diff options
Diffstat (limited to 'third_party/libwebrtc/api/transport/stun.cc')
| -rw-r--r-- | third_party/libwebrtc/api/transport/stun.cc | 1515 |
1 files changed, 1515 insertions, 0 deletions
diff --git a/third_party/libwebrtc/api/transport/stun.cc b/third_party/libwebrtc/api/transport/stun.cc new file mode 100644 index 0000000000..1098c6720e --- /dev/null +++ b/third_party/libwebrtc/api/transport/stun.cc @@ -0,0 +1,1515 @@ +/* + * 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 "api/transport/stun.h" + +#include <string.h> + +#include <algorithm> +#include <cstdint> +#include <iterator> +#include <memory> +#include <utility> + +#include "rtc_base/byte_order.h" +#include "rtc_base/checks.h" +#include "rtc_base/crc32.h" +#include "rtc_base/helpers.h" +#include "rtc_base/logging.h" +#include "rtc_base/message_digest.h" +#include "system_wrappers/include/metrics.h" + +using rtc::ByteBufferReader; +using rtc::ByteBufferWriter; + +namespace cricket { + +namespace { + +const int k127Utf8CharactersLengthInBytes = 508; +const int kMessageIntegrityAttributeLength = 20; +const int kTheoreticalMaximumAttributeLength = 65535; + +uint32_t ReduceTransactionId(absl::string_view transaction_id) { + RTC_DCHECK(transaction_id.length() == cricket::kStunTransactionIdLength || + transaction_id.length() == cricket::kStunLegacyTransactionIdLength) + << transaction_id.length(); + ByteBufferReader reader(transaction_id.data(), transaction_id.size()); + uint32_t result = 0; + uint32_t next; + while (reader.ReadUInt32(&next)) { + result ^= next; + } + return result; +} + +// Check the maximum length of a BYTE_STRING attribute against specifications. +bool LengthValid(int type, int length) { + // "Less than 509 bytes" is intended to indicate a maximum of 127 + // UTF-8 characters, which may take up to 4 bytes per character. + switch (type) { + case STUN_ATTR_USERNAME: + return length <= + k127Utf8CharactersLengthInBytes; // RFC 8489 section 14.3 + case STUN_ATTR_MESSAGE_INTEGRITY: + return length == + kMessageIntegrityAttributeLength; // RFC 8489 section 14.5 + case STUN_ATTR_REALM: + return length <= + k127Utf8CharactersLengthInBytes; // RFC 8489 section 14.9 + case STUN_ATTR_NONCE: + return length <= + k127Utf8CharactersLengthInBytes; // RFC 8489 section 14.10 + case STUN_ATTR_SOFTWARE: + return length <= + k127Utf8CharactersLengthInBytes; // RFC 8489 section 14.14 + case STUN_ATTR_DATA: + // No length restriction in RFC; it's the content of an UDP datagram, + // which in theory can be up to 65.535 bytes. + // TODO(bugs.webrtc.org/12179): Write a test to find the real limit. + return length <= kTheoreticalMaximumAttributeLength; + default: + // Return an arbitrary restriction for all other types. + return length <= kTheoreticalMaximumAttributeLength; + } + RTC_DCHECK_NOTREACHED(); + return true; +} + +} // namespace + +const char STUN_ERROR_REASON_TRY_ALTERNATE_SERVER[] = "Try Alternate Server"; +const char STUN_ERROR_REASON_BAD_REQUEST[] = "Bad Request"; +const char STUN_ERROR_REASON_UNAUTHORIZED[] = "Unauthorized"; +const char STUN_ERROR_REASON_UNKNOWN_ATTRIBUTE[] = "Unknown Attribute"; +const char STUN_ERROR_REASON_FORBIDDEN[] = "Forbidden"; +const char STUN_ERROR_REASON_ALLOCATION_MISMATCH[] = "Allocation Mismatch"; +const char STUN_ERROR_REASON_STALE_NONCE[] = "Stale Nonce"; +const char STUN_ERROR_REASON_WRONG_CREDENTIALS[] = "Wrong Credentials"; +const char STUN_ERROR_REASON_UNSUPPORTED_PROTOCOL[] = "Unsupported Protocol"; +const char STUN_ERROR_REASON_ROLE_CONFLICT[] = "Role Conflict"; +const char STUN_ERROR_REASON_SERVER_ERROR[] = "Server Error"; + +const char TURN_MAGIC_COOKIE_VALUE[] = {'\x72', '\xC6', '\x4B', '\xC6'}; +const char EMPTY_TRANSACTION_ID[] = "0000000000000000"; +const uint32_t STUN_FINGERPRINT_XOR_VALUE = 0x5354554E; +const int SERVER_NOT_REACHABLE_ERROR = 701; + +// StunMessage + +StunMessage::StunMessage() + : StunMessage(STUN_INVALID_MESSAGE_TYPE, EMPTY_TRANSACTION_ID) {} + +StunMessage::StunMessage(uint16_t type) + : StunMessage(type, GenerateTransactionId()) {} + +StunMessage::StunMessage(uint16_t type, absl::string_view transaction_id) + : type_(type), + transaction_id_(transaction_id), + reduced_transaction_id_(ReduceTransactionId(transaction_id_)) { + RTC_DCHECK(IsValidTransactionId(transaction_id_)); +} + +StunMessage::~StunMessage() = default; + +bool StunMessage::IsLegacy() const { + if (transaction_id_.size() == kStunLegacyTransactionIdLength) + return true; + RTC_DCHECK(transaction_id_.size() == kStunTransactionIdLength); + return false; +} + +static bool DesignatedExpertRange(int attr_type) { + return (attr_type >= 0x4000 && attr_type <= 0x7FFF) || + (attr_type >= 0xC000 && attr_type <= 0xFFFF); +} + +void StunMessage::AddAttribute(std::unique_ptr<StunAttribute> attr) { + // Fail any attributes that aren't valid for this type of message, + // but allow any type for the range that in the RFC is reserved for + // the "designated experts". + if (!DesignatedExpertRange(attr->type())) { + RTC_DCHECK_EQ(attr->value_type(), GetAttributeValueType(attr->type())); + } + + attr->SetOwner(this); + size_t attr_length = attr->length(); + if (attr_length % 4 != 0) { + attr_length += (4 - (attr_length % 4)); + } + length_ += static_cast<uint16_t>(attr_length + 4); + + attrs_.push_back(std::move(attr)); +} + +std::unique_ptr<StunAttribute> StunMessage::RemoveAttribute(int type) { + std::unique_ptr<StunAttribute> attribute; + for (auto it = attrs_.rbegin(); it != attrs_.rend(); ++it) { + if ((*it)->type() == type) { + attribute = std::move(*it); + attrs_.erase(std::next(it).base()); + break; + } + } + if (attribute) { + attribute->SetOwner(nullptr); + size_t attr_length = attribute->length(); + if (attr_length % 4 != 