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| -rw-r--r-- | libopkg/sha256.c | 554 | ||||
| -rw-r--r-- | libopkg/sha256.h | 91 |
2 files changed, 645 insertions, 0 deletions
diff --git a/libopkg/sha256.c b/libopkg/sha256.c new file mode 100644 index 0000000..0ad9444 --- /dev/null +++ b/libopkg/sha256.c @@ -0,0 +1,554 @@ +/* sha256.c - Functions to compute SHA256 and SHA224 message digest of files or + memory blocks according to the NIST specification FIPS-180-2. + + Copyright (C) 2005, 2006, 2008 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. */ + +/* Written by David Madore, considerably copypasting from + Scott G. Miller's sha1.c +*/ + +#include <config.h> + +#include "sha256.h" + +#include <stddef.h> +#include <string.h> + +#if USE_UNLOCKED_IO +# include "unlocked-io.h" +#endif + +#ifdef WORDS_BIGENDIAN +# define SWAP(n) (n) +#else +# define SWAP(n) \ + (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24)) +#endif + +#define BLOCKSIZE 4096 +#if BLOCKSIZE % 64 != 0 +# error "invalid BLOCKSIZE" +#endif + +/* This array contains the bytes used to pad the buffer to the next + 64-byte boundary. */ +static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ }; + + +/* + Takes a pointer to a 256 bit block of data (eight 32 bit ints) and + intializes it to the start constants of the SHA256 algorithm. This + must be called before using hash in the call to sha256_hash +*/ +void +sha256_init_ctx (struct sha256_ctx *ctx) +{ + ctx->state[0] = 0x6a09e667UL; + ctx->state[1] = 0xbb67ae85UL; + ctx->state[2] = 0x3c6ef372UL; + ctx->state[3] = 0xa54ff53aUL; + ctx->state[4] = 0x510e527fUL; + ctx->state[5] = 0x9b05688cUL; + ctx->state[6] = 0x1f83d9abUL; + ctx->state[7] = 0x5be0cd19UL; + + ctx->total[0] = ctx->total[1] = 0; + ctx->buflen = 0; +} + +void +sha224_init_ctx (struct sha256_ctx *ctx) +{ + ctx->state[0] = 0xc1059ed8UL; + ctx->state[1] = 0x367cd507UL; + ctx->state[2] = 0x3070dd17UL; + ctx->state[3] = 0xf70e5939UL; + ctx->state[4] = 0xffc00b31UL; + ctx->state[5] = 0x68581511UL; + ctx->state[6] = 0x64f98fa7UL; + ctx->state[7] = 0xbefa4fa4UL; + + ctx->total[0] = ctx->total[1] = 0; + ctx->buflen = 0; +} + +/* Copy the value from v into the memory location pointed to by *cp, + If your architecture allows unaligned access this is equivalent to + * (uint32_t *) cp = v */ +static inline void +set_uint32 (char *cp, uint32_t v) +{ + memcpy (cp, &v, sizeof v); +} + +/* Put result from CTX in first 32 bytes following RESBUF. The result + must be in little endian byte order. */ +void * +sha256_read_ctx (const struct sha256_ctx *ctx, void *resbuf) +{ + int i; + char *r = resbuf; + + for (i = 0; i < 8; i++) + set_uint32 (r + i * sizeof ctx->state[0], SWAP (ctx->state[i])); + + return resbuf; +} + +void * +sha224_read_ctx (const struct sha256_ctx *ctx, void *resbuf) +{ + int i; + char *r = resbuf; + + for (i = 0; i < 7; i++) + set_uint32 (r + i * sizeof ctx->state[0], SWAP (ctx->state[i])); + + return resbuf; +} + +/* Process the remaining bytes in the internal buffer and the usual + prolog according to the standard and write the result to RESBUF. */ +static void +sha256_conclude_ctx (struct sha256_ctx *ctx) +{ + /* Take yet unprocessed bytes into account. */ + size_t bytes = ctx->buflen; + size_t size = (bytes < 56) ? 