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