0) { + attr_length += (4 - (attr_length % 4)); + } + length_ -= static_cast<uint16_t>(attr_length + 4); + } + return attribute; +} + +void StunMessage::ClearAttributes() { + for (auto it = attrs_.rbegin(); it != attrs_.rend(); ++it) { + (*it)->SetOwner(nullptr); + } + attrs_.clear(); + length_ = 0; +} + +std::vector<uint16_t> StunMessage::GetNonComprehendedAttributes() const { + std::vector<uint16_t> unknown_attributes; + for (auto& attr : attrs_) { + // "comprehension-required" range is 0x0000-0x7FFF. + if (attr->type() >= 0x0000 && attr->type() <= 0x7FFF && + GetAttributeValueType(attr->type()) == STUN_VALUE_UNKNOWN) { + unknown_attributes.push_back(attr->type()); + } + } + return unknown_attributes; +} + +const StunAddressAttribute* StunMessage::GetAddress(int type) const { + switch (type) { + case STUN_ATTR_MAPPED_ADDRESS: { + // Return XOR-MAPPED-ADDRESS when MAPPED-ADDRESS attribute is + // missing. + const StunAttribute* mapped_address = + GetAttribute(STUN_ATTR_MAPPED_ADDRESS); + if (!mapped_address) + mapped_address = GetAttribute(STUN_ATTR_XOR_MAPPED_ADDRESS); + return reinterpret_cast<const StunAddressAttribute*>(mapped_address); + } + + default: + return static_cast<const StunAddressAttribute*>(GetAttribute(type)); + } +} + +const StunUInt32Attribute* StunMessage::GetUInt32(int type) const { + return static_cast<const StunUInt32Attribute*>(GetAttribute(type)); +} + +const StunUInt64Attribute* StunMessage::GetUInt64(int type) const { + return static_cast<const StunUInt64Attribute*>(GetAttribute(type)); +} + +const StunByteStringAttribute* StunMessage::GetByteString(int type) const { + return static_cast<const StunByteStringAttribute*>(GetAttribute(type)); +} + +const StunUInt16ListAttribute* StunMessage::GetUInt16List(int type) const { + return static_cast<const StunUInt16ListAttribute*>(GetAttribute(type)); +} + +const StunErrorCodeAttribute* StunMessage::GetErrorCode() const { + return static_cast<const StunErrorCodeAttribute*>( + GetAttribute(STUN_ATTR_ERROR_CODE)); +} + +int StunMessage::GetErrorCodeValue() const { + const StunErrorCodeAttribute* error_attribute = GetErrorCode(); + return error_attribute ? error_attribute->code() : STUN_ERROR_GLOBAL_FAILURE; +} + +const StunUInt16ListAttribute* StunMessage::GetUnknownAttributes() const { + return static_cast<const StunUInt16ListAttribute*>( + GetAttribute(STUN_ATTR_UNKNOWN_ATTRIBUTES)); +} + +StunMessage::IntegrityStatus StunMessage::ValidateMessageIntegrity( + const std::string& password) { + RTC_DCHECK(integrity_ == IntegrityStatus::kNotSet) + << "Usage error: Verification should only be done once"; + password_ = password; + if (GetByteString(STUN_ATTR_MESSAGE_INTEGRITY)) { + if (ValidateMessageIntegrityOfType( + STUN_ATTR_MESSAGE_INTEGRITY, kStunMessageIntegritySize, + buffer_.c_str(), buffer_.size(), password)) { + integrity_ = IntegrityStatus::kIntegrityOk; + } else { + integrity_ = IntegrityStatus::kIntegrityBad; + } + } else if (GetByteString(STUN_ATTR_GOOG_MESSAGE_INTEGRITY_32)) { + if (ValidateMessageIntegrityOfType( + STUN_ATTR_GOOG_MESSAGE_INTEGRITY_32, kStunMessageIntegrity32Size, + buffer_.c_str(), buffer_.size(), password)) { + integrity_ = IntegrityStatus::kIntegrityOk; + } else { + integrity_ = IntegrityStatus::kIntegrityBad; + } + } else { + integrity_ = IntegrityStatus::kNoIntegrity; + } + // Log the result of integrity checking. See crbug.com/1177125 for background. + // Convert args to integer for the benefit of the macros. + int bucket_count = static_cast<int>(IntegrityStatus::kMaxValue) + 1; + int integrity = static_cast<int>(integrity_); + if (IsStunRequestType(type_)) { + RTC_HISTOGRAM_ENUMERATION("WebRTC.Stun.Integrity.Request", integrity, + bucket_count); + } else if (IsStunSuccessResponseType(type_)) { + RTC_HISTOGRAM_ENUMERATION("WebRTC.Stun.Integrity.Response", integrity, + bucket_count); + } else if (IsStunIndicationType(type_)) { + RTC_HISTOGRAM_ENUMERATION("WebRTC.Stun.Integrity.Indication", integrity, + bucket_count); + } else { + RTC_DCHECK(IsStunErrorResponseType(type_)); + auto* error_attribute = GetErrorCode(); + if (!error_attribute) { + RTC_HISTOGRAM_ENUMERATION( + "WebRTC.Stun.Integrity.ErrorResponse.NoErrorAttribute", integrity, + bucket_count); + } else { + switch (error_attribute->code()) { + case STUN_ERROR_TRY_ALTERNATE: + RTC_HISTOGRAM_ENUMERATION( + "WebRTC.Stun.Integrity.ErrorResponse.TryAlternate", integrity, + bucket_count); + break; + case STUN_ERROR_BAD_REQUEST: + RTC_HISTOGRAM_ENUMERATION( + "WebRTC.Stun.Integrity.ErrorResponse.BadRequest", integrity, + bucket_count); + break; + case STUN_ERROR_UNAUTHORIZED: + RTC_HISTOGRAM_ENUMERATION( + "WebRTC.Stun.Integrity.ErrorResponse.Unauthorized", integrity, + bucket_count); + break; + case STUN_ERROR_UNKNOWN_ATTRIBUTE: + RTC_HISTOGRAM_ENUMERATION( + "WebRTC.Stun.Integrity.ErrorResponse.UnknownAttribute", integrity, + bucket_count); + break; + case STUN_ERROR_STALE_NONCE: + RTC_HISTOGRAM_ENUMERATION( + "WebRTC.Stun.Integrity.ErrorResponse.StaleNonce", integrity, + bucket_count); + break; + case STUN_ERROR_SERVER_ERROR: + RTC_HISTOGRAM_ENUMERATION( + "WebRTC.Stun.Integrity.ErrorResponse.ServerError", integrity, + bucket_count); + break; + case STUN_ERROR_GLOBAL_FAILURE: + RTC_HISTOGRAM_ENUMERATION( + "WebRTC.Stun.Integrity.ErrorResponse.GlobalFailure", integrity, + bucket_count); + break; + default: + RTC_HISTOGRAM_ENUMERATION( + "WebRTC.Stun.Integrity.ErrorResponse.ErrorOther", integrity, + bucket_count); + break; + } + } + } + return integrity_; +} + +StunMessage::IntegrityStatus StunMessage::RevalidateMessageIntegrity( + const std::string& password) { + RTC_LOG(LS_INFO) << "Message revalidation, old status was " + << static_cast<int>(integrity_); + integrity_ = IntegrityStatus::kNotSet; + return ValidateMessageIntegrity(password); +} + +bool StunMessage::ValidateMessageIntegrityForTesting( + const char* data, + size_t size, + const std::string& password) { + return ValidateMessageIntegrityOfType(STUN_ATTR_MESSAGE_INTEGRITY, + kStunMessageIntegritySize, data, size, + password); +} + +bool StunMessage::ValidateMessageIntegrity32ForTesting( + const char* data, + size_t size, + const std::string& password) { + return ValidateMessageIntegrityOfType(STUN_ATTR_GOOG_MESSAGE_INTEGRITY_32, + kStunMessageIntegrity32Size, data, size, + password); +} + +// Deprecated +bool StunMessage::ValidateMessageIntegrity(const char* data, + size_t size, + const std::string& password) { + return ValidateMessageIntegrityOfType(STUN_ATTR_MESSAGE_INTEGRITY, + kStunMessageIntegritySize, data, size, + password); +} + +// Deprecated +bool StunMessage::ValidateMessageIntegrity32(const char* data, + size_t size, + const std::string& password) { + return ValidateMessageIntegrityOfType(STUN_ATTR_GOOG_MESSAGE_INTEGRITY_32, + kStunMessageIntegrity32Size, data, size, + password); +} + +// Verifies a STUN message has a valid MESSAGE-INTEGRITY attribute, using the +// procedure outlined in RFC 5389, section 15.4. +bool StunMessage::ValidateMessageIntegrityOfType(int mi_attr_type, + size_t mi_attr_size, + const char* data, + size_t size, + const std::string& password) { + RTC_DCHECK(mi_attr_size <= kStunMessageIntegritySize); + + // Verifying the size of the message. + if ((size % 4) != 0 || size < kStunHeaderSize) { + return false; + } + + // Getting the message length from the STUN header. + uint16_t msg_length = rtc::GetBE16(&data[2]); + if (size != (msg_length + kStunHeaderSize)) { + return false; + } + + // Finding Message Integrity attribute in stun message. + size_t current_pos = kStunHeaderSize; + bool has_message_integrity_attr = false; + while (current_pos + 4 <= size) { + uint16_t attr_type, attr_length; + // Getting attribute type and length. + attr_type = rtc::GetBE16(&data[current_pos]); + attr_length = rtc::GetBE16(&data[current_pos + sizeof(attr_type)]); + + // If M-I, sanity check it, and break out. + if (attr_type == mi_attr_type) { + if (attr_length != mi_attr_size || + current_pos + sizeof(attr_type) + sizeof(attr_length) + attr_length > + size) { + return false; + } + has_message_integrity_attr = true; + break; + } + + // Otherwise, skip to the next attribute. + current_pos += sizeof(attr_type) + sizeof(attr_length) + attr_length; + if ((attr_length % 4) != 0) { + current_pos += (4 - (attr_length % 4)); + } + } + + if (!has_message_integrity_attr) { + return false; + } + + // Getting length of the message to calculate Message Integrity. + size_t mi_pos = current_pos; + std::unique_ptr<char[]> temp_data(new char[current_pos]); + memcpy(temp_data.get(), data, current_pos); + if (size > mi_pos + kStunAttributeHeaderSize + mi_attr_size) { + // Stun message has other attributes after message integrity. + // Adjust the length parameter in stun message to calculate HMAC. + size_t extra_offset = + size - (mi_pos + kStunAttributeHeaderSize + mi_attr_size); + size_t new_adjusted_len = size - extra_offset - kStunHeaderSize; + + // Writing new length of the STUN message @ Message Length in temp buffer. + // 0 1 2 3 + // 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + // |0 0| STUN Message Type | Message Length | + // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + rtc::SetBE16(temp_data.get() + 2, static_cast<uint16_t>(new_adjusted_len)); + } + + char hmac[kStunMessageIntegritySize]; + size_t ret = + rtc::ComputeHmac(rtc::DIGEST_SHA_1, password.c_str(), password.size(), + temp_data.get(), mi_pos, hmac, sizeof(hmac)); + RTC_DCHECK(ret == sizeof(hmac)); + if (ret != sizeof(hmac)) { + return false; + } + + // Comparing the calculated HMAC with the one present in the message. + return memcmp(data + current_pos + kStunAttributeHeaderSize, hmac, + mi_attr_size) == 0; +} + +bool StunMessage::AddMessageIntegrity(absl::string_view password) { + return AddMessageIntegrityOfType(STUN_ATTR_MESSAGE_INTEGRITY, + kStunMessageIntegritySize, password); +} + +bool StunMessage::AddMessageIntegrity32(absl::string_view password) { + return AddMessageIntegrityOfType(STUN_ATTR_GOOG_MESSAGE_INTEGRITY_32, + kStunMessageIntegrity32Size, password); +} + +bool StunMessage::AddMessageIntegrityOfType(int attr_type, + size_t attr_size, + absl::string_view key) { + // Add the attribute with a dummy value. Since this is a known attribute, it + // can't fail. + RTC_DCHECK(attr_size <= kStunMessageIntegritySize); + auto msg_integrity_attr_ptr = std::make_unique<StunByteStringAttribute>( + attr_type, std::string(attr_size, '0')); + auto* msg_integrity_attr = msg_integrity_attr_ptr.get(); + AddAttribute(std::move(msg_integrity_attr_ptr)); + + // Calculate the HMAC for the message. + ByteBufferWriter buf; + if (!Write(&buf)) + return false; + + int msg_len_for_hmac = static_cast<int>( + buf.Length() - kStunAttributeHeaderSize - msg_integrity_attr->length()); + char hmac[kStunMessageIntegritySize]; + size_t ret = + rtc::ComputeHmac(rtc::DIGEST_SHA_1, key.data(), key.size(), buf.Data(), + msg_len_for_hmac, hmac, sizeof(hmac)); + RTC_DCHECK(ret == sizeof(hmac)); + if (ret != sizeof(hmac)) { + RTC_LOG(LS_ERROR) << "HMAC computation failed. Message-Integrity " + "has dummy value."; + return false; + } + + // Insert correct HMAC into the attribute. + msg_integrity_attr->CopyBytes(hmac, attr_size); + password_ = std::string(key); + integrity_ = IntegrityStatus::kIntegrityOk; + return true; +} + +// Verifies a message is in fact a STUN message, by performing the checks +// outlined in RFC 5389, section 7.3, including the FINGERPRINT check detailed +// in