gost_omac.c

   1 #include <string.h>
   2 #include <openssl/cmac.h>
   3 #include <openssl/conf.h>
   4 #include <openssl/err.h>
   5 #include <openssl/evp.h>
   6
   7 #include "e_gost_err.h"
   8 #include "gost_lcl.h"
   9
  10 #define min(a,b) (((a) < (b)) ? (a) : (b))
  11
  12 typedef struct omac_ctx {
  13         CMAC_CTX *cmac_ctx;
  14         size_t   dgst_size;
  15         int      cipher_nid;
  16         int      key_set;
  17 } OMAC_CTX;
  18
  19 #define MAX_GOST_OMAC_SIZE 16
  20
  21 static int omac_init(EVP_MD_CTX *ctx, int cipher_nid)
  22 {
  23     OMAC_CTX *c = EVP_MD_CTX_md_data(ctx);
  24                 memset(c, 0, sizeof(OMAC_CTX));
  25                 c->cipher_nid = cipher_nid;
  26                 c->key_set    = 0;
  27
  28                 switch(cipher_nid) {
  29                         case NID_magma_cbc:
  30                                 c->dgst_size = 4;
  31                         break;
  32
  33                         case NID_grasshopper_cbc:
  34                                 c->dgst_size = 8;
  35                         break;
  36                 }
  37
  38     return 1;
  39 }
  40
  41 static int magma_imit_init(EVP_MD_CTX *ctx)
  42 {
  43     return omac_init(ctx, NID_magma_cbc);
  44 }
  45
  46 static int grasshopper_imit_init(EVP_MD_CTX *ctx)
  47 {
  48     return omac_init(ctx, NID_grasshopper_cbc);
  49 }
  50
  51 static int omac_imit_update(EVP_MD_CTX *ctx, const void *data, size_t count)
  52 {
  53     OMAC_CTX *c = EVP_MD_CTX_md_data(ctx);
  54                 if (!c->key_set)
  55                 {
  56         GOSTerr(GOST_F_OMAC_IMIT_UPDATE, GOST_R_MAC_KEY_NOT_SET);
  57         return 0;
  58                 }
  59
  60                 return CMAC_Update(c->cmac_ctx, data, count);
  61 }
  62
  63 int omac_imit_final(EVP_MD_CTX *ctx, unsigned char *md)
  64 {
  65     OMAC_CTX *c = EVP_MD_CTX_md_data(ctx);
  66                 unsigned char mac[MAX_GOST_OMAC_SIZE];
  67                 size_t mac_size = sizeof(mac);
  68
  69     if (!c->key_set) {
  70         GOSTerr(GOST_F_OMAC_IMIT_FINAL, GOST_R_MAC_KEY_NOT_SET);
  71         return 0;
  72     }
  73
  74                 CMAC_Final(c->cmac_ctx, mac, &mac_size);
  75
  76     int md_size = EVP_MD_meth_get_result_size(EVP_MD_CTX_md(ctx));
  77     memcpy(md, mac, min(md_size, c->dgst_size));
  78     return 1;
  79 }
  80
  81 int omac_imit_copy(EVP_MD_CTX *to, const EVP_MD_CTX *from)
  82 {
  83     OMAC_CTX *c_to = EVP_MD_CTX_md_data(to);
  84                 const OMAC_CTX *c_from = EVP_MD_CTX_md_data(from);
  85
  86     if (c_from && c_to) {
  87                         c_to->dgst_size  = c_from->dgst_size;
  88                         c_to->cipher_nid = c_from->cipher_nid;
  89                         c_to->key_set    = c_from->key_set;
  90     }
  91                 else
  92                 {
  93                         return 0;
  94                 }
  95                 if (c_to->cmac_ctx == c_from->cmac_ctx)
  96                 {
  97                     c_to->cmac_ctx = CMAC_CTX_new();
  98                 }
  99                 return CMAC_CTX_copy(c_to->cmac_ctx, c_from->cmac_ctx);
 100 }
 101
 102 /* Clean up imit ctx */
 103 int omac_imit_cleanup(EVP_MD_CTX *ctx)
 104 {
 105     OMAC_CTX *c = EVP_MD_CTX_md_data(ctx);
 106
 107                 if (c)
 108                 {
 109                         CMAC_CTX_free(c->cmac_ctx);
 110             memset(EVP_MD_CTX_md_data(ctx), 0, sizeof(OMAC_CTX));
 111                 }
 112     return 1;
 113 }
 114
 115 static int omac_key(OMAC_CTX *c, const EVP_CIPHER *cipher, const unsigned char *key, size_t key_size)
