crypto/sm2/sm2_pmeth.c

   1 /*
   2  * Copyright 2006-2018 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include "internal/cryptlib.h"
  11 #include <openssl/asn1t.h>
  12 #include <openssl/ec.h>
  13 #include <openssl/evp.h>
  14 #include "internal/evp_int.h"
  15 #include "internal/sm2.h"
  16 #include "internal/sm2err.h"
  17
  18 /* EC pkey context structure */
  19
  20 typedef struct {
  21     /* Key and paramgen group */
  22     EC_GROUP *gen_group;
  23     /* message digest */
  24     const EVP_MD *md;
  25     /* Distinguishing Identifier, ISO/IEC 15946-3 */
  26     uint8_t *id;
  27     size_t id_len;
  28     /* id_set indicates if the 'id' field is set (1) or not (0) */
  29     int id_set;
  30 } SM2_PKEY_CTX;
  31
  32 static int pkey_sm2_init(EVP_PKEY_CTX *ctx)
  33 {
  34     SM2_PKEY_CTX *smctx;
  35
  36     if ((smctx = OPENSSL_zalloc(sizeof(*smctx))) == NULL) {
  37         SM2err(SM2_F_PKEY_SM2_INIT, ERR_R_MALLOC_FAILURE);
  38         return 0;
  39     }
  40
  41     ctx->data = smctx;
  42     return 1;
  43 }
  44
  45 static void pkey_sm2_cleanup(EVP_PKEY_CTX *ctx)
  46 {
  47     SM2_PKEY_CTX *smctx = ctx->data;
  48
  49     if (smctx != NULL) {
  50         EC_GROUP_free(smctx->gen_group);
  51         OPENSSL_free(smctx->id);
  52         OPENSSL_free(smctx);
  53         ctx->data = NULL;
  54     }
  55 }
  56
  57 static int pkey_sm2_copy(EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src)
  58 {
  59     SM2_PKEY_CTX *dctx, *sctx;
  60
  61     if (!pkey_sm2_init(dst))
  62         return 0;
  63     sctx = src->data;
  64     dctx = dst->data;
  65     if (sctx->gen_group != NULL) {
  66         dctx->gen_group = EC_GROUP_dup(sctx->gen_group);
  67         if (dctx->gen_group == NULL) {
  68             pkey_sm2_cleanup(dst);
  69             return 0;
  70         }
  71     }
  72     if (sctx->id != NULL) {
  73         dctx->id = OPENSSL_malloc(sctx->id_len);
  74         if (dctx->id == NULL) {
  75             pkey_sm2_cleanup(dst);
  76             return 0;
  77         }
  78         memcpy(dctx->id, sctx->id, sctx->id_len);
  79     }
  80     dctx->id_len = sctx->id_len;
  81     dctx->id_set = sctx->id_set;
  82     dctx->md = sctx->md;
  83
  84     return 1;
  85 }
  86
  87 static int pkey_sm2_sign(EVP_PKEY_CTX *ctx, unsigned char *sig, size_t *siglen,
  88                          const unsigned char *tbs, size_t tbslen)
  89 {
  90     int ret;
  91     unsigned int sltmp;
  92     EC_KEY *ec = ctx->pkey->pkey.ec;
  93     const int sig_sz = ECDSA_size(ctx->pkey->pkey.ec);
  94
  95     if (sig_sz <= 0) {
  96         return 0;
  97     }
  98
  99     if (sig == NULL) {
 100         *siglen = (size_t)sig_sz;
 101         return 1;
 102     }
 103
 104     if (*siglen < (size_t)sig_sz) {
 105         SM2err(SM2_F_PKEY_SM2_SIGN, SM2_R_BUFFER_TOO_SMALL);
 106         return 0;
 107     }
 108
 109     ret = sm2_sign(tbs, tbslen, sig, &sltmp, ec);
 110
 111     if (ret <= 0)
 112         return ret;
 113     *siglen = (size_t)sltmp;
 114     return 1;
 115 }
 116
 117 static int pkey_sm2_verify(EVP_PKEY_CTX *ctx,
 118                            const unsigned char *sig, size_t siglen,
 119                            const unsigned char *tbs, size_t tbslen)
 120 {
 121     EC_KEY *ec = ctx->pkey->pkey.ec;
 122
 123     return sm2_verify(tbs, tbslen, sig, siglen, ec);
 124 }
 125
 126 static int pkey_sm2_encrypt(EVP_PKEY_CTX *ctx,
 127                             unsigned char *out, size_t *outlen,
 128                             const unsigned char *in, size_t inlen)
 129 {
 130     EC_KEY *ec = ctx->pkey->pkey.ec;
 131     SM2_PKEY_CTX *dctx = ctx->data;
 132     const EVP_MD *md = (dctx->md == NULL) ? EVP_sm3() : dctx->md;
 133
 134     if (out == NULL) {
 135         if (!sm2_ciphertext_size(ec, md, inlen, outlen))
 136             return -1;
 137         else
 138             return 1;
 139     }
 140
 141     return sm2_encrypt(ec, md, in, inlen, out, outlen);
 142 }
 143
 144 static int pkey_sm2_decrypt(EVP_PKEY_CTX *ctx,
 145                             unsigned char *out, size_t *outlen,
 146                             const unsigned char *in, size_t inlen)
 147 {
 148     EC_KEY *ec = ctx->pkey->pkey.ec;
 149     SM2_PKEY_CTX *dctx = ctx->data;
 150     const EVP_MD *md = (dctx->md == NULL) ? EVP_sm3() : dctx->md;
 151
 152     if (out == NULL) {
