rtc_base/openssl_certificate.cc - src - Git at Google

 /*
  *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */

 #include "rtc_base/openssl_certificate.h"

 #if defined(WEBRTC_WIN)
 // Must be included first before openssl headers.
 #include "rtc_base/win32.h"  // NOLINT
 #endif                       // WEBRTC_WIN

 #include <openssl/bio.h>
 #include <openssl/bn.h>
 #include <openssl/pem.h>
 #include <time.h>

 #include "absl/memory/memory.h"
 #include "rtc_base/checks.h"
 #include "rtc_base/helpers.h"
 #include "rtc_base/logging.h"
 #include "rtc_base/message_digest.h"
 #include "rtc_base/openssl_digest.h"
 #include "rtc_base/openssl_identity.h"
 #include "rtc_base/openssl_utility.h"

 namespace rtc {
 namespace {

 // Random bits for certificate serial number
 static const int SERIAL_RAND_BITS = 64;

 #if !defined(NDEBUG)
 // Print a certificate to the log, for debugging.
 static void PrintCert(X509* x509) {
   BIO* temp_memory_bio = BIO_new(BIO_s_mem());
   if (!temp_memory_bio) {
     RTC_DLOG_F(LS_ERROR) << "Failed to allocate temporary memory bio";
     return;
   }
   X509_print_ex(temp_memory_bio, x509, XN_FLAG_SEP_CPLUS_SPC, 0);
   BIO_write(temp_memory_bio, "\0", 1);
   char* buffer;
   BIO_get_mem_data(temp_memory_bio, &buffer);
   RTC_DLOG(LS_VERBOSE) << buffer;
   BIO_free(temp_memory_bio);
 }
 #endif

 // Generate a self-signed certificate, with the public key from the
 // given key pair. Caller is responsible for freeing the returned object.
 static X509* MakeCertificate(EVP_PKEY* pkey, const SSLIdentityParams& params) {
   RTC_LOG(LS_INFO) << "Making certificate for " << params.common_name;

   ASN1_INTEGER* asn1_serial_number = nullptr;
   BIGNUM* serial_number = nullptr;
   X509* x509 = nullptr;
   X509_NAME* name = nullptr;
   time_t epoch_off = 0;  // Time offset since epoch.

   if ((x509 = X509_new()) == nullptr) {
     goto error;
   }
   if (!X509_set_pubkey(x509, pkey)) {
     goto error;
   }
   // serial number - temporary reference to serial number inside x509 struct
   if ((serial_number = BN_new()) == nullptr ||
       !BN_pseudo_rand(serial_number, SERIAL_RAND_BITS, 0, 0) ||
       (asn1_serial_number = X509_get_serialNumber(x509)) == nullptr ||
       !BN_to_ASN1_INTEGER(serial_number, asn1_serial_number)) {
     goto error;
   }
   // Set version to X509.V3
   if (!X509_set_version(x509, 2L)) {
     goto error;
   }

   // There are a lot of possible components for the name entries. In
   // our P2P SSL mode however, the certificates are pre-exchanged
   // (through the secure XMPP channel), and so the certificate
   // identification is arbitrary. It can't be empty, so we set some
   // arbitrary common_name. Note that this certificate goes out in
   // clear during SSL negotiation, so there may be a privacy issue in
   // putting anything recognizable here.
   if ((name = X509_NAME_new()) == nullptr ||
       !X509_NAME_add_entry_by_NID(name, NID_commonName, MBSTRING_UTF8,
                                   (unsigned char*)params.common_name.c_str(),
                                   -1, -1, 0) ||
       !X509_set_subject_name(x509, name) || !X509_set_issuer_name(x509, name)) {
     goto error;
   }
   if (!X509_time_adj(X509_get_notBefore(x509), params.not_before, &epoch_off) ||
       !X509_time_adj(X509_get_notAfter(x509), params.not_after, &epoch_off)) {
     goto error;
   }
   if (!X509_sign(x509, pkey, EVP_sha256())) {
     goto error;
   }

   BN_free(serial_number);
   X509_NAME_free(name);
   RTC_LOG(LS_INFO) << "Returning certificate";
   return x509;

 error:
   BN_free(serial_number);
   X509_NAME_free(name);
   X509_free(x509);
   return nullptr;
 }

