Paul Eggert <[EMAIL PROTECTED]> writes:
> Jim Meyering <[EMAIL PROTECTED]> writes:
>
>> verify (offsetof (struct S, member_m) % 4 == 0);
>>
>> Hmm... that assumes 8-bit bytes.
>
> And it also assumes no holes in integer representations.
> This is more portable:
>
> verify (offsetof (struct S, member_m) % alignof (uint32_t) == 0);
>
> where alignof is defined as with md5.c etc.
The "verify" module is GPL. If you re-license it, md4 would be able
to use it.
> But I agree with Bruno; it'd be better to change the type of the
> following member from char to uint32_t to avoid all this hassle.
The following patch works. What do you think? Should I install this?
And similar to the MD5 and SHA-1 module too?
Frankly, I think it should be possible to implement MD4 (and MD5, and
SHA-1) without these casts and alignment checks. Is the rest of the
file really portable? The code look rather messy to me.
Thanks.
Index: md4.h
===================================================================
RCS file: /cvsroot/gnulib/gnulib/lib/md4.h,v
retrieving revision 1.1
diff -u -p -r1.1 md4.h
--- md4.h 18 Oct 2005 22:59:17 -0000 1.1
+++ md4.h 22 Oct 2005 15:29:13 -0000
@@ -22,7 +22,7 @@
# include <stdio.h>
# include <stdint.h>
-#define MD4_DIGEST_SIZE 16
+# define MD4_DIGEST_SIZE 16
/* Structure to save state of computation between the single steps. */
struct md4_ctx
@@ -34,7 +34,7 @@ struct md4_ctx
uint32_t total[2];
uint32_t buflen;
- char buffer[128] __attribute__ ((__aligned__ (__alignof__ (uint32_t))));
+ uint32_t buffer[128];
};
Index: md4.c
===================================================================
RCS file: /cvsroot/gnulib/gnulib/lib/md4.c,v
retrieving revision 1.3
diff -u -p -r1.3 md4.c
--- md4.c 21 Oct 2005 12:46:48 -0000 1.3
+++ md4.c 22 Oct 2005 15:29:13 -0000
@@ -100,12 +100,12 @@ md4_finish_ctx (struct md4_ctx *ctx, voi
++ctx->total[1];
pad = bytes >= 56 ? 64 + 56 - bytes : 56 - bytes;
- memcpy (&ctx->buffer[bytes], fillbuf, pad);
+ memcpy (&((char*)ctx->buffer)[bytes], fillbuf, pad);
/* Put the 64-bit file length in *bits* at the end of the buffer. */
- *(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));
+ ctx->buffer[(bytes + pad) / 4] = SWAP (ctx->total[0] << 3);
+ ctx->buffer[(bytes + pad) / 4 + 1] = SWAP ((ctx->total[1] << 3) |
+ (ctx->total[0] >> 29));
/* Process last bytes. */
md4_process_block (ctx->buffer, bytes + pad + 8, ctx);
@@ -208,7 +208,7 @@ md4_process_bytes (const void *buffer, s
size_t left_over = ctx->buflen;
size_t add = 128 - left_over > len ? len : 128 - left_over;
- memcpy (&ctx->buffer[left_over], buffer, add);
+ memcpy (&((char*)ctx->buffer)[left_over], buffer, add);
ctx->buflen += add;
if (ctx->buflen > 64)
@@ -217,7 +217,7 @@ md4_process_bytes (const void *buffer, s
ctx->buflen &= 63;
/* The regions in the following copy operation cannot overlap. */
- memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~63],
+ memcpy (ctx->buffer, &((char*)ctx->buffer)[(left_over + add) & ~63],
ctx->buflen);
}
@@ -240,7 +240,7 @@ md4_process_bytes (const void *buffer, s
if (UNALIGNED_P (buffer))
while (len > 64)
{
- md4_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx);
+ md4_process_block (memcpy (ctx->buffer, buffer, 16), 64, ctx);
buffer = (const char *) buffer + 64;
len -= 64;
}
@@ -258,13 +258,13 @@ md4_process_bytes (const void *buffer, s
{
size_t left_over = ctx->buflen;
- memcpy (&ctx->buffer[left_over], buffer, len);
+ memcpy (&((char*)ctx->buffer)[left_over], buffer, len);
left_over += len;
if (left_over >= 64)
{
md4_process_block (ctx->buffer, 64, ctx);
left_over -= 64;
- memcpy (ctx->buffer, &ctx->buffer[64], left_over);
+ memcpy (ctx->buffer, &ctx->buffer[16], left_over);
}
ctx->buflen = left_over;
}
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