| // Copyright 2017 The Chromium Authors |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "net/ntlm/ntlm_client.h" |
| |
| #include <string.h> |
| |
| #include "base/check_op.h" |
| #include "base/containers/span.h" |
| #include "base/logging.h" |
| #include "base/numerics/safe_math.h" |
| #include "base/strings/utf_string_conversions.h" |
| #include "net/ntlm/ntlm.h" |
| #include "net/ntlm/ntlm_buffer_reader.h" |
| #include "net/ntlm/ntlm_buffer_writer.h" |
| #include "net/ntlm/ntlm_constants.h" |
| |
| namespace net::ntlm { |
| |
| namespace { |
| // Parses the challenge message and returns the |challenge_flags| and |
| // |server_challenge| into the supplied buffer. |
| bool ParseChallengeMessage( |
| base::span<const uint8_t> challenge_message, |
| NegotiateFlags* challenge_flags, |
| base::span<uint8_t, kChallengeLen> server_challenge) { |
| NtlmBufferReader challenge_reader(challenge_message); |
| |
| return challenge_reader.MatchMessageHeader(MessageType::kChallenge) && |
| challenge_reader.SkipSecurityBufferWithValidation() && |
| challenge_reader.ReadFlags(challenge_flags) && |
| challenge_reader.ReadBytes(server_challenge); |
| } |
| |
| // Parses the challenge message and extracts the information necessary to |
| // make an NTLMv2 response. |
| bool ParseChallengeMessageV2( |
| base::span<const uint8_t> challenge_message, |
| NegotiateFlags* challenge_flags, |
| base::span<uint8_t, kChallengeLen> server_challenge, |
| std::vector<AvPair>* av_pairs) { |
| NtlmBufferReader challenge_reader(challenge_message); |
| |
| return challenge_reader.MatchMessageHeader(MessageType::kChallenge) && |
| challenge_reader.SkipSecurityBufferWithValidation() && |
| challenge_reader.ReadFlags(challenge_flags) && |
| challenge_reader.ReadBytes(server_challenge) && |
| challenge_reader.SkipBytes(8) && |
| // challenge_reader.ReadTargetInfoPayload(av_pairs); |
| (((*challenge_flags & NegotiateFlags::kTargetInfo) == |
| NegotiateFlags::kTargetInfo) |
| ? challenge_reader.ReadTargetInfoPayload(av_pairs) |
| : true); |
| } |
| |
| bool WriteAuthenticateMessage(NtlmBufferWriter* authenticate_writer, |
| SecurityBuffer lm_payload, |
| SecurityBuffer ntlm_payload, |
| SecurityBuffer domain_payload, |
| SecurityBuffer username_payload, |
| SecurityBuffer hostname_payload, |
| SecurityBuffer session_key_payload, |
| NegotiateFlags authenticate_flags) { |
| return authenticate_writer->WriteMessageHeader(MessageType::kAuthenticate) && |
| authenticate_writer->WriteSecurityBuffer(lm_payload) && |
| authenticate_writer->WriteSecurityBuffer(ntlm_payload) && |
| authenticate_writer->WriteSecurityBuffer(domain_payload) && |
| authenticate_writer->WriteSecurityBuffer(username_payload) && |
| authenticate_writer->WriteSecurityBuffer(hostname_payload) && |
| authenticate_writer->WriteSecurityBuffer(session_key_payload) && |
| authenticate_writer->WriteFlags(authenticate_flags); |
| } |
| |
| // Writes the NTLMv1 LM Response and NTLM Response. |
| bool WriteResponsePayloads( |
| NtlmBufferWriter* authenticate_writer, |
| base::span<const uint8_t, kResponseLenV1> lm_response, |
| base::span<const uint8_t, kResponseLenV1> ntlm_response) { |
| return authenticate_writer->WriteBytes(lm_response) && |
| authenticate_writer->WriteBytes(ntlm_response); |
| } |
| |
| // Writes the |lm_response| and writes the NTLMv2 response by concatenating |
| // |v2_proof|, |v2_proof_input|, |updated_target_info| and 4 zero bytes. |
| bool WriteResponsePayloadsV2( |
| NtlmBufferWriter* authenticate_writer, |
| base::span<const uint8_t, kResponseLenV1> lm_response, |
| base::span<const uint8_t, kNtlmProofLenV2> v2_proof, |
| base::span<const uint8_t> v2_proof_input, |
| base::span<const uint8_t> updated_target_info) { |
