freeswan/libcrypto/include/cbc_generic.h

   1 #ifndef _CBC_GENERIC_H
   2 #define _CBC_GENERIC_H
   3 /*
   4  * CBC macro helpers
   5  *
   6  * Author: JuanJo Ciarlante <jjo-ipsec@mendoza.gov.ar>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License as published by the
  10  * Free Software Foundation; either version 2 of the License, or (at your
  11  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  15  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16  * for more details.
  17  *
  18  */
  19
  20 /*
  21  *      Heavily inspired in loop_AES
  22  */
  23 #define CBC_IMPL_BLK16(name, ctx_type, addr_type, enc_func, dec_func) \
  24 int name(ctx_type *ctx, const u_int8_t * in, u_int8_t * out, int ilen, const u_int8_t * iv, int encrypt) { \
  25         int ret=ilen, pos; \
  26         const u_int32_t *iv_i; \
  27         if ((ilen) % 16) return 0; \
  28         if (encrypt) { \
  29                 pos=0; \
  30                 while(pos<ilen) { \
  31                         if (pos==0) \
  32                                 iv_i=(const u_int32_t*) iv; \
  33                         else \
  34                                 iv_i=(const u_int32_t*) (out-16); \
  35                         *((u_int32_t *)(&out[ 0])) = iv_i[0]^*((const u_int32_t *)(&in[ 0])); \
  36                         *((u_int32_t *)(&out[ 4])) = iv_i[1]^*((const u_int32_t *)(&in[ 4])); \
  37                         *((u_int32_t *)(&out[ 8])) = iv_i[2]^*((const u_int32_t *)(&in[ 8])); \
  38                         *((u_int32_t *)(&out[12])) = iv_i[3]^*((const u_int32_t *)(&in[12])); \
  39                         enc_func(ctx, (addr_type) out, (addr_type) out); \
  40                         in+=16; \
  41                         out+=16; \
  42                         pos+=16; \
  43                 } \
  44         } else { \
  45                 pos=ilen-16; \
  46                 in+=pos; \
  47                 out+=pos; \
  48                 while(pos>=0) { \
  49                         dec_func(ctx, (const addr_type) in, (addr_type) out); \
  50                         if (pos==0) \
  51                                 iv_i=(const u_int32_t*) (iv); \
  52                         else \
  53                                 iv_i=(const u_int32_t*) (in-16); \
  54                         *((u_int32_t *)(&out[ 0])) ^= iv_i[0]; \
  55                         *((u_int32_t *)(&out[ 4])) ^= iv_i[1]; \
  56                         *((u_int32_t *)(&out[ 8])) ^= iv_i[2]; \
  57                         *((u_int32_t *)(&out[12])) ^= iv_i[3]; \
  58                         in-=16; \
  59                         out-=16; \
  60                         pos-=16; \
  61                 } \
  62         } \
  63         return ret; \
  64 }
  65 #define CBC_IMPL_BLK8(name, ctx_type, addr_type,  enc_func, dec_func) \
  66 int name(ctx_type *ctx, u_int8_t * in, u_int8_t * out, int ilen, const u_int8_t * iv, int encrypt) { \  int ret=ilen, pos; \
  67         int ret=ilen, pos; \
  68         const u_int32_t *iv_i; \
  69         if ((ilen) % 8) return 0; \
  70         if (encrypt) { \
  71                 pos=0; \
  72                 while(pos<ilen) { \
  73                         if (pos==0) \
  74                                 iv_i=(const u_int32_t*) iv; \
  75                         else \
  76                                 iv_i=(const u_int32_t*) (out-8); \
  77                         *((u_int32_t *)(&out[ 0])) = iv_i[0]^*((const u_int32_t *)(&in[ 0])); \
  78                         *((u_int32_t *)(&out[ 4])) = iv_i[1]^*((const u_int32_t *)(&in[ 4])); \
  79                         enc_func(ctx, (addr_type)out, (addr_type)out); \
  80                         in+=8; \
  81                         out+=8; \
  82                         pos+=8; \
  83                 } \
  84         } else { \
  85                 pos=ilen-8; \
  86                 in+=pos; \
  87                 out+=pos; \
  88                 while(pos>=0) { \
  89                         dec_func(ctx, (const addr_type)in, (addr_type)out); \
  90                         if (pos==0) \
  91                                 iv_i=(const u_int32_t*) (iv); \
  92                         else \
  93                                 iv_i=(const u_int32_t*) (in-8); \
  94                         *((u_int32_t *)(&out[ 0])) ^= iv_i[0]; \
  95                         *((u_int32_t *)(&out[ 4])) ^= iv_i[1]; \
  96                         in-=8; \
  97                         out-=8; \
  98                         pos-=8; \
  99                 } \
 100         } \
 101         return ret; \
 102 }
 103 #define CBC_DECL(name, ctx_type) \
 104 int name(ctx_type *ctx, u_int8_t * in, u_int8_t * out, int ilen, const u_int8_t * iv, int encrypt)
 105 /*
 106 Eg.:
 107 CBC_IMPL_BLK16(AES_cbc_encrypt, aes_context, u_int8_t *, aes_encrypt, aes_decrypt);
 108 CBC_DECL(AES_cbc_encrypt, aes_context);
 109 */
 110 #endif /* _CBC_GENERIC_H */