[thirdparty/openssl.git] / crypto / modes / wrap128.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;
	}
Commit	Line	Data
97cf1f6c DSH	1	/* crypto/modes/wrap128.c */
	2	/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
	3	* project.
d31fed73	4	* Mode with padding contributed by Petr Spacek (pspacek@redhat.com).
97cf1f6c DSH	5	*/
	6	/* ====================================================================
	7	* Copyright (c) 2013 The OpenSSL Project. All rights reserved.
	8	*
	9	* Redistribution and use in source and binary forms, with or without
	10	* modification, are permitted provided that the following conditions
	11	* are met:
	12	*
	13	* 1. Redistributions of source code must retain the above copyright
	14	* notice, this list of conditions and the following disclaimer.
	15	*
	16	* 2. Redistributions in binary form must reproduce the above copyright
	17	* notice, this list of conditions and the following disclaimer in
	18	* the documentation and/or other materials provided with the
	19	* distribution.
	20	*
	21	* 3. All advertising materials mentioning features or use of this
	22	* software must display the following acknowledgment:
	23	* "This product includes software developed by the OpenSSL Project
	24	* for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
	25	*
	26	* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
	27	* endorse or promote products derived from this software without
	28	* prior written permission. For written permission, please contact
	29	* licensing@OpenSSL.org.
	30	*
	31	* 5. Products derived from this software may not be called "OpenSSL"
	32	* nor may "OpenSSL" appear in their names without prior written
	33	* permission of the OpenSSL Project.
	34	*
	35	* 6. Redistributions of any form whatsoever must retain the following
	36	* acknowledgment:
	37	* "This product includes software developed by the OpenSSL Project
	38	* for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
	39	*
	40	* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
	41	* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	42	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	43	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
	44	* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	45	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	46	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	47	* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	48	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
	49	* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	50	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
	51	* OF THE POSSIBILITY OF SUCH DAMAGE.
	52	* ====================================================================
	53	*/
	54
d31fed73 DSH	55	/** Beware!
	56	*
	57	* Following wrapping modes were designed for AES but this implementation
	58	* allows you to use them for any 128 bit block cipher.
	59	*/
	60
97cf1f6c DSH	61	#include "cryptlib.h"
	62	#include <openssl/modes.h>
	63
d31fed73	64	/** RFC 3394 section 2.2.3.1 Default Initial Value */
97cf1f6c DSH	65	static const unsigned char default_iv[] = {
	66	0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6,
	67	};
d31fed73 DSH	68
	69	/** RFC 5649 section 3 Alternative Initial Value 32-bit constant */
	70	static const unsigned char default_aiv[] = {
	71	0xA6, 0x59, 0x59, 0xA6
	72	};
	73
	74	/** Input size limit: lower than maximum of standards but far larger than
	75	* anything that will be used in practice.
97cf1f6c DSH	76	*/
	77	#define CRYPTO128_WRAP_MAX (1UL << 31)
	78
d31fed73 DSH	79	/** Wrapping according to RFC 3394 section 2.2.1.
	80	*
	81	* @param[in] key Key value.
	82	* @param[in] iv IV value. Length = 8 bytes. NULL = use default_iv.
	83	* @param[in] in Plain text as n 64-bit blocks, n >= 2.
	84	* @param[in] inlen Length of in.
	85	* @param[out] out Cipher text. Minimal buffer length = (inlen + 8) bytes.
	86	* Input and output buffers can overlap if block function
	87	* supports that.
	88	* @param[in] block Block processing function.
	89	* @return 0 if inlen does not consist of n 64-bit blocks, n >= 2.
	90	* or if inlen > CRYPTO128_WRAP_MAX.
	91	* Output length if wrapping succeeded.
