| /* ==================================================================== |
| * Copyright (c) 2008 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 |
| * openssl-core@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. |
| * ==================================================================== */ |
| |
| #include <assert.h> |
| #include <string.h> |
| |
| #include "internal.h" |
| |
| |
| void CRYPTO_cbc128_encrypt(const uint8_t *in, uint8_t *out, size_t len, |
| const void *key, uint8_t ivec[16], |
| block128_f block) { |
| size_t n; |
| const uint8_t *iv = ivec; |
| |
| assert(key != NULL && ivec != NULL); |
| assert(len == 0 || (in != NULL && out != NULL)); |
| |
| if (STRICT_ALIGNMENT && |
| ((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) != 0) { |
| while (len >= 16) { |
| for (n = 0; n < 16; ++n) { |
| out[n] = in[n] ^ iv[n]; |
| } |
| (*block)(out, out, key); |
| iv = out; |
| len -= 16; |
| in += 16; |
| out += 16; |
| } |
| } else { |
| while (len >= 16) { |
| for (n = 0; n < 16; n += sizeof(size_t)) { |
| *(size_t *)(out + n) = *(size_t *)(in + n) ^ *(size_t *)(iv + n); |
| } |
| (*block)(out, out, key); |
| iv = out; |
| len -= 16; |
| in += 16; |
| out += 16; |
| } |
| } |
| |
| while (len) { |
| for (n = 0; n < 16 && n < len; ++n) { |
| out[n] = in[n] ^ iv[n]; |
| } |
| for (; n < 16; ++n) { |
| out[n] = iv[n]; |
| } |
| (*block)(out, out, key); |
| iv = out; |
| if (len <= 16) { |
| break; |
| } |
| len -= 16; |
| in += 16; |
| out += 16; |
| } |
| |
| memcpy(ivec, iv, 16); |
| } |
| |
| void CRYPTO_cbc128_decrypt(const uint8_t *in, uint8_t *out, size_t len, |
| const void *key, uint8_t ivec[16], |
| block128_f block) { |
| size_t n; |
| union { |
| size_t t[16 / sizeof(size_t)]; |
| uint8_t c[16]; |
| } tmp; |
| |
| assert(key != NULL && ivec != NULL); |
| assert(len == 0 || (in != NULL && out != NULL)); |
| |
| const uintptr_t inptr = (uintptr_t) in; |
| const uintptr_t outptr = (uintptr_t) out; |
| /* If |in| and |out| alias, |in| must be ahead. */ |
| assert(inptr >= outptr || inptr + len <= outptr); |
| |
| if ((inptr >= 32 && outptr <= inptr - 32) || inptr < outptr) { |
| /* If |out| is at least two blocks behind |in| or completely disjoint, there |
| * is no need to decrypt to a temporary block. */ |
| const uint8_t *iv = ivec; |
| |
| if (STRICT_ALIGNMENT && |
| ((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) != 0) { |
| while (len >= 16) { |
| (*block)(in, out, key); |
| for (n = 0; n < 16; ++n) { |
| out[n] ^= iv[n]; |
| } |
| iv = in; |
| len -= 16; |
| in += 16; |
| out += 16; |
| } |
| } else if (16 % sizeof(size_t) == 0) { /* always true */ |
| while (len >= 16) { |
| size_t *out_t = (size_t *)out, *iv_t = (size_t *)iv; |
| |
| (*block)(in, out, key); |
| for (n = 0; n < 16 / sizeof(size_t); n++) { |
| out_t[n] ^= iv_t[n]; |
| } |
| iv = in; |
| len -= 16; |
| in += 16; |
| out += 16; |
| } |
| } |
| memcpy(ivec, iv, 16); |
| } else { |
| /* |out| is less than two blocks behind |in|. Decrypting an input block |
| * directly to |out| would overwrite a ciphertext block before it is used as |
| * the next block's IV. Decrypt to a temporary block instead. */ |
| if (STRICT_ALIGNMENT && |
| ((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) != 0) { |
| uint8_t c; |
| while (len >= 16) { |
| (*block)(in, tmp.c, key); |
| for (n = 0; n < 16; ++n) { |
| c = in[n]; |
| out[n] = tmp.c[n] ^ ivec[n]; |
| ivec[n] = c; |
| } |
| len -= 16; |
| in += 16; |
| out += 16; |
| } |
| } else if (16 % sizeof(size_t) == 0) { /* always true */ |
| while (len >= 16) { |
| size_t c, *out_t = (size_t *)out, *ivec_t = (size_t *)ivec; |
| const size_t *in_t = (const size_t *)in; |
| |
| (*block)(in, tmp.c, key); |
| for (n = 0; n < 16 / sizeof(size_t); n++) { |
| c = in_t[n]; |
| out_t[n] = tmp.t[n] ^ ivec_t[n]; |
| ivec_t[n] = c; |
| } |
| len -= 16; |
| in += 16; |
| out += 16; |
| } |
| } |
| } |
| |
| while (len) { |
| uint8_t c; |
| (*block)(in, tmp.c, key); |
| for (n = 0; n < 16 && n < len; ++n) { |
| c = in[n]; |
| out[n] = tmp.c[n] ^ ivec[n]; |
| ivec[n] = c; |
| } |
| if (len <= 16) { |
| for (; n < 16; ++n) { |
| ivec[n] = in[n]; |
| } |
| break; |
| } |
| len -= 16; |
| in += 16; |
| out += 16; |
| } |
| } |