section 15.5. +bool StunMessage::ValidateFingerprint(const char* data, size_t size) { + // Check the message length. + size_t fingerprint_attr_size = + kStunAttributeHeaderSize + StunUInt32Attribute::SIZE; + if (size % 4 != 0 || size < kStunHeaderSize + fingerprint_attr_size) + return false; + + // Skip the rest if the magic cookie isn't present. + const char* magic_cookie = + data + kStunTransactionIdOffset - kStunMagicCookieLength; + if (rtc::GetBE32(magic_cookie) != kStunMagicCookie) + return false; + + // Check the fingerprint type and length. + const char* fingerprint_attr_data = data + size - fingerprint_attr_size; + if (rtc::GetBE16(fingerprint_attr_data) != STUN_ATTR_FINGERPRINT || + rtc::GetBE16(fingerprint_attr_data + sizeof(uint16_t)) != + StunUInt32Attribute::SIZE) + return false; + + // Check the fingerprint value. + uint32_t fingerprint = + rtc::GetBE32(fingerprint_attr_data + kStunAttributeHeaderSize); + return ((fingerprint ^ STUN_FINGERPRINT_XOR_VALUE) == + rtc::ComputeCrc32(data, size - fingerprint_attr_size)); +} + +// static +std::string StunMessage::GenerateTransactionId() { + return rtc::CreateRandomString(kStunTransactionIdLength); +} + +bool StunMessage::IsStunMethod(rtc::ArrayView<int> methods, + const char* data, + size_t size) { + // Check the message length. + if (size % 4 != 0 || size < kStunHeaderSize) + return false; + + // Skip the rest if the magic cookie isn't present. + const char* magic_cookie = + data + kStunTransactionIdOffset - kStunMagicCookieLength; + if (rtc::GetBE32(magic_cookie) != kStunMagicCookie) + return false; + + int method = rtc::GetBE16(data); + for (int m : methods) { + if (m == method) { + return true; + } + } + return false; +} + +bool StunMessage::AddFingerprint() { + // Add the attribute with a dummy value. Since this is a known attribute, + // it can't fail. + auto fingerprint_attr_ptr = + std::make_unique<StunUInt32Attribute>(STUN_ATTR_FINGERPRINT, 0); + auto* fingerprint_attr = fingerprint_attr_ptr.get(); + AddAttribute(std::move(fingerprint_attr_ptr)); + + // Calculate the CRC-32 for the message and insert it. + ByteBufferWriter buf; + if (!Write(&buf)) + return false; + + int msg_len_for_crc32 = static_cast<int>( + buf.Length() - kStunAttributeHeaderSize - fingerprint_attr->length()); + uint32_t c = rtc::ComputeCrc32(buf.Data(), msg_len_for_crc32); + + // Insert the correct CRC-32, XORed with a constant, into the attribute. + fingerprint_attr->SetValue(c ^ STUN_FINGERPRINT_XOR_VALUE); + return true; +} + +bool StunMessage::Read(ByteBufferReader* buf) { + // Keep a copy of the buffer data around for later verification. + buffer_.assign(buf->Data(), buf->Length()); + + if (!buf->ReadUInt16(&type_)) { + return false; + } + + if (type_ & 0x8000) { + // RTP and RTCP set the MSB of first byte, since first two bits are version, + // and version is always 2 (10). If set, this is not a STUN packet. + return false; + } + + if (!buf->ReadUInt16(&length_)) { + return false; + } + + std::string magic_cookie; + if (!buf->ReadString(&magic_cookie, kStunMagicCookieLength)) { + return false; + } + + std::string transaction_id; + if (!buf->ReadString(&transaction_id, kStunTransactionIdLength)) { + return false; + } + + uint32_t magic_cookie_int; + static_assert(sizeof(magic_cookie_int) == kStunMagicCookieLength, + "Integer size mismatch: magic_cookie_int and kStunMagicCookie"); + std::memcpy(&magic_cookie_int, magic_cookie.data(), sizeof(magic_cookie_int)); + if (rtc::NetworkToHost32(magic_cookie_int) != kStunMagicCookie) { + // If magic cookie is invalid it means that the peer implements + // RFC3489 instead of RFC5389. + transaction_id.insert(0, magic_cookie); + } + RTC_DCHECK(IsValidTransactionId(transaction_id)); + transaction_id_ = transaction_id; + reduced_transaction_id_ = ReduceTransactionId(transaction_id_); + + if (length_ != buf->Length()) { + return false; + } + + attrs_.resize(0); + + size_t rest = buf->Length() - length_; + while (buf->Length() > rest) { + uint16_t attr_type, attr_length; + if (!buf->ReadUInt16(&attr_type)) + return false; + if (!buf->ReadUInt16(&attr_length)) + return false; + + std::unique_ptr<StunAttribute> attr( + CreateAttribute(attr_type, attr_length)); + if (!attr) { + // Skip any unknown or malformed attributes. + if ((attr_length % 4) != 0) { + attr_length += (4 - (attr_length % 4)); + } + if (!buf->Consume(attr_length)) { + return false; + } + } else { + if (!attr->Read(buf)) { + return false; + } + attrs_.push_back(std::move(attr)); + } + } + + RTC_DCHECK(buf->Length() == rest); + return true; +} + +bool StunMessage::Write(ByteBufferWriter* buf) const { + buf->WriteUInt16(type_); + buf->WriteUInt16(length_); + if (!IsLegacy()) + buf->WriteUInt32(stun_magic_cookie_); + buf->WriteString(transaction_id_); + + for (const auto& attr : attrs_) { + buf->WriteUInt16(attr->type()); + buf->WriteUInt16(static_cast<uint16_t>(attr->length())); + if (!attr->Write(buf)) { + return false; + } + } + + return true; +} + +StunMessage* StunMessage::CreateNew() const { + return new StunMessage(); +} + +void StunMessage::SetStunMagicCookie(uint32_t val) { + stun_magic_cookie_ = val; +} + +void StunMessage::SetTransactionIdForTesting(absl::string_view transaction_id) { + RTC_DCHECK(IsValidTransactionId(transaction_id)); + transaction_id_ = std::string(transaction_id); + reduced_transaction_id_ = ReduceTransactionId(transaction_id_); +} + +StunAttributeValueType StunMessage::GetAttributeValueType(int type) const { + switch (type) { + case STUN_ATTR_MAPPED_ADDRESS: + return STUN_VALUE_ADDRESS; + case STUN_ATTR_USERNAME: + return STUN_VALUE_BYTE_STRING; + case STUN_ATTR_MESSAGE_INTEGRITY: + return STUN_VALUE_BYTE_STRING; + case STUN_ATTR_ERROR_CODE: + return