openssl/crypto/modes/wrap128.c
Dr. Stephen Henson d31fed73e2 RFC 5649 support.
Add support for RFC5649 key wrapping with padding.

Add RFC5649 tests to evptests.txt

Based on PR#3434 contribution by Petr Spacek <pspacek@redhat.com>.

EVP support and minor changes added by Stephen Henson.

Doxygen comment block updates by Tim Hudson.

Reviewed-by: Tim Hudson <tjh@openssl.org>
2014-07-18 21:37:13 +01:00

373 lines
12 KiB
C

/* crypto/modes/wrap128.c */
/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
* project.
* Mode with padding contributed by Petr Spacek (pspacek@redhat.com).
*/
/* ====================================================================
* Copyright (c) 2013 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* licensing@OpenSSL.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*/
/** Beware!
*
* Following wrapping modes were designed for AES but this implementation
* allows you to use them for any 128 bit block cipher.
*/
#include "cryptlib.h"
#include <openssl/modes.h>
/** RFC 3394 section 2.2.3.1 Default Initial Value */
static const unsigned char default_iv[] = {
0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6,
};
/** RFC 5649 section 3 Alternative Initial Value 32-bit constant */
static const unsigned char default_aiv[] = {
0xA6, 0x59, 0x59, 0xA6
};
/** Input size limit: lower than maximum of standards but far larger than
* anything that will be used in practice.
*/
#define CRYPTO128_WRAP_MAX (1UL << 31)
/** Wrapping according to RFC 3394 section 2.2.1.
*
* @param[in] key Key value.
* @param[in] iv IV value. Length = 8 bytes. NULL = use default_iv.
* @param[in] in Plain text as n 64-bit blocks, n >= 2.
* @param[in] inlen Length of in.
* @param[out] out Cipher text. Minimal buffer length = (inlen + 8) bytes.
* Input and output buffers can overlap if block function
* supports that.
* @param[in] block Block processing function.
* @return 0 if inlen does not consist of n 64-bit blocks, n >= 2.
* or if inlen > CRYPTO128_WRAP_MAX.
* Output length if wrapping succeeded.
*/
size_t CRYPTO_128_wrap(void *key, const unsigned char *iv,
unsigned char *out,
const unsigned char *in, size_t inlen, block128_f block)
{
unsigned char *A, B[16], *R;
size_t i, j, t;
if ((inlen & 0x7) || (inlen < 16) || (inlen > CRYPTO128_WRAP_MAX))
return 0;
A = B;
t = 1;
memmove(out + 8, in, inlen);
if (!iv)
iv = default_iv;
memcpy(A, iv, 8);
for (j = 0; j < 6; j++)
{
R = out + 8;
for (i = 0; i < inlen; i += 8, t++, R += 8)
{
memcpy(B + 8, R, 8);
block(B, B, key);
A[7] ^= (unsigned char)(t & 0xff);
if (t > 0xff)
{
A[6] ^= (unsigned char)((t >> 8) & 0xff);
A[5] ^= (unsigned char)((t >> 16) & 0xff);
A[4] ^= (unsigned char)((t >> 24) & 0xff);
}
memcpy(R, B + 8, 8);
}
}
memcpy(out, A, 8);
return inlen + 8;
}
/** Unwrapping according to RFC 3394 section 2.2.2 steps 1-2.
* IV check (step 3) is responsibility of the caller.
*
* @param[in] key Key value.
* @param[out] iv Unchecked IV value. Minimal buffer length = 8 bytes.
* @param[out] out Plain text without IV.
* Minimal buffer length = (inlen - 8) bytes.
* Input and output buffers can overlap if block function
* supports that.
* @param[in] in Ciphertext text as n 64-bit blocks
* @param[in] inlen Length of in.