 116 {
 117         int ret = 0;
 118
 119         c->cmac_ctx = CMAC_CTX_new();
 120         if (c->cmac_ctx == NULL)
 121         {
 122                 GOSTerr(GOST_F_OMAC_KEY, ERR_R_MALLOC_FAILURE);
 123                 return 0;
 124         }
 125
 126         ret = CMAC_Init(c->cmac_ctx, key, key_size, cipher, NULL);
 127         if (ret > 0)
 128         {
 129                 c->key_set = 1;
 130         }
 131         return 1;
 132 }
 133
 134 int omac_imit_ctrl(EVP_MD_CTX *ctx, int type, int arg, void *ptr)
 135 {
 136     switch (type) {
 137     case EVP_MD_CTRL_KEY_LEN:
 138         *((unsigned int *)(ptr)) = 32;
 139         return 1;
 140     case EVP_MD_CTRL_SET_KEY:
 141                                 {
 142                                         OMAC_CTX *c = EVP_MD_CTX_md_data(ctx);
 143                                         const EVP_MD *md = EVP_MD_CTX_md(ctx);
 144                                         const EVP_CIPHER *cipher = NULL;
 145
 146                                         if (c->cipher_nid == NID_undef)
 147                                         {
 148                                                 switch (EVP_MD_nid(md))
 149                                                 {
 150                                                         case NID_magma_mac:
 151                                                                 c->cipher_nid = NID_magma_cbc;
 152                                                                 break;
 153
 154                                                         case NID_grasshopper_mac:
 155                                                                 c->cipher_nid = NID_grasshopper_cbc;
 156                                                                 break;
 157                                                 }
 158                                         }
 159                                         cipher = EVP_get_cipherbynid(c->cipher_nid);
 160
 161                                         if (cipher == NULL)
 162                                         {
 163                                                 GOSTerr(GOST_F_OMAC_IMIT_CTRL, GOST_R_CIPHER_NOT_FOUND);
 164                                         }
 165
 166                                         if (EVP_MD_meth_get_init(EVP_MD_CTX_md(ctx)) (ctx) <= 0) {
 167                                                 GOSTerr(GOST_F_OMAC_IMIT_CTRL, GOST_R_MAC_KEY_NOT_SET);
 168                                                 return 0;
 169                                         }
 170                                         EVP_MD_CTX_set_flags(ctx, EVP_MD_CTX_FLAG_NO_INIT);
 171
 172                                         if (c->key_set)
 173                                         {
 174                                                 GOSTerr(GOST_F_OMAC_IMIT_CTRL, GOST_R_BAD_ORDER);
 175                                                 return 0;
 176                                         }
 177
 178                                         if (arg == 0) {
 179                                                 struct gost_mac_key *key = (struct gost_mac_key *)ptr;
 180                                                 return omac_key(c, cipher, key->key, 32);
 181
 182                                         } else if (arg == 32) {
 183                                                 return omac_key(c, cipher, ptr, 32);
 184                                         }
 185                                         GOSTerr(GOST_F_OMAC_IMIT_CTRL, GOST_R_INVALID_MAC_KEY_SIZE);
 186                                         return 0;
 187                                 }
