/* vi: set sw=4 ts=4: */ /* * Based on shasum from http://www.netsw.org/crypto/hash/ * Majorly hacked up to use Dr Brian Gladman's sha1 code * * Copyright (C) 2002 Dr Brian Gladman , Worcester, UK. * Copyright (C) 2003 Glenn L. McGrath * Copyright (C) 2003 Erik Andersen * * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. * * --------------------------------------------------------------------------- * Issue Date: 10/11/2002 * * This is a byte oriented version of SHA1 that operates on arrays of bytes * stored in memory. It runs at 22 cycles per byte on a Pentium P4 processor * * --------------------------------------------------------------------------- * * SHA256 and SHA512 parts are: * Released into the Public Domain by Ulrich Drepper . * TODO: shrink them. */ #include "libbb.h" #define rotl32(x,n) (((x) << (n)) | ((x) >> (32 - (n)))) #define rotr32(x,n) (((x) >> (n)) | ((x) << (32 - (n)))) /* for sha512: */ #define rotr64(x,n) (((x) >> (n)) | ((x) << (64 - (n)))) #if BB_LITTLE_ENDIAN static inline uint64_t hton64(uint64_t v) { return (((uint64_t)htonl(v)) << 32) | htonl(v >> 32); } #else #define hton64(v) (v) #endif #define ntoh64(v) hton64(v) /* To check alignment gcc has an appropriate operator. Other compilers don't. */ #if defined(__GNUC__) && __GNUC__ >= 2 # define UNALIGNED_P(p,type) (((uintptr_t) p) % __alignof__(type) != 0) #else # define UNALIGNED_P(p,type) (((uintptr_t) p) % sizeof(type) != 0) #endif #define SHA1_BLOCK_SIZE 64 #define SHA1_DIGEST_SIZE 20 #define SHA1_HASH_SIZE SHA1_DIGEST_SIZE #define SHA1_MASK (SHA1_BLOCK_SIZE - 1) static void sha1_compile(sha1_ctx_t *ctx) { uint32_t w[80], i, a, b, c, d, e, t; /* note that words are compiled from the buffer into 32-bit */ /* words in big-endian order so an order reversal is needed */ /* here on little endian machines */ for (i = 0; i < SHA1_BLOCK_SIZE / 4; ++i) w[i] = ntohl(ctx->wbuf[i]); for (/*i = SHA1_BLOCK_SIZE / 4*/; i < 80; ++i) { t = w[i - 3] ^ w[i - 8] ^ w[i - 14] ^ w[i - 16]; w[i] = rotl32(t, 1); } a = ctx->hash[0]; b = ctx->hash[1]; c = ctx->hash[2]; d = ctx->hash[3]; e = ctx->hash[4]; /* Reverse byte order in 32-bit words */ #define ch(x,y,z) ((z) ^ ((x) & ((y) ^ (z)))) #define parity(x,y,z) ((x) ^ (y) ^ (z)) #define maj(x,y,z) (((x) & (y)) | ((z) & ((x) | (y)))) /* A normal version as set out in the FIPS. This version uses */ /* partial loop unrolling and is optimised for the Pentium 4 */ #define rnd(f,k) \ do { \ t = a; a = rotl32(a,5) + f(b,c,d) + e + k + w[i]; \ e = d; d = c; c = rotl32(b, 30); b = t; \ } while (0) for (i = 0; i < 20; ++i) rnd(ch, 0x5a827999); for (i = 20; i < 40; ++i) rnd(parity, 0x6ed9eba1); for (i = 40; i < 60; ++i) rnd(maj, 0x8f1bbcdc); for (i = 60; i < 80; ++i) rnd(parity, 0xca62c1d6); #undef ch #undef parity #undef maj #undef rnd ctx->hash[0] += a; ctx->hash[1] += b; ctx->hash[2] += c; ctx->hash[3] += d; ctx->hash[4] += e; } /* Process LEN bytes of BUFFER, accumulating context into CTX. It is assumed that LEN % 64 == 0. */ static void sha256_process_block(const