 }  // namespace

 OpenSSLCertificate::OpenSSLCertificate(X509* x509) : x509_(x509) {
   RTC_DCHECK(x509_ != nullptr);
   X509_up_ref(x509_);
 }

 std::unique_ptr<OpenSSLCertificate> OpenSSLCertificate::Generate(
     OpenSSLKeyPair* key_pair,
     const SSLIdentityParams& params) {
   SSLIdentityParams actual_params(params);
   if (actual_params.common_name.empty()) {
     // Use a random string, arbitrarily 8chars long.
     actual_params.common_name = CreateRandomString(8);
   }
   X509* x509 = MakeCertificate(key_pair->pkey(), actual_params);
   if (!x509) {
     openssl::LogSSLErrors("Generating certificate");
     return nullptr;
   }
 #if !defined(NDEBUG)
   PrintCert(x509);
 #endif
   auto ret = absl::make_unique<OpenSSLCertificate>(x509);
   X509_free(x509);
   return ret;
 }

 std::unique_ptr<OpenSSLCertificate> OpenSSLCertificate::FromPEMString(
     const std::string& pem_string) {
   BIO* bio = BIO_new_mem_buf(const_cast<char*>(pem_string.c_str()), -1);
   if (!bio) {
     return nullptr;
   }

   BIO_set_mem_eof_return(bio, 0);
   X509* x509 =
       PEM_read_bio_X509(bio, nullptr, nullptr, const_cast<char*>("\0"));
   BIO_free(bio);  // Frees the BIO, but not the pointed-to string.

   if (!x509) {
     return nullptr;
   }
   auto ret = absl::make_unique<OpenSSLCertificate>(x509);
   X509_free(x509);
   return ret;
 }

 // NOTE: This implementation only functions correctly after InitializeSSL
 // and before CleanupSSL.
 bool OpenSSLCertificate::GetSignatureDigestAlgorithm(
     std::string* algorithm) const {
   int nid = X509_get_signature_nid(x509_);
   switch (nid) {
     case NID_md5WithRSA:
     case NID_md5WithRSAEncryption:
       *algorithm = DIGEST_MD5;
       break;
     case NID_ecdsa_with_SHA1:
     case NID_dsaWithSHA1:
     case NID_dsaWithSHA1_2:
     case NID_sha1WithRSA:
     case NID_sha1WithRSAEncryption:
       *algorithm = DIGEST_SHA_1;
       break;
     case NID_ecdsa_with_SHA224:
     case NID_sha224WithRSAEncryption:
     case NID_dsa_with_SHA224:
       *algorithm = DIGEST_SHA_224;
       break;
     case NID_ecdsa_with_SHA256:
     case NID_sha256WithRSAEncryption:
     case NID_dsa_with_SHA256:
       *algorithm = DIGEST_SHA_256;
       break;
     case NID_ecdsa_with_SHA384:
     case NID_sha384WithRSAEncryption:
       *algorithm = DIGEST_SHA_384;
       break;
     case NID_ecdsa_with_SHA512:
     case NID_sha512WithRSAEncryption:
       *algorithm = DIGEST_SHA_512;
       break;
     default:
       // Unknown algorithm.  There are several unhandled options that are less
       // common and more complex.
       RTC_LOG(LS_ERROR) << "Unknown signature algorithm NID: " << nid;
       algorithm->clear();
       return false;
   }
   return true;
 }

 bool OpenSSLCertificate::ComputeDigest(const std::string& algorithm,
                                        unsigned char* digest,
                                        size_t size,
                                        size_t* length) const {
   return ComputeDigest(x509_, algorithm, digest, size, length);
 }

 bool OpenSSLCertificate::ComputeDigest(const X509* x509,
                                        const std::string& algorithm,
                                        unsigned char* digest,
                                        size_t size,
                                        size_t* length) {
   const EVP_MD* md = nullptr;
   unsigned int n = 0;
   if (!OpenSSLDigest::GetDigestEVP(algorithm, &md)) {
     return false;
   }
   if (size < static_cast<size_t>(EVP_MD_size(md))) {
     return false;
   }
   X509_digest(x509, md, digest, &n);
   *length = n;
   return true;
 }

