/*
 * Copyright 2016-present Facebook, Inc.
 *
 * 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
 *
 *   http://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 <folly/portability/OpenSSL.h>
#include <folly/ssl/detail/OpenSSLThreading.h>

#include <stdexcept>

namespace folly {
namespace portability {
namespace ssl {

#if OPENSSL_IS_BORINGSSL
int SSL_CTX_set1_sigalgs_list(SSL_CTX*, const char*) {
  return 1; // 0 implies error
}

int TLS1_get_client_version(SSL* s) {
  // Note that this isn't the client version, and the API to
  // get this has been hidden. It may be found by parsing the
  // ClientHello (there is a callback via the SSL_HANDSHAKE struct)
  return s->version;
}
#endif

#if FOLLY_OPENSSL_IS_100
uint32_t SSL_CIPHER_get_id(const SSL_CIPHER* c) {
  return c->id;
}

int TLS1_get_client_version(const SSL* s) {
  return (s->client_version >> 8) == TLS1_VERSION_MAJOR ? s->client_version : 0;
}
#endif

#if FOLLY_OPENSSL_IS_100 || FOLLY_OPENSSL_IS_101
int X509_get_signature_nid(X509* cert) {
  return OBJ_obj2nid(cert->sig_alg->algorithm);
}
#endif

#if FOLLY_OPENSSL_IS_100 || FOLLY_OPENSSL_IS_101 || FOLLY_OPENSSL_IS_102
int SSL_CTX_up_ref(SSL_CTX* ctx) {
  return CRYPTO_add(&ctx->references, 1, CRYPTO_LOCK_SSL_CTX);
}

int SSL_SESSION_up_ref(SSL_SESSION* session) {
  return CRYPTO_add(&session->references, 1, CRYPTO_LOCK_SSL_SESSION);
}

int X509_up_ref(X509* x) {
  return CRYPTO_add(&x->references, 1, CRYPTO_LOCK_X509);
}

int EVP_PKEY_up_ref(EVP_PKEY* evp) {
  return CRYPTO_add(&evp->references, 1, CRYPTO_LOCK_EVP_PKEY);
}

void RSA_get0_key(
    const RSA* r,
    const BIGNUM** n,
    const BIGNUM** e,
    const BIGNUM** d) {
  if (n != nullptr) {
    *n = r->n;
  }
  if (e != nullptr) {
    *e = r->e;
  }
  if (d != nullptr) {
    *d = r->d;
  }
}

RSA* EVP_PKEY_get0_RSA(EVP_PKEY* pkey) {
  if (pkey->type != EVP_PKEY_RSA) {
    return nullptr;
  }
  return pkey->pkey.rsa;
}

DSA* EVP_PKEY_get0_DSA(EVP_PKEY* pkey) {
  if (pkey->type != EVP_PKEY_DSA) {
    return nullptr;
  }
  return pkey->pkey.dsa;
}

DH* EVP_PKEY_get0_DH(EVP_PKEY* pkey) {
  if (pkey->type != EVP_PKEY_DH) {
    return nullptr;
  }
  return pkey->pkey.dh;
}

EC_KEY* EVP_PKEY_get0_EC_KEY(EVP_PKEY* pkey) {
  if (pkey->type != EVP_PKEY_EC) {
    return nullptr;
  }
  return pkey->pkey.ec;
}
#endif

#if !FOLLY_OPENSSL_IS_110
void BIO_meth_free(BIO_METHOD* biom) {
  OPENSSL_free((void*)biom);
}

int BIO_meth_set_read(BIO_METHOD* biom, int (*read)(BIO*, char*, int)) {
  biom->bread = read;
  return 1;
}

int BIO_meth_set_write(BIO_METHOD* biom, int (*write)(BIO*, const char*, int)) {
  biom->bwrite = write;
  return 1;
}

const char* SSL_SESSION_get0_hostname(const SSL_SESSION* s) {
  return s->tlsext_hostname;
}

unsigned char* ASN1_STRING_get0_data(const ASN1_STRING* x) {
  return ASN1_STRING_data((ASN1_STRING*)x);
}

int SSL_SESSION_has_ticket(const SSL_SESSION* s) {
  return (s->tlsext_ticklen > 0) ? 1 : 0;
}

unsigned long SSL_SESSION_get_ticket_lifetime_hint(const SSL_SESSION* s) {
  return s->tlsext_tick_lifetime_hint;
}