 188     case EVP_MD_CTRL_MAC_LEN:
 189         {
 190                                         OMAC_CTX *c = EVP_MD_CTX_md_data(ctx);
 191                                         switch (c->cipher_nid)
 192                                         {
 193                                                 case NID_magma_cbc:
 194             if (arg < 1 || arg > 8) {
 195                 GOSTerr(GOST_F_OMAC_IMIT_CTRL, GOST_R_INVALID_MAC_SIZE);
 196                 return 0;
 197             }
 198             c->dgst_size = arg;
 199                                                 break;
 200                                                 case NID_grasshopper_cbc:
 201             if (arg < 1 || arg > 16) {
 202                 GOSTerr(GOST_F_OMAC_IMIT_CTRL, GOST_R_INVALID_MAC_SIZE);
 203                 return 0;
 204             }
 205             c->dgst_size = arg;
 206                                                 break;
 207                                                 default:
 208                                                 return 0;
 209                                         }
 210           return 1;
 211         }
 212
 213     default:
 214         return 0;
 215     }
 216 }
 217
 218 static EVP_MD *_hidden_magma_mac_md = NULL;
 219
 220 EVP_MD *magma_omac(void)
 221 {
 222     if (_hidden_magma_mac_md == NULL) {
 223         EVP_MD *md;
 224
 225         if ((md = EVP_MD_meth_new(NID_magma_mac, NID_undef)) == NULL
 226             || !EVP_MD_meth_set_result_size(md, 4)
 227             || !EVP_MD_meth_set_input_blocksize(md, 8)
 228             || !EVP_MD_meth_set_app_datasize(md, sizeof(OMAC_CTX))
 229             || !EVP_MD_meth_set_flags(md, 0)
 230             || !EVP_MD_meth_set_init(md, magma_imit_init)
 231             || !EVP_MD_meth_set_update(md, omac_imit_update)
 232             || !EVP_MD_meth_set_final(md, omac_imit_final)
 233             || !EVP_MD_meth_set_copy(md, omac_imit_copy)
 234             || !EVP_MD_meth_set_cleanup(md, omac_imit_cleanup)
 235             || !EVP_MD_meth_set_ctrl(md, omac_imit_ctrl)) {
 236             EVP_MD_meth_free(md);
 237             md = NULL;
 238         }
 239        _hidden_magma_mac_md = md;
 240     }
 241     return _hidden_magma_mac_md;
 242 }
 243
 244 void magma_omac_destroy(void)
 245 {
 246     EVP_MD_meth_free(_hidden_magma_mac_md);
 247     _hidden_magma_mac_md = NULL;
 248 }
 249
 250 static EVP_MD *_hidden_grasshopper_mac_md = NULL;
 251
 252 EVP_MD *grasshopper_omac(void)
 253 {
 254     if (_hidden_grasshopper_mac_md == NULL) {
 255         EVP_MD *md;
 256
 257         if ((md = EVP_MD_meth_new(NID_grasshopper_mac, NID_undef)) == NULL
 258             || !EVP_MD_meth_set_result_size(md, 8)
 259             || !EVP_MD_meth_set_input_blocksize(md, 8)
 260             || !EVP_MD_meth_set_app_datasize(md, sizeof(OMAC_CTX))
 261             || !EVP_MD_meth_set_flags(md, 0)
 262             || !EVP_MD_meth_set_init(md, grasshopper_imit_init)
 263             || !EVP_MD_meth_set_update(md, omac_imit_update)
 264             || !EVP_MD_meth_set_final(md, omac_imit_final)
 265             || !EVP_MD_meth_set_copy(md, omac_imit_copy)
 266             || !EVP_MD_meth_set_cleanup(md, omac_imit_cleanup)
 267             || !EVP_MD_meth_set_ctrl(md, omac_imit_ctrl)) {
 268             EVP_MD_meth_free(md);
 269             md = NULL;
 270         }
 271        _hidden_grasshopper_mac_md = md;
 272     }
 273     return _hidden_grasshopper_mac_md;
 274 }
 275
 276 void grasshopper_omac_destroy(void)
 277 {
 278     EVP_MD_meth_free(_hidden_grasshopper_mac_md);
 279     _hidden_grasshopper_mac_md = NULL;
 280 }
 281