STUN_VALUE_ERROR_CODE; + case STUN_ATTR_UNKNOWN_ATTRIBUTES: + return STUN_VALUE_UINT16_LIST; + case STUN_ATTR_REALM: + return STUN_VALUE_BYTE_STRING; + case STUN_ATTR_NONCE: + return STUN_VALUE_BYTE_STRING; + case STUN_ATTR_XOR_MAPPED_ADDRESS: + return STUN_VALUE_XOR_ADDRESS; + case STUN_ATTR_SOFTWARE: + return STUN_VALUE_BYTE_STRING; + case STUN_ATTR_ALTERNATE_SERVER: + return STUN_VALUE_ADDRESS; + case STUN_ATTR_FINGERPRINT: + return STUN_VALUE_UINT32; + case STUN_ATTR_RETRANSMIT_COUNT: + return STUN_VALUE_UINT32; + case STUN_ATTR_GOOG_LAST_ICE_CHECK_RECEIVED: + return STUN_VALUE_BYTE_STRING; + case STUN_ATTR_GOOG_MISC_INFO: + return STUN_VALUE_UINT16_LIST; + default: + return STUN_VALUE_UNKNOWN; + } +} + +StunAttribute* StunMessage::CreateAttribute(int type, size_t length) /*const*/ { + StunAttributeValueType value_type = GetAttributeValueType(type); + if (value_type != STUN_VALUE_UNKNOWN) { + return StunAttribute::Create(value_type, type, + static_cast<uint16_t>(length), this); + } else if (DesignatedExpertRange(type)) { + // Read unknown attributes as STUN_VALUE_BYTE_STRING + return StunAttribute::Create(STUN_VALUE_BYTE_STRING, type, + static_cast<uint16_t>(length), this); + } else { + return NULL; + } +} + +const StunAttribute* StunMessage::GetAttribute(int type) const { + for (const auto& attr : attrs_) { + if (attr->type() == type) { + return attr.get(); + } + } + return NULL; +} + +bool StunMessage::IsValidTransactionId(absl::string_view transaction_id) { + return transaction_id.size() == kStunTransactionIdLength || + transaction_id.size() == kStunLegacyTransactionIdLength; +} + +bool StunMessage::EqualAttributes( + const StunMessage* other, + std::function<bool(int type)> attribute_type_mask) const { + RTC_DCHECK(other != nullptr); + rtc::ByteBufferWriter tmp_buffer_ptr1; + rtc::ByteBufferWriter tmp_buffer_ptr2; + for (const auto& attr : attrs_) { + if (attribute_type_mask(attr->type())) { + const StunAttribute* other_attr = other->GetAttribute(attr->type()); + if (other_attr == nullptr) { + return false; + } + tmp_buffer_ptr1.Clear(); + tmp_buffer_ptr2.Clear(); + attr->Write(&tmp_buffer_ptr1); + other_attr->Write(&tmp_buffer_ptr2); + if (tmp_buffer_ptr1.Length() != tmp_buffer_ptr2.Length()) { + return false; + } + if (memcmp(tmp_buffer_ptr1.Data(), tmp_buffer_ptr2.Data(), + tmp_buffer_ptr1.Length()) != 0) { + return false; + } + } + } + + for (const auto& attr : other->attrs_) { + if (attribute_type_mask(attr->type())) { + const StunAttribute* own_attr = GetAttribute(attr->type()); + if (own_attr == nullptr) { + return false; + } + // we have already compared all values... + } + } + return true; +} + +// StunAttribute + +StunAttribute::StunAttribute(uint16_t type, uint16_t length) + : type_(type), length_(length) {} + +void StunAttribute::ConsumePadding(ByteBufferReader* buf) const { + int remainder = length_ % 4; + if (remainder > 0) { + buf->Consume(4 - remainder); + } +} + +void StunAttribute::WritePadding(ByteBufferWriter* buf) const { + int remainder = length_ % 4; + if (remainder > 0) { + char zeroes[4] = {0}; + buf->WriteBytes(zeroes, 4 - remainder); + } +} + +StunAttribute* StunAttribute::Create(StunAttributeValueType value_type, + uint16_t type, + uint16_t length, + StunMessage* owner) { + switch (value_type) { + case STUN_VALUE_ADDRESS: + return new StunAddressAttribute(type, length); + case STUN_VALUE_XOR_ADDRESS: + return new StunXorAddressAttribute(type, length, owner); + case STUN_VALUE_UINT32: + return new StunUInt32Attribute(type); + case STUN_VALUE_UINT64: + return new StunUInt64Attribute(type); + case STUN_VALUE_BYTE_STRING: + return new StunByteStringAttribute(type, length); + case STUN_VALUE_ERROR_CODE: + return new StunErrorCodeAttribute(type, length); + case STUN_VALUE_UINT16_LIST: + return new StunUInt16ListAttribute(type, length); + default: + return NULL; + } +} + +std::unique_ptr<StunAddressAttribute> StunAttribute::CreateAddress( + uint16_t type) { + return std::make_unique<StunAddressAttribute>(type, 0); +} + +std::unique_ptr<StunXorAddressAttribute> StunAttribute::CreateXorAddress( + uint16_t type) { + return std::make_unique<StunXorAddressAttribute>(type, 0, nullptr); +} + +std::unique_ptr<StunUInt64Attribute> StunAttribute::CreateUInt64( + uint16_t type) { + return std::make_unique<StunUInt64Attribute>(type); +} + +std::unique_ptr<StunUInt32Attribute> StunAttribute::CreateUInt32( + uint16_t type) { + return std::make_unique<StunUInt32Attribute>(type); +} + +std::unique_ptr<StunByteStringAttribute> StunAttribute::CreateByteString( + uint16_t type) { + return std::make_unique<StunByteStringAttribute>(type, 0); +} + +std::unique_ptr<StunErrorCodeAttribute> StunAttribute::CreateErrorCode() { + return std::make_unique<StunErrorCodeAttribute>( + STUN_ATTR_ERROR_CODE, StunErrorCodeAttribute::MIN_SIZE); +} + +std::unique_ptr<StunUInt16ListAttribute> +StunAttribute::CreateUInt16ListAttribute(uint16_t type) { + return std::make_unique<StunUInt16ListAttribute>(type, 0); +} + +std::unique_ptr<StunUInt16ListAttribute> +StunAttribute::CreateUnknownAttributes() { + return std::make_unique<StunUInt16ListAttribute>(STUN_ATTR_UNKNOWN_ATTRIBUTES, + 0); +} + +StunAddressAttribute::StunAddressAttribute(uint16_t type, + const rtc::SocketAddress& addr) + : StunAttribute(type, 0) { + SetAddress(addr); +} + +StunAddressAttribute::StunAddressAttribute(uint16_t type, uint16_t length) + : StunAttribute(type, length) {} + +StunAttributeValueType StunAddressAttribute::value_type() const { + return STUN_VALUE_ADDRESS; +} + +bool StunAddressAttribute::Read(ByteBufferReader* buf) { + uint8_t dummy; + if (!buf->ReadUInt8(&dummy)) + return false; + + uint8_t stun_family; + if (!buf->ReadUInt8(&stun_family)) { + return false; + } + uint16_t