/* * FIPS-46-3 compliant Triple-DES implementation * * Copyright (C) 2006-2007 Christophe Devine * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License, version 2.1 as published by the Free Software Foundation. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, * MA 02110-1301 USA */ /* * DES, on which TDES is based, was originally designed by IBM in * 1974 and adopted as a standard by NIST (formerly NBS). * * http://csrc.nist.gov/publications/fips/fips46-3/fips46-3.pdf */ #ifndef __GNUC__ #pragma hdrstop #endif #ifndef _CRT_SECURE_NO_DEPRECATE #define _CRT_SECURE_NO_DEPRECATE 1 #endif #include #include "des.h" /* * 32-bit integer manipulation macros (big endian) */ #ifndef GET_UINT32_BE #define GET_UINT32_BE(n,b,i) \ { \ (n) = ( (unsigned long) (b)[(i) ] << 24 ) \ | ( (unsigned long) (b)[(i) + 1] << 16 ) \ | ( (unsigned long) (b)[(i) + 2] << 8 ) \ | ( (unsigned long) (b)[(i) + 3] ); \ } #endif #ifndef PUT_UINT32_BE #define PUT_UINT32_BE(n,b,i) \ { \ (b)[(i) ] = (unsigned char) ( (n) >> 24 ); \ (b)[(i) + 1] = (unsigned char) ( (n) >> 16 ); \ (b)[(i) + 2] = (unsigned char) ( (n) >> 8 ); \ (b)[(i) + 3] = (unsigned char) ( (n) ); \ } #endif /* * Expanded DES S-boxes */ static const unsigned long SB1[64] = { 0x01010400, 0x00000000, 0x00010000, 0x01010404, 0x01010004, 0x00010404, 0x00000004, 0x00010000, 0x00000400, 0x01010400, 0x01010404, 0x00000400, 0x01000404, 0x01010004, 0x01000000, 0x00000004, 0x00000404, 0x01000400, 0x01000400, 0x00010400, 0x00010400, 0x01010000, 0x01010000, 0x01000404, 0x00010004, 0x01000004, 0x01000004, 0x00010004, 0x00000000, 0x00000404, 0x00010404, 0x01000000, 0x00010000, 0x01010404, 0x00000004, 0x01010000, 0x01010400, 0x01000000, 0x01000000, 0x00000400, 0x01010004, 0x00010000, 0x00010400, 0x01000004, 0x00000400, 0x00000004, 0x01000404, 0x00010404, 0x01010404, 0x00010004, 0x01010000, 0x01000404, 0x01000004, 0x00000404, 0x00010404, 0x01010400, 0x00000404, 0x01000400, 0x01000400, 0x00000000, 0x00010004, 0x00010400, 0x00000000, 0x01010004 }; static const unsigned long SB2[64] = { 0x80108020, 0x80008000, 0x00008000, 0x00108020, 0x00100000, 0x00000020, 0x80100020, 0x80008020, 0x80000020, 0x80108020, 0x80108000, 0x80000000, 0x80008000, 0x00100000, 0x00000020, 0x80100020, 0x00108000, 0x00100020, 0x80008020, 0x00000000, 0x80000000, 0x00008000, 0x00108020, 0x80100000, 0x00100020, 0x80000020, 0x00000000, 0x00108000, 0x00008020, 0x80108000, 0x80100000, 0x00008020, 0x00000000, 0x00108020, 0x80100020, 0x00100000, 0x80008020, 0x80100000, 0x80108000, 0x00008000, 0x80100000, 0x80008000, 0x00000020, 0x80108020, 0x00108020, 0x00000020, 0x00008000, 