* @param[in] block Block processing function.
* @return 0 if inlen is out of range [24, CRYPTO128_WRAP_MAX]
* or if inlen is not multiply of 8.
* Output length otherwise.
*/
static size_t crypto_128_unwrap_raw(void *key, unsigned char *iv,
unsigned char *out, const unsigned char *in,
size_t inlen, block128_f block)
{
unsigned char *A, B[16], *R;
size_t i, j, t;
inlen -= 8;
if ((inlen & 0x7) || (inlen < 16) || (inlen > CRYPTO128_WRAP_MAX))
return 0;
A = B;
t = 6 * (inlen >> 3);
memcpy(A, in, 8);
memmove(out, in + 8, inlen);
for (j = 0; j < 6; j++)
{
R = out + inlen - 8;
for (i = 0; i < inlen; i += 8, t--, R -= 8)
{
A[7] ^= (unsigned char)(t & 0xff);
if (t > 0xff)
{
A[6] ^= (unsigned char)((t >> 8) & 0xff);
A[5] ^= (unsigned char)((t >> 16) & 0xff);
A[4] ^= (unsigned char)((t >> 24) & 0xff);
}
memcpy(B + 8, R, 8);
block(B, B, key);
memcpy(R, B + 8, 8);
}
}
memcpy(iv, A, 8);
return inlen;
}
/** Unwrapping according to RFC 3394 section 2.2.2 including IV check.
* First block of plain text have to match supplied IV otherwise an error is
* returned.
*
* @param[in] key Key value.
* @param[out] iv Unchecked IV value. Minimal buffer length = 8 bytes.
* @param[out] out Plain text without IV.
* Minimal buffer length = (inlen - 8) bytes.
* Input and output buffers can overlap if block function
* supports that.
* @param[in] in Ciphertext text as n 64-bit blocks
* @param[in] inlen Length of in.
* @param[in] block Block processing function.
* @return 0 if inlen is out of range [24, CRYPTO128_WRAP_MAX]
* or if inlen is not multiply of 8
* or if IV doesn't match expected value.
* Output length otherwise.
*/
size_t CRYPTO_128_unwrap(void *key, const unsigned char *iv,
unsigned char *out, const unsigned char *in, size_t inlen,
block128_f block)
{
size_t ret;
unsigned char got_iv[8];
ret = crypto_128_unwrap_raw(key, got_iv, out, in, inlen, block);
if (ret != inlen)
return ret;
if (!iv)
iv = default_iv;
if (CRYPTO_memcmp(out, iv, 8))
{
OPENSSL_cleanse(out, inlen);
return 0;
}
return inlen;
}
/** Wrapping according to RFC 5649 section 4.1.
*
* @param[in] key Key value.
* @param[in] icv (Non-standard) IV, 4 bytes. NULL = use default_aiv.
* @param[out] out Cipher text. Minimal buffer length = (inlen + 15) bytes.
* Input and output buffers can overlap if block function
* supports that.
* @param[in] in Plain text as n 64-bit blocks, n >= 2.
* @param[in] inlen Length of in.
* @param[in] block Block processing function.
* @return 0 if inlen is out of range [1, CRYPTO128_WRAP_MAX].
* Output length if wrapping succeeded.
*/
size_t CRYPTO_128_wrap_pad(void *key, const unsigned char *icv,
unsigned char *out,
const unsigned char *in, size_t inlen, block128_f block)
{
/* n: number of 64-bit blocks in the padded key data */
const size_t blocks_padded = (inlen + 8) / 8;
const size_t padded_len = blocks_padded * 8;
const size_t padding_len = padded_len - inlen;
/* RFC 5649 section 3: Alternative Initial Value */
unsigned char aiv[8];
int ret;
/* Section 1: use 32-bit fixed field for plaintext octet length */
if (inlen == 0 || inlen >= CRYPTO128_WRAP_MAX)
return 0;
/* Section 3: Alternative Initial Value */
if (!icv)
memcpy(aiv, default_aiv, 4);
else
