libopkg: switch to GPL2 SHA256 implementation

[oweals/opkg-lede.git] / libopkg / sha256.c

diff --git a/libopkg/sha256.c b/libopkg/sha256.c
index 75d94e9953f5896ca7308edaee9cd6d66d7afb3e..e0c4e3e0d42357b13afd9e271ea7e6a4ec8aae29 100644 (file)
--- 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
@@ -80,23 +81,17 @@ void 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;
 }
@@ -104,20 +99,22 @@ void *sha256_read_ctx(const struct sha256_ctx *ctx, void *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]));
+               ((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.  */
@@ -125,12 +122,10 @@ static void 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);