0x80000000, 0x00008020, 0x80108000, 0x00100000, 0x80000020, 0x00100020, 0x80008020, 0x80000020, 0x00100020, 0x00108000, 0x00000000, 0x80008000, 0x00008020, 0x80000000, 0x80100020, 0x80108020, 0x00108000 }; static const unsigned long SB3[64] = { 0x00000208, 0x08020200, 0x00000000, 0x08020008, 0x08000200, 0x00000000, 0x00020208, 0x08000200, 0x00020008, 0x08000008, 0x08000008, 0x00020000, 0x08020208, 0x00020008, 0x08020000, 0x00000208, 0x08000000, 0x00000008, 0x08020200, 0x00000200, 0x00020200, 0x08020000, 0x08020008, 0x00020208, 0x08000208, 0x00020200, 0x00020000, 0x08000208, 0x00000008, 0x08020208, 0x00000200, 0x08000000, 0x08020200, 0x08000000, 0x00020008, 0x00000208, 0x00020000, 0x08020200, 0x08000200, 0x00000000, 0x00000200, 0x00020008, 0x08020208, 0x08000200, 0x08000008, 0x00000200, 0x00000000, 0x08020008, 0x08000208, 0x00020000, 0x08000000, 0x08020208, 0x00000008, 0x00020208, 0x00020200, 0x08000008, 0x08020000, 0x08000208, 0x00000208, 0x08020000, 0x00020208, 0x00000008, 0x08020008, 0x00020200 }; static const unsigned long SB4[64] = { 0x00802001, 0x00002081, 0x00002081, 0x00000080, 0x00802080, 0x00800081, 0x00800001, 0x00002001, 0x00000000, 0x00802000, 0x00802000, 0x00802081, 0x00000081, 0x00000000, 0x00800080, 0x00800001, 0x00000001, 0x00002000, 0x00800000, 0x00802001, 0x00000080, 0x00800000, 0x00002001, 0x00002080, 0x00800081, 0x00000001, 0x00002080, 0x00800080, 0x00002000, 0x00802080, 0x00802081, 0x00000081, 0x00800080, 0x00800001, 0x00802000, 0x00802081, 0x00000081, 0x00000000, 0x00000000, 0x00802000, 0x00002080, 0x00800080, 0x00800081, 0x00000001, 0x00802001, 0x00002081, 0x00002081, 0x00000080, 0x00802081, 0x00000081, 0x00000001, 0x00002000, 0x00800001, 0x00002001, 0x00802080, 0x00800081, 0x00002001, 0x00002080, 0x00800000, 0x00802001, 0x00000080, 0x00800000, 0x00002000, 0x00802080 }; static const unsigned long SB5[64] = { 0x00000100, 0x02080100, 0x02080000, 0x42000100, 0x00080000, 0x00000100, 0x40000000, 0x02080000, 0x40080100, 0x00080000, 0x02000100, 0x40080100, 0x42000100, 0x42080000, 0x00080100, 0x40000000, 0x02000000, 0x40080000, 0x40080000, 0x00000000, 0x40000100, 0x42080100, 0x42080100, 0x02000100, 0x42080000, 0x40000100, 0x00000000, 0x42000000, 0x02080100, 0x02000000, 0x42000000, 0x00080100, 0x00080000, 0x42000100, 0x00000100, 0x02000000, 0x40000000, 0x02080000, 0x42000100, 0x40080100, 0x02000100, 0x40000000, 0x42080000, 0x02080100, 0x40080100, 0x00000100, 0x02000000, 0x42080000, 0x42080100, 0x00080100, 0x42000000, 0x42080100, 0x02080000, 0x00000000, 0x40080000, 0x42000000, 0x00080100, 0x02000100, 0x40000100, 0x00080000, 0x00000000, 0x40080000, 