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_from->cmac_ctx) {
  96                     if (c_to->cmac_ctx) {
  97                         CMAC_CTX_free(c_to->cmac_ctx);
  98                         c_to->cmac_ctx = NULL;
  99                     }
 100                     return 1;
 101                 }
 102                 if (c_to->cmac_ctx == c_from->cmac_ctx)
 103                 {
 104                     c_to->cmac_ctx = CMAC_CTX_new();
 105                 }
 106                 return CMAC_CTX_copy(c_to->cmac_ctx, c_from->cmac_ctx);
 107 }
 108
 109 /* Clean up imit ctx */
 110 int omac_imit_cleanup(EVP_MD_CTX *ctx)
 111 {
 112     OMAC_CTX *c = EVP_MD_CTX_md_data(ctx);
 113
 114                 if (c)
 115                 {
 116                         CMAC_CTX_free(c->cmac_ctx);
 117             memset(EVP_MD_CTX_md_data(ctx), 0, sizeof(OMAC_CTX));
 118                 }
 119     return 1;
 120 }
 121
 122 static int omac_key(OMAC_CTX *c, const EVP_CIPHER *cipher, const unsigned char *key, size_t key_size)
 123 {
 124         int ret = 0;
 125
 126         c->cmac_ctx = CMAC_CTX_new();
 127         if (c->cmac_ctx == NULL)
 128         {
 129                 GOSTerr(GOST_F_OMAC_KEY, ERR_R_MALLOC_FAILURE);
 130                 return 0;
 131         }
 132
 133         ret = CMAC_Init(c->cmac_ctx, key, key_size, cipher, NULL);
 134         if (ret > 0)
 135         {
 136                 c->key_set = 1;
 137         }
 138         return 1;
 139 }
 140
 141 int omac_imit_ctrl(EVP_MD_CTX *ctx, int type, int arg, void *ptr)
 142 {
 143     switch (type) {
 144     case EVP_MD_CTRL_KEY_LEN:
 145         *((unsigned int *)(ptr)) = 32;
 146         return 1;
 147     case EVP_MD_CTRL_SET_KEY:
 148                                 {
 149                                         OMAC_CTX *c = EVP_MD_CTX_md_data(ctx);
 150                                         const EVP_MD *md = EVP_MD_CTX_md(ctx);
 151                                         const EVP_CIPHER *cipher = NULL;
 152
 153                                         if (c->cipher_nid == NID_undef)
 154                                         {
 155                                                 switch (EVP_MD_nid(md))
 156                                                 {
 157                                                         case NID_magma_mac:
 158                                                                 c->cipher_nid = NID_magma_cbc;
 159                                                                 break;
 160
 161                                                         case NID_grasshopper_mac:
 162                                                                 c->cipher_nid = NID_grasshopper_cbc;
 163                                                                 break;
 164                                                 }
 165                                         }
 166                                         cipher = EVP_get_cipherbynid(c->cipher_nid);
 167
 168                                         if (cipher == NULL)
 169                                         {
 170                                                 GOSTerr(GOST_F_OMAC_IMIT_CTRL, GOST_R_CIPHER_NOT_FOUND);
 171                                         }
 172
 173                                         if (EVP_MD_meth_get_init(EVP_MD_CTX_md(ctx)) (ctx) <= 0) {
 174                                                 GOSTerr(GOST_F_OMAC_IMIT_CTRL, GOST_R_MAC_KEY_NOT_SET);
 175                                                 return 0;
 176                                         }
 177                                         EVP_MD_CTX_set_flags(ctx, EVP_MD_CTX_FLAG_NO_INIT);
 178
 179                                         if (c->key_set)
 180                                         {
 181                                                 GOSTerr(GOST_F_OMAC_IMIT_CTRL, GOST_R_BAD_ORDER);
 182                                                 return 0;
 183                                         }
 184
 185                                         if (arg == 0) {
 186                                                 struct gost_mac_key *key = (struct gost_mac_key *)ptr;