	92	*/
97cf1f6c DSH	93	size_t CRYPTO_128_wrap(void key, const unsigned char iv,
	94	unsigned char *out,
	95	const unsigned char *in, size_t inlen, block128_f block)
	96	{
	97	unsigned char A, B[16], R;
	98	size_t i, j, t;
d31fed73	99	if ((inlen & 0x7) \|\| (inlen < 16) \|\| (inlen > CRYPTO128_WRAP_MAX))
97cf1f6c DSH	100	return 0;
	101	A = B;
	102	t = 1;
d31fed73	103	memmove(out + 8, in, inlen);
97cf1f6c DSH	104	if (!iv)
	105	iv = default_iv;
	106
	107	memcpy(A, iv, 8);
	108
	109	for (j = 0; j < 6; j++)
	110	{
	111	R = out + 8;
	112	for (i = 0; i < inlen; i += 8, t++, R += 8)
	113	{
	114	memcpy(B + 8, R, 8);
	115	block(B, B, key);
	116	A[7] ^= (unsigned char)(t & 0xff);
	117	if (t > 0xff)
	118	{
	119	A[6] ^= (unsigned char)((t >> 8) & 0xff);
	120	A[5] ^= (unsigned char)((t >> 16) & 0xff);
	121	A[4] ^= (unsigned char)((t >> 24) & 0xff);
	122	}
	123	memcpy(R, B + 8, 8);
	124	}
	125	}
	126	memcpy(out, A, 8);
	127	return inlen + 8;
	128	}
	129
d31fed73 DSH	130
	131	/** Unwrapping according to RFC 3394 section 2.2.2 steps 1-2.
	132	* IV check (step 3) is responsibility of the caller.
	133	*
	134	* @param[in] key Key value.
	135	* @param[out] iv Unchecked IV value. Minimal buffer length = 8 bytes.
	136	* @param[out] out Plain text without IV.
	137	* Minimal buffer length = (inlen - 8) bytes.
	138	* Input and output buffers can overlap if block function
	139	* supports that.
	140	* @param[in] in Ciphertext text as n 64-bit blocks
	141	* @param[in] inlen Length of in.
	142	* @param[in] block Block processing function.
	143	* @return 0 if inlen is out of range [24, CRYPTO128_WRAP_MAX]
	144	* or if inlen is not multiply of 8.
	145	* Output length otherwise.
	146	*/
	147	static size_t crypto_128_unwrap_raw(void key, unsigned char iv,
	148	unsigned char out, const unsigned char in,
	149	size_t inlen, block128_f block)
97cf1f6c DSH	150	{
	151	unsigned char A, B[16], R;
	152	size_t i, j, t;
	153	inlen -= 8;
d12eef15	154	if ((inlen & 0x7) \|\| (inlen < 16) \|\| (inlen > CRYPTO128_WRAP_MAX))
97cf1f6c DSH	155	return 0;
	156	A = B;
	157	t = 6 * (inlen >> 3);
	158	memcpy(A, in, 8);
d31fed73	159	memmove(out, in + 8, inlen);
97cf1f6c DSH	160	for (j = 0; j < 6; j++)
	161	{
	162	R = out + inlen - 8;
	163	for (i = 0; i < inlen; i += 8, t--, R -= 8)
	164	{
	165	A[7] ^= (unsigned char)(t & 0xff);
	166	if (t > 0xff)
	167	{
	168	A[6] ^= (unsigned char)((t >> 8) & 0xff);
	169	A[5] ^= (unsigned char)((t >> 16) & 0xff);
	170	A[4] ^= (unsigned char)((t >> 24) & 0xff);
	171	}
	172	memcpy(B + 8, R, 8);
	173	block(B, B, key);
	174	memcpy(R, B + 8, 8);
	175	}
	176	}
d31fed73 DSH	177	memcpy(iv, A, 8);
	178	return inlen;
	179	}
	180
	181	/** Unwrapping according to RFC 3394 section 2.2.2 including IV check.
	182	* First block of plain text have to match supplied IV otherwise an error is
	183	* returned.
	184	*
	185	* @param[in] key Key value.
	186	* @param[out] iv Unchecked IV value. Minimal buffer length = 8 bytes.
