433 lines
14 KiB
C
433 lines
14 KiB
C
/* sha256.c - Functions to compute SHA256 and SHA224 message digest of files or
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memory blocks according to the NIST specification FIPS-180-2.
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Copyright (C) 2005-2006, 2008-2023 Free Software Foundation, Inc.
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This file is free software: you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as
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published by the Free Software Foundation; either version 2.1 of the
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License, or (at your option) any later version.
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This file is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with this program. If not, see <https://www.gnu.org/licenses/>. */
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/* Written by David Madore, considerably copypasting from
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Scott G. Miller's sha1.c
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*/
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#include <config.h>
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/* Specification. */
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#if HAVE_OPENSSL_SHA256
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# define GL_OPENSSL_INLINE _GL_EXTERN_INLINE
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#endif
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#include "sha256.h"
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#include <stdint.h>
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#include <string.h>
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#include <byteswap.h>
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#ifdef WORDS_BIGENDIAN
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# define SWAP(n) (n)
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#else
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# define SWAP(n) bswap_32 (n)
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#endif
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#if ! HAVE_OPENSSL_SHA256
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/* This array contains the bytes used to pad the buffer to the next
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64-byte boundary. */
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static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ };
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/*
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Takes a pointer to a 256 bit block of data (eight 32 bit ints) and
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initializes it to the start constants of the SHA256 algorithm. This
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must be called before using hash in the call to sha256_hash
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*/
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void
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sha256_init_ctx (struct sha256_ctx *ctx)
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{
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ctx->state[0] = 0x6a09e667UL;
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ctx->state[1] = 0xbb67ae85UL;
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ctx->state[2] = 0x3c6ef372UL;
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ctx->state[3] = 0xa54ff53aUL;
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ctx->state[4] = 0x510e527fUL;
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ctx->state[5] = 0x9b05688cUL;
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ctx->state[6] = 0x1f83d9abUL;
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ctx->state[7] = 0x5be0cd19UL;
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ctx->total[0] = ctx->total[1] = 0;
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ctx->buflen = 0;
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}
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void
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sha224_init_ctx (struct sha256_ctx *ctx)
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{
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ctx->state[0] = 0xc1059ed8UL;
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ctx->state[1] = 0x367cd507UL;
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ctx->state[2] = 0x3070dd17UL;
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ctx->state[3] = 0xf70e5939UL;
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ctx->state[4] = 0xffc00b31UL;
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ctx->state[5] = 0x68581511UL;
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ctx->state[6] = 0x64f98fa7UL;
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ctx->state[7] = 0xbefa4fa4UL;
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ctx->total[0] = ctx->total[1] = 0;
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ctx->buflen = 0;
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}
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/* Copy the value from v into the memory location pointed to by *CP,
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If your architecture allows unaligned access, this is equivalent to
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* (__typeof__ (v) *) cp = v */
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static void
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set_uint32 (char *cp, uint32_t v)
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{
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memcpy (cp, &v, sizeof v);
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}
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/* Put result from CTX in first 32 bytes following RESBUF.
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The result must be in little endian byte order. */
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void *
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sha256_read_ctx (const struct sha256_ctx *ctx, void *resbuf)
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{
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int i;
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char *r = resbuf;
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for (i = 0; i < 8; i++)
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set_uint32 (r + i * sizeof ctx->state[0], SWAP (ctx->state[i]));
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return resbuf;
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}
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void *
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sha224_read_ctx (const struct sha256_ctx *ctx, void *resbuf)
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{
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int i;
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char *r = resbuf;
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for (i = 0; i < 7; i++)
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set_uint32 (r + i * sizeof ctx->state[0], SWAP (ctx->state[i]));
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return resbuf;
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}
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/* Process the remaining bytes in the internal buffer and the usual
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prolog according to the standard and write the result to RESBUF. */
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static void
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sha256_conclude_ctx (struct sha256_ctx *ctx)
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{
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/* Take yet unprocessed bytes into account. */
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size_t bytes = ctx->buflen;
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size_t size = (bytes < 56) ? 64 / 4 : 64 * 2 / 4;
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/* Now count remaining bytes. */
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ctx->total[0] += bytes;
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if (ctx->total[0] < bytes)
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++ctx->total[1];
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/* Put the 64-bit file length in *bits* at the end of the buffer.
