| // Copyright (c) 2013 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "net/third_party/quiche/src/quic/core/crypto/crypto_utils.h" |
| |
| #include <memory> |
| #include <string> |
| |
| #include "third_party/boringssl/src/include/openssl/bytestring.h" |
| #include "third_party/boringssl/src/include/openssl/hkdf.h" |
| #include "third_party/boringssl/src/include/openssl/sha.h" |
| #include "net/third_party/quiche/src/quic/core/crypto/aes_128_gcm_decrypter.h" |
| #include "net/third_party/quiche/src/quic/core/crypto/aes_128_gcm_encrypter.h" |
| #include "net/third_party/quiche/src/quic/core/crypto/crypto_handshake.h" |
| #include "net/third_party/quiche/src/quic/core/crypto/crypto_protocol.h" |
| #include "net/third_party/quiche/src/quic/core/crypto/quic_decrypter.h" |
| #include "net/third_party/quiche/src/quic/core/crypto/quic_encrypter.h" |
| #include "net/third_party/quiche/src/quic/core/crypto/quic_hkdf.h" |
| #include "net/third_party/quiche/src/quic/core/crypto/quic_random.h" |
| #include "net/third_party/quiche/src/quic/core/quic_data_writer.h" |
| #include "net/third_party/quiche/src/quic/core/quic_time.h" |
| #include "net/third_party/quiche/src/quic/core/quic_utils.h" |
| #include "net/third_party/quiche/src/quic/platform/api/quic_arraysize.h" |
| #include "net/third_party/quiche/src/quic/platform/api/quic_bug_tracker.h" |
| #include "net/third_party/quiche/src/quic/platform/api/quic_logging.h" |
| #include "net/third_party/quiche/src/quic/platform/api/quic_ptr_util.h" |
| #include "net/third_party/quiche/src/quic/platform/api/quic_str_cat.h" |
| |
| namespace quic { |
| |
| // TODO(nharper): HkdfExpandLabel and SetKeyAndIV (below) implement what is |
| // specified in draft-ietf-quic-tls-16. The latest editors' draft has changed |
| // derivation again, and this will need to be updated to reflect those (and any |
| // other future) changes. |
| // static |
| std::vector<uint8_t> CryptoUtils::HkdfExpandLabel( |
| const EVP_MD* prf, |
| const std::vector<uint8_t>& secret, |
| const std::string& label, |
| size_t out_len) { |
| bssl::ScopedCBB quic_hkdf_label; |
| CBB inner_label; |
| const char label_prefix[] = "tls13 "; |
| // 19 = size(u16) + size(u8) + len("tls13 ") + len ("client in") + size(u8) |
| static const size_t max_quic_hkdf_label_length = 19; |
| if (!CBB_init(quic_hkdf_label.get(), max_quic_hkdf_label_length) || |
| !CBB_add_u16(quic_hkdf_label.get(), out_len) || |
| !CBB_add_u8_length_prefixed(quic_hkdf_label.get(), &inner_label) || |
| !CBB_add_bytes(&inner_label, |
| reinterpret_cast<const uint8_t*>(label_prefix), |
| QUIC_ARRAYSIZE(label_prefix) - 1) || |
| !CBB_add_bytes(&inner_label, |
| reinterpret_cast<const uint8_t*>(label.data()), |
| label.size()) || |
| !CBB_add_u8(quic_hkdf_label.get(), 0) || |
| !CBB_flush(quic_hkdf_label.get())) { |
| QUIC_LOG(ERROR) << "Building HKDF label failed"; |
| return std::vector<uint8_t>(); |
| } |
| std::vector<uint8_t> out; |
| out.resize(out_len); |
| if (!HKDF_expand(out.data(), out_len, prf, secret.data(), secret.size(), |
| CBB_data(quic_hkdf_label.get()), |
| CBB_len(quic_hkdf_label.get()))) { |
| QUIC_LOG(ERROR) << "Running HKDF-Expand-Label failed"; |
| return std::vector<uint8_t>(); |
| } |
| return out; |
| } |
| |
| void CryptoUtils::SetKeyAndIV(const EVP_MD* prf, |
