Commit 12100500 authored by Niels Möller's avatar Niels Möller

(des_cbc_cksum): Pad input with NUL:s, if it's not

an integral number of blocks.

Rev: src/nettle/des-compat.c:1.15
parent 13318da8
......@@ -71,6 +71,10 @@ des_ecb3_encrypt(const_des_cblock *src, des_cblock *dst,
(&keys, DES_BLOCK_SIZE, *dst, *src);
}
/* If input is not a integral number of blocks, the final block is
padded with zeros, no length field or anything like that. That's
pretty broken, since it means that "$100" and "$100\0" always have
the same checksum, but I think that's how it's supposed to work. */
uint32_t
des_cbc_cksum(const uint8_t *src, des_cblock *dst,
long length, des_key_schedule ctx,
......@@ -80,16 +84,21 @@ des_cbc_cksum(const uint8_t *src, des_cblock *dst,
* work, in particular what it should return, and if iv can be
* modified. */
uint8_t block[DES_BLOCK_SIZE];
const uint8_t *p;
memcpy(block, *iv, DES_BLOCK_SIZE);
assert(!(length % DES_BLOCK_SIZE));
for (p = src; length; length -= DES_BLOCK_SIZE, p += DES_BLOCK_SIZE)
while (length >= DES_BLOCK_SIZE)
{
memxor(block, p, DES_BLOCK_SIZE);
memxor(block, src, DES_BLOCK_SIZE);
nettle_des_encrypt(ctx, DES_BLOCK_SIZE, block, block);
src += DES_BLOCK_SIZE;
length -= DES_BLOCK_SIZE;
}
if (length > 0)
{
memxor(block, src, length);
nettle_des_encrypt(ctx, DES_BLOCK_SIZE, block, block);
}
memcpy(*dst, block, DES_BLOCK_SIZE);
......
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