 187                                                 return omac_key(c, cipher, key->key, 32);
 188
 189                                         } else if (arg == 32) {
 190                                                 return omac_key(c, cipher, ptr, 32);
 191                                         }
 192                                         GOSTerr(GOST_F_OMAC_IMIT_CTRL, GOST_R_INVALID_MAC_KEY_SIZE);
 193                                         return 0;
 194                                 }
 195     case EVP_MD_CTRL_MAC_LEN:
 196         {
 197                                         OMAC_CTX *c = EVP_MD_CTX_md_data(ctx);
 198                                         switch (c->cipher_nid)
 199                                         {
 200                                                 case NID_magma_cbc:
 201             if (arg < 1 || arg > 8) {
 202                 GOSTerr(GOST_F_OMAC_IMIT_CTRL, GOST_R_INVALID_MAC_SIZE);
 203                 return 0;
 204             }
 205             c->dgst_size = arg;
 206                                                 break;
 207                                                 case NID_grasshopper_cbc:
 208             if (arg < 1 || arg > 16) {
 209                 GOSTerr(GOST_F_OMAC_IMIT_CTRL, GOST_R_INVALID_MAC_SIZE);
 210                 return 0;
 211             }
 212             c->dgst_size = arg;
 213                                                 break;
 214                                                 default:
 215                                                 return 0;
 216                                         }
 217           return 1;
 218         }
 219
 220     default:
 221         return 0;
 222     }
 223 }
 224
 225 static EVP_MD *_hidden_magma_mac_md = NULL;
 226
 227 EVP_MD *magma_omac(void)
 228 {
 229     if (_hidden_magma_mac_md == NULL) {
 230         EVP_MD *md;
 231
 232         if ((md = EVP_MD_meth_new(NID_magma_mac, NID_undef)) == NULL
 233             || !EVP_MD_meth_set_result_size(md, 4)
 234             || !EVP_MD_meth_set_input_blocksize(md, 8)
 235             || !EVP_MD_meth_set_app_datasize(md, sizeof(OMAC_CTX))
 236             || !EVP_MD_meth_set_flags(md, 0)
 237             || !EVP_MD_meth_set_init(md, magma_imit_init)
 238             || !EVP_MD_meth_set_update(md, omac_imit_update)
 239             || !EVP_MD_meth_set_final(md, omac_imit_final)
 240             || !EVP_MD_meth_set_copy(md, omac_imit_copy)
 241             || !EVP_MD_meth_set_cleanup(md, omac_imit_cleanup)
 242             || !EVP_MD_meth_set_ctrl(md, omac_imit_ctrl)) {
 243             EVP_MD_meth_free(md);
 244             md = NULL;
 245         }
 246        _hidden_magma_mac_md = md;
 247     }
 248     return _hidden_magma_mac_md;
 249 }
 250
 251 void magma_omac_destroy(void)
 252 {
 253     EVP_MD_meth_free(_hidden_magma_mac_md);
 254     _hidden_magma_mac_md = NULL;
 255 }
 256
 257 static EVP_MD *_hidden_grasshopper_mac_md = NULL;
 258
 259 EVP_MD *grasshopper_omac(void)
 260 {
 261     if (_hidden_grasshopper_mac_md == NULL) {
 262         EVP_MD *md;
 263
 264         if ((md = EVP_MD_meth_new(NID_grasshopper_mac, NID_undef)) == NULL
 265             || !EVP_MD_meth_set_result_size(md, 8)
 266             || !EVP_MD_meth_set_input_blocksize(md, 8)
 267             || !EVP_MD_meth_set_app_datasize(md, sizeof(OMAC_CTX))
 268             || !EVP_MD_meth_set_flags(md, 0)
 269             || !EVP_MD_meth_set_init(md, grasshopper_imit_init)
 270             || !EVP_MD_meth_set_update(md, omac_imit_update)
 271             || !EVP_MD_meth_set_final(md, omac_imit_final)
 272             || !EVP_MD_meth_set_copy(md, omac_imit_copy)
 273             || !EVP_MD_meth_set_cleanup(md, omac_imit_cleanup)
 274             || !EVP_MD_meth_set_ctrl(md, omac_imit_ctrl)) {
 275             EVP_MD_meth_free(md);
 276             md = NULL;
 277         }
 278        _hidden_grasshopper_mac_md = md;
 279     }
 280     return _hidden_grasshopper_mac_md;
 281 }
 282
 283 void grasshopper_omac_destroy(void)
 284 {
 285     EVP_MD_meth_free(_hidden_grasshopper_mac_md);
 286     _hidden_grasshopper_mac_md = NULL;
 287 }
 288