| const std::vector<uint8_t>& pp_secret, |
| QuicCrypter* crypter) { |
| std::vector<uint8_t> key = CryptoUtils::HkdfExpandLabel( |
| prf, pp_secret, "quic key", crypter->GetKeySize()); |
| std::vector<uint8_t> iv = CryptoUtils::HkdfExpandLabel( |
| prf, pp_secret, "quic iv", crypter->GetIVSize()); |
| std::vector<uint8_t> pn = CryptoUtils::HkdfExpandLabel( |
| prf, pp_secret, "quic hp", crypter->GetKeySize()); |
| crypter->SetKey( |
| QuicStringPiece(reinterpret_cast<char*>(key.data()), key.size())); |
| crypter->SetIV( |
| QuicStringPiece(reinterpret_cast<char*>(iv.data()), iv.size())); |
| crypter->SetHeaderProtectionKey( |
| QuicStringPiece(reinterpret_cast<char*>(pn.data()), pn.size())); |
| } |
| |
| namespace { |
| |
| const uint8_t kInitialSalt[] = {0x7f, 0xbc, 0xdb, 0x0e, 0x7c, 0x66, 0xbb, |
| 0xe9, 0x19, 0x3a, 0x96, 0xcd, 0x21, 0x51, |
| 0x9e, 0xbd, 0x7a, 0x02, 0x64, 0x4a}; |
| |
| const char kPreSharedKeyLabel[] = "QUIC PSK"; |
| |
| } // namespace |
| |
| // static |
| void CryptoUtils::CreateTlsInitialCrypters(Perspective perspective, |
| QuicTransportVersion version, |
| QuicConnectionId connection_id, |
| CrypterPair* crypters) { |
| QUIC_DLOG(INFO) << "Creating " |
| << (perspective == Perspective::IS_CLIENT ? "client" |
| : "server") |
| << " TLS crypters for " << connection_id; |
| QUIC_BUG_IF(!QuicUtils::IsConnectionIdValidForVersion(connection_id, version)) |
| << "CreateTlsInitialCrypters: attempted to use connection ID " |
| << connection_id << " which is invalid with version " |
| << QuicVersionToString(version); |
| const EVP_MD* hash = EVP_sha256(); |
| |
| std::vector<uint8_t> handshake_secret; |
| handshake_secret.resize(EVP_MAX_MD_SIZE); |
| size_t handshake_secret_len; |
| const bool hkdf_extract_success = HKDF_extract( |
| handshake_secret.data(), &handshake_secret_len, hash, |
| reinterpret_cast<const uint8_t*>(connection_id.data()), |
| connection_id.length(), kInitialSalt, QUIC_ARRAYSIZE(kInitialSalt)); |
| QUIC_BUG_IF(!hkdf_extract_success) |
| << "HKDF_extract failed when creating initial crypters"; |
| handshake_secret.resize(handshake_secret_len); |
| |
| const std::string client_label = "client in"; |
| const std::string server_label = "server in"; |
| std::string encryption_label, decryption_label; |
| if (perspective == Perspective::IS_CLIENT) { |
| encryption_label = client_label; |
| decryption_label = server_label; |
| } else { |
| encryption_label = server_label; |
| decryption_label = client_label; |
| } |
| crypters->encrypter = QuicMakeUnique<Aes128GcmEncrypter>(); |
| std::vector<uint8_t> encryption_secret = HkdfExpandLabel( |
| hash, handshake_secret, encryption_label, EVP_MD_size(hash)); |
| SetKeyAndIV(hash, encryption_secret, crypters->encrypter.get()); |
| |
| crypters->decrypter = QuicMakeUnique<Aes128GcmDecrypter>(); |
| std::vector<uint8_t> decryption_secret = HkdfExpandLabel( |
| hash, handshake_secret, decryption_label, EVP_MD_size(hash)); |
| SetKeyAndIV(hash, decryption_secret, crypters->decrypter.get()); |
| } |
| |
| // static |
| void CryptoUtils::GenerateNonce(QuicWallTime now, |
| QuicRandom* random_generator, |
| QuicStringPiece orbit, |
| std::string* nonce) { |
| // a 4-byte timestamp + 28 random bytes. |
| nonce->reserve(kNonceSize); |
| nonce->resize(kNonceSize); |
| |