| return authenticate_writer->WriteBytes(lm_response) && |
| authenticate_writer->WriteBytes(v2_proof) && |
| authenticate_writer->WriteBytes(v2_proof_input) && |
| authenticate_writer->WriteBytes(updated_target_info) && |
| authenticate_writer->WriteUInt32(0); |
| } |
| |
| bool WriteStringPayloads(NtlmBufferWriter* authenticate_writer, |
| bool is_unicode, |
| const std::u16string& domain, |
| const std::u16string& username, |
| const std::string& hostname) { |
| if (is_unicode) { |
| return authenticate_writer->WriteUtf16String(domain) && |
| authenticate_writer->WriteUtf16String(username) && |
| authenticate_writer->WriteUtf8AsUtf16String(hostname); |
| } else { |
| return authenticate_writer->WriteUtf16AsUtf8String(domain) && |
| authenticate_writer->WriteUtf16AsUtf8String(username) && |
| authenticate_writer->WriteUtf8String(hostname); |
| } |
| } |
| |
| // Returns the size in bytes of a string16 depending whether unicode |
| // was negotiated. |
| size_t GetStringPayloadLength(const std::u16string& str, bool is_unicode) { |
| if (is_unicode) |
| return str.length() * 2; |
| |
| // When |WriteUtf16AsUtf8String| is called with a |std::u16string|, the string |
| // is converted to UTF8. Do the conversion to ensure that the character |
| // count is correct. |
| return base::UTF16ToUTF8(str).length(); |
| } |
| |
| // Returns the size in bytes of a std::string depending whether unicode |
| // was negotiated. |
| size_t GetStringPayloadLength(const std::string& str, bool is_unicode) { |
| if (!is_unicode) |
| return str.length(); |
| |
| return base::UTF8ToUTF16(str).length() * 2; |
| } |
| |
| // Sets |buffer| to point to |length| bytes from |offset| and updates |offset| |
| // past those bytes. In case of overflow, returns false. |
| bool ComputeSecurityBuffer(uint32_t* offset, |
| size_t length, |
| SecurityBuffer* buffer) { |
| base::CheckedNumeric<uint16_t> length_checked = length; |
| if (!length_checked.IsValid()) { |
| return false; |
| } |
| base::CheckedNumeric<uint32_t> new_offset = *offset + length_checked; |
| if (!new_offset.IsValid()) { |
| return false; |
| } |
| buffer->offset = *offset; |
| buffer->length = length_checked.ValueOrDie(); |
| *offset = new_offset.ValueOrDie(); |
| return true; |
| } |
| |
| } // namespace |
| |
| NtlmClient::NtlmClient(NtlmFeatures features) |
| : features_(features), negotiate_flags_(kNegotiateMessageFlags) { |
| // Just generate the negotiate message once and hold on to it. It never |
| // changes and in NTLMv2 it's used as an input to the Message Integrity |
| // Check (MIC) in the Authenticate message. |
| GenerateNegotiateMessage(); |
| } |
| |
| NtlmClient::~NtlmClient() = default; |
| |
| std::vector<uint8_t> NtlmClient::GetNegotiateMessage() const { |
| return negotiate_message_; |
| } |
| |
| void NtlmClient::GenerateNegotiateMessage() { |
| NtlmBufferWriter writer(kNegotiateMessageLen); |
| bool result = |
| writer.WriteMessageHeader(MessageType::kNegotiate) && |
| writer.WriteFlags(negotiate_flags_) && |
| writer.WriteSecurityBuffer(SecurityBuffer(kNegotiateMessageLen, 0)) && |
| writer.WriteSecurityBuffer(SecurityBuffer(kNegotiateMessageLen, 0)) && |
| writer.IsEndOfBuffer(); |
| |
| DCHECK(result); |
| |
| negotiate_message_ = writer.Pass(); |
| } |
| |
| std::vector<uint8_t> NtlmClient::GenerateAuthenticateMessage( |
| const std::u16string& domain, |
| const std::u16string& username, |
| const std::u16string& password, |
| const std::string& hostname, |
| const std::string& channel_bindings, |
| const std::string& spn, |
| uint64_t client_time, |
| base::span<const uint8_t, kChallengeLen> client_challenge, |
| base::span<const uint8_t> server_challenge_message) const { |