0x02080100, 0x40000100 }; static const unsigned long SB6[64] = { 0x20000010, 0x20400000, 0x00004000, 0x20404010, 0x20400000, 0x00000010, 0x20404010, 0x00400000, 0x20004000, 0x00404010, 0x00400000, 0x20000010, 0x00400010, 0x20004000, 0x20000000, 0x00004010, 0x00000000, 0x00400010, 0x20004010, 0x00004000, 0x00404000, 0x20004010, 0x00000010, 0x20400010, 0x20400010, 0x00000000, 0x00404010, 0x20404000, 0x00004010, 0x00404000, 0x20404000, 0x20000000, 0x20004000, 0x00000010, 0x20400010, 0x00404000, 0x20404010, 0x00400000, 0x00004010, 0x20000010, 0x00400000, 0x20004000, 0x20000000, 0x00004010, 0x20000010, 0x20404010, 0x00404000, 0x20400000, 0x00404010, 0x20404000, 0x00000000, 0x20400010, 0x00000010, 0x00004000, 0x20400000, 0x00404010, 0x00004000, 0x00400010, 0x20004010, 0x00000000, 0x20404000, 0x20000000, 0x00400010, 0x20004010 }; static const unsigned long SB7[64] = { 0x00200000, 0x04200002, 0x04000802, 0x00000000, 0x00000800, 0x04000802, 0x00200802, 0x04200800, 0x04200802, 0x00200000, 0x00000000, 0x04000002, 0x00000002, 0x04000000, 0x04200002, 0x00000802, 0x04000800, 0x00200802, 0x00200002, 0x04000800, 0x04000002, 0x04200000, 0x04200800, 0x00200002, 0x04200000, 0x00000800, 0x00000802, 0x04200802, 0x00200800, 0x00000002, 0x04000000, 0x00200800, 0x04000000, 0x00200800, 0x00200000, 0x04000802, 0x04000802, 0x04200002, 0x04200002, 0x00000002, 0x00200002, 0x04000000, 0x04000800, 0x00200000, 0x04200800, 0x00000802, 0x00200802, 0x04200800, 0x00000802, 0x04000002, 0x04200802, 0x04200000, 0x00200800, 0x00000000, 0x00000002, 0x04200802, 0x00000000, 0x00200802, 0x04200000, 0x00000800, 0x04000002, 0x04000800, 0x00000800, 0x00200002 }; static const unsigned long SB8[64] = { 0x10001040, 0x00001000, 0x00040000, 0x10041040, 0x10000000, 0x10001040, 0x00000040, 0x10000000, 0x00040040, 0x10040000, 0x10041040, 0x00041000, 0x10041000, 0x00041040, 0x00001000, 0x00000040, 0x10040000, 0x10000040, 0x10001000, 0x00001040, 0x00041000, 0x00040040, 0x10040040, 0x10041000, 0x00001040, 0x00000000, 0x00000000, 0x10040040, 0x10000040, 0x10001000, 0x00041040, 0x00040000, 0x00041040, 0x00040000, 0x10041000, 0x00001000, 0x00000040, 0x10040040, 0x00001000, 0x00041040, 0x10001000, 0x00000040, 0x10000040, 0x10040000, 0x10040040, 0x10000000, 0x00040000, 0x10001040, 0x00000000, 0x10041040, 0x00040040, 0x10000040, 0x10040000, 0x10001000, 0x10001040, 0x00000000, 0x10041040, 0x00041000, 0x00041000, 0x00001040, 0x00001040, 0x00040040, 0x10000000, 0x10041000 }; /* * PC1: left and right halves bit-swap */ static const unsigned long LHs[16] = { 0x00000000, 0x00000001, 0x00000100, 0x00000101, 0x00010000, 0x00010001, 