64 / 4 : 64 * 2 / 4; + + /* Now count remaining bytes. */ + ctx->total[0] += bytes; + if (ctx->total[0] < bytes) + ++ctx->total[1]; + + /* Put the 64-bit file length in *bits* at the end of the buffer. + Use set_uint32 rather than a simple assignment, to avoid risk of + unaligned access. */ + set_uint32 ((char *) &ctx->buffer[size - 2], + SWAP ((ctx->total[1] << 3) | (ctx->total[0] >> 29))); + set_uint32 ((char *) &ctx->buffer[size - 1], + SWAP (ctx->total[0] << 3)); + + memcpy (&((char *) ctx->buffer)[bytes], fillbuf, (size - 2) * 4 - bytes); + + /* Process last bytes. */ + sha256_process_block (ctx->buffer, size * 4, ctx); +} + +void * +sha256_finish_ctx (struct sha256_ctx *ctx, void *resbuf) +{ + sha256_conclude_ctx (ctx); + return sha256_read_ctx (ctx, resbuf); +} + +void * +sha224_finish_ctx (struct sha256_ctx *ctx, void *resbuf) +{ + sha256_conclude_ctx (ctx); + return sha224_read_ctx (ctx, resbuf); +} + +/* Compute SHA256 message digest for bytes read from STREAM. The + resulting message digest number will be written into the 32 bytes + beginning at RESBLOCK. */ +int +sha256_stream (FILE *stream, void *resblock) +{ + struct sha256_ctx ctx; + char buffer[BLOCKSIZE + 72]; + size_t sum; + + /* Initialize the computation context. */ + sha256_init_ctx (&ctx); + + /* Iterate over full file contents. */ + while (1) + { + /* We read the file in blocks of BLOCKSIZE bytes. One call of the + computation function processes the whole buffer so that with the + next round of the loop another block can be read. */ + size_t n; + sum = 0; + + /* Read block. Take care for partial reads. */ + while (1) + { + n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream); + + sum += n; + + if (sum == BLOCKSIZE) + break; + + if (n == 0) + { + /* Check for the error flag IFF N == 0, so that we don't + exit the loop after a partial read due to e.g., EAGAIN + or EWOULDBLOCK. */ + if (ferror (stream)) + return 1; + goto process_partial_block; + } + + /* We've read at least one byte, so ignore errors. But always + check for EOF, since feof may be true even though N > 0. + Otherwise, we could end up calling fread after EOF. */ + if (feof (stream)) + goto process_partial_block; + } + + /* Process buffer with BLOCKSIZE bytes. Note that + BLOCKSIZE % 64 == 0 + */ + sha256_process_block (buffer, BLOCKSIZE, &ctx); + } + + process_partial_block:; + + /* Process any remaining bytes. */ + if (sum > 0) + sha256_process_bytes (buffer, sum, &ctx); + + /* Construct result in desired memory. */ + sha256_finish_ctx (&ctx, resblock); + return 0; +} + +/* FIXME: Avoid code duplication */ +int +sha224_stream (FILE *stream, void *resblock) +{ + struct sha256_ctx ctx; + char buffer[BLOCKSIZE + 72]; + size_t sum; + + /* Initialize the computation context. */ + sha224_init_ctx (&ctx); + + /* Iterate over full file contents. */ + while (1) + { + /* We read the file in blocks of BLOCKSIZE bytes. One call of the + computation function processes the whole buffer so that with the + next round of the loop another block can be read. */ + size_t n; + sum = 0; + + /* Read block. Take care for partial reads. */ + while (1) + { + n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream); + + sum += n; + + if (sum == BLOCKSIZE) + break; + + if (n == 0) + { + /* Check for the error flag IFF N == 0, so that we don't + exit the loop after a partial read due to e.g., EAGAIN + or EWOULDBLOCK. */ + if (ferror (stream)) + return 1; + goto process_partial_block; + } + + /* We've read at least one byte, so ignore errors. But always + check for EOF, since feof may be true even though N > 0. + Otherwise, we could end up calling fread after EOF. */ + if (feof (stream)) + goto process_partial_block; + } + + /* Process buffer with BLOCKSIZE bytes. Note that + BLOCKSIZE % 64 == 0 + */ + sha256_process_block (buffer, BLOCKSIZE, &ctx); + } + + process_partial_block:; + + /* Process any remaining bytes. */ + if (sum > 0) + sha256_process_bytes (buffer, sum, &ctx); + + /* Construct result in desired memory. */ + sha224_finish_ctx (&ctx, resblock); + return 0; +} + +/* Compute SHA512 message digest for LEN bytes beginning at BUFFER. The + result is always in little endian byte order, so that a byte-wise + output yields to the wanted ASCII representation of the message + digest. */ +void * +sha256_buffer (const char *buffer, size_t len, void *resblock) +{ + struct sha256_ctx ctx; + + /* Initialize the computation context. */ + sha256_init_ctx (&ctx); + + /* Process whole buffer but last len % 64 bytes. */ + sha256_process_bytes (buffer, len, &ctx); + + /* Put result in desired memory area. */ + return sha256_finish_ctx (&ctx, resblock); +} + +void * +sha224_buffer (const char *buffer, size_t len, void *resblock) +{ + struct sha256_ctx ctx; + + /* Initialize the computation context. */ + sha224_init_ctx (&ctx); + + /* Process whole buffer but last len % 64 bytes. */ + sha256_process_bytes (buffer, len, &ctx); + + /* Put result in desired memory area. */ + return sha224_finish_ctx (&ctx, resblock); +} + +void +sha256_process_bytes (const void *buffer, size_t len, struct sha256_ctx *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 (&((char *) 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, + &((char *) ctx->buffer)[(left_over + add) & ~63], + ctx->buflen); + } + + buffer = (const char *) buffer + add; + len -= add; + } + + /* Process available complete blocks. */ + if (len >= 64) + { +#if !_STRING_ARCH_unaligned +# define alignof(type) offsetof (struct { char c; type x; }, x) +# define UNALIGNED_P(p) (((size_t) p) % alignof (uint32_t) != 0) + if (UNALIGNED_P (buffer)) + while (len > 64) + { + sha256_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx); + buffer = (const char *) buffer + 64; + len -= 64; + } + else +#endif + { + sha256_process_block (buffer, len & ~63, ctx); + buffer = (const char *) buffer + (len & ~63); + len &= 63; + } + } + + /* Move remaining bytes in internal buffer. */ + if (len > 0) + { + size_t left_over = ctx->buflen; + + memcpy (&((char *) 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[16], left_over); + } + ctx->buflen = left_over; + } +} + +/* --- Code below is the primary difference between sha1.c and sha256.c --- */ + +/* SHA256 round constants */ +#define K(I) sha256_round_constants[I] +static const uint32_t sha256_round_constants[64] = { + 0x428a2f98UL, 0x71374491UL, 0xb5c0fbcfUL, 0xe9b5dba5UL, + 0x3956c25bUL, 0x59f111f1UL, 0x923f82a4UL, 0xab1c5ed5UL, + 0xd807aa98UL, 0x12835b01UL, 0x243185beUL, 0x550c7dc3UL, + 0x72be5d74UL, 0x80deb1feUL, 0x9bdc06a7UL, 0xc19bf174UL, + 0xe49b69c1UL, 0xefbe4786UL, 0x0fc19dc6UL, 0x240ca1ccUL, + 0x2de92c6fUL, 0x4a7484aaUL, 0x5cb0a9dcUL, 0x76f988daUL, + 0x983e5152UL, 0xa831c66dUL, 0xb00327c8UL, 0xbf597fc7UL, + 0xc6e00bf3UL, 0xd5a79147UL, 0x06ca6351UL, 0x14292967UL, + 0x27b70a85UL, 0x2e1b2138UL, 0x4d2c6dfcUL, 0x53380d13UL, + 0x650a7354UL, 0x766a0abbUL, 0x81c2c92eUL, 0x92722c85UL, + 0xa2bfe8a1UL, 0xa81a664bUL, 0xc24b8b70UL, 0xc76c51a3UL, + 0xd192e819UL, 0xd6990624UL, 0xf40e3585UL, 0x106aa070UL, + 0x19a4c116UL, 0x1e376c08UL, 0x2748774cUL, 0x34b0bcb5UL, + 0x391c0cb3UL, 0x4ed8aa4aUL, 0x5b9cca4fUL, 0x682e6ff3UL, + 0x748f82eeUL, 0x78a5636fUL, 0x84c87814UL, 0x8cc70208UL, + 0x90befffaUL, 0xa4506cebUL, 0xbef9a3f7UL, 0xc67178f2UL, +}; + +/* Round functions. */ +#define F2(A,B,C) ( ( A & B ) | ( C & ( A | B ) ) ) +#define F1(E,F,G) ( G ^ ( E & ( F ^ G ) ) ) + +/* Process LEN bytes of BUFFER, accumulating context into CTX. + It is assumed that LEN % 64 == 0. + Most of this code comes from GnuPG's cipher/sha1.c. */ + +void +sha256_process_block (const void *buffer, size_t len, struct sha256_ctx *ctx) +{ + const uint32_t *words = buffer; + size_t nwords = len / sizeof (uint32_t); + const uint32_t *endp = words + nwords; + uint32_t x[16]; + uint32_t a = ctx->state[0]; + uint32_t b = ctx->state[1]; + uint32_t c = ctx->state[2]; + uint32_t d = ctx->state[3]; + uint32_t e = ctx->state[4]; + uint32_t f = ctx->state[5]; + uint32_t g = ctx->state[6]; + uint32_t h = ctx->state[7]; + + /* First increment the byte count. FIPS PUB 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]; + +#define rol(x, n) (((x) << (n)) | ((x) >> (32 - (n)))) +#define S0(x) (rol(x,25)^rol(x,14)^(x>>3)) +#define S1(x) (rol(x,15)^rol(x,13)^(x>>10)) +#define SS0(x) (rol(x,30)^rol(x,19)^rol(x,10)) +#define SS1(x) (rol(x,26)^rol(x,21)^rol(x,7)) + +#define M(I) ( tm = S1(x[(I-2)&0x0f]) + x[(I-7)&0x0f] \ + + S0(x[(I-15)&0x0f]) + x[I&0x0f] \ + , x[I&0x0f] = tm ) + +#define R(A,B,C,D,E,F,G,H,K,M) do { t0 = SS0(A) + F2(A,B,C); \ + t1 = H + SS1(E) \ + + F1(E,F,G) \ + + K \ + + M; \ + D += t1; H = t0 + t1; \ + } while(0) + + while (words < endp) + { + uint32_t tm; + uint32_t t0, t1; + int t; + /* FIXME: see sha1.c for a better implementation. */ + for (t = 0; t < 16; t++) + { + x[t] = SWAP (*words); + words++; + } + + R( a, b, c, d, e, f, g, h, K( 0), x[ 0] ); + R( h, a, b, c, d, e, f, g, K( 1), x[ 1] ); + R( g, h, a, b, c, d, e, f, K( 2), x[ 2] ); + R( f, g, h, a, b, c, d, e, K( 3), x[ 3] ); + R( e, f, g, h, a, b, c, d, K( 4), x[ 4] ); + R( d, e, f, g, h, a, b, c, K( 5), x[ 5] ); + R( c, d, e, f, g, h, a, b, K( 6), x[ 6] ); + R( b, c, d, e, f, g, h, a, K( 7), x[ 7] ); + R( a, b, c, d, e, f, g, h, K( 8), x[ 8] ); + R( h, a, b, c, d, e, f, g, K( 9), x[ 9] ); + R( g, h, a, b, c, d, e, f, K(10), x[10] ); + R( f, g, h, a, b, c, d, e, K(11), x[11] ); + R( e, f, g, h, a, b, c, d, K(12), x[12] ); + R( d, e, f, g, h, a, b, c, K(13), x[13] ); + R( c, d, e, f, g, h, a, b, K(14), x[14] ); + R( b, c, d, e, f, g, h, a, K(15), x[15] ); + R( a, b, c, d, e, f, g, h, K(16), M(16) ); + R( h, a, b, c, d, e, f, g, K(17), M(17) ); + R( g, h, a, b, c, d, e, f, K(18), M(18) ); + R( f, g, h, a, b, c, d, e, K(19), M(19) ); + R( e, f, g, h, a, b, c, d, K(20), M(20) ); + R( d, e, f, g, h, a, b, c, K(21), M(21) ); + R( c, d, e, f, g, h, a, b, K(22), M(22) ); + R( b, c, d, e, f, g, h, a, K(23), M(23) ); + R( a, b, c, d, e, f, g, h, K(24), M(24) ); + R( h, a, b, c, d, e, f, g, K(25), M(25) ); + R( g, h, a, b, c, d, e, f, K(26), M(26) ); + R( f, g, h, a, b, c, d, e, K(27), M(27) ); + R( e, f, g, h, a, b, c, d, K(28), M(28) ); + R( d, e, f, g, h, a, b, c, K(29), M(29) ); + R( c, d, e, f, g, h, a, b, K(30), M(30) ); + R( b, c, d, e, f, g, h, a, K(31), M(31) ); + R( a, b, c, d, e, f, g, h, K(32), M(32) ); + R( h, a, b, c, d, e, f, g, K(33), M(33) ); + R( g, h, a, b, c, d, e, f, K(34), M(34) ); + R( f, g, h, a, b, c, d, e, K(35), M(35) ); + R( e, f, g, h, a, b, c, d, K(36), M(36) ); + R( d, e, f, g, h, a, b, c, K(37), M(37) ); + R( c, d, e, f, g, h, a, b, K(38), M(38) ); + R( b, c, d, e, f, g, h, a, K(39), M(39) ); + R( a, b, c, d, e, f, g, h, K(40), M(40) ); + R( h, a, b, c, d, e, f, g, K(41), M(41) ); + R( g, h, a, b, c, d, e, f, K(42), M(42) ); + R( f, g, h, a, b, c, d, e, K(43), M(43) ); + R( e, f, g, h, a, b, c, d, K(44), M(44) ); + R( d, e, f, g, h, a, b, c, K(45), M(45) ); + R( c, d, e, f, g, h, a, b, K(46), M(46) ); + R( b, c, d, e, f, g, h, a, K(47), M(47) ); + R( a, b, c, d, e, f, g, h, K(48), M(48) ); + R( h, a, b, c, d, e, f, g, K(49), M(49) ); + R( g, h, a, b, c, d, e, f, K(50), M(50) ); + R( f, g, h, a, b, c, d, e, K(51), M(51) ); + R( e, f, g, h, a, b, c, d, K(52), M(52) ); + R( d, e, f, g, h, a, b, c, K(53), M(53) ); + R( c, d, e, f, g, h, a, b, K(54), M(54) ); + R( b, c, d, e, f, g, h, a, K(55), M(55) ); + R( a, b, c, d, e, f, g, h, K(56), M(56) ); + R( h, a, b, c, d, e, f, g, K(57), M(57) ); + R( g, h, a, b, c, d, e, f, K(58), M(58) ); + R( f, g, h, a, b, c, d, e, K(59), M(59) ); + R( e, f, g, h, a, b, c, d, K(60), M(60) ); + R( d, e, f, g, h, a, b, c, K(61), M(61) ); + R( c, d, e, f, g, h, a, b, K(62), M(62) ); + R( b, c, d, e, f, g, h, a, K(63), M(63) ); + + a = ctx->state[0] += a; + b = ctx->state[1] += b; + c = ctx->state[2] += c; + d = ctx->state[3] += d; + e = ctx->state[4] += e; + f = ctx->state[5] += f; + g = ctx->state[6] += g; + h = ctx->state[7] += h; + } +} diff --git a/libopkg/sha256.h b/libopkg/sha256.h new file mode 100644 index 0000000..6a9aed4 --- /dev/null +++ b/libopkg/sha256.h @@ -0,0 +1,91 @@ +/* Declarations of functions and data types used for SHA256 and SHA224 sum + library functions. + Copyright (C) 2005, 2006, 2008, 2009 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. */ + +#ifndef SHA256_H +# define SHA256_H 1 + +# include <stdio.h> +# include <stdint.h> + +# ifdef __cplusplus +extern "C" { +# endif + +/* Structure to save state of computation between the single steps. */ +struct sha256_ctx +{ + uint32_t state[8]; + + uint32_t total[2]; + size_t buflen; + uint32_t buffer[32]; +}; + +enum { SHA224_DIGEST_SIZE = 224 / 8 }; +enum { SHA256_DIGEST_SIZE = 256 / 8 }; + +/* Initialize structure containing state of computation. */ +extern void sha256_init_ctx (struct sha256_ctx *ctx); +extern void sha224_init_ctx (struct sha256_ctx *ctx); + +/* Starting with the result of former calls of this function (or the + initialization function update the context for the next LEN bytes + starting at BUFFER. + It is necessary that LEN is a multiple of 64!!! */ +extern void sha256_process_block (const void *buffer, size_t len, + struct sha256_ctx *ctx); + +/* Starting with the result of former calls of this function (or the + initialization function update the context for the next LEN bytes + starting at BUFFER. + It is NOT required that LEN is a multiple of 64. */ +extern void sha256_process_bytes (const void *buffer, size_t len, + struct sha256_ctx *ctx); + +/* Process the remaining bytes in the buffer and put result from CTX + in first 32 (28) bytes following RESBUF. The result is always in little + endian byte order, so that a byte-wise output yields to the wanted + ASCII representation of the message digest. */ +extern void *sha256_finish_ctx (struct sha256_ctx *ctx, void *resbuf); +extern void *sha224_finish_ctx (struct sha256_ctx *ctx, void *resbuf); + + +/* Put result from CTX in first 32 (28) bytes following RESBUF. The result is + always in little endian byte order, so that a byte-wise output yields + to the wanted ASCII representation of the message digest. */ +extern void *sha256_read_ctx (const struct sha256_ctx *ctx, void *resbuf); +extern void *sha224_read_ctx (const struct sha256_ctx *ctx, void *resbuf); + + +/* Compute SHA256 (SHA224) message digest for bytes read from STREAM. The + resulting message digest number will be written into the 32 (28) bytes + beginning at RESBLOCK. */ +extern int sha256_stream (FILE *stream, void *resblock); +extern int sha224_stream (FILE *stream, void *resblock); + +/* Compute SHA256 (SHA224) message digest for LEN bytes beginning at BUFFER. The + result is always in little endian byte order, so that a byte-wise + output yields to the wanted ASCII representation of the message + digest. */ +extern void *sha256_buffer (const char *buffer, size_t len, void *resblock); +extern void *sha224_buffer (const char *buffer, size_t len, void *resblock); + +# ifdef __cplusplus +} +# endif + +#endif |