 153         if (!sm2_plaintext_size(ec, md, inlen, outlen))
 154             return -1;
 155         else
 156             return 1;
 157     }
 158
 159     return sm2_decrypt(ec, md, in, inlen, out, outlen);
 160 }
 161
 162 static int pkey_sm2_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
 163 {
 164     SM2_PKEY_CTX *smctx = ctx->data;
 165     EC_GROUP *group;
 166
 167     switch (type) {
 168     case EVP_PKEY_CTRL_EC_PARAMGEN_CURVE_NID:
 169         group = EC_GROUP_new_by_curve_name(p1);
 170         if (group == NULL) {
 171             SM2err(SM2_F_PKEY_SM2_CTRL, SM2_R_INVALID_CURVE);
 172             return 0;
 173         }
 174         EC_GROUP_free(smctx->gen_group);
 175         smctx->gen_group = group;
 176         return 1;
 177
 178     case EVP_PKEY_CTRL_EC_PARAM_ENC:
 179         if (smctx->gen_group == NULL) {
 180             SM2err(SM2_F_PKEY_SM2_CTRL, SM2_R_NO_PARAMETERS_SET);
 181             return 0;
 182         }
 183         EC_GROUP_set_asn1_flag(smctx->gen_group, p1);
 184         return 1;
 185
 186     case EVP_PKEY_CTRL_MD:
 187         smctx->md = p2;
 188         return 1;
 189
 190     case EVP_PKEY_CTRL_GET_MD:
 191         *(const EVP_MD **)p2 = smctx->md;
 192         return 1;
 193
 194     case EVP_PKEY_CTRL_SET1_ID:
 195         OPENSSL_free(smctx->id);
 196         if (p1 > 0) {
 197             smctx->id = OPENSSL_malloc(p1);
 198             if (smctx->id == NULL)
 199                 return 0;
 200             memcpy(smctx->id, p2, p1);
 201         } else {
 202             /* set null-ID */
 203             smctx->id = NULL;
 204         }
 205         smctx->id_len = (size_t)p1;
 206         smctx->id_set = 1;
 207         return 1;
 208
 209     case EVP_PKEY_CTRL_GET1_ID:
 210         memcpy(p2, smctx->id, smctx->id_len);
 211         return 1;
 212
 213     case EVP_PKEY_CTRL_GET1_ID_LEN:
 214         *(size_t *)p2 = smctx->id_len;
 215         return 1;
 216
 217     default:
 218         return -2;
 219     }
 220 }
 221
 222 static int pkey_sm2_ctrl_str(EVP_PKEY_CTX *ctx,
 223                              const char *type, const char *value)
 224 {
 225     if (strcmp(type, "ec_paramgen_curve") == 0) {
 226         int nid = NID_undef;
 227
 228         if (((nid = EC_curve_nist2nid(value)) == NID_undef)
 229             && ((nid = OBJ_sn2nid(value)) == NID_undef)
 230             && ((nid = OBJ_ln2nid(value)) == NID_undef)) {
 231             SM2err(SM2_F_PKEY_SM2_CTRL_STR, SM2_R_INVALID_CURVE);
 232             return 0;
 233         }
 234         return EVP_PKEY_CTX_set_ec_paramgen_curve_nid(ctx, nid);
 235     } else if (strcmp(type, "ec_param_enc") == 0) {
 236         int param_enc;
 237
 238         if (strcmp(value, "explicit") == 0)
 239             param_enc = 0;
 240         else if (strcmp(value, "named_curve") == 0)
 241             param_enc = OPENSSL_EC_NAMED_CURVE;
 242         else
 243             return -2;
 244         return EVP_PKEY_CTX_set_ec_param_enc(ctx, param_enc);
 245     }
 246
 247     return -2;
 248 }
 249
 250 static int pkey_sm2_digest_custom(EVP_PKEY_CTX *ctx, EVP_MD_CTX *mctx)
 251 {
 252     uint8_t z[EVP_MAX_MD_SIZE];
 253     SM2_PKEY_CTX *smctx = ctx->data;
 254     EC_KEY *ec = ctx->pkey->pkey.ec;
 255     const EVP_MD *md = EVP_MD_CTX_md(mctx);
 256
 257     if (!smctx->id_set) {
 258         /*
 259          * An ID value must be set. The specifications are not clear whether a
 260          * NULL is allowed. We only allow it if set explicitly for maximum
 261          * flexibility.
 262          */
 263         return 0;
 264     }
 265
 266     /* get hashed prefix 'z' of tbs message */
 267     if (!sm2_compute_z_digest(z, md, smctx->id, smctx->id_len, ec))
 268         return 0;
 269
 270     return EVP_DigestUpdate(mctx, z, EVP_MD_size(md));
 271 }
 272
 273 const EVP_PKEY_METHOD sm2_pkey_meth = {
 274     EVP_PKEY_SM2,
 275     0,
 276     pkey_sm2_init,
 277     pkey_sm2_copy,
 278     pkey_sm2_cleanup,
 279
 280     0,
 281     0,
 282
 283     0,
 284     0,
 285
 286     0,
 287     pkey_sm2_sign,
 288
 289     0,
 290     pkey_sm2_verify,
 291
 292     0, 0,
 293
 294     0, 0, 0, 0,
 295
 296     0,
 297     pkey_sm2_encrypt,
 298
 299     0,
 300     pkey_sm2_decrypt,
 301
 302     0,
 303     0,
 304     pkey_sm2_ctrl,
 305     pkey_sm2_ctrl_str,
 306
 307     0, 0,
 308
 309     0, 0, 0,
 310
 311     pkey_sm2_digest_custom
 312 };