text: /*
   * Copyright 2006-2018 The OpenSSL Project Authors. All Rights Reserved.
   *
   * Licensed under the OpenSSL license (the "License").  You may not use
   * this file except in compliance with the License.  You can obtain a copy
   * in the file LICENSE in the source distribution or at
   * https://www.openssl.org/source/license.html
   */
  
  #include "internal/cryptlib.h"
  #include <openssl/asn1t.h>
  #include <openssl/ec.h>
  #include <openssl/evp.h>
  #include "internal/evp_int.h"
  #include "internal/sm2.h"
  #include "internal/sm2err.h"
  
  /* EC pkey context structure */
  
  typedef struct {
      /* Key and paramgen group */
      EC_GROUP *gen_group;
      /* message digest */
      const EVP_MD *md;
      /* Distinguishing Identifier, ISO/IEC 15946-3 */
      uint8_t *id;
      size_t id_len;
      /* id_set indicates if the 'id' field is set (1) or not (0) */
      int id_set;
  } SM2_PKEY_CTX;
  
  static int pkey_sm2_init(EVP_PKEY_CTX *ctx)
  {
      SM2_PKEY_CTX *smctx;
  
      if ((smctx = OPENSSL_zalloc(sizeof(*smctx))) == NULL) {
          SM2err(SM2_F_PKEY_SM2_INIT, ERR_R_MALLOC_FAILURE);
          return 0;
      }
  
      ctx->data = smctx;
      return 1;
  }
  
  static void pkey_sm2_cleanup(EVP_PKEY_CTX *ctx)
  {
      SM2_PKEY_CTX *smctx = ctx->data;
  
      if (smctx != NULL) {
          EC_GROUP_free(smctx->gen_group);
          OPENSSL_free(smctx->id);
          OPENSSL_free(smctx);
          ctx->data = NULL;
      }
  }
  
  static int pkey_sm2_copy(EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src)
  {
      SM2_PKEY_CTX *dctx, *sctx;
  
      if (!pkey_sm2_init(dst))
          return 0;
      sctx = src->data;
      dctx = dst->data;
      if (sctx->gen_group != NULL) {
          dctx->gen_group = EC_GROUP_dup(sctx->gen_group);
          if (dctx->gen_group == NULL) {
              pkey_sm2_cleanup(dst);
              return 0;
          }
      }
      if (sctx->id != NULL) {
          dctx->id = OPENSSL_malloc(sctx->id_len);
          if (dctx->id == NULL) {
              SM2err(SM2_F_PKEY_SM2_COPY, ERR_R_MALLOC_FAILURE);
              pkey_sm2_cleanup(dst);
              return 0;
          }
          memcpy(dctx->id, sctx->id, sctx->id_len);
      }
      dctx->id_len = sctx->id_len;
      dctx->id_set = sctx->id_set;
      dctx->md = sctx->md;
  
      return 1;
  }
  
  static int pkey_sm2_sign(EVP_PKEY_CTX *ctx, unsigned char *sig, size_t *siglen,
                           const unsigned char *tbs, size_t tbslen)
  {
      int ret;
      unsigned int sltmp;
      EC_KEY *ec = ctx->pkey->pkey.ec;
      const int sig_sz = ECDSA_size(ctx->pkey->pkey.ec);
  
      if (sig_sz <= 0) {
          return 0;
      }
  
      if (sig == NULL) {
          *siglen = (size_t)sig_sz;
          return 1;
      }
  
      if (*siglen < (size_t)sig_sz) {
          SM2err(SM2_F_PKEY_SM2_SIGN, SM2_R_BUFFER_TOO_SMALL);
          return 0;
      }
  
      ret = sm2_sign(tbs, tbslen, sig, &sltmp, ec);
  
      if (ret <= 0)
          return ret;
      *siglen = (size_t)sltmp;
      return 1;
  }
  
  static int pkey_sm2_verify(EVP_PKEY_CTX *ctx,
                             const unsigned char *sig, size_t siglen,
                             const unsigned char *tbs, size_t tbslen)
  {
      EC_KEY *ec = ctx->pkey->pkey.ec;
  
      return sm2_verify(tbs, tbslen, sig, siglen, ec);
  }
  
  static int pkey_sm2_encrypt(EVP_PKEY_CTX *ctx,
                              unsigned char *out, size_t *outlen,
                              const unsigned char *in, size_t inlen)
  {
      EC_KEY *ec = ctx->pkey->pkey.ec;
      SM2_PKEY_CTX *dctx = ctx->data;
      const EVP_MD *md = (dctx->md == NULL) ? EVP_sm3() : dctx->md;
  
      if (out == NULL) {
          if (!sm2_ciphertext_size(ec, md, inlen, outlen))
              return -1;
          else
              return 1;
      }
  
      return sm2_encrypt(ec, md, in, inlen, out, outlen);
  }
  
  static int pkey_sm2_decrypt(EVP_PKEY_CTX *ctx,
                              unsigned char *out, size_t *outlen,
                              const unsigned char *in, size_t inlen)
  {
      EC_KEY *ec = ctx->pkey->pkey.ec;
      SM2_PKEY_CTX *dctx = ctx->data;
      const EVP_MD *md = (dctx->md == NULL) ? EVP_sm3() : dctx->md;
  
      if (out == NULL) {
          if (!sm2_plaintext_size(ec, md, inlen, outlen))
              return -1;
          else
              return 1;
      }
  
