[Bug-gnulib] md5.c, md5.h merge from coreutils

[Paul Eggert]

I merged this fix from coreutils:

2003-08-14  Jim Meyering  <address@hidden>

        * md5.c: Include <string.h> and <stdlib.h> unconditionally.
        (memcpy): Remove definition.
        Merge in some clean-up and optimization changes from glibc.
        [BLOCKSIZE]: Move definition to top of file.
        Ensure that it is a multiple of 64.
        Rearrange loop exit tests so as to avoid performing an
        additional fread after encountering an error or EOF.
        * md5.h (md5_uintptr): Define.

Index: lib/md5.h
===================================================================
RCS file: /cvsroot/gnulib/gnulib/lib/md5.h,v
retrieving revision 1.11
diff -p -u -r1.11 md5.h
--- lib/md5.h   27 Nov 2000 09:33:53 -0000      1.11
+++ lib/md5.h   14 Aug 2003 23:09:05 -0000
@@ -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, 1999, 2000, 2003 Free Software Foundation, Inc.
    NOTE: The canonical source of this file is maintained with the GNU C
    Library.  Bugs can be reported to address@hidden
 
@@ -35,8 +35,9 @@
    is usually not possible.  */
 
 #ifdef _LIBC
-# include <sys/types.h>
-typedef u_int32_t md5_uint32;
+# include <stdint.h>
+typedef uint32_t md5_uint32;
+typedef uintptr_t md5_uintptr;
 #else
 # if defined __STDC__ && __STDC__
 #  define UINT_MAX_32_BITS 4294967295U
@@ -68,6 +69,9 @@ typedef u_int32_t md5_uint32;
 #   endif
 #  endif
 # endif
+/* We have to make a guess about the integer type equivalent in size
+   to pointers which should always be correct.  */
+typedef unsigned long int md5_uintptr;
 #endif
 
 #undef __P
Index: lib/md5.c
===================================================================
RCS file: /cvsroot/gnulib/gnulib/lib/md5.c,v
retrieving revision 1.13
diff -p -u -r1.13 md5.c
--- lib/md5.c   17 Nov 2001 13:29:42 -0000      1.13
+++ lib/md5.c   14 Aug 2003 23:09:05 -0000
@@ -1,6 +1,6 @@
 /* md5.c - 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, 2001 Free Software Foundation, Inc.
+   Copyright (C) 1995, 1996, 2001, 2003 Free Software Foundation, Inc.
    NOTE: The canonical source of this file is maintained with the GNU C
    Library.  Bugs can be reported to address@hidden
 
@@ -26,14 +26,8 @@
 
 #include <sys/types.h>
 
-#if STDC_HEADERS || defined _LIBC
-# include <stdlib.h>
-# include <string.h>
-#else
-# ifndef HAVE_MEMCPY
-#  define memcpy(d, s, n) bcopy ((s), (d), (n))
-# endif
-#endif
+#include <stdlib.h>
+#include <string.h>
 
 #include "md5.h"
 #include "unlocked-io.h"
@@ -43,6 +37,15 @@
 # if __BYTE_ORDER == __BIG_ENDIAN
 #  define WORDS_BIGENDIAN 1
 # endif
+/* We need to keep the namespace clean so define the MD5 function
+   protected using leading __ .  */
+# define md5_init_ctx __md5_init_ctx
+# define md5_process_block __md5_process_block
+# define md5_process_bytes __md5_process_bytes
+# define md5_finish_ctx __md5_finish_ctx
+# define md5_read_ctx __md5_read_ctx
+# define md5_stream __md5_stream
+# define md5_buffer __md5_buffer
 #endif
 
 #ifdef WORDS_BIGENDIAN
@@ -52,6 +55,12 @@
 # define SWAP(n) (n)
 #endif
 
+#define BLOCKSIZE 4096
+/* Ensure that BLOCKSIZE is a multiple of 64.  */
+#if BLOCKSIZE % 64 != 0
+/* FIXME-someday (soon?): use #error instead of this kludge.  */
+"invalid BLOCKSIZE"
+#endif
 
 /* This array contains the bytes used to pad the buffer to the next
    64-byte boundary.  (RFC 1321, 3.1: Step 1)  */
@@ -132,8 +141,6 @@ md5_stream (stream, resblock)
      FILE *stream;
      void *resblock;
 {
-  /* Important: BLOCKSIZE must be a multiple of 64.  */
-#define BLOCKSIZE 4096
   struct md5_ctx ctx;
   char buffer[BLOCKSIZE + 72];
   size_t sum;
@@ -151,19 +158,31 @@ md5_stream (stream, resblock)
       sum = 0;
 