memcpy(aiv, icv, 4); /* Standard doesn't mention this. */
aiv[4] = (inlen >> 24) & 0xFF;
aiv[5] = (inlen >> 16) & 0xFF;
aiv[6] = (inlen >> 8) & 0xFF;
aiv[7] = inlen & 0xFF;
if (padded_len == 8)
{
/* Section 4.1 - special case in step 2:
* If the padded plaintext contains exactly eight octets, then
* prepend the AIV and encrypt the resulting 128-bit block
* using AES in ECB mode. */
memmove(out + 8, in, inlen);
memcpy(out, aiv, 8);
memset(out + 8 + inlen, 0, padding_len);
block(out, out, key);
ret = 16; /* AIV + padded input */
}
else
{
memmove(out, in, inlen);
memset(out + inlen, 0, padding_len); /* Section 4.1 step 1 */
ret = CRYPTO_128_wrap(key, aiv, out, out, padded_len, block);
}
return ret;
}
/** Unwrapping according to RFC 5649 section 4.2.
*
* @param[in] key Key value.
* @param[in] icv (Non-standard) IV, 4 bytes. NULL = use default_aiv.
* @param[out] out Plain text. Minimal buffer length = inlen bytes.
* Input and output buffers can overlap if block function
* supports that.
* @param[in] in Ciphertext text as n 64-bit blocks
* @param[in] inlen Length of in.
* @param[in] block Block processing function.
* @return 0 if inlen is out of range [16, CRYPTO128_WRAP_MAX],
* or if inlen is not multiply of 8
* or if IV and message length indicator doesn't match.
* Output length if unwrapping succeeded and IV matches.
*/
size_t CRYPTO_128_unwrap_pad(void *key, const unsigned char *icv,
unsigned char *out,
const unsigned char *in, size_t inlen, block128_f block)
{
/* n: number of 64-bit blocks in the padded key data */
size_t n = inlen / 8 - 1;
size_t padded_len;
size_t padding_len;
size_t ptext_len;
/* RFC 5649 section 3: Alternative Initial Value */
unsigned char aiv[8];
static unsigned char zeros[8] = {0x0};
size_t ret;
/* Section 4.2: Cipher text length has to be (n+1) 64-bit blocks. */
if ((inlen & 0x7) != 0 || inlen < 16 || inlen >= CRYPTO128_WRAP_MAX)
return 0;
memmove(out, in, inlen);
if (inlen == 16)
{
/* Section 4.2 - special case in step 1:
* When n=1, the ciphertext contains exactly two 64-bit
* blocks and they are decrypted as a single AES
* block using AES in ECB mode:
* AIV | P[1] = DEC(K, C[0] | C[1])
*/
block(out, out, key);
memcpy(aiv, out, 8);
/* Remove AIV */
memmove(out, out + 8, 8);
padded_len = 8;
}
else
{
padded_len = inlen - 8;
ret = crypto_128_unwrap_raw(key, aiv, out, out, inlen, block);
if (padded_len != ret)
{
OPENSSL_cleanse(out, inlen);
return 0;
}
}
/* Section 3: AIV checks: Check that MSB(32,A) = A65959A6.
* Optionally a user-supplied value can be used
* (even if standard doesn't mention this). */
if ((!icv && CRYPTO_memcmp(aiv, default_aiv, 4))
|| (icv && CRYPTO_memcmp(aiv, icv, 4)))
{
OPENSSL_cleanse(out, inlen);
return 0;
}
/* Check that 8*(n-1) < LSB(32,AIV) <= 8*n.
* If so, let ptext_len = LSB(32,AIV). */
ptext_len = (aiv[4] << 24) | (aiv[5] << 16) | (aiv[6] << 8) | aiv[7];
if (8*(n-1) >= ptext_len || ptext_len > 8*n)
{
OPENSSL_cleanse(out, inlen);
return 0;
}
/* Check that the rightmost padding_len octets of the output data
* are zero. */
padding_len = padded_len - ptext_len;
if (CRYPTO_memcmp(out + ptext_len, zeros, padding_len) != 0)
{
OPENSSL_cleanse(out, inlen);
return 0;
}
/* Section 4.2 step 3: Remove padding */
return ptext_len;
}