[Bug libc/1439] New: fixes for crypt/md5.? to permit syncing with gnulib

["simon at josefsson dot org" <sourceware-bugzilla at sourceware dot org>]

Hi!  I believe this patch would make it possible to fully sync your md5.?
against gnulib.

2005-10-08  Simon Josefsson  <jas@extundo.com>

	* crypt/md5.h: Synchronize with gnulib: Use stdint.h instead of
	computing local md5_uint32 etc types.  Add guards for
	__attribute__ and __THROW.  Add name space mapping for gnulib.
	Use uint32_t instead of md5_uint.

	* crypt/md5.c: Synchronize with gnulib: Include md5.h first.
	Replace md5_uint32 with uint32_t, and md5_uintptr with uintptr.
	Include C89 headers unconditionally.  Remove obsolete memcpy
	workaround.  Include unlocked-io.h if USE_UNLOCKED_IO, for gnulib.
	Define BLOCKSIZE early, and check the size.  Use C89 function
	prototypes rather than K&R.
	(md5_stream): Retry fread when it return 0 and set errno to EAGAIN
	and EWOULDBLOCK.
	(UNALIGNED_P) [__GNUC__ < 2]: Add better workaround for missing
	__alignof__.
	(md5_process_block): Add comment on how to reproduce values.


Index: md5.h
===================================================================
RCS file: /cvs/glibc/libc/crypt/md5.h,v
retrieving revision 1.6
diff -u -p -u -w -r1.6 md5.h
--- md5.h	5 Oct 2005 20:22:57 -0000	1.6
+++ md5.h	8 Oct 2005 10:55:45 -0000
@@ -23,72 +23,55 @@
 #define _MD5_H 1
 
 #include <stdio.h>
-
-#if defined HAVE_LIMITS_H || _LIBC
-# include <limits.h>
-#endif
-
-#define MD5_DIGEST_SIZE 16
-#define MD5_BLOCK_SIZE 64
-
-/* The following contortions are an attempt to use the C preprocessor
-   to determine an unsigned integral type that is 32 bits wide.  An
-   alternative approach is to use autoconf's AC_CHECK_SIZEOF macro, but
-   doing that would require that the configure script compile and *run*
-   the resulting executable.  Locally running cross-compiled executables
-   is usually not possible.  */
-
-#ifdef _LIBC
 # include <stdint.h>
-typedef uint32_t md5_uint32;
-typedef uintptr_t md5_uintptr;
-#else
-# if defined __STDC__ && __STDC__
-#  define UINT_MAX_32_BITS 4294967295U
+
+#ifndef __GNUC_PREREQ
+# if defined __GNUC__ && defined __GNUC_MINOR__
+#  define __GNUC_PREREQ(maj, min)					\
+  ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
 # else
-#  define UINT_MAX_32_BITS 0xFFFFFFFF
+#  define __GNUC_PREREQ(maj, min) 0
 # endif
-
-/* If UINT_MAX isn't defined, assume it's a 32-bit type.
-   This should be valid for all systems GNU cares about because
-   that doesn't include 16-bit systems, and only modern systems
-   (that certainly have <limits.h>) have 64+-bit integral types.  */
-
-# ifndef UINT_MAX
-#  define UINT_MAX UINT_MAX_32_BITS
 # endif
 
-# if UINT_MAX == UINT_MAX_32_BITS
-   typedef unsigned int md5_uint32;
-# else
-#  if USHRT_MAX == UINT_MAX_32_BITS
-    typedef unsigned short md5_uint32;
-#  else
-#   if ULONG_MAX == UINT_MAX_32_BITS
-     typedef unsigned long md5_uint32;
+#ifndef __THROW
+# if defined __cplusplus && __GNUC_PREREQ (2,8)
+#  define __THROW	throw ()
 #   else
-     /* The following line is intended to evoke an error.
-        Using #error is not portable enough.  */
-     "Cannot determine unsigned 32-bit data type."
+#  define __THROW
 #   endif
 #  endif
+
+#ifndef __attribute__
+# if ! __GNUC_PREREQ (2,8) || __STRICT_ANSI__
+#  define __attribute__(x)
 # 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
 