	187	* @param[out] out Plain text without IV.
	188	* Minimal buffer length = (inlen - 8) bytes.
	189	* Input and output buffers can overlap if block function
	190	* supports that.
	191	* @param[in] in Ciphertext text as n 64-bit blocks
	192	* @param[in] inlen Length of in.
	193	* @param[in] block Block processing function.
	194	* @return 0 if inlen is out of range [24, CRYPTO128_WRAP_MAX]
	195	* or if inlen is not multiply of 8
	196	* or if IV doesn't match expected value.
	197	* Output length otherwise.
	198	*/
	199	size_t CRYPTO_128_unwrap(void key, const unsigned char iv,
	200	unsigned char out, const unsigned char in, size_t inlen,
	201	block128_f block)
	202	{
	203	size_t ret;
	204	unsigned char got_iv[8];
	205
	206	ret = crypto_128_unwrap_raw(key, got_iv, out, in, inlen, block);
	207	if (ret != inlen)
	208	return ret;
	209
97cf1f6c DSH	210	if (!iv)
97cf1f6c DSH	211	iv = default_iv;
d31fed73	212	if (CRYPTO_memcmp(out, iv, 8))
97cf1f6c DSH	213	{
	214	OPENSSL_cleanse(out, inlen);
	215	return 0;
	216	}
	217	return inlen;
	218	}
d31fed73 DSH	219
	220	/** Wrapping according to RFC 5649 section 4.1.
	221	*
	222	* @param[in] key Key value.
	223	* @param[in] icv (Non-standard) IV, 4 bytes. NULL = use default_aiv.
	224	* @param[out] out Cipher text. Minimal buffer length = (inlen + 15) bytes.
	225	* Input and output buffers can overlap if block function
	226	* supports that.
	227	* @param[in] in Plain text as n 64-bit blocks, n >= 2.
	228	* @param[in] inlen Length of in.
	229	* @param[in] block Block processing function.
	230	* @return 0 if inlen is out of range [1, CRYPTO128_WRAP_MAX].
	231	* Output length if wrapping succeeded.
	232	*/
	233	size_t CRYPTO_128_wrap_pad(void key, const unsigned char icv,
	234	unsigned char *out,
	235	const unsigned char *in, size_t inlen, block128_f block)
	236	{
	237	/* n: number of 64-bit blocks in the padded key data */
	238	const size_t blocks_padded = (inlen + 8) / 8;
	239	const size_t padded_len = blocks_padded * 8;
	240	const size_t padding_len = padded_len - inlen;
	241	/* RFC 5649 section 3: Alternative Initial Value */
	242	unsigned char aiv[8];
	243	int ret;
	244
	245	/* Section 1: use 32-bit fixed field for plaintext octet length */
	246	if (inlen == 0 \|\| inlen >= CRYPTO128_WRAP_MAX)
	247	return 0;
	248
	249	/* Section 3: Alternative Initial Value */
	250	if (!icv)
	251	memcpy(aiv, default_aiv, 4);
	252	else
	253	memcpy(aiv, icv, 4); /* Standard doesn't mention this. */
	254
	255	aiv[4] = (inlen >> 24) & 0xFF;
	256	aiv[5] = (inlen >> 16) & 0xFF;
	257	aiv[6] = (inlen >> 8) & 0xFF;
	258	aiv[7] = inlen & 0xFF;
	259
	260	if (padded_len == 8)
	261	{
	262	/* Section 4.1 - special case in step 2:
	263	* If the padded plaintext contains exactly eight octets, then
	264	* prepend the AIV and encrypt the resulting 128-bit block
	265	* using AES in ECB mode. */
	266	memmove(out + 8, in, inlen);
	267	memcpy(out, aiv, 8);
	268	memset(out + 8 + inlen, 0, padding_len);
	269	block(out, out, key);
	270	ret = 16; /* AIV + padded input */
	271	}
	272	else
	273	{
	274	memmove(out, in, inlen);
	275	memset(out + inlen, 0, padding_len); /* Section 4.1 step 1 */
	276	ret = CRYPTO_128_wrap(key, aiv, out, out, padded_len, block);
	277	}
	278
	279	return ret;
	280	}
	281
	282	/** Unwrapping according to RFC 5649 section 4.2.
