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Diffstat (limited to 'src/lib/dns/rdata/generic/dnskey_48.cc')
-rw-r--r-- | src/lib/dns/rdata/generic/dnskey_48.cc | 316 |
1 files changed, 316 insertions, 0 deletions
diff --git a/src/lib/dns/rdata/generic/dnskey_48.cc b/src/lib/dns/rdata/generic/dnskey_48.cc new file mode 100644 index 0000000..7bea847 --- /dev/null +++ b/src/lib/dns/rdata/generic/dnskey_48.cc @@ -0,0 +1,316 @@ +// Copyright (C) 2010-2016 Internet Systems Consortium, Inc. ("ISC") +// +// This Source Code Form is subject to the terms of the Mozilla Public +// License, v. 2.0. If a copy of the MPL was not distributed with this +// file, You can obtain one at http://mozilla.org/MPL/2.0/. + +#include <config.h> + +#include <iostream> +#include <string> +#include <sstream> +#include <vector> + +#include <boost/lexical_cast.hpp> +#include <boost/foreach.hpp> + +#include <util/encode/base64.h> +#include <util/buffer.h> +#include <dns/messagerenderer.h> +#include <dns/name.h> +#include <dns/rdata.h> +#include <dns/rdataclass.h> + +#include <memory> + +#include <stdio.h> +#include <time.h> + +using namespace std; +using namespace isc::util; +using namespace isc::util::encode; + +// BEGIN_ISC_NAMESPACE +// BEGIN_RDATA_NAMESPACE + +struct DNSKEYImpl { + // straightforward representation of DNSKEY RDATA fields + DNSKEYImpl(uint16_t flags, uint8_t protocol, uint8_t algorithm, + const vector<uint8_t>& keydata) : + flags_(flags), protocol_(protocol), algorithm_(algorithm), + keydata_(keydata) + {} + + uint16_t flags_; + uint8_t protocol_; + uint8_t algorithm_; + const vector<uint8_t> keydata_; +}; + +/// \brief Constructor from string. +/// +/// The given string must represent a valid DNSKEY RDATA. There can be +/// extra space characters at the beginning or end of the text (which +/// are simply ignored), but other extra text, including a new line, +/// will make the construction fail with an exception. +/// +/// The Protocol and Algorithm fields must be within their valid +/// ranges. The Public Key field must be present and must contain a +/// Base64 encoding of the public key. Whitespace is allowed within the +/// Base64 text. +/// +/// It is okay for the key data to be missing. Note: BIND 9 also accepts +/// DNSKEY missing key data. While the RFC is silent in this case, and it +/// may be debatable what an implementation should do, but since this field +/// is algorithm dependent and this implementations doesn't reject unknown +/// algorithms, it's lenient here. +/// +/// \throw InvalidRdataText if any fields are out of their valid range, +/// or are incorrect. +/// +/// \param dnskey_str A string containing the RDATA to be created +DNSKEY::DNSKEY(const std::string& dnskey_str) : + impl_(NULL) +{ + // We use unique_ptr here because if there is an exception in this + // constructor, the destructor is not called and there could be a + // leak of the DNSKEYImpl that constructFromLexer() returns. + std::unique_ptr<DNSKEYImpl> impl_ptr; + + try { + std::istringstream ss(dnskey_str); + MasterLexer lexer; + lexer.pushSource(ss); + + impl_ptr.reset(constructFromLexer(lexer)); + + if (lexer.getNextToken().getType() != MasterToken::END_OF_FILE) { + isc_throw(InvalidRdataText, + "Extra input text for DNSKEY: " << dnskey_str); + } + } catch (const MasterLexer::LexerError& ex) { + isc_throw(InvalidRdataText, + "Failed to construct DNSKEY from '" << dnskey_str << "': " + << ex.what()); + } + + impl_ = impl_ptr.release(); +} + +/// \brief Constructor from InputBuffer. +/// +/// The passed buffer must contain a valid DNSKEY RDATA. +/// +/// The Protocol and Algorithm fields are not checked for unknown +/// values. It is okay for the key data to be missing (see the description +/// of the constructor from string). +DNSKEY::DNSKEY(InputBuffer& buffer, size_t rdata_len) : + impl_(NULL) +{ + if (rdata_len < 4) { + isc_throw(InvalidRdataLength, "DNSKEY too short: " << rdata_len); + } + + const uint16_t flags = buffer.readUint16(); + const uint16_t protocol = buffer.readUint8(); + const uint16_t algorithm = buffer.readUint8(); + + rdata_len -= 4; + + vector<uint8_t> keydata; + // If key data is missing, it's OK. See the API documentation of the + // constructor. + if (rdata_len > 0) { + keydata.resize(rdata_len); + buffer.readData(&keydata[0], rdata_len); + } + + impl_ = new DNSKEYImpl(flags, protocol, algorithm, keydata); +} + +/// \brief Constructor with a context of MasterLexer. +/// +/// The \c lexer should point to the beginning of valid textual +/// representation of an DNSKEY RDATA. +/// +/// See \c DNSKEY::DNSKEY(const std::string&) for description of the +/// expected RDATA fields. +/// +/// \throw MasterLexer::LexerError General parsing error such as +/// missing field. +/// \throw InvalidRdataText