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Diffstat (limited to 'crypto/des/ofb_enc.c')
| -rw-r--r-- | crypto/des/ofb_enc.c | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/crypto/des/ofb_enc.c b/crypto/des/ofb_enc.c new file mode 100644 index 0000000000..9b2ecb6749 --- /dev/null +++ b/crypto/des/ofb_enc.c @@ -0,0 +1,122 @@ +/* crypto/des/ofb_enc.c */ +/* Copyright (C) 1995-1997 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.] + */ + +#include "des_locl.h" + +/* The input and output are loaded in multiples of 8 bits. + * What this means is that if you hame numbits=12 and length=2 + * the first 12 bits will be retrieved from the first byte and half + * the second. The second 12 bits will come from the 3rd and half the 4th + * byte. + */ +void des_ofb_encrypt(in, out, numbits, length, schedule, ivec) +unsigned char *in; +unsigned char *out; +int numbits; +long length; +des_key_schedule schedule; +des_cblock (*ivec); + { + register DES_LONG d0,d1,v0,v1,n=(numbits+7)/8; + register DES_LONG mask0,mask1; + register long l=length; + register int num=numbits; + DES_LONG ti[2]; + unsigned char *iv; + + if (num > 64) return; + if (num > 32) + { + mask0=0xffffffffL; + if (num >= 64) + mask1=mask0; + else + mask1=(1L<<(num-32))-1; + } + else + { + if (num == 32) + mask0=0xffffffffL; + else + mask0=(1L<<num)-1; + mask1=0x00000000; + } + + iv=(unsigned char *)ivec; + c2l(iv,v0); + c2l(iv,v1); + ti[0]=v0; + ti[1]=v1; + while (l-- > 0) + { + des_encrypt((DES_LONG *)ti,schedule,DES_ENCRYPT); + c2ln(in,d0,d1,n); + in+=n; + d0=(d0^ti[0])&mask0; + d1=(d1^ti[1])&mask1; + l2cn(d0,d1,out,n); + out+=n; + } + v0=ti[0]; + v1=ti[1]; + iv=(unsigned char *)ivec; + l2c(v0,iv); + l2c(v1,iv); + v0=v1=d0=d1=ti[0]=ti[1]=0; + } + |