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crypto: restrict cipher block size to power of 2. 

All current ciphers have blocks which are power of 2 and it's
unlikely to change. Other block length would be tricky to handle anyway.
This restriction allows avoiding extra divisions.
This commit is contained in:
Vladimir Serbinenko 2015-02-26 22:04:40 +01:00
parent 7213c1e028
commit 94f701a826
2 changed files with 48 additions and 30 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
grub-core/disk/cryptodisk.c
View File

@ -110,20 +110,23 @@ grub_crypto_pcbc_decrypt (grub_crypto_cipher_handle_t cipher,
{
grub_uint8_t *inptr, *outptr, *end;
grub_uint8_t ivt[GRUB_CRYPTO_MAX_CIPHER_BLOCKSIZE];
if (cipher->cipher->blocksize > GRUB_CRYPTO_MAX_CIPHER_BLOCKSIZE)
return GPG_ERR_INV_ARG;
grub_size_t blocksize;
if (!cipher->cipher->decrypt)
return GPG_ERR_NOT_SUPPORTED;
if (size % cipher->cipher->blocksize != 0)
blocksize = cipher->cipher->blocksize;
if (blocksize == 0 || (((blocksize - 1) & blocksize) != 0)
|| ((size & (blocksize - 1)) != 0))
return GPG_ERR_INV_ARG;
if (blocksize > GRUB_CRYPTO_MAX_CIPHER_BLOCKSIZE)
return GPG_ERR_INV_ARG;
end = (grub_uint8_t *) in + size;
for (inptr = in, outptr = out; inptr < end;
inptr += cipher->cipher->blocksize, outptr += cipher->cipher->blocksize)
inptr += blocksize, outptr += blocksize)
{
grub_memcpy (ivt, inptr, cipher->cipher->blocksize);
grub_memcpy (ivt, inptr, blocksize);
cipher->cipher->decrypt (cipher->ctx, outptr, inptr);
grub_crypto_xor (outptr, outptr, iv, cipher->cipher->blocksize);
grub_crypto_xor (iv, ivt, outptr, cipher->cipher->blocksize);
grub_crypto_xor (outptr, outptr, iv, blocksize);
grub_crypto_xor (iv, ivt, outptr, blocksize);
}
return GPG_ERR_NO_ERROR;
}
@ -135,20 +138,23 @@ grub_crypto_pcbc_encrypt (grub_crypto_cipher_handle_t cipher,
{
grub_uint8_t *inptr, *outptr, *end;
grub_uint8_t ivt[GRUB_CRYPTO_MAX_CIPHER_BLOCKSIZE];
if (cipher->cipher->blocksize > GRUB_CRYPTO_MAX_CIPHER_BLOCKSIZE)
return GPG_ERR_INV_ARG;
if (!cipher->cipher->decrypt)
grub_size_t blocksize;
if (!cipher->cipher->encrypt)
return GPG_ERR_NOT_SUPPORTED;
if (size % cipher->cipher->blocksize != 0)
blocksize = cipher->cipher->blocksize;
if (blocksize > GRUB_CRYPTO_MAX_CIPHER_BLOCKSIZE)
return GPG_ERR_INV_ARG;
if (blocksize == 0 || (((blocksize - 1) & blocksize) != 0)
|| ((size & (blocksize - 1)) != 0))
return GPG_ERR_INV_ARG;
end = (grub_uint8_t *) in + size;
for (inptr = in, outptr = out; inptr < end;
inptr += cipher->cipher->blocksize, outptr += cipher->cipher->blocksize)
inptr += blocksize, outptr += blocksize)
{
grub_memcpy (ivt, inptr, cipher->cipher->blocksize);
grub_crypto_xor (outptr, outptr, iv, cipher->cipher->blocksize);
grub_memcpy (ivt, inptr, blocksize);
grub_crypto_xor (outptr, outptr, iv, blocksize);
cipher->cipher->encrypt (cipher->ctx, outptr, inptr);
grub_crypto_xor (iv, ivt, outptr, cipher->cipher->blocksize);
grub_crypto_xor (iv, ivt, outptr, blocksize);
}
return GPG_ERR_NO_ERROR;
}