283	*
284	* @param[in] key Key value.
285	* @param[in] icv (Non-standard) IV, 4 bytes. NULL = use default_aiv.
286	* @param[out] out Plain text. Minimal buffer length = inlen bytes.
287	* Input and output buffers can overlap if block function
288	* supports that.
289	* @param[in] in Ciphertext text as n 64-bit blocks
290	* @param[in] inlen Length of in.
291	* @param[in] block Block processing function.
292	* @return 0 if inlen is out of range [16, CRYPTO128_WRAP_MAX],
293	* or if inlen is not multiply of 8
294	* or if IV and message length indicator doesn't match.
295	* Output length if unwrapping succeeded and IV matches.
296	*/
297	size_t CRYPTO_128_unwrap_pad(void key, const unsigned char icv,
298	unsigned char *out,
299	const unsigned char *in, size_t inlen, block128_f block)
300	{
301	/* n: number of 64-bit blocks in the padded key data */
302	size_t n = inlen / 8 - 1;
303	size_t padded_len;
304	size_t padding_len;
305	size_t ptext_len;
306	/* RFC 5649 section 3: Alternative Initial Value */
307	unsigned char aiv[8];
308	static unsigned char zeros[8] = {0x0};
309	size_t ret;
310
311	/* Section 4.2: Cipher text length has to be (n+1) 64-bit blocks. */
312	if ((inlen & 0x7) != 0 \|\| inlen < 16 \|\| inlen >= CRYPTO128_WRAP_MAX)
313	return 0;
314
315	memmove(out, in, inlen);
316	if (inlen == 16)
317	{
318	/* Section 4.2 - special case in step 1:
319	* When n=1, the ciphertext contains exactly two 64-bit
320	* blocks and they are decrypted as a single AES
321	* block using AES in ECB mode:
322	* AIV \| P[1] = DEC(K, C[0] \| C[1])
323	*/
324	block(out, out, key);
325	memcpy(aiv, out, 8);
326	/* Remove AIV */
327	memmove(out, out + 8, 8);
328	padded_len = 8;
329	}
330	else
331	{
332	padded_len = inlen - 8;
333	ret = crypto_128_unwrap_raw(key, aiv, out, out, inlen, block);
334	if (padded_len != ret)
335	{
336	OPENSSL_cleanse(out, inlen);
337	return 0;
338	}
339	}
340
341	/* Section 3: AIV checks: Check that MSB(32,A) = A65959A6.
342	* Optionally a user-supplied value can be used
343	* (even if standard doesn't mention this). */
344	if ((!icv && CRYPTO_memcmp(aiv, default_aiv, 4))
345	\|\| (icv && CRYPTO_memcmp(aiv, icv, 4)))
346	{
347	OPENSSL_cleanse(out, inlen);
348	return 0;
349	}
350
351	/* Check that 8(n-1) < LSB(32,AIV) <= 8n.
352	* If so, let ptext_len = LSB(32,AIV). */
353
354	ptext_len = (aiv[4] << 24) \| (aiv[5] << 16) \| (aiv[6] << 8) \| aiv[7];
355	if (8(n-1) >= ptext_len \|\| ptext_len > 8n)
356	{
357	OPENSSL_cleanse(out, inlen);
358	return 0;
359	}
360
361	/* Check that the rightmost padding_len octets of the output data
362	* are zero. */
363	padding_len = padded_len - ptext_len;
364	if (CRYPTO_memcmp(out + ptext_len, zeros, padding_len) != 0)
365	{
366	OPENSSL_cleanse(out, inlen);
367	return 0;
368	}
369
370	/* Section 4.2 step 3: Remove padding */
371	return ptext_len;
372	}