0x00010100, 0x00010101, 0x01000000, 0x01000001, 0x01000100, 0x01000101, 0x01010000, 0x01010001, 0x01010100, 0x01010101 }; static const unsigned long RHs[16] = { 0x00000000, 0x01000000, 0x00010000, 0x01010000, 0x00000100, 0x01000100, 0x00010100, 0x01010100, 0x00000001, 0x01000001, 0x00010001, 0x01010001, 0x00000101, 0x01000101, 0x00010101, 0x01010101, }; /* * Initial Permutation macro */ #define DES_IP(X,Y) \ { \ T = ((X >> 4) ^ Y) & 0x0F0F0F0F; Y ^= T; X ^= (T << 4); \ T = ((X >> 16) ^ Y) & 0x0000FFFF; Y ^= T; X ^= (T << 16); \ T = ((Y >> 2) ^ X) & 0x33333333; X ^= T; Y ^= (T << 2); \ T = ((Y >> 8) ^ X) & 0x00FF00FF; X ^= T; Y ^= (T << 8); \ Y = ((Y << 1) | (Y >> 31)) & 0xFFFFFFFF; \ T = (X ^ Y) & 0xAAAAAAAA; Y ^= T; X ^= T; \ X = ((X << 1) | (X >> 31)) & 0xFFFFFFFF; \ } /* * Final Permutation macro */ #define DES_FP(X,Y) \ { \ X = ((X << 31) | (X >> 1)) & 0xFFFFFFFF; \ T = (X ^ Y) & 0xAAAAAAAA; X ^= T; Y ^= T; \ Y = ((Y << 31) | (Y >> 1)) & 0xFFFFFFFF; \ T = ((Y >> 8) ^ X) & 0x00FF00FF; X ^= T; Y ^= (T << 8); \ T = ((Y >> 2) ^ X) & 0x33333333; X ^= T; Y ^= (T << 2); \ T = ((X >> 16) ^ Y) & 0x0000FFFF; Y ^= T; X ^= (T << 16); \ T = ((X >> 4) ^ Y) & 0x0F0F0F0F; Y ^= T; X ^= (T << 4); \ } /* * DES round macro */ #define DES_ROUND(X,Y) \ { \ T = *SK++ ^ X; \ Y ^= SB8[ (T ) & 0x3F ] ^ \ SB6[ (T >> 8) & 0x3F ] ^ \ SB4[ (T >> 16) & 0x3F ] ^ \ SB2[ (T >> 24) & 0x3F ]; \ \ T = *SK++ ^ ((X << 28) | (X >> 4)); \ Y ^= SB7[ (T ) & 0x3F ] ^ \ SB5[ (T >> 8) & 0x3F ] ^ \ SB3[ (T >> 16) & 0x3F ] ^ \ SB1[ (T >> 24) & 0x3F ]; \ } static void des_main_ks( unsigned long SK[32], unsigned char key[8] ) { int i; unsigned long X, Y, T; GET_UINT32_BE( X, key, 0 ); GET_UINT32_BE( Y, key, 4 ); /* * Permuted Choice 1 */ T = ((Y >> 4) ^ X) & 0x0F0F0F0F; X ^= T; Y ^= (T << 4); T = ((Y ) ^ X) & 0x10101010; X ^= T; Y ^= (T ); X = (LHs[ (X ) & 0xF] << 3) | (LHs[ (X >> 8) & 0xF ] << 2) | (LHs[ (X >> 16) & 0xF] << 1) | (LHs[ (X >> 24) & 0xF ] ) | (LHs[ (X >> 5) & 0xF] << 7) | (LHs[ (X >> 13) & 0xF ] << 6) | (LHs[ (X >> 21) & 0xF] << 5) | (LHs[ (X >> 29) & 0xF ] << 4); Y = (RHs[ (Y >> 1) & 0xF] << 3) | (RHs[ (Y >> 9) & 0xF ] << 2) | (RHs[ (Y >> 17) & 0xF] << 1) | (RHs[ (Y >> 25) & 0xF ] ) | (RHs[ (Y >> 4) & 0xF] << 7) | (RHs[ (Y >> 12) & 0xF ] << 6) | (RHs[ (Y >> 20) & 0xF] << 5) | (RHs[ (Y >> 28) & 0xF ] << 4); X &= 0x0FFFFFFF; Y &= 0x0FFFFFFF; /* * calculate subkeys */ for( i = 0; i < 16; i++ ) { if( i < 2 || i == 8 || i == 15 ) { X = ((X << 1) | (X >> 27)) & 0x0FFFFFFF; Y = ((Y << 1) | (Y >> 27)) & 0x0FFFFFFF; } else { X = ((X << 2) | (X >> 26)) & 0x0FFFFFFF; Y = ((Y << 2) | (Y >> 26)) & 