 OpenSSLCertificate::~OpenSSLCertificate() {
   X509_free(x509_);
 }

 std::unique_ptr<SSLCertificate> OpenSSLCertificate::Clone() const {
   return absl::make_unique<OpenSSLCertificate>(x509_);
 }

 std::string OpenSSLCertificate::ToPEMString() const {
   BIO* bio = BIO_new(BIO_s_mem());
   if (!bio) {
     FATAL() << "Unreachable code.";
   }
   if (!PEM_write_bio_X509(bio, x509_)) {
     BIO_free(bio);
     FATAL() << "Unreachable code.";
   }
   BIO_write(bio, "\0", 1);
   char* buffer;
   BIO_get_mem_data(bio, &buffer);
   std::string ret(buffer);
   BIO_free(bio);
   return ret;
 }

 void OpenSSLCertificate::ToDER(Buffer* der_buffer) const {
   // In case of failure, make sure to leave the buffer empty.
   der_buffer->SetSize(0);
   // Calculates the DER representation of the certificate, from scratch.
   BIO* bio = BIO_new(BIO_s_mem());
   if (!bio) {
     FATAL() << "Unreachable code.";
   }
   if (!i2d_X509_bio(bio, x509_)) {
     BIO_free(bio);
     FATAL() << "Unreachable code.";
   }
   char* data = nullptr;
   size_t length = BIO_get_mem_data(bio, &data);
   der_buffer->SetData(data, length);
   BIO_free(bio);
 }

 bool OpenSSLCertificate::operator==(const OpenSSLCertificate& other) const {
   return X509_cmp(x509_, other.x509_) == 0;
 }

 bool OpenSSLCertificate::operator!=(const OpenSSLCertificate& other) const {
   return !(*this == other);
 }

 int64_t OpenSSLCertificate::CertificateExpirationTime() const {
   ASN1_TIME* expire_time = X509_get_notAfter(x509_);
   bool long_format;
   if (expire_time->type == V_ASN1_UTCTIME) {
     long_format = false;
   } else if (expire_time->type == V_ASN1_GENERALIZEDTIME) {
     long_format = true;
   } else {
     return -1;
   }
   return ASN1TimeToSec(expire_time->data, expire_time->length, long_format);
 }

 }  // namespace rtc
	/*
	* Copyright 2004 The WebRTC Project Authors. All rights reserved.
	*
	* Use of this source code is governed by a BSD-style license
	* that can be found in the LICENSE file in the root of the source
	* tree. An additional intellectual property rights grant can be found
	* in the file PATENTS. All contributing project authors may
	* be found in the AUTHORS file in the root of the source tree.
	*/

	#include "rtc_base/openssl_certificate.h"

	#if defined(WEBRTC_WIN)
	// Must be included first before openssl headers.
	#include "rtc_base/win32.h" // NOLINT
	#endif // WEBRTC_WIN

	#include <openssl/bio.h>
	#include <openssl/bn.h>
	#include <openssl/pem.h>
	#include <time.h>

	#include "absl/memory/memory.h"
	#include "rtc_base/checks.h"
	#include "rtc_base/helpers.h"
	#include "rtc_base/logging.h"
	#include "rtc_base/message_digest.h"
	#include "rtc_base/openssl_digest.h"
	#include "rtc_base/openssl_identity.h"
	#include "rtc_base/openssl_utility.h"

	namespace rtc {
	namespace {

	// Random bits for certificate serial number
	static const int SERIAL_RAND_BITS = 64;

	#if !defined(NDEBUG)
	// Print a certificate to the log, for debugging.
	static void PrintCert(X509* x509) {
	BIO* temp_memory_bio = BIO_new(BIO_s_mem());
	if (!temp_memory_bio) {
	RTC_DLOG_F(LS_ERROR) << "Failed to allocate temporary memory bio";
	return;
	}
	X509_print_ex(temp_memory_bio, x509, XN_FLAG_SEP_CPLUS_SPC, 0);
	BIO_write(temp_memory_bio, "\0", 1);
	char* buffer;
	BIO_get_mem_data(temp_memory_bio, &buffer);
	RTC_DLOG(LS_VERBOSE) << buffer;
	BIO_free(temp_memory_bio);
	}
	#endif

	// Generate a self-signed certificate, with the public key from the
	// given key pair. Caller is responsible for freeing the returned object.
	static X509* MakeCertificate(EVP_PKEY* pkey, const SSLIdentityParams& params) {
	RTC_LOG(LS_INFO) << "Making certificate for " << params.common_name;