port; + if (!buf->ReadUInt16(&port)) + return false; + if (stun_family == STUN_ADDRESS_IPV4) { + in_addr v4addr; + if (length() != SIZE_IP4) { + return false; + } + if (!buf->ReadBytes(reinterpret_cast<char*>(&v4addr), sizeof(v4addr))) { + return false; + } + rtc::IPAddress ipaddr(v4addr); + SetAddress(rtc::SocketAddress(ipaddr, port)); + } else if (stun_family == STUN_ADDRESS_IPV6) { + in6_addr v6addr; + if (length() != SIZE_IP6) { + return false; + } + if (!buf->ReadBytes(reinterpret_cast<char*>(&v6addr), sizeof(v6addr))) { + return false; + } + rtc::IPAddress ipaddr(v6addr); + SetAddress(rtc::SocketAddress(ipaddr, port)); + } else { + return false; + } + return true; +} + +bool StunAddressAttribute::Write(ByteBufferWriter* buf) const { + StunAddressFamily address_family = family(); + if (address_family == STUN_ADDRESS_UNDEF) { + RTC_LOG(LS_ERROR) << "Error writing address attribute: unknown family."; + return false; + } + buf->WriteUInt8(0); + buf->WriteUInt8(address_family); + buf->WriteUInt16(address_.port()); + switch (address_.family()) { + case AF_INET: { + in_addr v4addr = address_.ipaddr().ipv4_address(); + buf->WriteBytes(reinterpret_cast<char*>(&v4addr), sizeof(v4addr)); + break; + } + case AF_INET6: { + in6_addr v6addr = address_.ipaddr().ipv6_address(); + buf->WriteBytes(reinterpret_cast<char*>(&v6addr), sizeof(v6addr)); + break; + } + } + return true; +} + +StunXorAddressAttribute::StunXorAddressAttribute(uint16_t type, + const rtc::SocketAddress& addr) + : StunAddressAttribute(type, addr), owner_(NULL) {} + +StunXorAddressAttribute::StunXorAddressAttribute(uint16_t type, + uint16_t length, + StunMessage* owner) + : StunAddressAttribute(type, length), owner_(owner) {} + +StunAttributeValueType StunXorAddressAttribute::value_type() const { + return STUN_VALUE_XOR_ADDRESS; +} + +void StunXorAddressAttribute::SetOwner(StunMessage* owner) { + owner_ = owner; +} + +rtc::IPAddress StunXorAddressAttribute::GetXoredIP() const { + if (owner_) { + rtc::IPAddress ip = ipaddr(); + switch (ip.family()) { + case AF_INET: { + in_addr v4addr = ip.ipv4_address(); + v4addr.s_addr = + (v4addr.s_addr ^ rtc::HostToNetwork32(kStunMagicCookie)); + return rtc::IPAddress(v4addr); + } + case AF_INET6: { + in6_addr v6addr = ip.ipv6_address(); + const std::string& transaction_id = owner_->transaction_id(); + if (transaction_id.length() == kStunTransactionIdLength) { + uint32_t transactionid_as_ints[3]; + memcpy(&transactionid_as_ints[0], transaction_id.c_str(), + transaction_id.length()); + uint32_t* ip_as_ints = reinterpret_cast<uint32_t*>(&v6addr.s6_addr); + // Transaction ID is in network byte order, but magic cookie + // is stored in host byte order. + ip_as_ints[0] = + (ip_as_ints[0] ^ rtc::HostToNetwork32(kStunMagicCookie)); + ip_as_ints[1] = (ip_as_ints[1] ^ transactionid_as_ints[0]); + ip_as_ints[2] = (ip_as_ints[2] ^ transactionid_as_ints[1]); + ip_as_ints[3] = (ip_as_ints[3] ^ transactionid_as_ints[2]); + return rtc::IPAddress(v6addr); + } + break; + } + } + } + // Invalid ip family or transaction ID, or missing owner. + // Return an AF_UNSPEC address. + return rtc::IPAddress(); +} + +bool StunXorAddressAttribute::Read(ByteBufferReader* buf) { + if (!StunAddressAttribute::Read(buf)) + return false; + uint16_t xoredport = port() ^ (kStunMagicCookie >> 16); + rtc::IPAddress xored_ip = GetXoredIP(); + SetAddress(rtc::SocketAddress(xored_ip, xoredport)); + return true; +} + +bool StunXorAddressAttribute::Write(ByteBufferWriter* buf) const { + StunAddressFamily address_family = family(); + if (address_family == STUN_ADDRESS_UNDEF) { + RTC_LOG(LS_ERROR) << "Error writing xor-address attribute: unknown family."; + return false; + } + rtc::IPAddress xored_ip = GetXoredIP(); + if (xored_ip.family() == AF_UNSPEC) { + return false; + } + buf->WriteUInt8(0); + buf->WriteUInt8(family()); + buf->WriteUInt16(port() ^ (kStunMagicCookie >> 16)); + switch (xored_ip.family()) { + case AF_INET: { + in_addr v4addr = xored_ip.ipv4_address(); + buf->WriteBytes(reinterpret_cast<const char*>(&v4addr), sizeof(v4addr)); + break; + } + case AF_INET6: { + in6_addr v6addr = xored_ip.ipv6_address(); + buf->WriteBytes(reinterpret_cast<const char*>(&v6addr), sizeof(v6addr)); + break; + } + } + return true; +} + +StunUInt32Attribute::StunUInt32Attribute(uint16_t type, uint32_t value) + : StunAttribute(type, SIZE), bits_(value) {} + +StunUInt32Attribute::StunUInt32Attribute(uint16_t type) + : StunAttribute(type, SIZE), bits_(0) {} + +StunAttributeValueType StunUInt32Attribute::value_type() const { + return STUN_VALUE_UINT32; +} + +bool StunUInt32Attribute::GetBit(size_t index) const { + RTC_DCHECK(index < 32); + return static_cast<bool>((bits_ >> index) & 0x1); +} + +void StunUInt32Attribute::SetBit(size_t index, bool value) { + RTC_DCHECK(index < 32); + bits_ &= ~(1 << index); + bits_ |= value ? (1 << index) : 0; +} + +bool StunUInt32Attribute::Read(ByteBufferReader* buf) { + if (length() != SIZE || !buf->ReadUInt32(&bits_)) + return false; + return true; +} + +bool StunUInt32Attribute::Write(ByteBufferWriter* buf) const { + buf->WriteUInt32(bits_); + return true; +} + +StunUInt64Attribute::StunUInt64Attribute(uint16_t type, uint64_t value) + : StunAttribute(type, SIZE), bits_(value) {} + +StunUInt64Attribute::StunUInt64Attribute(uint16_t type) + : StunAttribute(type, SIZE), bits_(0) {} + +StunAttributeValueType StunUInt64Attribute::value_type() const { + return STUN_VALUE_UINT64; +} + +bool StunUInt64Attribute::Read(ByteBufferReader* buf) { + if (length() != SIZE || !buf->ReadUInt64(&bits_)) + return false; + return true; +} + +bool StunUInt64Attribute::Write(ByteBufferWriter* buf) const { + buf->WriteUInt64(bits_); + return