42
grub-core/lib/crypto.c
View File

@ -205,13 +205,16 @@ grub_crypto_ecb_decrypt (grub_crypto_cipher_handle_t cipher,
{
const grub_uint8_t *inptr, *end;
grub_uint8_t *outptr;
grub_size_t blocksize;
if (!cipher->cipher->decrypt)
return GPG_ERR_NOT_SUPPORTED;
if (size % cipher->cipher->blocksize != 0)
blocksize = cipher->cipher->blocksize;
if (blocksize == 0 || (((blocksize - 1) & blocksize) != 0)
|| ((size & (blocksize - 1)) != 0))
return GPG_ERR_INV_ARG;
end = (const grub_uint8_t *) in + size;
for (inptr = in, outptr = out; inptr < end;
inptr += cipher->cipher->blocksize, outptr += cipher->cipher->blocksize)
inptr += blocksize, outptr += blocksize)
cipher->cipher->decrypt (cipher->ctx, outptr, inptr);
return GPG_ERR_NO_ERROR;
}
@ -222,13 +225,16 @@ grub_crypto_ecb_encrypt (grub_crypto_cipher_handle_t cipher,
{
const grub_uint8_t *inptr, *end;
grub_uint8_t *outptr;
grub_size_t blocksize;
if (!cipher->cipher->encrypt)
return GPG_ERR_NOT_SUPPORTED;
if (size % cipher->cipher->blocksize != 0)
blocksize = cipher->cipher->blocksize;
if (blocksize == 0 || (((blocksize - 1) & blocksize) != 0)
|| ((size & (blocksize - 1)) != 0))
return GPG_ERR_INV_ARG;
end = (const grub_uint8_t *) in + size;
for (inptr = in, outptr = out; inptr < end;
inptr += cipher->cipher->blocksize, outptr += cipher->cipher->blocksize)
inptr += blocksize, outptr += blocksize)
cipher->cipher->encrypt (cipher->ctx, outptr, inptr);
return GPG_ERR_NO_ERROR;
}
@ -241,20 +247,23 @@ grub_crypto_cbc_encrypt (grub_crypto_cipher_handle_t cipher,
grub_uint8_t *outptr;
const grub_uint8_t *inptr, *end;
void *iv;
if (!cipher->cipher->decrypt)
grub_size_t blocksize;
if (!cipher->cipher->encrypt)
return GPG_ERR_NOT_SUPPORTED;
if (size % cipher->cipher->blocksize != 0)
blocksize = cipher->cipher->blocksize;
if (blocksize == 0 || (((blocksize - 1) & blocksize) != 0)
|| ((size & (blocksize - 1)) != 0))
return GPG_ERR_INV_ARG;
end = (const grub_uint8_t *) in + size;
iv = iv_in;
for (inptr = in, outptr = out; inptr < end;
inptr += cipher->cipher->blocksize, outptr += cipher->cipher->blocksize)
inptr += blocksize, outptr += blocksize)
{
grub_crypto_xor (outptr, inptr, iv, cipher->cipher->blocksize);
grub_crypto_xor (outptr, inptr, iv, blocksize);
cipher->cipher->encrypt (cipher->ctx, outptr, outptr);
iv = outptr;
}
grub_memcpy (iv_in, iv, cipher->cipher->blocksize);
grub_memcpy (iv_in, iv, blocksize);
return GPG_ERR_NO_ERROR;
}
@ -266,20 +275,23 @@ grub_crypto_cbc_decrypt (grub_crypto_cipher_handle_t cipher,
const grub_uint8_t *inptr, *end;
grub_uint8_t *outptr;
grub_uint8_t ivt[GRUB_CRYPTO_MAX_CIPHER_BLOCKSIZE];
grub_size_t blocksize;
if (!cipher->cipher->decrypt)
return GPG_ERR_NOT_SUPPORTED;
if (size % cipher->cipher->blocksize != 0)
blocksize = cipher->cipher->blocksize;
if (blocksize == 0 || (((blocksize - 1) & blocksize) != 0)
|| ((size & (blocksize - 1)) != 0))
return GPG_ERR_INV_ARG;
if (cipher->cipher->blocksize > GRUB_CRYPTO_MAX_CIPHER_BLOCKSIZE)
if (blocksize > GRUB_CRYPTO_MAX_CIPHER_BLOCKSIZE)
return GPG_ERR_INV_ARG;
end = (const grub_uint8_t *) in + size;
for (inptr = in, outptr = out; inptr < end;
inptr += cipher->cipher->blocksize, outptr += cipher->cipher->blocksize)
inptr += blocksize, outptr += blocksize)
{
grub_memcpy (ivt, inptr, cipher->cipher->blocksize);
grub_memcpy (ivt, inptr, blocksize);
cipher->cipher->decrypt (cipher->ctx, outptr, inptr);
grub_crypto_xor (outptr, outptr, iv, cipher->cipher->blocksize);
grub_memcpy (iv, ivt, cipher->cipher->blocksize);
grub_crypto_xor (outptr, outptr, iv, blocksize);
grub_memcpy (iv, ivt, blocksize);
}
return GPG_ERR_NO_ERROR;
}