| // Copyright 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 "chrome/browser/extensions/api/cast_channel/cast_auth_util.h" |
| |
| #include <cert.h> |
| #include <cryptohi.h> |
| #include <pk11pub.h> |
| #include <seccomon.h> |
| #include <string> |
| |
| #include "base/logging.h" |
| #include "chrome/browser/extensions/api/cast_channel/cast_channel.pb.h" |
| #include "chrome/browser/extensions/api/cast_channel/cast_message_util.h" |
| #include "crypto/nss_util.h" |
| #include "crypto/scoped_nss_types.h" |
| |
| namespace { |
| |
| // Public key of the certificate with which the peer cert should be signed. |
| static const unsigned char kCAPublicKeyDER[] = { |
| 0x30, 0x82, 0x01, 0x0a, 0x02, 0x82, 0x01, 0x01, 0x00, 0xbc, 0x22, 0x80, |
| 0xbd, 0x80, 0xf6, 0x3a, 0x21, 0x00, 0x3b, 0xae, 0x76, 0x5e, 0x35, 0x7f, |
| 0x3d, 0xc3, 0x64, 0x5c, 0x55, 0x94, 0x86, 0x34, 0x2f, 0x05, 0x87, 0x28, |
| 0xcd, 0xf7, 0x69, 0x8c, 0x17, 0xb3, 0x50, 0xa7, 0xb8, 0x82, 0xfa, 0xdf, |
| 0xc7, 0x43, 0x2d, 0xd6, 0x7e, 0xab, 0xa0, 0x6f, 0xb7, 0x13, 0x72, 0x80, |
| 0xa4, 0x47, 0x15, 0xc1, 0x20, 0x99, 0x50, 0xcd, 0xec, 0x14, 0x62, 0x09, |
| 0x5b, 0xa4, 0x98, 0xcd, 0xd2, 0x41, 0xb6, 0x36, 0x4e, 0xff, 0xe8, 0x2e, |
| 0x32, 0x30, 0x4a, 0x81, 0xa8, 0x42, 0xa3, 0x6c, 0x9b, 0x33, 0x6e, 0xca, |
| 0xb2, 0xf5, 0x53, 0x66, 0xe0, 0x27, 0x53, 0x86, 0x1a, 0x85, 0x1e, 0xa7, |
| 0x39, 0x3f, 0x4a, 0x77, 0x8e, 0xfb, 0x54, 0x66, 0x66, 0xfb, 0x58, 0x54, |
| 0xc0, 0x5e, 0x39, 0xc7, 0xf5, 0x50, 0x06, 0x0b, 0xe0, 0x8a, 0xd4, 0xce, |
| 0xe1, 0x6a, 0x55, 0x1f, 0x8b, 0x17, 0x00, 0xe6, 0x69, 0xa3, 0x27, 0xe6, |
| 0x08, 0x25, 0x69, 0x3c, 0x12, 0x9d, 0x8d, 0x05, 0x2c, 0xd6, 0x2e, 0xa2, |
| 0x31, 0xde, 0xb4, 0x52, 0x50, 0xd6, 0x20, 0x49, 0xde, 0x71, 0xa0, 0xf9, |
| 0xad, 0x20, 0x40, 0x12, 0xf1, 0xdd, 0x25, 0xeb, 0xd5, 0xe6, 0xb8, 0x36, |
| 0xf4, 0xd6, 0x8f, 0x7f, 0xca, 0x43, 0xdc, 0xd7, 0x10, 0x5b, 0xe6, 0x3f, |
| 0x51, 0x8a, 0x85, 0xb3, 0xf3, 0xff, 0xf6, 0x03, 0x2d, 0xcb, 0x23, 0x4f, |
| 0x9c, 0xad, 0x18, 0xe7, 0x93, 0x05, 0x8c, 0xac, 0x52, 0x9a, 0xf7, 0x4c, |
| 0xe9, 0x99, 0x7a, 0xbe, 0x6e, 0x7e, 0x4d, 0x0a, 0xe3, 0xc6, 0x1c, 0xa9, |
| 0x93, 0xfa, 0x3a, 0xa5, 0x91, 0x5d, 0x1c, 0xbd, 0x66, 0xeb, 0xcc, 0x60, |
| 0xdc, 0x86, 0x74, 0xca, 0xcf, 0xf8, 0x92, 0x1c, 0x98, 0x7d, 0x57, 0xfa, |
| 0x61, 0x47, 0x9e, 0xab, 0x80, 0xb7, 0xe4, 0x48, 0x80, 0x2a, 0x92, 0xc5, |
| 0x1b, 0x02, 0x03, 0x01, 0x00, 0x01 }; |
| |
| typedef scoped_ptr_malloc< |
| CERTCertificate, |
| crypto::NSSDestroyer<CERTCertificate, CERT_DestroyCertificate> > |
| ScopedCERTCertificate; |
| |
| // Parses out DeviceAuthMessage from CastMessage |
| static bool ParseAuthMessage( |
| const extensions::api::cast_channel::CastMessage& challenge_reply, |
| extensions::api::cast_channel::DeviceAuthMessage* auth_message) { |
| if (challenge_reply.payload_type() != |
| extensions::api::cast_channel::CastMessage_PayloadType_BINARY) { |
| DVLOG(1) << "Wrong payload type in challenge reply"; |
| return false; |
| } |
| if (!challenge_reply.has_payload_binary()) { |
| DVLOG(1) << "Payload type is binary but payload_binary field not set"; |
| return false; |
| } |
| if (!auth_message->ParseFromString(challenge_reply.payload_binary())) { |
| DVLOG(1) << "Cannot parse binary payload into DeviceAuthMessage"; |
| return false; |
| } |
| DVLOG(1) << "Auth message: " << AuthMessageToString(*auth_message); |