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Use set_uint32 rather than a simple assignment, to avoid risk of
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unaligned access. */
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set_uint32 ((char *) &ctx->buffer[size - 2],
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SWAP ((ctx->total[1] << 3) | (ctx->total[0] >> 29)));
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set_uint32 ((char *) &ctx->buffer[size - 1],
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SWAP (ctx->total[0] << 3));
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memcpy (&((char *) ctx->buffer)[bytes], fillbuf, (size - 2) * 4 - bytes);
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/* Process last bytes. */
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sha256_process_block (ctx->buffer, size * 4, ctx);
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}
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void *
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sha256_finish_ctx (struct sha256_ctx *ctx, void *resbuf)
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{
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sha256_conclude_ctx (ctx);
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return sha256_read_ctx (ctx, resbuf);
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}
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void *
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sha224_finish_ctx (struct sha256_ctx *ctx, void *resbuf)
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{
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sha256_conclude_ctx (ctx);
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return sha224_read_ctx (ctx, resbuf);
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}
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/* Compute SHA256 message digest for LEN bytes beginning at BUFFER. The
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result is always in little endian byte order, so that a byte-wise
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output yields to the wanted ASCII representation of the message
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digest. */
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void *
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sha256_buffer (const char *buffer, size_t len, void *resblock)
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{
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struct sha256_ctx ctx;
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/* Initialize the computation context. */
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sha256_init_ctx (&ctx);
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/* Process whole buffer but last len % 64 bytes. */
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sha256_process_bytes (buffer, len, &ctx);
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/* Put result in desired memory area. */
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return sha256_finish_ctx (&ctx, resblock);
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}
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void *
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sha224_buffer (const char *buffer, size_t len, void *resblock)
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{
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struct sha256_ctx ctx;
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/* Initialize the computation context. */
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sha224_init_ctx (&ctx);
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/* Process whole buffer but last len % 64 bytes. */
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sha256_process_bytes (buffer, len, &ctx);
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/* Put result in desired memory area. */
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return sha224_finish_ctx (&ctx, resblock);
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}
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void
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sha256_process_bytes (const void *buffer, size_t len, struct sha256_ctx *ctx)
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{
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/* When we already have some bits in our internal buffer concatenate
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both inputs first. */
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if (ctx->buflen != 0)
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{
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size_t left_over = ctx->buflen;
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size_t add = 128 - left_over > len ? len : 128 - left_over;
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memcpy (&((char *) ctx->buffer)[left_over], buffer, add);
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ctx->buflen += add;
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if (ctx->buflen > 64)
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{
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sha256_process_block (ctx->buffer, ctx->buflen & ~63, ctx);
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ctx->buflen &= 63;
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/* The regions in the following copy operation cannot overlap,
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because ctx->buflen < 64 ≤ (left_over + add) & ~63. */
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memcpy (ctx->buffer,
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&((char *) ctx->buffer)[(left_over + add) & ~63],
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ctx->buflen);
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}
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buffer = (const char *) buffer + add;
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len -= add;
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}
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/* Process available complete blocks. */
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if (len >= 64)
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{
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#if !(_STRING_ARCH_unaligned || _STRING_INLINE_unaligned)
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# define UNALIGNED_P(p) ((uintptr_t) (p) % alignof (uint32_t) != 0)
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if (UNALIGNED_P (buffer))
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while (len > 64)
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{
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sha256_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx);
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buffer = (const char *) buffer + 64;
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len -= 64;
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}
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else
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#endif
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{
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sha256_process_block (buffer, len & ~63, ctx);
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buffer = (const char *) buffer + (len & ~63);
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len &= 63;
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}
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}
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/* Move remaining bytes in internal buffer. */