true; +} + +StunByteStringAttribute::StunByteStringAttribute(uint16_t type) + : StunAttribute(type, 0), bytes_(NULL) {} + +StunByteStringAttribute::StunByteStringAttribute(uint16_t type, + absl::string_view str) + : StunAttribute(type, 0), bytes_(NULL) { + CopyBytes(str); +} + +StunByteStringAttribute::StunByteStringAttribute(uint16_t type, + const void* bytes, + size_t length) + : StunAttribute(type, 0), bytes_(NULL) { + CopyBytes(bytes, length); +} + +StunByteStringAttribute::StunByteStringAttribute(uint16_t type, uint16_t length) + : StunAttribute(type, length), bytes_(NULL) {} + +StunByteStringAttribute::~StunByteStringAttribute() { + delete[] bytes_; +} + +StunAttributeValueType StunByteStringAttribute::value_type() const { + return STUN_VALUE_BYTE_STRING; +} + +void StunByteStringAttribute::CopyBytes(absl::string_view bytes) { + char* new_bytes = new char[bytes.size()]; + memcpy(new_bytes, bytes.data(), bytes.size()); + SetBytes(new_bytes, bytes.size()); +} + +void StunByteStringAttribute::CopyBytes(const void* bytes, size_t length) { + char* new_bytes = new char[length]; + memcpy(new_bytes, bytes, length); + SetBytes(new_bytes, length); +} + +uint8_t StunByteStringAttribute::GetByte(size_t index) const { + RTC_DCHECK(bytes_ != NULL); + RTC_DCHECK(index < length()); + return static_cast<uint8_t>(bytes_[index]); +} + +void StunByteStringAttribute::SetByte(size_t index, uint8_t value) { + RTC_DCHECK(bytes_ != NULL); + RTC_DCHECK(index < length()); + bytes_[index] = value; +} + +bool StunByteStringAttribute::Read(ByteBufferReader* buf) { + bytes_ = new char[length()]; + if (!buf->ReadBytes(bytes_, length())) { + return false; + } + + ConsumePadding(buf); + return true; +} + +bool StunByteStringAttribute::Write(ByteBufferWriter* buf) const { + // Check that length is legal according to specs + if (!LengthValid(type(), length())) { + return false; + } + buf->WriteBytes(bytes_, length()); + WritePadding(buf); + return true; +} + +void StunByteStringAttribute::SetBytes(char* bytes, size_t length) { + delete[] bytes_; + bytes_ = bytes; + SetLength(static_cast<uint16_t>(length)); +} + +const uint16_t StunErrorCodeAttribute::MIN_SIZE = 4; + +StunErrorCodeAttribute::StunErrorCodeAttribute(uint16_t type, + int code, + const std::string& reason) + : StunAttribute(type, 0) { + SetCode(code); + SetReason(reason); +} + +StunErrorCodeAttribute::StunErrorCodeAttribute(uint16_t type, uint16_t length) + : StunAttribute(type, length), class_(0), number_(0) {} + +StunErrorCodeAttribute::~StunErrorCodeAttribute() {} + +StunAttributeValueType StunErrorCodeAttribute::value_type() const { + return STUN_VALUE_ERROR_CODE; +} + +int StunErrorCodeAttribute::code() const { + return class_ * 100 + number_; +} + +void StunErrorCodeAttribute::SetCode(int code) { + class_ = static_cast<uint8_t>(code / 100); + number_ = static_cast<uint8_t>(code % 100); +} + +void StunErrorCodeAttribute::SetReason(const std::string& reason) { + SetLength(MIN_SIZE + static_cast<uint16_t>(reason.size())); + reason_ = reason; +} + +bool StunErrorCodeAttribute::Read(ByteBufferReader* buf) { + uint32_t val; + if (length() < MIN_SIZE || !buf->ReadUInt32(&val)) + return false; + + if ((val >> 11) != 0) + RTC_LOG(LS_ERROR) << "error-code bits not zero"; + + class_ = ((val >> 8) & 0x7); + number_ = (val & 0xff); + + if (!buf->ReadString(&reason_, length() - 4)) + return false; + + ConsumePadding(buf); + return true; +} + +bool StunErrorCodeAttribute::Write(ByteBufferWriter* buf) const { + buf->WriteUInt32(class_ << 8 | number_); + buf->WriteString(reason_); + WritePadding(buf); + return true; +} + +StunUInt16ListAttribute::StunUInt16ListAttribute(uint16_t type, uint16_t length) + : StunAttribute(type, length) { + attr_types_ = new std::vector<uint16_t>(); +} + +StunUInt16ListAttribute::~StunUInt16ListAttribute() { + delete attr_types_; +} + +StunAttributeValueType StunUInt16ListAttribute::value_type() const { + return STUN_VALUE_UINT16_LIST; +} + +size_t StunUInt16ListAttribute::Size() const { + return attr_types_->size(); +} + +uint16_t StunUInt16ListAttribute::GetType(int index) const { + return (*attr_types_)[index]; +} + +void StunUInt16ListAttribute::SetType(int index, uint16_t value) { + (*attr_types_)[index] = value; +} + +void StunUInt16ListAttribute::AddType(uint16_t value) { + attr_types_->push_back(value); + SetLength(static_cast<uint16_t>(attr_types_->size() * 2)); +} + +void StunUInt16ListAttribute::AddTypeAtIndex(uint16_t index, uint16_t value) { + if (attr_types_->size() < static_cast<size_t>(index + 1)) { + attr_types_->resize(index + 1); + } + (*attr_types_)[index] = value; + SetLength(static_cast<uint16_t>(attr_types_->size() * 2)); +} + +bool StunUInt16ListAttribute::Read(ByteBufferReader* buf) { + if (length() % 2) { + return false; + } + + for (size_t i = 0; i < length() / 2; i++) { + uint16_t attr; + if (!buf->ReadUInt16(&attr)) + return false; + attr_types_->push_back(attr); + } + // Padding of these attributes is done in RFC 5389 style. This is + // slightly different from RFC3489, but it shouldn't be important. + // RFC3489 pads out to a 32 bit boundary by duplicating one of the + // entries in the list (not necessarily the last one - it's unspecified). + // RFC5389 pads on the end, and the bytes are always ignored. + ConsumePadding(buf); + return true; +} + +bool StunUInt16ListAttribute::Write(ByteBufferWriter* buf) const { + for (size_t i = 0; i < attr_types_->size(); ++i) { + buf->WriteUInt16((*attr_types_)[i]); + } + WritePadding(buf); + return true; +} + +std::string StunMethodToString(int msg_type) { + switch (msg_type) { + case STUN_BINDING_REQUEST: + return "STUN BINDING request"; + case STUN_BINDING_INDICATION: + return "STUN BINDING indication"; + case STUN_BINDING_RESPONSE: + return "STUN BINDING response"; + case STUN_BINDING_ERROR_RESPONSE: + return "STUN BINDING error response"; + case GOOG_PING_REQUEST: + return "GOOG PING request"; + case GOOG_PING_RESPONSE: + return "GOOG PING response"; + case GOOG_PING_ERROR_RESPONSE: + return "GOOG PING error response"; + case STUN_ALLOCATE_REQUEST: + return "TURN ALLOCATE request"; + case STUN_ALLOCATE_RESPONSE: + return "TURN ALLOCATE response"; + case STUN_ALLOCATE_ERROR_RESPONSE: + return "TURN ALLOCATE error response"; + case TURN_REFRESH_REQUEST: + return "TURN REFRESH request"; + case TURN_REFRESH_RESPONSE: + return "TURN REFRESH response"; + case TURN_REFRESH_ERROR_RESPONSE: + return "TURN REFRESH error response"; + case TURN_SEND_INDICATION: + return "TURN SEND INDICATION"; + case TURN_DATA_INDICATION: + return "TURN DATA INDICATION"; + case TURN_CREATE_PERMISSION_REQUEST: + return "TURN CREATE PERMISSION request"; + case TURN_CREATE_PERMISSION_RESPONSE: + return "TURN CREATE PERMISSION response"; + case TURN_CREATE_PERMISSION_ERROR_RESPONSE: + return "TURN CREATE PERMISSION error response"; + case TURN_CHANNEL_BIND_REQUEST: + return "TURN CHANNEL BIND request"; + case TURN_CHANNEL_BIND_RESPONSE: + return "TURN CHANNEL BIND response"; + case TURN_CHANNEL_BIND_ERROR_RESPONSE: + return "TURN CHANNEL BIND error response"; + default: + return "UNKNOWN<" + std::to_string(msg_type) + ">"; + } +} + +int GetStunSuccessResponseType(int req_type) { + return IsStunRequestType(req_type) ? (req_type | 0x100) : -1; +} + +int GetStunErrorResponseType(int req_type) { + return IsStunRequestType(req_type) ? (req_type | 0x110) : -1; +} + +bool IsStunRequestType(int msg_type) { + return ((msg_type & kStunTypeMask) == 0x000); +} + +bool IsStunIndicationType(int msg_type) { + return ((msg_type & kStunTypeMask) == 0x010); +} + +bool IsStunSuccessResponseType(int msg_type) { + return ((msg_type & kStunTypeMask) == 0x100); +} + +bool IsStunErrorResponseType(int msg_type) { + return ((msg_type & kStunTypeMask) == 0x110); +} + +bool ComputeStunCredentialHash(const std::string& username, + const std::string& realm, + const std::string& password, + std::string* hash) { + // http://tools.ietf.org/html/rfc5389#section-15.4 + // long-term credentials will be calculated using the key and key is + // key = MD5(username ":" realm ":" SASLprep(password)) + std::string input = username; + input += ':'; + input += realm; + input += ':'; + input += password; + + char digest[rtc::MessageDigest::kMaxSize]; + size_t size = rtc::ComputeDigest(rtc::DIGEST_MD5, input.c_str(), input.size(), + digest, sizeof(digest)); + if (size == 0) { + return false; + } + + *hash = std::string(digest, size); + return true; +} + +std::unique_ptr<StunAttribute> CopyStunAttribute( + const StunAttribute& attribute, + rtc::ByteBufferWriter* tmp_buffer_ptr) { + ByteBufferWriter tmpBuffer; + if (tmp_buffer_ptr == nullptr) { + tmp_buffer_ptr = &tmpBuffer; + } + + std::unique_ptr<StunAttribute> copy(StunAttribute::Create( + attribute.value_type(), attribute.type(), + static_cast<uint16_t>(attribute.length()), nullptr)); + + if (!copy) { + return nullptr; + } + tmp_buffer_ptr->Clear(); + if (!attribute.Write(tmp_buffer_ptr)) { + return nullptr; + } + rtc::ByteBufferReader reader(*tmp_buffer_ptr); + if (!copy->Read(&reader)) { + return nullptr; + } + + return copy; +} + +StunAttributeValueType RelayMessage::GetAttributeValueType(int type) const { + switch (type) { + case STUN_ATTR_LIFETIME: + return STUN_VALUE_UINT32; + case STUN_ATTR_MAGIC_COOKIE: + return STUN_VALUE_BYTE_STRING; + case STUN_ATTR_BANDWIDTH: + return STUN_VALUE_UINT32; + case STUN_ATTR_DESTINATION_ADDRESS: + return STUN_VALUE_ADDRESS; + case STUN_ATTR_SOURCE_ADDRESS2: + return STUN_VALUE_ADDRESS; + case STUN_ATTR_DATA: + return STUN_VALUE_BYTE_STRING; + case STUN_ATTR_OPTIONS: + return STUN_VALUE_UINT32; + default: + return StunMessage::GetAttributeValueType(type); + } +} + +StunMessage* RelayMessage::CreateNew() const { + return new RelayMessage(); +} + +StunAttributeValueType TurnMessage::GetAttributeValueType(int type) const { + switch (type) { + case STUN_ATTR_CHANNEL_NUMBER: + return STUN_VALUE_UINT32; + case STUN_ATTR_TURN_LIFETIME: + return STUN_VALUE_UINT32; + case STUN_ATTR_XOR_PEER_ADDRESS: + return STUN_VALUE_XOR_ADDRESS; + case STUN_ATTR_DATA: + return STUN_VALUE_BYTE_STRING; + case STUN_ATTR_XOR_RELAYED_ADDRESS: + return STUN_VALUE_XOR_ADDRESS; + case STUN_ATTR_EVEN_PORT: + return STUN_VALUE_BYTE_STRING; + case STUN_ATTR_REQUESTED_TRANSPORT: + return STUN_VALUE_UINT32; + case STUN_ATTR_DONT_FRAGMENT: + return STUN_VALUE_BYTE_STRING; + case STUN_ATTR_RESERVATION_TOKEN: + return STUN_VALUE_BYTE_STRING; + default: + return StunMessage::GetAttributeValueType(type); + } +} + +StunMessage* TurnMessage::CreateNew() const { + return new TurnMessage(); +} + +StunAttributeValueType IceMessage::GetAttributeValueType(int type) const { + switch (type) { + case STUN_ATTR_PRIORITY: + case STUN_ATTR_GOOG_NETWORK_INFO: + case STUN_ATTR_NOMINATION: + return STUN_VALUE_UINT32; + case STUN_ATTR_USE_CANDIDATE: + return STUN_VALUE_BYTE_STRING; + case STUN_ATTR_ICE_CONTROLLED: + return STUN_VALUE_UINT64; + case STUN_ATTR_ICE_CONTROLLING: + return STUN_VALUE_UINT64; + default: + return StunMessage::GetAttributeValueType(type); + } +} + +StunMessage* IceMessage::CreateNew() const { + return new IceMessage(); +} + +std::unique_ptr<StunMessage> StunMessage::Clone() const { + std::unique_ptr<StunMessage> copy(CreateNew()); + if (!copy) { + return nullptr; + } + rtc::ByteBufferWriter buf; + if (!Write(&buf)) { + return nullptr; + } + rtc::ByteBufferReader reader(buf); + if (!copy->Read(&reader)) { + return nullptr; + } + return copy; +} + +} // namespace cricket |