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-rw-r--r--libopkg/sha256.c50
1 files changed, 21 insertions, 29 deletions
diff --git a/libopkg/sha256.c b/libopkg/sha256.c
index 0ad9444..d23c509 100644
--- a/libopkg/sha256.c
+++ b/libopkg/sha256.c
@@ -1,12 +1,12 @@
/* 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.
+ Copyright (C) 2005, 2006 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 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 2, 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
@@ -14,7 +14,8 @@
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/>. */
+ along with this program; if not, write to the Free Software Foundation,
+ Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
/* Written by David Madore, considerably copypasting from
Scott G. Miller's sha1.c
@@ -85,25 +86,18 @@ sha224_init_ctx (struct sha256_ctx *ctx)
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. */
+ must be in little endian byte order.
+
+ IMPORTANT: On some systems it is required that RESBUF is correctly
+ aligned for a 32-bit value. */
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]));
+ ((uint32_t *) resbuf)[i] = SWAP (ctx->state[i]);
return resbuf;
}
@@ -112,21 +106,23 @@ 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]));
+ ((uint32_t *) resbuf)[i] = 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. */
+ 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-bit value. */
static void
sha256_conclude_ctx (struct sha256_ctx *ctx)
{
/* Take yet unprocessed bytes into account. */
- size_t bytes = ctx->buflen;
+ uint32_t bytes = ctx->buflen;
size_t size = (bytes < 56) ? 64 / 4 : 64 * 2 / 4;
/* Now count remaining bytes. */
@@ -134,13 +130,9 @@ sha256_conclude_ctx (struct sha256_ctx *ctx)
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));
+ /* Put the 64-bit file length in *bits* at the end of the buffer. */
+ ctx->buffer[size - 2] = SWAP ((ctx->total[1] << 3) | (ctx->total[0] >> 29));
+ ctx->buffer[size - 1] = SWAP (ctx->total[0] << 3);
memcpy (&((char *) ctx->buffer)[bytes], fillbuf, (size - 2) * 4 - bytes);