Description: Fix strict aliasing issues in MD5 and SHA1 code
Origin: upstream, http://git.fedorahosted.org/cgit/elfutils.git/commit/?id=32899ac4f69d4ca4856d5282464c1f9cee928c8a
Bug-Debian: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=684825
Last-Update: 2012-09-08
---
This patch header follows DEP-3: http://dep.debian.net/deps/dep3/
--- a/lib/md5.c
+++ b/lib/md5.c
@@ -82,6 +82,16 @@
   return resbuf;
 }
 
+static void
+le64_copy (char *dest, uint64_t x)
+{
+  for (size_t i = 0; i < 8; ++i)
+    {
+      dest[i] = (uint8_t) x;
+      x >>= 8;
+    }
+}
+
 /* Process the remaining bytes in the internal buffer and the usual
    prolog according to the standard and write the result to RESBUF.
 
@@ -105,9 +115,10 @@
   memcpy (&ctx->buffer[bytes], fillbuf, pad);
 
   /* Put the 64-bit file length in *bits* at the end of the buffer.  */
-  *(md5_uint32 *) &ctx->buffer[bytes + pad] = SWAP (ctx->total[0] << 3);
-  *(md5_uint32 *) &ctx->buffer[bytes + pad + 4] = SWAP ((ctx->total[1] << 3) |
-							(ctx->total[0] >> 29));
+  const uint64_t bit_length = ((ctx->total[0] << 3)
+                               + ((uint64_t) ((ctx->total[1] << 3) |
+                                              (ctx->total[0] >> 29)) << 32));
+  le64_copy (&ctx->buffer[bytes + pad], bit_length);
 
   /* Process last bytes.  */
   md5_process_block (ctx->buffer, bytes + pad + 8, ctx);
--- a/lib/sha1.c
+++ b/lib/sha1.c
@@ -83,6 +83,13 @@
   return resbuf;
 }
 
+static void
+be64_copy (char *dest, uint64_t x)
+{
+  for (size_t i = 8; i-- > 0; x >>= 8)
+    dest[i] = (uint8_t) x;
+}
+
 /* Process the remaining bytes in the internal buffer and the usual
    prolog according to the standard and write the result to RESBUF.
 
@@ -106,9 +113,10 @@
   memcpy (&ctx->buffer[bytes], fillbuf, pad);
 
   /* Put the 64-bit file length in *bits* at the end of the buffer.  */
-  *(sha1_uint32 *) &ctx->buffer[bytes + pad] = SWAP ((ctx->total[1] << 3) |
-						     (ctx->total[0] >> 29));
-  *(sha1_uint32 *) &ctx->buffer[bytes + pad + 4] = SWAP (ctx->total[0] << 3);
+  const uint64_t bit_length = ((ctx->total[0] << 3)
+                               + ((uint64_t) ((ctx->total[1] << 3) |
+                                              (ctx->total[0] >> 29)) << 32));
+  be64_copy (&ctx->buffer[bytes + pad], bit_length);
 
   /* Process last bytes.  */
   sha1_process_block (ctx->buffer, bytes + pad + 8, ctx);