       /* Read block.  Take care for partial reads.  */
-      do
+      while (1)
        {
          n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
 
          sum += n;
+
+         if (sum == BLOCKSIZE)
+           break;
+
+         if (n == 0)
+           {
+             /* Check for the error flag IFF N == 0, so that we don't
+                exit the loop after a partial read due to e.g., EAGAIN
+                or EWOULDBLOCK.  */
+             if (ferror (stream))
+               return 1;
+             goto process_partial_block;
+           }
+
+         /* We've read at least one byte, so ignore errors.  But always
+            check for EOF, since feof may be true even though N > 0.
+            Otherwise, we could end up calling fread after EOF.  */
+         if (feof (stream))
+           goto process_partial_block;
        }
-      while (sum < BLOCKSIZE && n != 0);
-      if (n == 0 && ferror (stream))
-        return 1;
-
-      /* If end of file is reached, end the loop.  */
-      if (n == 0)
-       break;
 
       /* Process buffer with BLOCKSIZE bytes.  Note that
                        BLOCKSIZE % 64 == 0
@@ -171,7 +190,9 @@ md5_stream (stream, resblock)
       md5_process_block (buffer, BLOCKSIZE, &ctx);
     }
 
-  /* Add the last bytes if necessary.  */
+ process_partial_block:;
+
+  /* Process any remaining bytes.  */
   if (sum > 0)
     md5_process_bytes (buffer, sum, &ctx);
 
@@ -219,13 +240,14 @@ md5_process_bytes (buffer, len, ctx)
       memcpy (&ctx->buffer[left_over], buffer, add);
       ctx->buflen += add;
 
-      if (left_over + add > 64)
+      if (ctx->buflen > 64)
        {
-         md5_process_block (ctx->buffer, (left_over + add) & ~63, ctx);
+         md5_process_block (ctx->buffer, ctx->buflen & ~63, ctx);
+
+         ctx->buflen &= 63;
          /* The regions in the following copy operation cannot overlap.  */
          memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~63],
-                 (left_over + add) & 63);
-         ctx->buflen = (left_over + add) & 63;
+                 ctx->buflen);
        }
 
       buffer = (const char *) buffer + add;
@@ -233,18 +255,46 @@ md5_process_bytes (buffer, len, ctx)
     }
 
   /* Process available complete blocks.  */
-  if (len > 64)
+  if (len >= 64)
     {
-      md5_process_block (buffer, len & ~63, ctx);
-      buffer = (const char *) buffer + (len & ~63);
-      len &= 63;
+#if !_STRING_ARCH_unaligned
+/* To check alignment gcc has an appropriate operator.  Other
+   compilers don't.  */
+# if __GNUC__ >= 2
+#  define UNALIGNED_P(p) (((md5_uintptr) p) % __alignof__ (md5_uint32) != 0)
+# else
+#  define UNALIGNED_P(p) (((md5_uintptr) p) % sizeof (md5_uint32) != 0)
+# endif
+      if (UNALIGNED_P (buffer))
+       while (len > 64)
+         {
+           md5_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx);
+           buffer = (const char *) buffer + 64;
+           len -= 64;
+         }
+      else
+#endif
+       {
+         md5_process_block (buffer, len & ~63, ctx);
+         buffer = (const char *) buffer + (len & ~63);
+         len &= 63;
+       }
     }
 
   /* Move remaining bytes in internal buffer.  */
   if (len > 0)
     {
-      memcpy (ctx->buffer, buffer, len);
-      ctx->buflen = len;
+      size_t left_over = ctx->buflen;
+
+      memcpy (&ctx->buffer[left_over], buffer, len);
+      left_over += len;
+      if (left_over >= 64)
+       {
+         md5_process_block (ctx->buffer, 64, ctx);
+         left_over -= 64;
+         memcpy (ctx->buffer, &ctx->buffer[64], left_over);
+       }
+      ctx->buflen = left_over;
     }
 }
 
@@ -340,7 +390,7 @@ md5_process_block (buffer, len, ctx)
         argument specifying the function to use.  */
 #undef OP
 #define OP(f, a, b, c, d, k, s, T)                                     \
-      do                                                               \
+      do                                                               \
        {                                                               \
          a += f (b, c, d) + correct_words[k] + T;                      \
          a = rol (a, s);                                               \