void *buffer, size_t len, sha256_ctx_t *ctx) { /* Constants for SHA256 from FIPS 180-2:4.2.2. */ static const 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 }; const uint32_t *words = buffer; size_t nwords = len / sizeof(uint32_t); uint32_t a = ctx->H[0]; uint32_t b = ctx->H[1]; uint32_t c = ctx->H[2]; uint32_t d = ctx->H[3]; uint32_t e = ctx->H[4]; uint32_t f = ctx->H[5]; uint32_t g = ctx->H[6]; uint32_t h = ctx->H[7]; /* First increment the byte count. FIPS 180-2 specifies the possible length of the file up to 2^64 bits. Here we only compute the number of bytes. Do a double word increment. */ ctx->total[0] += len; if (ctx->total[0] < len) ctx->total[1]++; /* Process all bytes in the buffer with 64 bytes in each round of the loop. */ while (nwords > 0) { uint32_t W[64]; uint32_t a_save = a; uint32_t b_save = b; uint32_t c_save = c; uint32_t d_save = d; uint32_t e_save = e; uint32_t f_save = f; uint32_t g_save = g; uint32_t h_save = h; /* Operators defined in FIPS 180-2:4.1.2. */ #define Ch(x, y, z) ((x & y) ^ (~x & z)) #define Maj(x, y, z) ((x & y) ^ (x & z) ^ (y & z)) #define S0(x) (rotr32(x, 2) ^ rotr32(x, 13) ^ rotr32(x, 22)) #define S1(x) (rotr32(x, 6) ^ rotr32(x, 11) ^ rotr32(x, 25)) #define R0(x) (rotr32(x, 7) ^ rotr32(x, 18) ^ (x >> 3)) #define R1(x) (rotr32(x, 17) ^ rotr32(x, 19) ^ (x >> 10)) /* Compute the message schedule according to FIPS 180-2:6.2.2 step 2. */ for (unsigned t = 0; t < 16; ++t) { W[t] = ntohl(*words); ++words; } for (unsigned t = 16; t < 64; ++t) W[t] = R1(W[t - 2]) + W[t - 7] + R0(W[t - 15]) + W[t - 16]; /* The actual computation according to FIPS 180-2:6.2.2 step 3. */ for (unsigned t = 0; t < 64; ++t) { uint32_t T1 = h + S1(e) + Ch(e, f, g) + K[t] + W[t]; uint32_t T2 = S0(a) + Maj(a, b, c); h = g; g = f; f = e; e = d + T1; d = c; c = b; b = a; a = T1 + T2; } #undef Ch #undef Maj #undef S0 #undef S1 #undef R0 #undef R1 /* Add the starting values of the context according to FIPS 180-2:6.2.2 step 4. */ a += a_save; b += b_save; c += c_save; d += d_save; e += e_save; f += f_save; g += g_save; h += h_save; /* Prepare for the next round. */ nwords -= 16; } /* Put checksum in context given as argument. */ ctx->H[0] = a; ctx->H[1] = b; ctx->H[2] = c; ctx->H[3] = d; ctx->H[4] = e; ctx->H[5] = f; ctx->H[6] = g; ctx->H[7] = h; } /* Process LEN bytes of BUFFER, accumulating context into CTX. It is assumed that LEN % 128 == 0. */ static void sha512_process_block(const void *buffer, size_t len, sha512_ctx_t *ctx) { /* Constants for SHA512 from FIPS 180-2:4.2.3. */ static const uint64_t K[80] = { 0x428a2f98d728ae22ULL, 0x7137449123ef65cdULL, 0xb5c0fbcfec4d3b2fULL, 0xe9b5dba58189dbbcULL, 0x3956c25bf348b538ULL, 0x59f111f1b605d019ULL, 0x923f82a4af194f9bULL, 0xab1c5ed5da6d8118ULL, 0xd807aa98a3030242ULL, 0x12835b0145706fbeULL, 0x243185be4ee4b28cULL, 0x550c7dc3d5ffb4e2ULL, 0x72be5d74f27b896fULL, 0x80deb1fe3b1696b1ULL, 0x9bdc06a725c71235ULL, 0xc19bf174cf692694ULL, 0xe49b69c19ef14ad2ULL, 0xefbe4786384f25e3ULL, 0x0fc19dc68b8cd5b5ULL, 