & 0x000000ff; + hash[i+28] = (ctx->state[7] >> (24-i*8)) & 0x000000ff; + } +} + +extern void sha256_hash(char *hash,const char *data,size_t len) +{ + sha256_ctx ctx; + sha256_init(&ctx); + sha256_update(&ctx,(uint8_t *)data,(int)len); + sha256_final((uint8_t *)hash,&ctx); +} |