	ASN1_INTEGER* asn1_serial_number = nullptr;
	BIGNUM* serial_number = nullptr;
	X509* x509 = nullptr;
	X509_NAME* name = nullptr;
	time_t epoch_off = 0; // Time offset since epoch.

	if ((x509 = X509_new()) == nullptr) {
	goto error;
	}
	if (!X509_set_pubkey(x509, pkey)) {
	goto error;
	}
	// serial number - temporary reference to serial number inside x509 struct
	if ((serial_number = BN_new()) == nullptr \|\|
	!BN_pseudo_rand(serial_number, SERIAL_RAND_BITS, 0, 0) \|\|
	(asn1_serial_number = X509_get_serialNumber(x509)) == nullptr \|\|
	!BN_to_ASN1_INTEGER(serial_number, asn1_serial_number)) {
	goto error;
	}
	// Set version to X509.V3
	if (!X509_set_version(x509, 2L)) {
	goto error;
	}

	// There are a lot of possible components for the name entries. In
	// our P2P SSL mode however, the certificates are pre-exchanged
	// (through the secure XMPP channel), and so the certificate
	// identification is arbitrary. It can't be empty, so we set some
	// arbitrary common_name. Note that this certificate goes out in
	// clear during SSL negotiation, so there may be a privacy issue in
	// putting anything recognizable here.
	if ((name = X509_NAME_new()) == nullptr \|\|
	!X509_NAME_add_entry_by_NID(name, NID_commonName, MBSTRING_UTF8,
	(unsigned char*)params.common_name.c_str(),
	-1, -1, 0) \|\|
	!X509_set_subject_name(x509, name) \|\| !X509_set_issuer_name(x509, name)) {
	goto error;
	}
	if (!X509_time_adj(X509_get_notBefore(x509), params.not_before, &epoch_off) \|\|
	!X509_time_adj(X509_get_notAfter(x509), params.not_after, &epoch_off)) {
	goto error;
	}
	if (!X509_sign(x509, pkey, EVP_sha256())) {
	goto error;
	}

	BN_free(serial_number);
	X509_NAME_free(name);
	RTC_LOG(LS_INFO) << "Returning certificate";
	return x509;

	error:
	BN_free(serial_number);
	X509_NAME_free(name);
	X509_free(x509);
	return nullptr;
	}

	} // namespace

	OpenSSLCertificate::OpenSSLCertificate(X509* x509) : x509_(x509) {
	RTC_DCHECK(x509_ != nullptr);
	X509_up_ref(x509_);
	}

	std::unique_ptr<OpenSSLCertificate> OpenSSLCertificate::Generate(
	OpenSSLKeyPair* key_pair,
	const SSLIdentityParams& params) {
	SSLIdentityParams actual_params(params);
	if (actual_params.common_name.empty()) {
	// Use a random string, arbitrarily 8chars long.
	actual_params.common_name = CreateRandomString(8);
	}
	X509* x509 = MakeCertificate(key_pair->pkey(), actual_params);
	if (!x509) {
	openssl::LogSSLErrors("Generating certificate");
	return nullptr;
	}
	#if !defined(NDEBUG)
	PrintCert(x509);
	#endif
	auto ret = absl::make_unique<OpenSSLCertificate>(x509);
	X509_free(x509);
	return ret;
	}

	std::unique_ptr<OpenSSLCertificate> OpenSSLCertificate::FromPEMString(
	const std::string& pem_string) {
	BIO* bio = BIO_new_mem_buf(const_cast<char*>(pem_string.c_str()), -1);
	if (!bio) {
	return nullptr;
	}

	BIO_set_mem_eof_return(bio, 0);
	X509* x509 =
	PEM_read_bio_X509(bio, nullptr, nullptr, const_cast<char*>("\0"));
	BIO_free(bio); // Frees the BIO, but not the pointed-to string.

	if (!x509) {
	return nullptr;
	}
	auto ret = absl::make_unique<OpenSSLCertificate>(x509);
	X509_free(x509);
	return ret;
	}