| if (auth_message->has_error()) { |
| DVLOG(1) << "Auth message error: " << auth_message->error().error_type(); |
| return false; |
| } |
| if (!auth_message->has_response()) { |
| DVLOG(1) << "Auth message has no response field"; |
| return false; |
| } |
| return true; |
| } |
| |
| // Authenticates the given credentials: |
| // 1. |signature| verification of |data| using |certificate|. |
| // 2. |certificate| is signed by a trusted CA. |
| bool VerifyCredentials(const std::string& certificate, |
| const std::string& signature, |
| const std::string& data) { |
| crypto::EnsureNSSInit(); |
| SECItem der_cert; |
| der_cert.type = siDERCertBuffer; |
| // Make a copy of certificate string so it is safe to type cast. |
| der_cert.data = reinterpret_cast<unsigned char*>(const_cast<char*>( |
| certificate.data())); |
| der_cert.len = certificate.length(); |
| |
| // Parse into a certificate structure. |
| ScopedCERTCertificate cert(CERT_NewTempCertificate( |
| CERT_GetDefaultCertDB(), &der_cert, NULL, PR_FALSE, PR_TRUE)); |
| if (!cert.get()) { |
| DVLOG(1) << "Failed to parse certificate."; |
| return false; |
| } |
| |
| // Check that the certificate is signed by trusted CA. |
| SECItem trusted_ca_key_der_item; |
| trusted_ca_key_der_item.type = siDERCertBuffer; |
| trusted_ca_key_der_item.data = const_cast<unsigned char*>(kCAPublicKeyDER); |
| trusted_ca_key_der_item.len = sizeof(kCAPublicKeyDER); |
| crypto::ScopedSECKEYPublicKey ca_public_key( |
| SECKEY_ImportDERPublicKey(&trusted_ca_key_der_item, CKK_RSA)); |
| SECStatus verified = CERT_VerifySignedDataWithPublicKey( |
| &cert->signatureWrap, ca_public_key.get(), NULL); |
| if (verified != SECSuccess) { |
| DVLOG(1)<< "Cert not signed by trusted CA"; |
| return false; |
| } |
| |
| // Verify that the |signature| matches |data|. |
| crypto::ScopedSECKEYPublicKey public_key(CERT_ExtractPublicKey(cert.get())); |
| if (!public_key.get()) { |
| DVLOG(1) << "Unable to extract public key from certificate."; |
| return false; |
| } |
| SECItem signature_item; |
| signature_item.type = siBuffer; |
| signature_item.data = reinterpret_cast<unsigned char*>( |
| const_cast<char*>(signature.data())); |
| signature_item.len = signature.length(); |
| verified = VFY_VerifyDataDirect( |
| reinterpret_cast<unsigned char*>(const_cast<char*>(data.data())), |
| data.size(), |
| public_key.get(), |
| &signature_item, |
| SEC_OID_PKCS1_RSA_ENCRYPTION, |
| SEC_OID_SHA1, NULL, NULL); |
| |
| if (verified != SECSuccess) { |
| DVLOG(1) << "Signed blobs did not match."; |
| return false; |
| } |
| return true; |
| } |
| |
| } // namespace |
| |
| namespace extensions { |
| namespace api { |
| namespace cast_channel { |
| |
| bool AuthenticateChallengeReply(const CastMessage& challenge_reply, |
| const std::string& peer_cert) { |
| if (peer_cert.empty()) |
| return false; |
| |
| DVLOG(1) << "Challenge reply: " << CastMessageToString(challenge_reply); |
| DeviceAuthMessage auth_message; |
| if (!ParseAuthMessage(challenge_reply, &auth_message)) |
| return false; |
| |
| const AuthResponse& response = auth_message.response(); |
| return VerifyCredentials(response.client_auth_certificate(), |
| response.signature(), |
| peer_cert); |
| } |
| |
| } // namespace cast_channel |
| } // namespace api |
| } // namespace extensions |