// This is taken from OpenSSL 1.1.0
int DH_set0_pqg(DH* dh, BIGNUM* p, BIGNUM* q, BIGNUM* g) {
  /* If the fields p and g in d are nullptr, the corresponding input
   * parameters MUST not be nullptr.  q may remain nullptr.
   */
  if (dh == nullptr || (dh->p == nullptr && p == nullptr) ||
      (dh->g == nullptr && g == nullptr)) {
    return 0;
  }

  if (p != nullptr) {
    BN_free(dh->p);
    dh->p = p;
  }
  if (q != nullptr) {
    BN_free(dh->q);
    dh->q = q;
  }
  if (g != nullptr) {
    BN_free(dh->g);
    dh->g = g;
  }

  // In OpenSSL 1.1.0, DH_set0_pqg also sets
  //   dh->length = BN_num_bits(q)
  // With OpenSSL 1.0.2, the output of openssl dhparam -C 2048 doesn't set
  // the length field. So as far as the compat lib is concerned, this wrapper
  // mimics the functionality of OpenSSL 1.0.2
  // Note: BoringSSL doesn't even have a length field anymore, just something
  // called 'priv_length'. Let's not mess with that for now.

  return 1;
}

void DH_get0_pqg(
    const DH* dh,
    const BIGNUM** p,
    const BIGNUM** q,
    const BIGNUM** g) {
  // Based off of https://wiki.openssl.org/index.php/OpenSSL_1.1.0_Changes
  if (p != nullptr) {
    *p = dh->p;
  }
  if (q != nullptr) {
    *q = dh->q;
  }
  if (g != nullptr) {
    *g = dh->g;
  }
}

void DH_get0_key(
    const DH* dh,
    const BIGNUM** pub_key,
    const BIGNUM** priv_key) {
  // Based off of https://wiki.openssl.org/index.php/OpenSSL_1.1.0_Changes
  if (pub_key != nullptr) {
    *pub_key = dh->pub_key;
  }
  if (priv_key != nullptr) {
    *priv_key = dh->priv_key;
  }
}

void DSA_get0_pqg(
    const DSA* dsa,
    const BIGNUM** p,
    const BIGNUM** q,
    const BIGNUM** g) {
  // Based off of https://wiki.openssl.org/index.php/OpenSSL_1.1.0_Changes
  if (p != nullptr) {
    *p = dsa->p;
  }
  if (q != nullptr) {
    *q = dsa->q;
  }
  if (g != nullptr) {
    *g = dsa->g;
  }
}

void DSA_get0_key(
    const DSA* dsa,
    const BIGNUM** pub_key,
    const BIGNUM** priv_key) {
  // Based off of https://wiki.openssl.org/index.php/OpenSSL_1.1.0_Changes
  if (pub_key != nullptr) {
    *pub_key = dsa->pub_key;
  }
  if (priv_key != nullptr) {
    *priv_key = dsa->priv_key;
  }
}

X509* X509_STORE_CTX_get0_cert(X509_STORE_CTX* ctx) {
  return ctx->cert;
}

STACK_OF(X509) * X509_STORE_CTX_get0_chain(X509_STORE_CTX* ctx) {
  return X509_STORE_CTX_get_chain(ctx);
}

STACK_OF(X509) * X509_STORE_CTX_get0_untrusted(X509_STORE_CTX* ctx) {
  return ctx->untrusted;
}

EVP_MD_CTX* EVP_MD_CTX_new() {
  EVP_MD_CTX* ctx = (EVP_MD_CTX*)OPENSSL_malloc(sizeof(EVP_MD_CTX));
  if (!ctx) {
    throw std::runtime_error("Cannot allocate EVP_MD_CTX");
  }
  EVP_MD_CTX_init(ctx);
  return ctx;
}

void EVP_MD_CTX_free(EVP_MD_CTX* ctx) {
  if (ctx) {
    EVP_MD_CTX_cleanup(ctx);
    OPENSSL_free(ctx);
  }
}