+#ifndef _LIBC
+# define __md5_buffer md5_buffer
+# define __md5_finish_ctx md5_finish_ctx
+# define __md5_init_ctx md5_init_ctx
+# define __md5_process_block md5_process_block
+# define __md5_process_bytes md5_process_bytes
+# define __md5_read_ctx md5_read_ctx
+# define __md5_stream md5_stream
+#endif
+
+#define MD5_DIGEST_SIZE 16
+#define MD5_BLOCK_SIZE 64
+
 /* Structure to save state of computation between the single steps.  */
 struct md5_ctx
 {
-  md5_uint32 A;
-  md5_uint32 B;
-  md5_uint32 C;
-  md5_uint32 D;
-
-  md5_uint32 total[2];
-  md5_uint32 buflen;
-  char buffer[128] __attribute__ ((__aligned__ (__alignof__ (md5_uint32))));
+  uint32_t A;
+  uint32_t B;
+  uint32_t C;
+  uint32_t D;
+
+  uint32_t total[2];
+  uint32_t buflen;
+  char buffer[128] __attribute__ ((__aligned__ (__alignof__ (uint32_t_t))));
 };
 
 /*

--- md5.c	11 Aug 2005 11:57:49 +0200	1.5
+++ md5.c	08 Oct 2005 12:42:18 +0200	
@@ -25,18 +25,16 @@
 # include <config.h>
 #endif
 
-#include <sys/types.h>
+#include "md5.h"
 
-#if STDC_HEADERS || defined _LIBC
+#include <stddef.h>
 # include <stdlib.h>
 # include <string.h>
-#else
-# ifndef HAVE_MEMCPY
-#  define memcpy(d, s, n) (bcopy ((s), (d), (n)), (d))
-# endif
-#endif
+#include <sys/types.h>
 
-#include "md5.h"
+#if USE_UNLOCKED_IO
+# include "unlocked-io.h"
+#endif
 
 #ifdef _LIBC
 # include <endian.h>
@@ -61,6 +59,10 @@
 # define SWAP(n) (n)
 #endif
 
+#define BLOCKSIZE 4096
+#if BLOCKSIZE % 64 != 0
+# error "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)  */
@@ -70,8 +72,7 @@
 /* Initialize structure containing state of computation.
    (RFC 1321, 3.3: Step 3)  */
 void
-md5_init_ctx (ctx)
-     struct md5_ctx *ctx;
+md5_init_ctx (struct md5_ctx *ctx)
 {
   ctx->A = 0x67452301;
   ctx->B = 0xefcdab89;
@@ -88,14 +89,12 @@
    IMPORTANT: On some systems it is required that RESBUF is correctly
    aligned for a 32 bits value.  */
 void *
-md5_read_ctx (ctx, resbuf)
-     const struct md5_ctx *ctx;
-     void *resbuf;
-{
-  ((md5_uint32 *) resbuf)[0] = SWAP (ctx->A);
-  ((md5_uint32 *) resbuf)[1] = SWAP (ctx->B);
-  ((md5_uint32 *) resbuf)[2] = SWAP (ctx->C);
-  ((md5_uint32 *) resbuf)[3] = SWAP (ctx->D);
+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);
 
   return resbuf;
 }
@@ -106,12 +105,10 @@
    IMPORTANT: On some systems it is required that RESBUF is correctly
    aligned for a 32 bits value.  */
 void *
-md5_finish_ctx (ctx, resbuf)
-     struct md5_ctx *ctx;
-     void *resbuf;
+md5_finish_ctx (struct md5_ctx *ctx, void *resbuf)
 {
   /* Take yet unprocessed bytes into account.  */
-  md5_uint32 bytes = ctx->buflen;
+  uint32_t bytes = ctx->buflen;
   size_t pad;
 
   /* Now count remaining bytes.  */
@@ -123,8 +120,8 @@
   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) |
+  *(uint32_t *) &ctx->buffer[bytes + pad] = SWAP (ctx->total[0] << 3);
+  *(uint32_t *) &ctx->buffer[bytes + pad + 4] = SWAP ((ctx->total[1] << 3) |
 							(ctx->total[0] >> 29));
 
   /* Process last bytes.  */
@@ -137,12 +134,8 @@
    resulting message digest number will be written into the 16 bytes
    beginning at RESBLOCK.  */
 int
-md5_stream (stream, resblock)
-     FILE *stream;
-     void *resblock;
+md5_stream (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;
@@ -160,27 +153,41 @@
       sum = 0;
 
