// Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//     https://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

#include <openssl/x509.h>

#include <limits.h>

#include <openssl/asn1.h>

#include <openssl/asn1t.h>

#include <openssl/bytestring.h>

#include <openssl/err.h>

#include <openssl/evp.h>

#include <openssl/mem.h>

#include <openssl/obj.h>

#include "../internal.h"

#include "internal.h"

static void x509_pubkey_changed(X509_PUBKEY *pub) {

  EVP_PKEY_free(pub->pkey);

  pub->pkey = NULL;

  // Re-encode the |X509_PUBKEY| to DER and parse it with EVP's APIs.

  uint8_t *spki = NULL;

  int spki_len = i2d_X509_PUBKEY(pub, &spki);

  EVP_PKEY *pkey;

  if (spki_len < 0) {

    goto err;

  }

  CBS cbs;

  CBS_init(&cbs, spki, (size_t)spki_len);

  pkey = EVP_parse_public_key(&cbs);

  if (pkey == NULL || CBS_len(&cbs) != 0) {

    EVP_PKEY_free(pkey);

    goto err;

  }

  pub->pkey = pkey;

err:

  OPENSSL_free(spki);

  // If the operation failed, clear errors. An |X509_PUBKEY| whose key we cannot

  // parse is still a valid SPKI. It just cannot be converted to an |EVP_PKEY|.

  ERR_clear_error();

}

static int pubkey_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,

                     void *exarg) {

  X509_PUBKEY *pubkey = (X509_PUBKEY *)*pval;

  if (operation == ASN1_OP_FREE_POST) {

    EVP_PKEY_free(pubkey->pkey);

  } else if (operation == ASN1_OP_D2I_POST) {

    x509_pubkey_changed(pubkey);

  }

  return 1;

}

ASN1_SEQUENCE_cb(X509_PUBKEY, pubkey_cb) = {

    ASN1_SIMPLE(X509_PUBKEY, algor, X509_ALGOR),

    ASN1_SIMPLE(X509_PUBKEY, public_key, ASN1_BIT_STRING),

} ASN1_SEQUENCE_END_cb(X509_PUBKEY, X509_PUBKEY)

IMPLEMENT_ASN1_FUNCTIONS_const(X509_PUBKEY)

int X509_PUBKEY_set(X509_PUBKEY **x, EVP_PKEY *pkey) {

  X509_PUBKEY *pk = NULL;

  uint8_t *spki = NULL;

  size_t spki_len;

  if (x == NULL) {

    return 0;

  }

  CBB cbb;

  const uint8_t *p;

  if (!CBB_init(&cbb, 0) ||  //

      !EVP_marshal_public_key(&cbb, pkey) ||

      !CBB_finish(&cbb, &spki, &spki_len) ||  //

      spki_len > LONG_MAX) {

    CBB_cleanup(&cbb);

    OPENSSL_PUT_ERROR(X509, X509_R_PUBLIC_KEY_ENCODE_ERROR);

    goto error;

  }

  p = spki;

  pk = d2i_X509_PUBKEY(NULL, &p, (long)spki_len);

  if (pk == NULL || p != spki + spki_len) {

    OPENSSL_PUT_ERROR(X509, X509_R_PUBLIC_KEY_DECODE_ERROR);

    goto error;

  }

  OPENSSL_free(spki);

  X509_PUBKEY_free(*x);

  *x = pk;

  return 1;

error:

  X509_PUBKEY_free(pk);

  OPENSSL_free(spki);

  return 0;

}

EVP_PKEY *X509_PUBKEY_get0(const X509_PUBKEY *key) {

  if (key == NULL) {

    return NULL;

  }

  if (key->pkey == NULL) {

    OPENSSL_PUT_ERROR(X509, X509_R_PUBLIC_KEY_DECODE_ERROR);

    return NULL;

  }

  return key->pkey;

}

EVP_PKEY *X509_PUBKEY_get(const X509_PUBKEY *key) {

  EVP_PKEY *pkey = X509_PUBKEY_get0(key);

  if (pkey != NULL) {

    EVP_PKEY_up_ref(pkey);

  }

  return pkey;

}

int X509_PUBKEY_set0_param(X509_PUBKEY *pub, ASN1_OBJECT *obj, int param_type,

                           void *param_value, uint8_t *key, int key_len) {

  if (!X509_ALGOR_set0(pub->algor, obj, param_type, param_value)) {

    return 0;

  }

  ASN1_STRING_set0(pub->public_key, key, key_len);

  // Set the number of unused bits to zero.

  pub->public_key->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);

  pub->public_key->flags |= ASN1_STRING_FLAG_BITS_LEFT;

  x509_pubkey_changed(pub);

  return 1;

}

int X509_PUBKEY_get0_param(ASN1_OBJECT **out_obj, const uint8_t **out_key,

                           int *out_key_len, X509_ALGOR **out_alg,

                           X509_PUBKEY *pub) {

  if (out_obj != NULL) {

    *out_obj = pub->algor->algorithm;

  }

  if (out_key != NULL) {

    *out_key = pub->public_key->data;

    *out_key_len = pub->public_key->length;

  }

  if (out_alg != NULL) {

    *out_alg = pub->algor;

  }

  return 1;

}

const ASN1_BIT_STRING *X509_PUBKEY_get0_public_key(const X509_PUBKEY *pub) {

  return pub->public_key;

}