0x0FFFFFFF; } *SK++ = ((X << 4) & 0x24000000) | ((X << 28) & 0x10000000) | ((X << 14) & 0x08000000) | ((X << 18) & 0x02080000) | ((X << 6) & 0x01000000) | ((X << 9) & 0x00200000) | ((X >> 1) & 0x00100000) | ((X << 10) & 0x00040000) | ((X << 2) & 0x00020000) | ((X >> 10) & 0x00010000) | ((Y >> 13) & 0x00002000) | ((Y >> 4) & 0x00001000) | ((Y << 6) & 0x00000800) | ((Y >> 1) & 0x00000400) | ((Y >> 14) & 0x00000200) | ((Y ) & 0x00000100) | ((Y >> 5) & 0x00000020) | ((Y >> 10) & 0x00000010) | ((Y >> 3) & 0x00000008) | ((Y >> 18) & 0x00000004) | ((Y >> 26) & 0x00000002) | ((Y >> 24) & 0x00000001); *SK++ = ((X << 15) & 0x20000000) | ((X << 17) & 0x10000000) | ((X << 10) & 0x08000000) | ((X << 22) & 0x04000000) | ((X >> 2) & 0x02000000) | ((X << 1) & 0x01000000) | ((X << 16) & 0x00200000) | ((X << 11) & 0x00100000) | ((X << 3) & 0x00080000) | ((X >> 6) & 0x00040000) | ((X << 15) & 0x00020000) | ((X >> 4) & 0x00010000) | ((Y >> 2) & 0x00002000) | ((Y << 8) & 0x00001000) | ((Y >> 14) & 0x00000808) | ((Y >> 9) & 0x00000400) | ((Y ) & 0x00000200) | ((Y << 7) & 0x00000100) | ((Y >> 7) & 0x00000020) | ((Y >> 3) & 0x00000011) | ((Y << 2) & 0x00000004) | ((Y >> 21) & 0x00000002); } } /* * DES key schedule (56-bit) */ void des_set_key( des_context *ctx, unsigned char key[8] ) { int i; des_main_ks( ctx->esk, key ); for( i = 0; i < 32; i += 2 ) { ctx->dsk[i ] = ctx->esk[30 - i]; ctx->dsk[i + 1] = ctx->esk[31 - i]; } } static void des_crypt( unsigned long SK[32], unsigned char input[8], unsigned char output[8] ) { unsigned long X, Y, T; GET_UINT32_BE( X, input, 0 ); GET_UINT32_BE( Y, input, 4 ); DES_IP( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_FP( Y, X ); PUT_UINT32_BE( Y, output, 0 ); PUT_UINT32_BE( X, output, 4 ); } /* * DES block encryption (ECB mode) */ void des_encrypt( des_context *ctx, unsigned char input[8], unsigned char output[8] ) { des_crypt( ctx->esk, input, output ); } /* * DES block decryption (ECB mode) */ void des_decrypt( des_context *ctx, unsigned char input[8], unsigned char output[8] ) { des_crypt( ctx->dsk, input, output ); } /* * DES-CBC buffer encryption */ void des_cbc_encrypt( des_context *ctx, unsigned char iv[8], unsigned char *input, unsigned char *output, int len ) { int i; while( len > 0 ) { for( i = 0; i < 8; i++ ) output[i] = input[i] ^ iv[i]; des_crypt( ctx->esk, output, output ); memcpy( iv, output, 8 ); input += 8; output += 8; len -= 8; } } /* * DES-CBC buffer decryption */ void des_cbc_decrypt( des_context *ctx, unsigned char iv[8], unsigned char *input, unsigned char *output, int len ) { int i; unsigned char temp[8]; while( len > 