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Diffstat (limited to 'openssl/crypto/aes/aes_cfb.c')
| -rw-r--r-- | openssl/crypto/aes/aes_cfb.c | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/openssl/crypto/aes/aes_cfb.c b/openssl/crypto/aes/aes_cfb.c new file mode 100644 index 000000000..49f041101 --- /dev/null +++ b/openssl/crypto/aes/aes_cfb.c @@ -0,0 +1,225 @@ +/* crypto/aes/aes_cfb.c -*- mode:C; c-file-style: "eay" -*- */ +/* ==================================================================== + * Copyright (c) 1998-2002 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. + * ==================================================================== + * + */ +/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) + * All rights reserved. + * + * This package is an SSL implementation written + * by Eric Young (eay@cryptsoft.com). + * The implementation was written so as to conform with Netscapes SSL. + * + * This library is free for commercial and non-commercial use as long as + * the following conditions are aheared to. The following conditions + * apply to all code found in this distribution, be it the RC4, RSA, + * lhash, DES, etc., code; not just the SSL code. The SSL documentation + * included with this distribution is covered by the same copyright terms + * except that the holder is Tim Hudson (tjh@cryptsoft.com). + * + * Copyright remains Eric Young's, and as such any Copyright notices in + * the code are not to be removed. + * If this package is used in a product, Eric Young should be given attribution + * as the author of the parts of the library used. + * This can be in the form of a textual message at program startup or + * in documentation (online or textual) provided with the package. + * + * 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 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 acknowledgement: + * "This product includes cryptographic software written by + * Eric Young (eay@cryptsoft.com)" + * The word 'cryptographic' can be left out if the rouines from the library + * being used are not cryptographic related :-). + * 4. If you include any Windows specific code (or a derivative thereof) from + * the apps directory (application code) you must include an acknowledgement: + * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" + * + * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND + * ANY EXPRESS 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 AUTHOR OR 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. + * + * The licence and distribution terms for any publically available version or + * derivative of this code cannot be changed. i.e. this code cannot simply be + * copied and put under another distribution licence + * [including the GNU Public Licence.] + */ + +#ifndef AES_DEBUG +# ifndef NDEBUG +# define NDEBUG +# endif +#endif +#include <assert.h> + +#include <openssl/aes.h> +#include "aes_locl.h" +#include "e_os.h" + +/* The input and output encrypted as though 128bit cfb mode is being + * used. The extra state information to record how much of the + * 128bit block we have used is contained in *num; + */ + +void AES_cfb128_encrypt(const unsigned char *in, unsigned char *out, + const unsigned long length, const AES_KEY *key, + unsigned char *ivec, int *num, const int enc) { + + unsigned int n; + unsigned long l = length; + unsigned char c; + + assert(in && out && key && ivec && num); + + n = *num; + + if (enc) { + while (l--) { + if (n == 0) { + AES_encrypt(ivec, ivec, key); + } + ivec[n] = *(out++) = *(in++) ^ ivec[n]; + n = (n+1) % AES_BLOCK_SIZE; + } + } else { + while (l--) { + if (n == 0) { + AES_encrypt(ivec, ivec, key); + } + c = *(in); + *(out++) = *(in++) ^ ivec[n]; + ivec[n] = c; + n = (n+1) % AES_BLOCK_SIZE; + } + } + + *num=n; +} + +/* This expects a single block of size nbits for both in and out. Note that + it corrupts any extra bits in the last byte of out */ +void AES_cfbr_encrypt_block(const unsigned char *in,unsigned char *out, + const int nbits,const AES_KEY *key, + unsigned char *ivec,const int enc) + { + int n,rem,num; + unsigned char ovec[AES_BLOCK_SIZE*2]; + + if (nbits<=0 || nbits>128) return; + + /* fill in the first half of the new IV with the current IV */ + memcpy(ovec,ivec,AES_BLOCK_SIZE); + /* construct the new IV */ + AES_encrypt(ivec,ivec,key); + num = (nbits+7)/8; + if (enc) /* encrypt the input */ + for(n=0 ; n < num ; ++n) + out[n] = (ovec[AES_BLOCK_SIZE+n] = in[n] ^ ivec[n]); + else /* decrypt the input */ + for(n=0 ; n < num ; ++n) + out[n] = (ovec[AES_BLOCK_SIZE+n] = in[n]) ^ ivec[n]; + /* shift ovec left... */ + rem = nbits%8; + num = nbits/8; + if(rem==0) + memcpy(ivec,ovec+num,AES_BLOCK_SIZE); + else + for(n=0 ; n < AES_BLOCK_SIZE ; ++n) + ivec[n] = ovec[n+num]<<rem | ovec[n+num+1]>>(8-rem); + + /* it is not necessary to cleanse ovec, since the IV is not secret */ + } + +/* N.B. This expects the input to be packed, MS bit first */ +void AES_cfb1_encrypt(const unsigned char *in, unsigned char *out, + const unsigned long length, const AES_KEY *key, + unsigned char *ivec, int *num, const int enc) + { + unsigned int n; + unsigned char c[1],d[1]; + + assert(in && out && key && ivec && num); + assert(*num == 0); + + memset(out,0,(length+7)/8); + for(n=0 ; n < length ; ++n) + { + c[0]=(in[n/8]&(1 << (7-n%8))) ? 0x80 : 0; + AES_cfbr_encrypt_block(c,d,1,key,ivec,enc); + out[n/8]=(out[n/8]&~(1 << (7-n%8)))|((d[0]&0x80) >> (n%8)); + } + } + +void AES_cfb8_encrypt(const unsigned char *in, unsigned char *out, + const unsigned long length, const AES_KEY *key, + unsigned char *ivec, int *num, const int enc) + { + unsigned int n; + + assert(in && out && key && ivec && num); + assert(*num == 0); + + for(n=0 ; n < length ; ++n) + AES_cfbr_encrypt_block(&in[n],&out[n],8,key,ivec,enc); + } + |