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-rw-r--r--src/sha256.c570
1 files changed, 570 insertions, 0 deletions
diff --git a/src/sha256.c b/src/sha256.c
new file mode 100644
index 0000000..bcb5f74
--- a/dev/null
+++ b/src/sha256.c
@@ -0,0 +1,570 @@
+/* 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, 2008-2013 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 <stdint.h>
+#include <stdlib.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 32768
+#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
+ initializes 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 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;
+ size_t sum;
+
+ char *buffer = malloc (BLOCKSIZE + 72);
+ if (!buffer)
+ return 1;
+
+ /* 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))
+ {
+ free (buffer);
+ 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);
+ free (buffer);
+ return 0;
+}
+
+/* FIXME: Avoid code duplication */
+int
+sha224_stream (FILE *stream, void *resblock)
+{
+ struct sha256_ctx ctx;
+ size_t sum;
+
+ char *buffer = malloc (BLOCKSIZE + 72);
+ if (!buffer)
+ return 1;
+
+ /* 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))
+ {
+ free (buffer);
+ 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);
+ free (buffer);
+ 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) ((uintptr_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];
+ uint32_t lolen = len;
+
+ /* 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] += lolen;
+ ctx->total[1] += (len >> 31 >> 1) + (ctx->total[0] < lolen);
+
+#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;
+ }
+}

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