Fix MD5 32-bit alignment bug.

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@2335 57a11ea4-9604-0410-9ed3-97b8803252fd

ChangeLog

@@ -1,3 +1,8 @@
+2000-05-15  Dave Peticolas  <peticola@cs.ucdavis.edu>
+
+	* src/engine/guid/md5.c (md5_process_bytes): fix 32-bit alignment
+	bug.
+
 2000-05-14  Dave Peticolas  <peticola@cs.ucdavis.edu>
 
 	* src/guile/guile-util.c: added several interface functions to

src/engine/guid/md5.c

@@ -208,12 +208,16 @@ md5_process_bytes (buffer, len, ctx)
      size_t len;
      struct md5_ctx *ctx;
 {
+#define NUM_MD5_WORDS 1024
+  size_t add = 0;
+
   /* When we already have some bits in our internal buffer concatenate
      both inputs first.  */
   if (ctx->buflen != 0)
     {
       size_t left_over = ctx->buflen;
-      size_t add = 128 - left_over > len ? len : 128 - left_over;
+
+      add = 128 - left_over > len ? len : 128 - left_over;
 
       memcpy (&ctx->buffer[left_over], buffer, add);
       ctx->buflen += add;
@@ -234,8 +238,29 @@ md5_process_bytes (buffer, len, ctx)
   /* Process available complete blocks.  */
   if (len > 64)
     {
-      md5_process_block (buffer, len & ~63, ctx);
-      buffer = (const char *) buffer + (len & ~63);
+      if ((add & 3) == 0) /* buffer is still 32-bit aligned */
+        {
+          md5_process_block (buffer, len & ~63, ctx);
+          buffer = (const char *) buffer + (len & ~63);
+        }
+      else                /* buffer is not 32-bit aligned */
+        {
+          md5_uint32 md5_buffer[NUM_MD5_WORDS];
+          size_t num_bytes;
+          size_t buf_bytes;
+
+          num_bytes = len & ~63;
+          while (num_bytes > 0)
+            {
+              buf_bytes = (num_bytes < sizeof(md5_buffer)) ?
+                           num_bytes : sizeof(md5_buffer);
+              memcpy (md5_buffer, buffer, buf_bytes);
+              md5_process_block (md5_buffer, buf_bytes, ctx);
+              num_bytes -= buf_bytes;
+              buffer = (const char *) buffer + buf_bytes;
+            }
+        }
+
       len &= 63;
     }
 

src/engine/guid/md5.h

@@ -1,6 +1,6 @@
 /* md5.h - Declaration of functions and data types used for MD5 sum
    computing library functions.
-   Copyright (C) 1995, 1996, 1999 Free Software Foundation, Inc.
+   Copyright (C) 1995, 1996 Free Software Foundation, Inc.
    NOTE: The canonical source of this file is maintained with the GNU C
    Library.  Bugs can be reported to bug-glibc@prep.ai.mit.edu.
 
@@ -99,17 +99,26 @@ struct md5_ctx
    (RFC 1321, 3.3: Step 3)  */
 extern void md5_init_ctx __P ((struct md5_ctx *ctx));
 
+
 /* Starting with the result of former calls of this function (or the
    initialization function update the context for the next LEN bytes
    starting at BUFFER.
-   It is necessary that LEN is a multiple of 64!!! */
+
+   It is necessary that LEN is a multiple of 64!!!
+
+   IMPORTANT: On some systems it is required that buffer be 32-bit
+   aligned.  */
 extern void md5_process_block __P ((const void *buffer, size_t len,
 				    struct md5_ctx *ctx));
 
 /* Starting with the result of former calls of this function (or the
-   initialization function update the context for the next LEN bytes
+   initialization function) update the context for the next LEN bytes
    starting at BUFFER.
-   It is NOT required that LEN is a multiple of 64.  */
+
+   It is NOT required that LEN is a multiple of 64.
+
+   IMPORTANT: On some systems it is required that buffer be 32-bit
+   aligned.  */
 extern void md5_process_bytes __P ((const void *buffer, size_t len,
 				    struct md5_ctx *ctx));
 
@@ -127,20 +136,27 @@ extern void *md5_finish_ctx __P ((struct md5_ctx *ctx, void *resbuf));
    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 it is required that RESBUF is correctly
+   IMPORTANT: On some systems it is required that RESBUF be correctly
    aligned for a 32 bits value.  */
 extern void *md5_read_ctx __P ((const struct md5_ctx *ctx, void *resbuf));
 
 
 /* Compute MD5 message digest for bytes read from STREAM.  The
    resulting message digest number will be written into the 16 bytes
-   beginning at RESBLOCK.  */
+   beginning at RESBLOCK.
+
+   IMPORTANT: On some systems it is required that resblock be 32-bit
+   aligned.  */
 extern int md5_stream __P ((FILE *stream, void *resblock));
 
+
 /* Compute MD5 message digest for LEN bytes beginning at BUFFER.  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.  */
+   digest.
+
+   IMPORTANT: On some systems it is required that buffer and resblock
+   be correctly 32-bit aligned.  */
 extern void *md5_buffer __P ((const char *buffer, size_t len, void *resblock));
 
 #endif