| uint32_t gmt_unix_time = static_cast<uint32_t>(now.ToUNIXSeconds()); |
| // The time in the nonce must be encoded in big-endian because the |
| // strike-register depends on the nonces being ordered by time. |
| (*nonce)[0] = static_cast<char>(gmt_unix_time >> 24); |
| (*nonce)[1] = static_cast<char>(gmt_unix_time >> 16); |
| (*nonce)[2] = static_cast<char>(gmt_unix_time >> 8); |
| (*nonce)[3] = static_cast<char>(gmt_unix_time); |
| size_t bytes_written = 4; |
| |
| if (orbit.size() == 8) { |
| memcpy(&(*nonce)[bytes_written], orbit.data(), orbit.size()); |
| bytes_written += orbit.size(); |
| } |
| |
| random_generator->RandBytes(&(*nonce)[bytes_written], |
| kNonceSize - bytes_written); |
| } |
| |
| // static |
| bool CryptoUtils::DeriveKeys(QuicStringPiece premaster_secret, |
| QuicTag aead, |
| QuicStringPiece client_nonce, |
| QuicStringPiece server_nonce, |
| QuicStringPiece pre_shared_key, |
| const std::string& hkdf_input, |
| Perspective perspective, |
| Diversification diversification, |
| CrypterPair* crypters, |
| std::string* subkey_secret) { |
| // If the connection is using PSK, concatenate it with the pre-master secret. |
| std::unique_ptr<char[]> psk_premaster_secret; |
| if (!pre_shared_key.empty()) { |
| const QuicStringPiece label(kPreSharedKeyLabel); |
| const size_t psk_premaster_secret_size = label.size() + 1 + |
| pre_shared_key.size() + 8 + |
| premaster_secret.size() + 8; |
| |
| psk_premaster_secret = QuicMakeUnique<char[]>(psk_premaster_secret_size); |
| QuicDataWriter writer(psk_premaster_secret_size, psk_premaster_secret.get(), |
| HOST_BYTE_ORDER); |
| |
| if (!writer.WriteStringPiece(label) || !writer.WriteUInt8(0) || |
| !writer.WriteStringPiece(pre_shared_key) || |
| !writer.WriteUInt64(pre_shared_key.size()) || |
| !writer.WriteStringPiece(premaster_secret) || |
| !writer.WriteUInt64(premaster_secret.size()) || |
| writer.remaining() != 0) { |
| return false; |
| } |
| |
| premaster_secret = |
| QuicStringPiece(psk_premaster_secret.get(), psk_premaster_secret_size); |
| } |
| |
| crypters->encrypter = QuicEncrypter::Create(aead); |
| crypters->decrypter = QuicDecrypter::Create(aead); |
| size_t key_bytes = crypters->encrypter->GetKeySize(); |
| size_t nonce_prefix_bytes = crypters->encrypter->GetNoncePrefixSize(); |
| size_t subkey_secret_bytes = |
| subkey_secret == nullptr ? 0 : premaster_secret.length(); |
| |
| QuicStringPiece nonce = client_nonce; |
| std::string nonce_storage; |
| if (!server_nonce.empty()) { |
| nonce_storage = std::string(client_nonce) + std::string(server_nonce); |
| nonce = nonce_storage; |
| } |
| |
| QuicHKDF hkdf(premaster_secret, nonce, hkdf_input, key_bytes, |
| nonce_prefix_bytes, subkey_secret_bytes); |
| |
| // Key derivation depends on the key diversification method being employed. |
| // both the client and the server support never doing key diversification. |
| // The server also supports immediate diversification, and the client |
| // supports pending diversification. |
| switch (diversification.mode()) { |
| case Diversification::NEVER: { |
| if (perspective == Perspective::IS_SERVER) { |
| if (!crypters->encrypter->SetKey(hkdf.server_write_key()) || |
| !crypters->encrypter->SetNoncePrefix(hkdf.server_write_iv()) || |
| !crypters->encrypter->SetHeaderProtectionKey( |