0x240ca1cc77ac9c65ULL, 0x2de92c6f592b0275ULL, 0x4a7484aa6ea6e483ULL, 0x5cb0a9dcbd41fbd4ULL, 0x76f988da831153b5ULL, 0x983e5152ee66dfabULL, 0xa831c66d2db43210ULL, 0xb00327c898fb213fULL, 0xbf597fc7beef0ee4ULL, 0xc6e00bf33da88fc2ULL, 0xd5a79147930aa725ULL, 0x06ca6351e003826fULL, 0x142929670a0e6e70ULL, 0x27b70a8546d22ffcULL, 0x2e1b21385c26c926ULL, 0x4d2c6dfc5ac42aedULL, 0x53380d139d95b3dfULL, 0x650a73548baf63deULL, 0x766a0abb3c77b2a8ULL, 0x81c2c92e47edaee6ULL, 0x92722c851482353bULL, 0xa2bfe8a14cf10364ULL, 0xa81a664bbc423001ULL, 0xc24b8b70d0f89791ULL, 0xc76c51a30654be30ULL, 0xd192e819d6ef5218ULL, 0xd69906245565a910ULL, 0xf40e35855771202aULL, 0x106aa07032bbd1b8ULL, 0x19a4c116b8d2d0c8ULL, 0x1e376c085141ab53ULL, 0x2748774cdf8eeb99ULL, 0x34b0bcb5e19b48a8ULL, 0x391c0cb3c5c95a63ULL, 0x4ed8aa4ae3418acbULL, 0x5b9cca4f7763e373ULL, 0x682e6ff3d6b2b8a3ULL, 0x748f82ee5defb2fcULL, 0x78a5636f43172f60ULL, 0x84c87814a1f0ab72ULL, 0x8cc702081a6439ecULL, 0x90befffa23631e28ULL, 0xa4506cebde82bde9ULL, 0xbef9a3f7b2c67915ULL, 0xc67178f2e372532bULL, 0xca273eceea26619cULL, 0xd186b8c721c0c207ULL, 0xeada7dd6cde0eb1eULL, 0xf57d4f7fee6ed178ULL, 0x06f067aa72176fbaULL, 0x0a637dc5a2c898a6ULL, 0x113f9804bef90daeULL, 0x1b710b35131c471bULL, 0x28db77f523047d84ULL, 0x32caab7b40c72493ULL, 0x3c9ebe0a15c9bebcULL, 0x431d67c49c100d4cULL, 0x4cc5d4becb3e42b6ULL, 0x597f299cfc657e2aULL, 0x5fcb6fab3ad6faecULL, 0x6c44198c4a475817ULL, }; const uint64_t *words = buffer; size_t nwords = len / sizeof(uint64_t); uint64_t a = ctx->H[0]; uint64_t b = ctx->H[1]; uint64_t c = ctx->H[2]; uint64_t d = ctx->H[3]; uint64_t e = ctx->H[4]; uint64_t f = ctx->H[5]; uint64_t g = ctx->H[6]; uint64_t h = ctx->H[7]; /* First increment the byte count. FIPS 180-2 specifies the possible length of the file up to 2^128 bits. Here we only compute the number of bytes. Do a double word increment. */ ctx->total[0] += len; if (ctx->total[0] < len) ctx->total[1]++; /* Process all bytes in the buffer with 128 bytes in each round of the loop. */ while (nwords > 0) { uint64_t W[80]; uint64_t a_save = a; uint64_t b_save = b; uint64_t c_save = c; uint64_t d_save = d; uint64_t e_save = e; uint64_t f_save = f; uint64_t g_save = g; uint64_t h_save = h; /* Operators defined in FIPS 180-2:4.1.2. */ #define Ch(x, y, z) ((x & y) ^ (~x & z)) #define Maj(x, y, z) ((x & y) ^ (x & z) ^ (y & z)) #define S0(x) (rotr64(x, 28) ^ rotr64(x, 34) ^ rotr64(x, 39)) #define S1(x) (rotr64(x, 14) ^ rotr64(x, 18) ^ rotr64(x, 41)) #define R0(x) (rotr64(x, 1) ^ rotr64(x, 8) ^ (x >> 7)) #define R1(x) (rotr64(x, 19) ^ rotr64(x, 61) ^ (x >> 6)) /* Compute the message schedule according to FIPS 180-2:6.3.2 step 2. */ for (unsigned t = 0; t < 16; ++t) { W[t] = ntoh64(*words); ++words; } for (unsigned t = 16; t < 80; ++t) W[t] = R1(W[t - 2]) + W[t - 7] + R0(W[t - 15]) + W[t - 16]; /* The actual computation according to FIPS 180-2:6.3.2 step 3. */ for (unsigned t = 0; t < 80; ++t) { uint64_t T1 = h + S1(e) + Ch(e, f, g) + K[t] + W[t]; uint64_t T2 = S0(a) + Maj(a, b, c); h = g; g = f; f = e; e = d + T1; d = c; c = b; b = a; a = T1 + T2; } #undef Ch #undef Maj #undef S0 #undef S1 #undef R0 #undef R1 /* Add the starting values of the context according to FIPS 180-2:6.3.2 step 4. */ a += a_save; b += b_save; c += c_save; d += d_save; e += e_save; f += f_save; g += g_save; h += h_save; /* Prepare for the next round. */ nwords -= 16; } /* Put checksum in context given as argument. */ ctx->H[0] = a; ctx->H[1] = b; ctx->H[2] = c; ctx->H[3] = d; ctx->H[4] = e; ctx->H[5] = f; ctx->H[6] = g; ctx->H[7] = h; } void FAST_FUNC sha1_begin(sha1_ctx_t *ctx) { ctx->count[0] = ctx->count[1] = 0; ctx->hash[0] = 0x67452301; ctx->hash[1] = 0xefcdab89; ctx->hash[2] = 0x98badcfe; ctx->hash[3] = 0x10325476; ctx->hash[4] = 0xc3d2e1f0; } /* Initialize structure containing state of computation. (FIPS 180-2:5.3.2) */ void FAST_FUNC sha256_begin(sha256_ctx_t *ctx) { ctx->H[0] = 0x6a09e667; ctx->H[1] = 0xbb67ae85; ctx->H[2] = 0x3c6ef372; ctx->H[3] = 0xa54ff53a; ctx->H[4] = 0x510e527f; ctx->H[5] = 0x9b05688c; ctx->H[6] = 0x1f83d9ab; ctx->H[7] = 0x5be0cd19; ctx->total[0] = ctx->total[1] = 0; ctx->buflen = 0; } /* Initialize structure containing state of computation. (FIPS 180-2:5.3.3) */ void FAST_FUNC sha512_begin(sha512_ctx_t *ctx) { ctx->H[0] = 0x6a09e667f3bcc908ULL; ctx->H[1] = 0xbb67ae8584caa73bULL; ctx->H[2] = 0x3c6ef372fe94f82bULL; ctx->H[3] = 0xa54ff53a5f1d36f1ULL; ctx->H[4] = 0x510e527fade682d1ULL; ctx->H[5] = 0x9b05688c2b3e6c1fULL; ctx->H[6] = 0x1f83d9abfb41bd6bULL; ctx->H[7] = 0x5be0cd19137e2179ULL; ctx->total[0] = ctx->total[1] = 0; ctx->buflen = 0; } /* SHA1 hash data in an array of bytes into hash buffer and call the */ /* hash_compile function as required. */ void FAST_FUNC sha1_hash(const void *data, size_t length, sha1_ctx_t *ctx) { uint32_t pos = (uint32_t) (ctx->count[0] & SHA1_MASK); uint32_t freeb = SHA1_BLOCK_SIZE - pos; const unsigned char *sp = data; ctx->count[0] += length; if (ctx->count[0] < length) ctx->count[1]++; while (length >= freeb) { /* transfer whole blocks while possible */ memcpy(((unsigned char *) ctx->wbuf) + pos, sp, freeb); sp += freeb; length -= freeb; freeb = SHA1_BLOCK_SIZE; pos = 0; sha1_compile(ctx); } memcpy(((unsigned char *) ctx->wbuf) + pos, sp, length); } void FAST_FUNC sha256_hash(const void *buffer, size_t len, sha256_ctx_t *ctx) { /* When we already have some bits in our internal buffer concatenate both inputs first. */ if (ctx->buflen != 0) { size_t left_over = ctx->buflen; size_t add = 128 - left_over > len ? len : 128 - left_over; memcpy(&ctx->buffer[left_over], buffer, add); ctx->buflen += add; if (ctx->buflen > 64) { sha256_process_block(ctx->buffer, ctx->buflen & ~63, ctx); ctx->buflen &= 63; /* The regions in the following copy operation cannot overlap. */ memcpy(ctx->buffer, &ctx->buffer[(left_over + add) & ~63], ctx->buflen); } buffer = (const char *)buffer + add; len -= add; } /* Process available complete blocks. */ if (len >= 64) { if (UNALIGNED_P(buffer, uint32_t)) { while (len > 