| // Limit the size of strings that are accepted. As an absolute limit any |
| // field represented by a |SecurityBuffer| or |AvPair| must be less than |
| // UINT16_MAX bytes long. The strings are restricted to the maximum sizes |
| // without regard to encoding. As such this isn't intended to restrict all |
| // invalid inputs, only to allow all possible valid inputs. |
| // |
| // |domain| and |hostname| can be no longer than 255 characters. |
| // |username| can be no longer than 104 characters. See [1]. |
| // |password| can be no longer than 256 characters. See [2]. |
| // |
| // [1] - https://technet.microsoft.com/en-us/library/bb726984.aspx |
| // [2] - https://technet.microsoft.com/en-us/library/cc512606.aspx |
| if (hostname.length() > kMaxFqdnLen || domain.length() > kMaxFqdnLen || |
| username.length() > kMaxUsernameLen || |
| password.length() > kMaxPasswordLen) { |
| return {}; |
| } |
| |
| NegotiateFlags challenge_flags; |
| uint8_t server_challenge[kChallengeLen]; |
| uint8_t lm_response[kResponseLenV1]; |
| uint8_t ntlm_response[kResponseLenV1]; |
| |
| // Response fields only for NTLMv2 |
| std::vector<uint8_t> updated_target_info; |
| std::vector<uint8_t> v2_proof_input; |
| uint8_t v2_proof[kNtlmProofLenV2]; |
| uint8_t v2_session_key[kSessionKeyLenV2]; |
| |
| if (IsNtlmV2()) { |
| std::vector<AvPair> av_pairs; |
| if (!ParseChallengeMessageV2(server_challenge_message, &challenge_flags, |
| server_challenge, &av_pairs)) { |
| return {}; |
| } |
| |
| uint64_t timestamp; |
| updated_target_info = |
| GenerateUpdatedTargetInfo(IsMicEnabled(), IsEpaEnabled(), |
| channel_bindings, spn, av_pairs, ×tamp); |
| |
| memset(lm_response, 0, kResponseLenV1); |
| if (timestamp == UINT64_MAX) { |
| // If the server didn't send a time, then use the clients time. |
| timestamp = client_time; |
| } |
| |
| uint8_t v2_hash[kNtlmHashLen]; |
| GenerateNtlmHashV2(domain, username, password, v2_hash); |
| v2_proof_input = GenerateProofInputV2(timestamp, client_challenge); |
| GenerateNtlmProofV2(v2_hash, server_challenge, |
| base::make_span<kProofInputLenV2>(v2_proof_input), |
| updated_target_info, v2_proof); |
| GenerateSessionBaseKeyV2(v2_hash, v2_proof, v2_session_key); |
| } else { |
| if (!ParseChallengeMessage(server_challenge_message, &challenge_flags, |
| server_challenge)) { |
| return {}; |
| } |
| |
| // Calculate the responses for the authenticate message. |
| GenerateResponsesV1WithSessionSecurity(password, server_challenge, |
| client_challenge, lm_response, |
| ntlm_response); |
| } |
| |
| // Always use extended session security even if the server tries to downgrade. |
| NegotiateFlags authenticate_flags = (challenge_flags & negotiate_flags_) | |
| NegotiateFlags::kExtendedSessionSecurity; |
| |
| // Calculate all the payload lengths and offsets. |
| bool is_unicode = (authenticate_flags & NegotiateFlags::kUnicode) == |
| NegotiateFlags::kUnicode; |
| |
| SecurityBuffer lm_info; |
| SecurityBuffer ntlm_info; |
| SecurityBuffer domain_info; |
| SecurityBuffer username_info; |
| SecurityBuffer hostname_info; |
| SecurityBuffer session_key_info; |
| size_t authenticate_message_len; |
| |
| if (!CalculatePayloadLayout(is_unicode, domain, username, hostname, |
| updated_target_info.size(), &lm_info, &ntlm_info, |
| &domain_info, &username_info, &hostname_info, |
| &session_key_info, &authenticate_message_len)) { |
| return {}; |
| } |
| |
| NtlmBufferWriter authenticate_writer(authenticate_message_len); |
| bool writer_result = WriteAuthenticateMessage( |
| &authenticate_writer, lm_info, ntlm_info, domain_info, username_info, |
| hostname_info, session_key_info, authenticate_flags); |
| DCHECK(writer_result); |
| |
| if (IsNtlmV2()) { |
| // Write the optional (for V1) Version and MIC fields. Note that they |