if any fields are out of their valid range, +/// or are incorrect. +/// +/// \param lexer A \c MasterLexer object parsing a master file for the +/// RDATA to be created +DNSKEY::DNSKEY(MasterLexer& lexer, const Name*, + MasterLoader::Options, MasterLoaderCallbacks&) : + impl_(NULL) +{ + impl_ = constructFromLexer(lexer); +} + +DNSKEYImpl* +DNSKEY::constructFromLexer(MasterLexer& lexer) { + const uint32_t flags = lexer.getNextToken(MasterToken::NUMBER).getNumber(); + if (flags > 0xffff) { + isc_throw(InvalidRdataText, + "DNSKEY flags out of range: " << flags); + } + + const uint32_t protocol = + lexer.getNextToken(MasterToken::NUMBER).getNumber(); + if (protocol > 0xff) { + isc_throw(InvalidRdataText, + "DNSKEY protocol out of range: " << protocol); + } + + const uint32_t algorithm = + lexer.getNextToken(MasterToken::NUMBER).getNumber(); + if (algorithm > 0xff) { + isc_throw(InvalidRdataText, + "DNSKEY algorithm out of range: " << algorithm); + } + + std::string keydata_str; + std::string keydata_substr; + while (true) { + const MasterToken& token = + lexer.getNextToken(MasterToken::STRING, true); + if ((token.getType() == MasterToken::END_OF_FILE) || + (token.getType() == MasterToken::END_OF_LINE)) { + break; + } + + // token is now assured to be of type STRING. + + token.getString(keydata_substr); + keydata_str.append(keydata_substr); + } + + lexer.ungetToken(); + + vector<uint8_t> keydata; + // If key data is missing, it's OK. See the API documentation of the + // constructor. + if (keydata_str.size() > 0) { + decodeBase64(keydata_str, keydata); + } + + return (new DNSKEYImpl(flags, protocol, algorithm, keydata)); +} + +DNSKEY::DNSKEY(const DNSKEY& source) : + Rdata(), impl_(new DNSKEYImpl(*source.impl_)) +{} + +DNSKEY& +DNSKEY::operator=(const DNSKEY& source) { + if (this == &source) { + return (*this); + } + + DNSKEYImpl* newimpl = new DNSKEYImpl(*source.impl_); + delete impl_; + impl_ = newimpl; + + return (*this); +} + +DNSKEY::~DNSKEY() { + delete impl_; +} + +string +DNSKEY::toText() const { + return (boost::lexical_cast<string>(static_cast<int>(impl_->flags_)) + + " " + boost::lexical_cast<string>(static_cast<int>(impl_->protocol_)) + + " " + boost::lexical_cast<string>(static_cast<int>(impl_->algorithm_)) + + " " + encodeBase64(impl_->keydata_)); +} + +void +DNSKEY::toWire(OutputBuffer& buffer) const { + buffer.writeUint16(impl_->flags_); + buffer.writeUint8(impl_->protocol_); + buffer.writeUint8(impl_->algorithm_); + buffer.writeData(&impl_->keydata_[0], impl_->keydata_.size()); +} + +void +DNSKEY::toWire(AbstractMessageRenderer& renderer) const { + renderer.writeUint16(impl_->flags_); + renderer.writeUint8(impl_->protocol_); + renderer.writeUint8(impl_->algorithm_); + renderer.writeData(&impl_->keydata_[0], impl_->keydata_.size()); +} + +int +DNSKEY::compare(const Rdata& other) const { + const DNSKEY& other_dnskey = dynamic_cast<const DNSKEY&>(other); + + if (impl_->flags_ != other_dnskey.impl_->flags_) { + return (impl_->flags_ < other_dnskey.impl_->flags_ ? -1 : 1); + } + if (impl_->protocol_ != other_dnskey.impl_->protocol_) { + return (impl_->protocol_ < other_dnskey.impl_->protocol_ ? -1 : 1); + } + if (impl_->algorithm_ != other_dnskey.impl_->algorithm_) { + return (impl_->algorithm_ < other_dnskey.impl_->algorithm_ ? -1 : 1); + } + + const size_t this_len = impl_->keydata_.size(); + const size_t other_len = other_dnskey.impl_->keydata_.size(); + const size_t cmplen = min(this_len, other_len); + if (cmplen == 0) { + return ((this_len == other_len) ? 0 : (this_len < other_len) ? -1 : 1); + } + const int cmp = memcmp(&impl_->keydata_[0], + &other_dnskey.impl_->keydata_[0], cmplen); + if (cmp != 0) { + return (cmp); + } else { + return ((this_len == other_len) ? 0 : (this_len < other_len) ? -1 : 1); + } +} + +uint16_t +DNSKEY::getTag() const { + if (impl_->algorithm_ == 1) { + // See RFC 4034 appendix B.1 for why the key data must contain + // at least 4 bytes with RSA/MD5: 3 trailing bytes to extract + // the tag from, and 1 byte of exponent length subfield before + // modulus. + const int len = impl_->keydata_.size(); + if (len < 4) { + isc_throw(isc::OutOfRange, + "DNSKEY keydata too short for tag extraction"); + } + + return ((impl_->keydata_[len - 3] << 8) + impl_->keydata_[len - 2]); + } + + uint32_t ac = impl_->flags_; + ac += (impl_->protocol_ << 8); + ac += impl_->algorithm_; + + const size_t size = impl_->keydata_.size(); + for (size_t i = 0; i < size; i ++) { + ac += (i & 1) ? impl_->keydata_[i] : (impl_->keydata_[i] << 8); + } + ac += (ac >> 16) & 0xffff; + return (ac & 0xffff); +} + +uint16_t +DNSKEY::getFlags() const { + return (impl_->flags_); +} + +uint8_t +DNSKEY::getAlgorithm() const { + return (impl_->algorithm_); +} + +// END_RDATA_NAMESPACE +// END_ISC_NAMESPACE |