      return sm2_decrypt(ec, md, in, inlen, out, outlen);
  }
  
  static int pkey_sm2_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
  {
      SM2_PKEY_CTX *smctx = ctx->data;
      EC_GROUP *group;
      uint8_t *tmp_id;
  
      switch (type) {
      case EVP_PKEY_CTRL_EC_PARAMGEN_CURVE_NID:
          group = EC_GROUP_new_by_curve_name(p1);
          if (group == NULL) {
              SM2err(SM2_F_PKEY_SM2_CTRL, SM2_R_INVALID_CURVE);
              return 0;
          }
          EC_GROUP_free(smctx->gen_group);
          smctx->gen_group = group;
          return 1;
  
      case EVP_PKEY_CTRL_EC_PARAM_ENC:
          if (smctx->gen_group == NULL) {
              SM2err(SM2_F_PKEY_SM2_CTRL, SM2_R_NO_PARAMETERS_SET);
              return 0;
          }
          EC_GROUP_set_asn1_flag(smctx->gen_group, p1);
          return 1;
  
      case EVP_PKEY_CTRL_MD:
          smctx->md = p2;
          return 1;
  
      case EVP_PKEY_CTRL_GET_MD:
          *(const EVP_MD **)p2 = smctx->md;
          return 1;
  
      case EVP_PKEY_CTRL_SET1_ID:
          if (p1 > 0) {
              tmp_id = OPENSSL_malloc(p1);
              if (tmp_id == NULL) {
                  SM2err(SM2_F_PKEY_SM2_CTRL, ERR_R_MALLOC_FAILURE);
                  return 0;
              }
              memcpy(tmp_id, p2, p1);
              OPENSSL_free(smctx->id);
              smctx->id = tmp_id;
          } else {
              /* set null-ID */
              OPENSSL_free(smctx->id);
              smctx->id = NULL;
          }
          smctx->id_len = (size_t)p1;
          smctx->id_set = 1;
          return 1;
  
      case EVP_PKEY_CTRL_GET1_ID:
          memcpy(p2, smctx->id, smctx->id_len);
          return 1;
  
      case EVP_PKEY_CTRL_GET1_ID_LEN:
          *(size_t *)p2 = smctx->id_len;
          return 1;
  
      default:
          return -2;
      }
  }
  
  static int pkey_sm2_ctrl_str(EVP_PKEY_CTX *ctx,
                               const char *type, const char *value)
  {
      if (strcmp(type, "ec_paramgen_curve") == 0) {
          int nid = NID_undef;
  
          if (((nid = EC_curve_nist2nid(value)) == NID_undef)
              && ((nid = OBJ_sn2nid(value)) == NID_undef)
              && ((nid = OBJ_ln2nid(value)) == NID_undef)) {
              SM2err(SM2_F_PKEY_SM2_CTRL_STR, SM2_R_INVALID_CURVE);
              return 0;
          }
          return EVP_PKEY_CTX_set_ec_paramgen_curve_nid(ctx, nid);
      } else if (strcmp(type, "ec_param_enc") == 0) {
          int param_enc;
  
          if (strcmp(value, "explicit") == 0)
              param_enc = 0;
          else if (strcmp(value, "named_curve") == 0)
              param_enc = OPENSSL_EC_NAMED_CURVE;
          else
              return -2;
          return EVP_PKEY_CTX_set_ec_param_enc(ctx, param_enc);
      }
  
      return -2;
  }
  
  static int pkey_sm2_digest_custom(EVP_PKEY_CTX *ctx, EVP_MD_CTX *mctx)
  {
      uint8_t z[EVP_MAX_MD_SIZE];
      SM2_PKEY_CTX *smctx = ctx->data;
      EC_KEY *ec = ctx->pkey->pkey.ec;
      const EVP_MD *md = EVP_MD_CTX_md(mctx);
      int mdlen = EVP_MD_size(md);
  
      if (!smctx->id_set) {
          /*
           * An ID value must be set. The specifications are not clear whether a
           * NULL is allowed. We only allow it if set explicitly for maximum
           * flexibility.
           */
          SM2err(SM2_F_PKEY_SM2_DIGEST_CUSTOM, SM2_R_ID_NOT_SET);
          return 0;
      }
  
      if (mdlen < 0) {
          SM2err(SM2_F_PKEY_SM2_DIGEST_CUSTOM, SM2_R_INVALID_DIGEST);
          return 0;
      }
  
      /* get hashed prefix 'z' of tbs message */
      if (!sm2_compute_z_digest(z, md, smctx->id, smctx->id_len, ec))
          return 0;
  
      return EVP_DigestUpdate(mctx, z, (size_t)mdlen);
  }
  
  const EVP_PKEY_METHOD sm2_pkey_meth = {
      EVP_PKEY_SM2,
      0,
      pkey_sm2_init,
      pkey_sm2_copy,
      pkey_sm2_cleanup,
  
      0,
      0,
  
      0,
      0,
  
      0,
      pkey_sm2_sign,
  
      0,
      pkey_sm2_verify,
  
      0, 0,
  
      0, 0, 0, 0,
  
      0,
      pkey_sm2_encrypt,
  
      0,
      pkey_sm2_decrypt,
  
      0,
      0,
      pkey_sm2_ctrl,
      pkey_sm2_ctrl_str,
  
      0, 0,
  
      0, 0, 0,
  
      pkey_sm2_digest_custom
  };
  