| hkdf.server_hp_key()) || |
| !crypters->decrypter->SetKey(hkdf.client_write_key()) || |
| !crypters->decrypter->SetNoncePrefix(hkdf.client_write_iv()) || |
| !crypters->decrypter->SetHeaderProtectionKey( |
| hkdf.client_hp_key())) { |
| return false; |
| } |
| } else { |
| if (!crypters->encrypter->SetKey(hkdf.client_write_key()) || |
| !crypters->encrypter->SetNoncePrefix(hkdf.client_write_iv()) || |
| !crypters->encrypter->SetHeaderProtectionKey( |
| hkdf.client_hp_key()) || |
| !crypters->decrypter->SetKey(hkdf.server_write_key()) || |
| !crypters->decrypter->SetNoncePrefix(hkdf.server_write_iv()) || |
| !crypters->decrypter->SetHeaderProtectionKey( |
| hkdf.server_hp_key())) { |
| return false; |
| } |
| } |
| break; |
| } |
| case Diversification::PENDING: { |
| if (perspective == Perspective::IS_SERVER) { |
| QUIC_BUG << "Pending diversification is only for clients."; |
| return false; |
| } |
| |
| if (!crypters->encrypter->SetKey(hkdf.client_write_key()) || |
| !crypters->encrypter->SetNoncePrefix(hkdf.client_write_iv()) || |
| !crypters->encrypter->SetHeaderProtectionKey(hkdf.client_hp_key()) || |
| !crypters->decrypter->SetPreliminaryKey(hkdf.server_write_key()) || |
| !crypters->decrypter->SetNoncePrefix(hkdf.server_write_iv()) || |
| !crypters->decrypter->SetHeaderProtectionKey(hkdf.server_hp_key())) { |
| return false; |
| } |
| break; |
| } |
| case Diversification::NOW: { |
| if (perspective == Perspective::IS_CLIENT) { |
| QUIC_BUG << "Immediate diversification is only for servers."; |
| return false; |
| } |
| |
| std::string key, nonce_prefix; |
| QuicDecrypter::DiversifyPreliminaryKey( |
| hkdf.server_write_key(), hkdf.server_write_iv(), |
| *diversification.nonce(), key_bytes, nonce_prefix_bytes, &key, |
| &nonce_prefix); |
| if (!crypters->decrypter->SetKey(hkdf.client_write_key()) || |
| !crypters->decrypter->SetNoncePrefix(hkdf.client_write_iv()) || |
| !crypters->decrypter->SetHeaderProtectionKey(hkdf.client_hp_key()) || |
| !crypters->encrypter->SetKey(key) || |
| !crypters->encrypter->SetNoncePrefix(nonce_prefix) || |
| !crypters->encrypter->SetHeaderProtectionKey(hkdf.server_hp_key())) { |
| return false; |
| } |
| break; |
| } |
| default: |
| DCHECK(false); |
| } |
| |
| if (subkey_secret != nullptr) { |
| *subkey_secret = std::string(hkdf.subkey_secret()); |
| } |
| |
| return true; |
| } |
| |
| // static |
| bool CryptoUtils::ExportKeyingMaterial(QuicStringPiece subkey_secret, |
| QuicStringPiece label, |
| QuicStringPiece context, |
| size_t result_len, |
| std::string* result) { |
| for (size_t i = 0; i < label.length(); i++) { |
| if (label[i] == '\0') { |
| QUIC_LOG(ERROR) << "ExportKeyingMaterial label may not contain NULs"; |
| return false; |
| } |
| } |
| // Create HKDF info input: null-terminated label + length-prefixed context |
| if (context.length() >= std::numeric_limits<uint32_t>::max()) { |
| QUIC_LOG(ERROR) << "Context value longer than 2^32"; |
| return false; |
| } |
| uint32_t context_length = static_cast<uint32_t>(context.length()); |
| std::string info = std::string(label); |
| info.push_back('\0'); |
| info.append(reinterpret_cast<char*>(&context_length), sizeof(context_length)); |
| info.append(context.data(), context.length()); |
| |
| QuicHKDF hkdf(subkey_secret, QuicStringPiece() /* no salt */, info, |
