md5: adapt alignment constraint fix from sha1.

* lib/md5.c (set_uint32): New function, from sha1.c
(md5_read_ctx): Use it.
(md5_finish_ctx): Doc fix.
* lib/md5.h: Doc fix.

diff --git a/ChangeLog b/ChangeLog
index e4224d1..2ac4484 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2008-01-31  Simon Josefsson  <simon@josefsson.org>
+
+       * md5: adapt alignment constraint fix from sha1.
+       * lib/md5.c (set_uint32): New function, from sha1.c
+       (md5_read_ctx): Use it.
+       (md5_finish_ctx): Doc fix.
+       * lib/md5.h: Doc fix.
+
 2008-01-30  Peter Palfrader  <weasel@debian.org>
 
        sha1: remove the result buffer alignment constraint

diff --git a/lib/md5.c b/lib/md5.c
index 917a899..50a2646 100644 (file)
--- a/lib/md5.c
+++ b/lib/md5.c
@@ -1,6 +1,6 @@
 /* Functions to compute MD5 message digest of files or memory blocks.
    according to the definition of MD5 in RFC 1321 from April 1992.
-   Copyright (C) 1995,1996,1997,1999,2000,2001,2005,2006
+   Copyright (C) 1995,1996,1997,1999,2000,2001,2005,2006,2008
        Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
@@ -80,27 +80,31 @@ md5_init_ctx (struct md5_ctx *ctx)
   ctx->buflen = 0;
 }
 
-/* Put result from CTX in first 16 bytes following RESBUF.  The result
-   must be in little endian byte order.
+/* Copy the 4 byte 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, 4);
+}
 
-   IMPORTANT: On some systems it is required that RESBUF is correctly
-   aligned for a 32-bit value.  */
+/* Put result from CTX in first 16 bytes following RESBUF.  The result
+   must be in little endian byte order.  */
 void *
 md5_read_ctx (const struct md5_ctx *ctx, void *resbuf)
 {
-  ((uint32_t *) resbuf)[0] = SWAP (ctx->A);
-  ((uint32_t *) resbuf)[1] = SWAP (ctx->B);
-  ((uint32_t *) resbuf)[2] = SWAP (ctx->C);
-  ((uint32_t *) resbuf)[3] = SWAP (ctx->D);
+  char *r = resbuf;
+  set_uint32 (r + 0*4, SWAP (ctx->A));
+  set_uint32 (r + 1*4, SWAP (ctx->B));
+  set_uint32 (r + 2*4, SWAP (ctx->C));
+  set_uint32 (r + 3*4, SWAP (ctx->D));
 
   return resbuf;
 }
 
 /* Process the remaining bytes in the internal buffer and the usual
-   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.  */
+   prolog according to the standard and write the result to RESBUF.  */
 void *
 md5_finish_ctx (struct md5_ctx *ctx, void *resbuf)
 {

diff --git a/lib/md5.h b/lib/md5.h
index c737040..3ae657b 100644 (file)
--- a/lib/md5.h
+++ b/lib/md5.h
@@ -1,6 +1,6 @@
 /* Declaration of functions and data types used for MD5 sum computing
    library functions.
-   Copyright (C) 1995-1997,1999,2000,2001,2004,2005,2006
+   Copyright (C) 1995-1997,1999,2000,2001,2004,2005,2006,2008
       Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
@@ -93,19 +93,13 @@ extern void __md5_process_bytes (const void *buffer, size_t len,
 /* Process the remaining bytes in the buffer and put result from CTX
    in first 16 bytes following RESBUF.  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.
-
-   IMPORTANT: On some systems, RESBUF must be aligned to a 32-bit
-   boundary. */
+   ASCII representation of the message digest.  */
 extern void *__md5_finish_ctx (struct md5_ctx *ctx, void *resbuf) __THROW;
 
 
 /* Put result from CTX in first 16 bytes following RESBUF.  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.
-
-   IMPORTANT: On some systems, RESBUF must be aligned to a 32-bit
-   boundary. */
+   to the wanted ASCII representation of the message digest.  */
 extern void *__md5_read_ctx (const struct md5_ctx *ctx, void *resbuf) __THROW;