0 ) { memcpy( temp, input, 8 ); des_crypt( ctx->dsk, input, output ); for( i = 0; i < 8; i++ ) output[i] = output[i] ^ iv[i]; memcpy( iv, temp, 8 ); input += 8; output += 8; len -= 8; } } /* * Triple-DES key schedule (112-bit) */ void des3_set_2keys( des3_context *ctx, unsigned char key[16] ) { int i; des_main_ks( ctx->esk , key ); des_main_ks( ctx->dsk + 32, key + 8 ); for( i = 0; i < 32; i += 2 ) { ctx->dsk[i ] = ctx->esk[30 - i]; ctx->dsk[i + 1] = ctx->esk[31 - i]; ctx->esk[i + 32] = ctx->dsk[62 - i]; ctx->esk[i + 33] = ctx->dsk[63 - i]; ctx->esk[i + 64] = ctx->esk[ i]; ctx->esk[i + 65] = ctx->esk[ 1 + i]; ctx->dsk[i + 64] = ctx->dsk[ i]; ctx->dsk[i + 65] = ctx->dsk[ 1 + i]; } } /* * Triple-DES key schedule (168-bit) */ void des3_set_3keys( des3_context *ctx, unsigned char key[24] ) { int i; des_main_ks( ctx->esk , key ); des_main_ks( ctx->dsk + 32, key + 8 ); des_main_ks( ctx->esk + 64, key + 16 ); for( i = 0; i < 32; i += 2 ) { ctx->dsk[i ] = ctx->esk[94 - i]; ctx->dsk[i + 1] = ctx->esk[95 - i]; ctx->esk[i + 32] = ctx->dsk[62 - i]; ctx->esk[i + 33] = ctx->dsk[63 - i]; ctx->dsk[i + 64] = ctx->esk[30 - i]; ctx->dsk[i + 65] = ctx->esk[31 - i]; } } static void des3_crypt( unsigned long SK[96], unsigned char input[8], unsigned char output[8] ) { unsigned long X, Y, T; GET_UINT32_BE( X, input, 0 ); GET_UINT32_BE( Y, input, 4 ); DES_IP( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_ROUND( Y, X ); DES_ROUND( X, Y ); DES_FP( Y, X ); PUT_UINT32_BE( Y, output, 0 ); PUT_UINT32_BE( X, output, 4 ); } /* * Triple-DES block encryption (ECB mode) */ void des3_encrypt( des3_context *ctx, unsigned char input[8], unsigned char output[8] ) { des3_crypt( ctx->esk, input, output ); } /* * Triple-DES block decryption (ECB mode) */ void des3_decrypt( des3_context *ctx, unsigned char input[8], unsigned char output[8] ) { des3_crypt( ctx->dsk, input, output ); } /* * 3DES-CBC buffer encryption */ void des3_cbc_encrypt( des3_context *ctx, unsigned char iv[8], unsigned char *input, unsigned char *output, int len ) { int i; while( len > 0 ) { for( i = 0; i < 8; i++ ) output[i] = input[i] ^ iv[i]; des3_crypt( ctx->esk, output, output ); memcpy( iv, output, 8 ); input += 8; output += 8; len -= 8; } } /* * 3DES-CBC buffer decryption */ void des3_cbc_decrypt( des3_context *ctx, unsigned char iv[8], unsigned char *input, unsigned char *output, int len ) { int i; unsigned char temp[8]; while( len > 0 ) { memcpy( temp, input, 8 ); des3_crypt( ctx->dsk, input, output ); for( i = 0; i < 8; i++ ) output[i] = output[i] ^ iv[i]; memcpy( iv, temp, 8 ); input += 8; output += 8; len -= 8; } }