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if (len > 0)
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{
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size_t left_over = ctx->buflen;
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memcpy (&((char *) ctx->buffer)[left_over], buffer, len);
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left_over += len;
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if (left_over >= 64)
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{
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sha256_process_block (ctx->buffer, 64, ctx);
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left_over -= 64;
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/* The regions in the following copy operation cannot overlap,
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because left_over ≤ 64. */
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memcpy (ctx->buffer, &ctx->buffer[16], left_over);
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}
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ctx->buflen = left_over;
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}
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}
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/* --- Code below is the primary difference between sha1.c and sha256.c --- */
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/* SHA256 round constants */
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#define K(I) sha256_round_constants[I]
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static const uint32_t sha256_round_constants[64] = {
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0x428a2f98UL, 0x71374491UL, 0xb5c0fbcfUL, 0xe9b5dba5UL,
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0x3956c25bUL, 0x59f111f1UL, 0x923f82a4UL, 0xab1c5ed5UL,
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0xd807aa98UL, 0x12835b01UL, 0x243185beUL, 0x550c7dc3UL,
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0x72be5d74UL, 0x80deb1feUL, 0x9bdc06a7UL, 0xc19bf174UL,
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0xe49b69c1UL, 0xefbe4786UL, 0x0fc19dc6UL, 0x240ca1ccUL,
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0x2de92c6fUL, 0x4a7484aaUL, 0x5cb0a9dcUL, 0x76f988daUL,
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0x983e5152UL, 0xa831c66dUL, 0xb00327c8UL, 0xbf597fc7UL,
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0xc6e00bf3UL, 0xd5a79147UL, 0x06ca6351UL, 0x14292967UL,
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0x27b70a85UL, 0x2e1b2138UL, 0x4d2c6dfcUL, 0x53380d13UL,
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0x650a7354UL, 0x766a0abbUL, 0x81c2c92eUL, 0x92722c85UL,
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0xa2bfe8a1UL, 0xa81a664bUL, 0xc24b8b70UL, 0xc76c51a3UL,
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0xd192e819UL, 0xd6990624UL, 0xf40e3585UL, 0x106aa070UL,
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0x19a4c116UL, 0x1e376c08UL, 0x2748774cUL, 0x34b0bcb5UL,
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0x391c0cb3UL, 0x4ed8aa4aUL, 0x5b9cca4fUL, 0x682e6ff3UL,
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0x748f82eeUL, 0x78a5636fUL, 0x84c87814UL, 0x8cc70208UL,
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0x90befffaUL, 0xa4506cebUL, 0xbef9a3f7UL, 0xc67178f2UL,
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};
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/* Round functions. */
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#define F2(A,B,C) ( ( A & B ) | ( C & ( A | B ) ) )
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#define F1(E,F,G) ( G ^ ( E & ( F ^ G ) ) )
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/* Process LEN bytes of BUFFER, accumulating context into CTX.
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It is assumed that LEN % 64 == 0.
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Most of this code comes from GnuPG's cipher/sha1.c. */
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void
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sha256_process_block (const void *buffer, size_t len, struct sha256_ctx *ctx)
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{
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const uint32_t *words = buffer;
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size_t nwords = len / sizeof (uint32_t);
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const uint32_t *endp = words + nwords;
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uint32_t x[16];
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uint32_t a = ctx->state[0];
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uint32_t b = ctx->state[1];
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uint32_t c = ctx->state[2];
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uint32_t d = ctx->state[3];
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uint32_t e = ctx->state[4];
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uint32_t f = ctx->state[5];
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uint32_t g = ctx->state[6];
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uint32_t h = ctx->state[7];
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uint32_t lolen = len;
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/* First increment the byte count. FIPS PUB 180-2 specifies the possible
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length of the file up to 2^64 bits. Here we only compute the
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number of bytes. Do a double word increment. */
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ctx->total[0] += lolen;
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ctx->total[1] += (len >> 31 >> 1) + (ctx->total[0] < lolen);
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#define rol(x, n) (((x) << (n)) | ((x) >> (32 - (n))))
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#define S0(x) (rol(x,25)^rol(x,14)^(x>>3))
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#define S1(x) (rol(x,15)^rol(x,13)^(x>>10))
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#define SS0(x) (rol(x,30)^rol(x,19)^rol(x,10))
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#define SS1(x) (rol(x,26)^rol(x,21)^rol(x,7))
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#define M(I) ( tm = S1(x[(I-2)&0x0f]) + x[(I-7)&0x0f] \
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+ S0(x[(I-15)&0x0f]) + x[I&0x0f] \
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, x[I&0x0f] = tm )
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#define R(A,B,C,D,E,F,G,H,K,M) do { t0 = SS0(A) + F2(A,B,C); \
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t1 = H + SS1(E) \
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+ F1(E,F,G) \
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+ K \
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+ M; \
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D += t1; H = t0 + t1; \
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} while(0)
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while (words < endp)
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{
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uint32_t tm;
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uint32_t t0, t1;
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int t;
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/* FIXME: see sha1.c for a better implementation. */
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for (t = 0; t < 16; t++)
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{