HMAC_CTX* HMAC_CTX_new() {
  HMAC_CTX* ctx = (HMAC_CTX*)OPENSSL_malloc(sizeof(HMAC_CTX));
  if (!ctx) {
    throw std::runtime_error("Cannot allocate HMAC_CTX");
  }
  HMAC_CTX_init(ctx);
  return ctx;
}

void HMAC_CTX_free(HMAC_CTX* ctx) {
  if (ctx) {
    HMAC_CTX_cleanup(ctx);
    OPENSSL_free(ctx);
  }
}

bool RSA_set0_key(RSA* r, BIGNUM* n, BIGNUM* e, BIGNUM* d) {
  // Based off of https://wiki.openssl.org/index.php/OpenSSL_1.1.0_Changes
  /**
   * If the fields n and e in r are nullptr, the corresponding input parameters
   * MUST be non-nullptr for n and e. d may be left NULL (in case only the
   * public key is used).
   */
  if ((r->n == nullptr && n == nullptr) || (r->e == nullptr && e == nullptr)) {
    return false;
  }
  if (n != nullptr) {
    BN_free(r->n);
    r->n = n;
  }
  if (e != nullptr) {
    BN_free(r->e);
    r->e = e;
  }
  if (d != nullptr) {
    BN_free(r->d);
    r->d = d;
  }
  return true;
}

void RSA_get0_factors(const RSA* r, const BIGNUM** p, const BIGNUM** q) {
  // Based off of https://wiki.openssl.org/index.php/OpenSSL_1.1.0_Changes
  if (p != nullptr) {
    *p = r->p;
  }
  if (q != nullptr) {
    *q = r->q;
  }
}

void RSA_get0_crt_params(
    const RSA* r,
    const BIGNUM** dmp1,
    const BIGNUM** dmq1,
    const BIGNUM** iqmp) {
  // Based off of https://wiki.openssl.org/index.php/OpenSSL_1.1.0_Changes
  if (dmp1 != nullptr) {
    *dmp1 = r->dmp1;
  }
  if (dmq1 != nullptr) {
    *dmq1 = r->dmq1;
  }
  if (iqmp != nullptr) {
    *iqmp = r->iqmp;
  }
}

int ECDSA_SIG_set0(ECDSA_SIG* sig, BIGNUM* r, BIGNUM* s) {
  // Based off of https://wiki.openssl.org/index.php/OpenSSL_1.1.0_Changes
  if (r == nullptr || s == nullptr) {
    return 0;
  }
  BN_clear_free(sig->r);
  BN_clear_free(sig->s);
  sig->r = r;
  sig->s = s;
  return 1;
}

void ECDSA_SIG_get0(
    const ECDSA_SIG* sig,
    const BIGNUM** pr,
    const BIGNUM** ps) {
  // Based off of https://wiki.openssl.org/index.php/OpenSSL_1.1.0_Changes
  if (pr != nullptr) {
    *pr = sig->r;
  }
  if (ps != nullptr) {
    *ps = sig->s;
  }
}

/**
 * Compatibility shim for OpenSSL < 1.1.0.
 *
 * For now, options and settings are ignored. We implement the most common
 * behavior, which is to add all digests, ciphers, and strings.
 */
int OPENSSL_init_ssl(uint64_t, const OPENSSL_INIT_SETTINGS*) {
  // OpenSSL >= 1.1.0 handles initializing the library, adding digests &
  // ciphers, loading strings. Additionally, OpenSSL >= 1.1.0 uses platform
  // native threading & mutexes, which means that we should handle setting up
  // the necessary threading initialization in the compat layer as well.
  SSL_library_init();
  OpenSSL_add_all_ciphers();
  OpenSSL_add_all_digests();
  OpenSSL_add_all_algorithms();

  SSL_load_error_strings();
  ERR_load_crypto_strings();

  // The caller should have used SSLContext::setLockTypes() prior to calling
  // this function.
  folly::ssl::detail::installThreadingLocks();
  return 0;
}

void OPENSSL_cleanup() {
  folly::ssl::detail::cleanupThreadingLocks();
  CRYPTO_cleanup_all_ex_data();
  ERR_free_strings();
  EVP_cleanup();
  ERR_clear_error();
}

const ASN1_INTEGER* X509_REVOKED_get0_serialNumber(const X509_REVOKED* r) {
  return r->serialNumber;
}

const ASN1_TIME* X509_REVOKED_get0_revocationDate(const X509_REVOKED* r) {
  return r->revocationDate;
}

#endif // !FOLLY_OPENSSL_IS_110
} // namespace ssl
} // namespace portability
} // namespace folly
