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Diffstat (limited to 'src/crypto/modes/ofb.c')
-rw-r--r-- | src/crypto/modes/ofb.c | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/src/crypto/modes/ofb.c b/src/crypto/modes/ofb.c new file mode 100644 index 0000000..5836a9f --- /dev/null +++ b/src/crypto/modes/ofb.c @@ -0,0 +1,107 @@ +/* ==================================================================== + * 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 <openssl/modes.h> + +#include <assert.h> + +#include "internal.h" + + +void CRYPTO_ofb128_encrypt(const uint8_t *in, uint8_t *out, size_t len, + const void *key, uint8_t ivec[16], int *num, + block128_f block) { + unsigned int n; + + assert(in && out && key && ivec && num); + assert((16 % sizeof(size_t)) == 0); + + n = *num; + + while (n && len) { + *(out++) = *(in++) ^ ivec[n]; + --len; + n = (n + 1) % 16; + } + +#if STRICT_ALIGNMENT + if (((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) != 0) { + size_t l = 0; + while (l < len) { + if (n == 0) { + (*block)(ivec, ivec, key); + } + out[l] = in[l] ^ ivec[n]; + ++l; + n = (n + 1) % 16; + } + + *num = n; + return; + } +#endif + + while (len >= 16) { + (*block)(ivec, ivec, key); + for (; n < 16; n += sizeof(size_t)) { + *(size_t *)(out + n) = *(size_t *)(in + n) ^ *(size_t *)(ivec + n); + } + len -= 16; + out += 16; + in += 16; + n = 0; + } + if (len) { + (*block)(ivec, ivec, key); + while (len--) { + out[n] = in[n] ^ ivec[n]; + ++n; + } + } + *num = n; +} |