diff options
Diffstat (limited to 'crypto/modes/wrap128.c')
| -rw-r--r-- | crypto/modes/wrap128.c | 313 |
1 files changed, 253 insertions, 60 deletions
diff --git a/crypto/modes/wrap128.c b/crypto/modes/wrap128.c index 384978371af2..d7e56cc260ad 100644 --- a/crypto/modes/wrap128.c +++ b/crypto/modes/wrap128.c @@ -1,70 +1,50 @@ -/* crypto/modes/wrap128.c */ /* - * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL - * project. - */ -/* ==================================================================== - * 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/)" + * Copyright 2013-2018 The OpenSSL Project Authors. All Rights Reserved. * - * 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/)" + * Licensed under the OpenSSL license (the "License"). You may not use + * this file except in compliance with the License. You can obtain a copy + * in the file LICENSE in the source distribution or at + * https://www.openssl.org/source/license.html + */ + +/** Beware! * - * 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. - * ==================================================================== + * 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 "internal/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, }; -/* - * Input size limit: lower than maximum of standards but far larger than - * anything that will be used in practice. +/** 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 Plaintext as n 64-bit blocks, n >= 2. + * @param[in] inlen Length of in. + * @param[out] out Ciphertext. 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, @@ -72,7 +52,7 @@ size_t CRYPTO_128_wrap(void *key, const unsigned char *iv, { unsigned char *A, B[16], *R; size_t i, j, t; - if ((inlen & 0x7) || (inlen < 8) || (inlen > CRYPTO128_WRAP_MAX)) + if ((inlen & 0x7) || (inlen < 16) || (inlen > CRYPTO128_WRAP_MAX)) return 0; A = B; t = 1; @@ -100,10 +80,26 @@ size_t CRYPTO_128_wrap(void *key, const unsigned char *iv, return inlen + 8; } -size_t CRYPTO_128_unwrap(void *key, const unsigned char *iv, - unsigned char *out, - const unsigned char *in, size_t inlen, - block128_f block) +/** Unwrapping according to RFC 3394 section 2.2.2 steps 1-2. + * The 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 Plaintext without IV. + * Minimal buffer length = (inlen - 8) bytes. + * Input and output buffers can overlap if block function + * supports that. + * @param[in] in Ciphertext 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 a multiple 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; @@ -128,11 +124,208 @@ size_t CRYPTO_128_unwrap(void *key, const unsigned char *iv, memcpy(R, B + 8, 8); } } + memcpy(iv, A, 8); + return inlen; +} + +/** Unwrapping according to RFC 3394 section 2.2.2, including the IV check. + * The first block of plaintext has to match the supplied IV, otherwise an + * error is returned. + * + * @param[in] key Key value. + * @param[out] iv IV value to match against. Length = 8 bytes. + * NULL = use default_iv. + * @param[out] out Plaintext without IV. + * Minimal buffer length = (inlen - 8) bytes. + * Input and output buffers can overlap if block function + * supports that. + * @param[in] in Ciphertext 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 a multiple 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 == 0) + return 0; + if (!iv) iv = default_iv; - if (memcmp(A, iv, 8)) { + if (CRYPTO_memcmp(got_iv, iv, 8)) { + OPENSSL_cleanse(out, ret); + return 0; + } + return ret; +} + +/** 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 Ciphertext. Minimal buffer length = (inlen + 15) bytes. + * Input and output buffers can overlap if block function + * supports that. + * @param[in] in Plaintext 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 + * + * If length of plain text is not a multiple of 8, pad the plain text octet + * string on the right with octets of zeros, where final length is the + * smallest multiple of 8 that is greater than length of plain text. + * If length of plain text is a multiple of 8, then there is no padding. */ + const size_t blocks_padded = (inlen + 7) / 8; /* CEILING(m/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 Plaintext. Minimal buffer length = (inlen - 8) bytes. + * Input and output buffers can overlap if block function + * supports that. + * @param[in] in Ciphertext 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 a multiple 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: Ciphertext length has to be (n+1) 64-bit blocks. */ + if ((inlen & 0x7) != 0 || inlen < 16 || inlen >= CRYPTO128_WRAP_MAX) + return 0; + + 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]) + */ + unsigned char buff[16]; + + block(in, buff, key); + memcpy(aiv, buff, 8); + /* Remove AIV */ + memcpy(out, buff + 8, 8); + padded_len = 8; + OPENSSL_cleanse(buff, inlen); + } else { + padded_len = inlen - 8; + ret = crypto_128_unwrap_raw(key, aiv, out, in, 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; } - return inlen; + + /* + * Check that 8*(n-1) < LSB(32,AIV) <= 8*n. If so, let ptext_len = + * LSB(32,AIV). + */ + + ptext_len = ((unsigned int)aiv[4] << 24) + | ((unsigned int)aiv[5] << 16) + | ((unsigned int)aiv[6] << 8) + | (unsigned int)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; } |