| result_len, 0 /* no fixed IV */, 0 /* no subkey secret */); |
| *result = std::string(hkdf.client_write_key()); |
| return true; |
| } |
| |
| // static |
| uint64_t CryptoUtils::ComputeLeafCertHash(QuicStringPiece cert) { |
| return QuicUtils::FNV1a_64_Hash(cert); |
| } |
| |
| QuicErrorCode CryptoUtils::ValidateServerHello( |
| const CryptoHandshakeMessage& server_hello, |
| const ParsedQuicVersionVector& negotiated_versions, |
| std::string* error_details) { |
| DCHECK(error_details != nullptr); |
| |
| if (server_hello.tag() != kSHLO) { |
| *error_details = "Bad tag"; |
| return QUIC_INVALID_CRYPTO_MESSAGE_TYPE; |
| } |
| |
| QuicVersionLabelVector supported_version_labels; |
| if (server_hello.GetVersionLabelList(kVER, &supported_version_labels) != |
| QUIC_NO_ERROR) { |
| *error_details = "server hello missing version list"; |
| return QUIC_INVALID_CRYPTO_MESSAGE_PARAMETER; |
| } |
| |
| return ValidateServerHelloVersions(supported_version_labels, |
| negotiated_versions, error_details); |
| } |
| |
| QuicErrorCode CryptoUtils::ValidateServerHelloVersions( |
| const QuicVersionLabelVector& server_versions, |
| const ParsedQuicVersionVector& negotiated_versions, |
| std::string* error_details) { |
| if (!negotiated_versions.empty()) { |
| bool mismatch = server_versions.size() != negotiated_versions.size(); |
| for (size_t i = 0; i < server_versions.size() && !mismatch; ++i) { |
| mismatch = |
| server_versions[i] != CreateQuicVersionLabel(negotiated_versions[i]); |
| } |
| // The server sent a list of supported versions, and the connection |
| // reports that there was a version negotiation during the handshake. |
| // Ensure that these two lists are identical. |
| if (mismatch) { |
| *error_details = QuicStrCat( |
| "Downgrade attack detected: ServerVersions(", server_versions.size(), |
| ")[", QuicVersionLabelVectorToString(server_versions, ",", 30), |
| "] NegotiatedVersions(", negotiated_versions.size(), ")[", |
| ParsedQuicVersionVectorToString(negotiated_versions, ",", 30), "]"); |
| return QUIC_VERSION_NEGOTIATION_MISMATCH; |
| } |
| } |
| return QUIC_NO_ERROR; |
| } |
| |
| QuicErrorCode CryptoUtils::ValidateClientHello( |
| const CryptoHandshakeMessage& client_hello, |
| ParsedQuicVersion version, |
| const ParsedQuicVersionVector& supported_versions, |
| std::string* error_details) { |
| if (client_hello.tag() != kCHLO) { |
| *error_details = "Bad tag"; |
| return QUIC_INVALID_CRYPTO_MESSAGE_TYPE; |
| } |
| |
| // If the client's preferred version is not the version we are currently |
| // speaking, then the client went through a version negotiation. In this |
| // case, we need to make sure that we actually do not support this version |
| // and that it wasn't a downgrade attack. |
| QuicVersionLabel client_version_label; |
| if (client_hello.GetVersionLabel(kVER, &client_version_label) != |
| QUIC_NO_ERROR) { |
| *error_details = "client hello missing version list"; |
| return QUIC_INVALID_CRYPTO_MESSAGE_PARAMETER; |
| } |
| return ValidateClientHelloVersion(client_version_label, version, |
| supported_versions, error_details); |
| } |
| |
| QuicErrorCode CryptoUtils::ValidateClientHelloVersion( |
| QuicVersionLabel client_version, |
| ParsedQuicVersion connection_version, |
| const ParsedQuicVersionVector& supported_versions, |