64) { sha256_process_block(memcpy(ctx->buffer, buffer, 64), 64, ctx); buffer = (const char *)buffer + 64; len -= 64; } } else { sha256_process_block(buffer, len & ~63, ctx); buffer = (const char *)buffer + (len & ~63); len &= 63; } } /* Move remaining bytes into internal buffer. */ if (len > 0) { size_t left_over = ctx->buflen; memcpy(&ctx->buffer[left_over], buffer, len); left_over += len; if (left_over >= 64) { sha256_process_block(ctx->buffer, 64, ctx); left_over -= 64; memcpy(ctx->buffer, &ctx->buffer[64], left_over); } ctx->buflen = left_over; } } void FAST_FUNC sha512_hash(const void *buffer, size_t len, sha512_ctx_t *ctx) { /* When we already have some bits in our internal buffer concatenate both inputs first. */ if (ctx->buflen != 0) { size_t left_over = ctx->buflen; size_t add = 256 - left_over > len ? len : 256 - left_over; memcpy(&ctx->buffer[left_over], buffer, add); ctx->buflen += add; if (ctx->buflen > 128) { sha512_process_block(ctx->buffer, ctx->buflen & ~127, ctx); ctx->buflen &= 127; /* The regions in the following copy operation cannot overlap. */ memcpy(ctx->buffer, &ctx->buffer[(left_over + add) & ~127], ctx->buflen); } buffer = (const char *)buffer + add; len -= add; } /* Process available complete blocks. */ if (len >= 128) { // #if BB_ARCH_REQUIRES_ALIGNMENT if (UNALIGNED_P(buffer, uint64_t)) { while (len > 128) { sha512_process_block(memcpy(ctx->buffer, buffer, 128), 128, ctx); buffer = (const char *)buffer + 128; len -= 128; } } else // #endif { sha512_process_block(buffer, len & ~127, ctx); buffer = (const char *)buffer + (len & ~127); len &= 127; } } /* Move remaining bytes into internal buffer. */ if (len > 0) { size_t left_over = ctx->buflen; memcpy(&ctx->buffer[left_over], buffer, len); left_over += len; if (left_over >= 128) { sha512_process_block(ctx->buffer, 128, ctx); left_over -= 128; memcpy(ctx->buffer, &ctx->buffer[128], left_over); } ctx->buflen = left_over; } } void FAST_FUNC sha1_end(void *resbuf, sha1_ctx_t *ctx) { /* SHA1 Final padding and digest calculation */ #if BB_BIG_ENDIAN static const uint32_t mask[4] = { 0x00000000, 0xff000000, 0xffff0000, 0xffffff00 }; static const uint32_t bits[4] = { 0x80000000, 0x00800000, 0x00008000, 0x00000080 }; #else static const uint32_t mask[4] = { 0x00000000, 0x000000ff, 0x0000ffff, 0x00ffffff }; static const uint32_t bits[4] = { 0x00000080, 0x00008000, 0x00800000, 0x80000000 }; #endif uint8_t *hval = resbuf; uint32_t i, cnt = (uint32_t) (ctx->count[0] & SHA1_MASK); /* mask out the rest of any partial 32-bit word and then set */ /* the next byte to 0x80. On big-endian machines any bytes in */ /* the buffer will be at the top end of 32 bit words, on little */ /* endian machines they will be at the bottom. Hence the AND */ /* and OR masks above are reversed for little endian systems */ ctx->wbuf[cnt >> 2] = (ctx->wbuf[cnt >> 2] & mask[cnt & 3]) | bits[cnt & 3]; /* we need 9 or more empty positions, one for the padding byte */ /* (above) and eight for the length count. If there is not */ /* enough space