| // could also safely be sent in V1. However, the server should never try to |
| // read them, because neither the version negotiate flag nor the |
| // |TargetInfoAvFlags::kMicPresent| in the target info are set. |
| // |
| // Version is never supported so it is filled with zeros. MIC is a hash |
| // calculated over all 3 messages while the MIC is set to zeros then |
| // backfilled at the end if the MIC feature is enabled. |
| writer_result = authenticate_writer.WriteZeros(kVersionFieldLen) && |
| authenticate_writer.WriteZeros(kMicLenV2); |
| |
| DCHECK(writer_result); |
| } |
| |
| // Verify the location in the payload buffer. |
| DCHECK(authenticate_writer.GetCursor() == GetAuthenticateHeaderLength()); |
| DCHECK(GetAuthenticateHeaderLength() == lm_info.offset); |
| |
| if (IsNtlmV2()) { |
| // Write the response payloads for V2. |
| writer_result = |
| WriteResponsePayloadsV2(&authenticate_writer, lm_response, v2_proof, |
| v2_proof_input, updated_target_info); |
| } else { |
| // Write the response payloads. |
| DCHECK_EQ(kResponseLenV1, lm_info.length); |
| DCHECK_EQ(kResponseLenV1, ntlm_info.length); |
| writer_result = |
| WriteResponsePayloads(&authenticate_writer, lm_response, ntlm_response); |
| } |
| |
| DCHECK(writer_result); |
| DCHECK_EQ(authenticate_writer.GetCursor(), domain_info.offset); |
| |
| writer_result = WriteStringPayloads(&authenticate_writer, is_unicode, domain, |
| username, hostname); |
| DCHECK(writer_result); |
| DCHECK(authenticate_writer.IsEndOfBuffer()); |
| DCHECK_EQ(authenticate_message_len, authenticate_writer.GetLength()); |
| |
| std::vector<uint8_t> auth_msg = authenticate_writer.Pass(); |
| |
| // Backfill the MIC if enabled. |
| if (IsMicEnabled()) { |
| // The MIC has to be generated over all 3 completed messages with the MIC |
| // set to zeros. |
| DCHECK_LT(kMicOffsetV2 + kMicLenV2, authenticate_message_len); |
| |
| base::span<uint8_t, kMicLenV2> mic( |
| const_cast<uint8_t*>(auth_msg.data()) + kMicOffsetV2, kMicLenV2); |
| GenerateMicV2(v2_session_key, negotiate_message_, server_challenge_message, |
| auth_msg, mic); |
| } |
| |
| return auth_msg; |
| } |
| |
| bool NtlmClient::CalculatePayloadLayout( |
| bool is_unicode, |
| const std::u16string& domain, |
| const std::u16string& username, |
| const std::string& hostname, |
| size_t updated_target_info_len, |
| SecurityBuffer* lm_info, |
| SecurityBuffer* ntlm_info, |
| SecurityBuffer* domain_info, |
| SecurityBuffer* username_info, |
| SecurityBuffer* hostname_info, |
| SecurityBuffer* session_key_info, |
| size_t* authenticate_message_len) const { |
| uint32_t offset = GetAuthenticateHeaderLength(); |
| if (!ComputeSecurityBuffer(&offset, 0, session_key_info) || |
| !ComputeSecurityBuffer(&offset, kResponseLenV1, lm_info) || |
| !ComputeSecurityBuffer( |
| &offset, GetNtlmResponseLength(updated_target_info_len), ntlm_info) || |
| !ComputeSecurityBuffer( |
| &offset, GetStringPayloadLength(domain, is_unicode), domain_info) || |
| !ComputeSecurityBuffer(&offset, |
| GetStringPayloadLength(username, is_unicode), |
| username_info) || |
| !ComputeSecurityBuffer(&offset, |
| GetStringPayloadLength(hostname, is_unicode), |
| hostname_info)) { |
| return false; |
| } |
| |
| *authenticate_message_len = offset; |
| return true; |
| } |
| |
| size_t NtlmClient::GetAuthenticateHeaderLength() const { |
| if (IsNtlmV2()) { |
| return kAuthenticateHeaderLenV2; |
| } |
| |
| return kAuthenticateHeaderLenV1; |
| } |
| |
| size_t NtlmClient::GetNtlmResponseLength(size_t updated_target_info_len) const { |
| if (IsNtlmV2()) { |
| return kNtlmResponseHeaderLenV2 + updated_target_info_len + 4; |
| } |
| |
| return kResponseLenV1; |
| } |
| |
| } // namespace net::ntlm |