| std::string* error_details) { |
| if (client_version != CreateQuicVersionLabel(connection_version)) { |
| // Check to see if |client_version| is actually on the supported versions |
| // list. If not, the server doesn't support that version and it's not a |
| // downgrade attack. |
| for (size_t i = 0; i < supported_versions.size(); ++i) { |
| if (client_version == CreateQuicVersionLabel(supported_versions[i])) { |
| *error_details = QuicStrCat( |
| "Downgrade attack detected: ClientVersion[", |
| QuicVersionLabelToString(client_version), "] SupportedVersions(", |
| supported_versions.size(), ")[", |
| ParsedQuicVersionVectorToString(supported_versions, ",", 30), "]"); |
| return QUIC_VERSION_NEGOTIATION_MISMATCH; |
| } |
| } |
| } |
| return QUIC_NO_ERROR; |
| } |
| |
| #define RETURN_STRING_LITERAL(x) \ |
| case x: \ |
| return #x |
| |
| // Returns the name of the HandshakeFailureReason as a char* |
| // static |
| const char* CryptoUtils::HandshakeFailureReasonToString( |
| HandshakeFailureReason reason) { |
| switch (reason) { |
| RETURN_STRING_LITERAL(HANDSHAKE_OK); |
| RETURN_STRING_LITERAL(CLIENT_NONCE_UNKNOWN_FAILURE); |
| RETURN_STRING_LITERAL(CLIENT_NONCE_INVALID_FAILURE); |
| RETURN_STRING_LITERAL(CLIENT_NONCE_NOT_UNIQUE_FAILURE); |
| RETURN_STRING_LITERAL(CLIENT_NONCE_INVALID_ORBIT_FAILURE); |
| RETURN_STRING_LITERAL(CLIENT_NONCE_INVALID_TIME_FAILURE); |
| RETURN_STRING_LITERAL(CLIENT_NONCE_STRIKE_REGISTER_TIMEOUT); |
| RETURN_STRING_LITERAL(CLIENT_NONCE_STRIKE_REGISTER_FAILURE); |
| |
| RETURN_STRING_LITERAL(SERVER_NONCE_DECRYPTION_FAILURE); |
| RETURN_STRING_LITERAL(SERVER_NONCE_INVALID_FAILURE); |
| RETURN_STRING_LITERAL(SERVER_NONCE_NOT_UNIQUE_FAILURE); |
| RETURN_STRING_LITERAL(SERVER_NONCE_INVALID_TIME_FAILURE); |
| RETURN_STRING_LITERAL(SERVER_NONCE_REQUIRED_FAILURE); |
| |
| RETURN_STRING_LITERAL(SERVER_CONFIG_INCHOATE_HELLO_FAILURE); |
| RETURN_STRING_LITERAL(SERVER_CONFIG_UNKNOWN_CONFIG_FAILURE); |
| |
| RETURN_STRING_LITERAL(SOURCE_ADDRESS_TOKEN_INVALID_FAILURE); |
| RETURN_STRING_LITERAL(SOURCE_ADDRESS_TOKEN_DECRYPTION_FAILURE); |
| RETURN_STRING_LITERAL(SOURCE_ADDRESS_TOKEN_PARSE_FAILURE); |
| RETURN_STRING_LITERAL(SOURCE_ADDRESS_TOKEN_DIFFERENT_IP_ADDRESS_FAILURE); |
| RETURN_STRING_LITERAL(SOURCE_ADDRESS_TOKEN_CLOCK_SKEW_FAILURE); |
| RETURN_STRING_LITERAL(SOURCE_ADDRESS_TOKEN_EXPIRED_FAILURE); |
| |
| RETURN_STRING_LITERAL(INVALID_EXPECTED_LEAF_CERTIFICATE); |
| RETURN_STRING_LITERAL(MAX_FAILURE_REASON); |
| } |
| // Return a default value so that we return this when |reason| doesn't match |
| // any HandshakeFailureReason.. This can happen when the message by the peer |
| // (attacker) has invalid reason. |
| return "INVALID_HANDSHAKE_FAILURE_REASON"; |
| } |
| |
| // static |
| std::string CryptoUtils::HashHandshakeMessage( |
| const CryptoHandshakeMessage& message, |
| Perspective /*perspective*/) { |
| std::string output; |
| const QuicData& serialized = message.GetSerialized(); |
| uint8_t digest[SHA256_DIGEST_LENGTH]; |
| SHA256(reinterpret_cast<const uint8_t*>(serialized.data()), |
| serialized.length(), digest); |
| output.assign(reinterpret_cast<const char*>(digest), sizeof(digest)); |
| return output; |
| } |
| |
| #undef RETURN_STRING_LITERAL // undef for jumbo builds |
| } // namespace quic |