	// NOTE: This implementation only functions correctly after InitializeSSL
	// and before CleanupSSL.
	bool OpenSSLCertificate::GetSignatureDigestAlgorithm(
	std::string* algorithm) const {
	int nid = X509_get_signature_nid(x509_);
	switch (nid) {
	case NID_md5WithRSA:
	case NID_md5WithRSAEncryption:
	*algorithm = DIGEST_MD5;
	break;
	case NID_ecdsa_with_SHA1:
	case NID_dsaWithSHA1:
	case NID_dsaWithSHA1_2:
	case NID_sha1WithRSA:
	case NID_sha1WithRSAEncryption:
	*algorithm = DIGEST_SHA_1;
	break;
	case NID_ecdsa_with_SHA224:
	case NID_sha224WithRSAEncryption:
	case NID_dsa_with_SHA224:
	*algorithm = DIGEST_SHA_224;
	break;
	case NID_ecdsa_with_SHA256:
	case NID_sha256WithRSAEncryption:
	case NID_dsa_with_SHA256:
	*algorithm = DIGEST_SHA_256;
	break;
	case NID_ecdsa_with_SHA384:
	case NID_sha384WithRSAEncryption:
	*algorithm = DIGEST_SHA_384;
	break;
	case NID_ecdsa_with_SHA512:
	case NID_sha512WithRSAEncryption:
	*algorithm = DIGEST_SHA_512;
	break;
	default:
	// Unknown algorithm. There are several unhandled options that are less
	// common and more complex.
	RTC_LOG(LS_ERROR) << "Unknown signature algorithm NID: " << nid;
	algorithm->clear();
	return false;
	}
	return true;
	}

	bool OpenSSLCertificate::ComputeDigest(const std::string& algorithm,
	unsigned char* digest,
	size_t size,
	size_t* length) const {
	return ComputeDigest(x509_, algorithm, digest, size, length);
	}

	bool OpenSSLCertificate::ComputeDigest(const X509* x509,
	const std::string& algorithm,
	unsigned char* digest,
	size_t size,
	size_t* length) {
	const EVP_MD* md = nullptr;
	unsigned int n = 0;
	if (!OpenSSLDigest::GetDigestEVP(algorithm, &md)) {
	return false;
	}
	if (size < static_cast<size_t>(EVP_MD_size(md))) {
	return false;
	}
	X509_digest(x509, md, digest, &n);
	*length = n;
	return true;
	}

	OpenSSLCertificate::~OpenSSLCertificate() {
	X509_free(x509_);
	}

	std::unique_ptr<SSLCertificate> OpenSSLCertificate::Clone() const {
	return absl::make_unique<OpenSSLCertificate>(x509_);
	}

	std::string OpenSSLCertificate::ToPEMString() const {
	BIO* bio = BIO_new(BIO_s_mem());
	if (!bio) {
	FATAL() << "Unreachable code.";
	}
	if (!PEM_write_bio_X509(bio, x509_)) {
	BIO_free(bio);
	FATAL() << "Unreachable code.";
	}
	BIO_write(bio, "\0", 1);
	char* buffer;
	BIO_get_mem_data(bio, &buffer);
	std::string ret(buffer);
	BIO_free(bio);
	return ret;
	}

	void OpenSSLCertificate::ToDER(Buffer* der_buffer) const {
	// In case of failure, make sure to leave the buffer empty.
	der_buffer->SetSize(0);
	// Calculates the DER representation of the certificate, from scratch.
	BIO* bio = BIO_new(BIO_s_mem());
	if (!bio) {
	FATAL() << "Unreachable code.";
	}
	if (!i2d_X509_bio(bio, x509_)) {
	BIO_free(bio);
	FATAL() << "Unreachable code.";
	}
	char* data = nullptr;
	size_t length = BIO_get_mem_data(bio, &data);
	der_buffer->SetData(data, length);
	BIO_free(bio);
	}

	bool OpenSSLCertificate::operator==(const OpenSSLCertificate& other) const {
	return X509_cmp(x509_, other.x509_) == 0;
	}

	bool OpenSSLCertificate::operator!=(const OpenSSLCertificate& other) const {
	return !(*this == other);
	}

	int64_t OpenSSLCertificate::CertificateExpirationTime() const {
	ASN1_TIME* expire_time = X509_get_notAfter(x509_);
	bool long_format;
	if (expire_time->type == V_ASN1_UTCTIME) {
	long_format = false;
	} else if (expire_time->type == V_ASN1_GENERALIZEDTIME) {
	long_format = true;
	} else {
	return -1;
	}
	return ASN1TimeToSec(expire_time->data, expire_time->length, long_format);
	}

	} // namespace rtc