pad and empty the buffer */ if (cnt > SHA1_BLOCK_SIZE - 9) { if (cnt < 60) ctx->wbuf[15] = 0; sha1_compile(ctx); cnt = 0; } else /* compute a word index for the empty buffer positions */ cnt = (cnt >> 2) + 1; while (cnt < 14) /* and zero pad all but last two positions */ ctx->wbuf[cnt++] = 0; /* assemble the eight byte counter in the buffer in big-endian */ /* format */ ctx->wbuf[14] = htonl((ctx->count[1] << 3) | (ctx->count[0] >> 29)); ctx->wbuf[15] = htonl(ctx->count[0] << 3); sha1_compile(ctx); /* extract the hash value as bytes in case the hash buffer is */ /* misaligned for 32-bit words */ for (i = 0; i < SHA1_DIGEST_SIZE; ++i) hval[i] = (unsigned char) (ctx->hash[i >> 2] >> 8 * (~i & 3)); } /* Process the remaining bytes in the internal buffer and the usual prolog according to the standard and write the result to RESBUF. IMPORTANT: On some systems it is required that RESBUF is correctly aligned for a 32 bits value. */ void FAST_FUNC sha256_end(void *resbuf, sha256_ctx_t *ctx) { /* Take yet unprocessed bytes into account. */ uint32_t bytes = ctx->buflen; size_t pad; /* Now count remaining bytes. */ ctx->total[0] += bytes; if (ctx->total[0] < bytes) ctx->total[1]++; /* Pad the buffer to the next 64-byte boundary with 0x80,0,0,0... (FIPS 180-2:5.1.1) */ pad = (bytes >= 56 ? 64 + 56 - bytes : 56 - bytes); memset(&ctx->buffer[bytes], 0, pad); ctx->buffer[bytes] = 0x80; /* Put the 64-bit file length in *bits* at the end of the buffer. */ *(uint32_t *) &ctx->buffer[bytes + pad + 4] = ntohl(ctx->total[0] << 3); *(uint32_t *) &ctx->buffer[bytes + pad] = ntohl((ctx->total[1] << 3) | (ctx->total[0] >> 29)); /* Process last bytes. */ sha256_process_block(ctx->buffer, bytes + pad + 8, ctx); /* Put result from CTX in first 32 bytes following RESBUF. */ for (unsigned i = 0; i < 8; ++i) ((uint32_t *) resbuf)[i] = ntohl(ctx->H[i]); } /* Process the remaining bytes in the internal buffer and the usual prolog according to the standard and write the result to RESBUF. IMPORTANT: On some systems it is required that RESBUF is correctly aligned for a 64 bits value. */ void FAST_FUNC sha512_end(void *resbuf, sha512_ctx_t *ctx) { /* Take yet unprocessed bytes into account. */ uint64_t bytes = ctx->buflen; size_t pad; /* Now count remaining bytes. */ ctx->total[0] += bytes; if (ctx->total[0] < bytes) ctx->total[1]++; /* Pad the buffer to the next 128-byte boundary with 0x80,0,0,0... (FIPS 180-2:5.1.2) */ pad = bytes >= 112 ? 128 + 112 - bytes : 112 - bytes; memset(&ctx->buffer[bytes], 0, pad); ctx->buffer[bytes] = 0x80; /* Put the 128-bit file length in *bits* at the end of the buffer. */ *(uint64_t *) &ctx->buffer[bytes + pad + 8] = hton64(ctx->total[0] << 3); *(uint64_t *) &ctx->buffer[bytes + pad] = hton64((ctx->total[1] << 3) | (ctx->total[0] >> 61)); /* Process last bytes. */ sha512_process_block(ctx->buffer, bytes + pad + 16, ctx); /* Put result from CTX in first 64 bytes following RESBUF. */ for (unsigned i = 0; i < 8; ++i) ((uint64_t *) resbuf)[i] = hton64(ctx->H[i]); }