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x[t] = SWAP (*words);
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words++;
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}
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R( a, b, c, d, e, f, g, h, K( 0), x[ 0] );
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R( h, a, b, c, d, e, f, g, K( 1), x[ 1] );
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R( g, h, a, b, c, d, e, f, K( 2), x[ 2] );
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R( f, g, h, a, b, c, d, e, K( 3), x[ 3] );
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R( e, f, g, h, a, b, c, d, K( 4), x[ 4] );
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R( d, e, f, g, h, a, b, c, K( 5), x[ 5] );
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R( c, d, e, f, g, h, a, b, K( 6), x[ 6] );
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R( b, c, d, e, f, g, h, a, K( 7), x[ 7] );
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R( a, b, c, d, e, f, g, h, K( 8), x[ 8] );
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R( h, a, b, c, d, e, f, g, K( 9), x[ 9] );
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R( g, h, a, b, c, d, e, f, K(10), x[10] );
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R( f, g, h, a, b, c, d, e, K(11), x[11] );
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R( e, f, g, h, a, b, c, d, K(12), x[12] );
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R( d, e, f, g, h, a, b, c, K(13), x[13] );
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R( c, d, e, f, g, h, a, b, K(14), x[14] );
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R( b, c, d, e, f, g, h, a, K(15), x[15] );
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R( a, b, c, d, e, f, g, h, K(16), M(16) );
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R( h, a, b, c, d, e, f, g, K(17), M(17) );
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R( g, h, a, b, c, d, e, f, K(18), M(18) );
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R( f, g, h, a, b, c, d, e, K(19), M(19) );
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R( e, f, g, h, a, b, c, d, K(20), M(20) );
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R( d, e, f, g, h, a, b, c, K(21), M(21) );
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R( c, d, e, f, g, h, a, b, K(22), M(22) );
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R( b, c, d, e, f, g, h, a, K(23), M(23) );
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R( a, b, c, d, e, f, g, h, K(24), M(24) );
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R( h, a, b, c, d, e, f, g, K(25), M(25) );
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R( g, h, a, b, c, d, e, f, K(26), M(26) );
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R( f, g, h, a, b, c, d, e, K(27), M(27) );
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R( e, f, g, h, a, b, c, d, K(28), M(28) );
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R( d, e, f, g, h, a, b, c, K(29), M(29) );
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R( c, d, e, f, g, h, a, b, K(30), M(30) );
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R( b, c, d, e, f, g, h, a, K(31), M(31) );
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R( a, b, c, d, e, f, g, h, K(32), M(32) );
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R( h, a, b, c, d, e, f, g, K(33), M(33) );
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R( g, h, a, b, c, d, e, f, K(34), M(34) );
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R( f, g, h, a, b, c, d, e, K(35), M(35) );
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R( e, f, g, h, a, b, c, d, K(36), M(36) );
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R( d, e, f, g, h, a, b, c, K(37), M(37) );
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R( c, d, e, f, g, h, a, b, K(38), M(38) );
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R( b, c, d, e, f, g, h, a, K(39), M(39) );
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R( a, b, c, d, e, f, g, h, K(40), M(40) );
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R( h, a, b, c, d, e, f, g, K(41), M(41) );
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R( g, h, a, b, c, d, e, f, K(42), M(42) );
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R( f, g, h, a, b, c, d, e, K(43), M(43) );
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R( e, f, g, h, a, b, c, d, K(44), M(44) );
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R( d, e, f, g, h, a, b, c, K(45), M(45) );
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R( c, d, e, f, g, h, a, b, K(46), M(46) );
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R( b, c, d, e, f, g, h, a, K(47), M(47) );
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R( a, b, c, d, e, f, g, h, K(48), M(48) );
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R( h, a, b, c, d, e, f, g, K(49), M(49) );
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R( g, h, a, b, c, d, e, f, K(50), M(50) );
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R( f, g, h, a, b, c, d, e, K(51), M(51) );
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R( e, f, g, h, a, b, c, d, K(52), M(52) );
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R( d, e, f, g, h, a, b, c, K(53), M(53) );
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R( c, d, e, f, g, h, a, b, K(54), M(54) );
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R( b, c, d, e, f, g, h, a, K(55), M(55) );
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R( a, b, c, d, e, f, g, h, K(56), M(56) );
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R( h, a, b, c, d, e, f, g, K(57), M(57) );
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R( g, h, a, b, c, d, e, f, K(58), M(58) );
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R( f, g, h, a, b, c, d, e, K(59), M(59) );
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R( e, f, g, h, a, b, c, d, K(60), M(60) );
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R( d, e, f, g, h, a, b, c, K(61), M(61) );
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R( c, d, e, f, g, h, a, b, K(62), M(62) );
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R( b, c, d, e, f, g, h, a, K(63), M(63) );
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|
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a = ctx->state[0] += a;
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b = ctx->state[1] += b;
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c = ctx->state[2] += c;
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|
d = ctx->state[3] += d;
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|
e = ctx->state[4] += e;
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|
f = ctx->state[5] += f;
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|
g = ctx->state[6] += g;
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|
h = ctx->state[7] += h;
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|
}
|
|
}
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|
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#endif
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|
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/*
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|
* Hey Emacs!
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|
* Local Variables:
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|
* coding: utf-8
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* End:
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*/
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