       /* Read block.  Take care for partial reads.  */
-      do
+      while (1)
 	{
 	  n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
 
 	  sum += n;
-	}
-      while (sum < BLOCKSIZE && n != 0);
-      if (n == 0 && ferror (stream))
-        return 1;
 
-      /* If end of file is reached, end the loop.  */
-      if (n == 0)
+	  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;
+	}
+
       /* Process buffer with BLOCKSIZE bytes.  Note that
 			BLOCKSIZE % 64 == 0
        */
       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);
 
@@ -194,10 +201,7 @@
    output yields to the wanted ASCII representation of the message
    digest.  */
 void *
-md5_buffer (buffer, len, resblock)
-     const char *buffer;
-     size_t len;
-     void *resblock;
+md5_buffer (const char *buffer, size_t len, void *resblock)
 {
   struct md5_ctx ctx;
 
@@ -213,10 +217,7 @@
 
 
 void
-md5_process_bytes (buffer, len, ctx)
-     const void *buffer;
-     size_t len;
-     struct md5_ctx *ctx;
+md5_process_bytes (const void *buffer, size_t len, struct md5_ctx *ctx)
 {
   /* When we already have some bits in our internal buffer concatenate
      both inputs first.  */
@@ -249,9 +250,10 @@
 /* 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)
+#  define UNALIGNED_P(p) (((uintptr_t) p) % __alignof__ (uint32_t) != 0)
 # else
-#  define UNALIGNED_P(p) (((md5_uintptr) p) % sizeof (md5_uint32) != 0)
+#  define alignof(type) offsetof (struct { char c; type x; }, x)
+#  define UNALIGNED_P(p) (((size_t) p) % alignof (uint32_t) != 0)
 # endif
       if (UNALIGNED_P (buffer))
 	while (len > 64)
@@ -300,19 +302,16 @@
    It is assumed that LEN % 64 == 0.  */
 
 void
-md5_process_block (buffer, len, ctx)
-     const void *buffer;
-     size_t len;
-     struct md5_ctx *ctx;
-{
-  md5_uint32 correct_words[16];
-  const md5_uint32 *words = buffer;
-  size_t nwords = len / sizeof (md5_uint32);
-  const md5_uint32 *endp = words + nwords;
-  md5_uint32 A = ctx->A;
-  md5_uint32 B = ctx->B;
-  md5_uint32 C = ctx->C;
-  md5_uint32 D = ctx->D;
+md5_process_block (const void *buffer, size_t len, struct md5_ctx *ctx)
+{
+  uint32_t correct_words[16];
+  const uint32_t *words = buffer;
+  size_t nwords = len / sizeof (uint32_t);
+  const uint32_t *endp = words + nwords;
+  uint32_t A = ctx->A;
+  uint32_t B = ctx->B;
+  uint32_t C = ctx->C;
+  uint32_t D = ctx->D;
 
   /* First increment the byte count.  RFC 1321 specifies the possible
      length of the file up to 2^64 bits.  Here we only compute the
@@ -325,11 +324,11 @@
      the loop.  */
   while (words < endp)
     {
-      md5_uint32 *cwp = correct_words;
-      md5_uint32 A_save = A;
-      md5_uint32 B_save = B;
-      md5_uint32 C_save = C;
-      md5_uint32 D_save = D;
+      uint32_t *cwp = correct_words;
+      uint32_t A_save = A;
+      uint32_t B_save = B;
+      uint32_t C_save = C;
+      uint32_t D_save = D;
 
       /* First round: using the given function, the context and a constant
 	 the next context is computed.  Because the algorithms processing
@@ -356,6 +355,10 @@
 	 They are defined in RFC 1321 as
 
 	 T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64
+
+	 Here is an equivalent invocation using Perl:
+
+	 perl -e 'foreach(1..64){printf "0x%08x\n", int (4294967296 * abs (sin $_))}'
        */
 
       /* Round 1.  */

-- 
           Summary: fixes for crypt/md5.? to permit syncing with gnulib
           Product: glibc
           Version: unspecified
            Status: NEW
          Severity: normal
          Priority: P2
         Component: libc
        AssignedTo: gotom at debian dot or dot jp
        ReportedBy: simon at josefsson dot org
                CC: glibc-bugs at sources dot redhat dot com


http://sourceware.org/bugzilla/show_bug.cgi?id=1439

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