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fbf672288f
i2pd/Reseed.cpp
orignal fbf672288f MAC and encryption keys
2015-02-17 16:50:37 -05:00

656 lines
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#include <string.h>
#include <fstream>
#include <sstream>
#include <boost/regex.hpp>
#include <boost/filesystem.hpp>
#include <cryptopp/hmac.h>
#include <cryptopp/osrng.h>
#include <cryptopp/asn.h>
#include <cryptopp/base64.h>
#include <cryptopp/crc.h>
#include <cryptopp/zinflate.h>
#include "I2PEndian.h"
#include "Reseed.h"
#include "Log.h"
#include "Identity.h"
#include "CryptoConst.h"
#include "NetDb.h"
#include "util.h"
namespace i2p
{
namespace data
{
static std::vector<std::string> httpReseedHostList = {
// "http://193.150.121.66/netDb/", // unstable
// "http://us.reseed.i2p2.no/", // misconfigured, not serving reseed data
// "http://jp.reseed.i2p2.no/", // Really outdated RIs
"http://netdb.i2p2.no/", // only SU3 (v2) support
"http://i2p.mooo.com/netDb/",
"http://uk.reseed.i2p2.no/",
"http://i2p-netdb.innovatio.no/"
};
//TODO: Remember to add custom port support. Not all serves on 443
static std::vector<std::string> httpsReseedHostList = {
// "https://193.150.121.66/netDb/", // unstable
// "https://i2p-netdb.innovatio.no/",// Vuln to POODLE
"https://netdb.i2p2.no/", // Only SU3 (v2) support
"https://reseed.i2p-projekt.de/", // Only HTTPS
"https://cowpuncher.drollette.com/netdb/", // Only HTTPS and SU3 (v2) support -- will move to a new location
"https://i2p.mooo.com/netDb/",
"https://link.mx24.eu/", // Only HTTPS and SU3 (v2) support
"https://i2pseed.zarrenspry.info/", // Only HTTPS and SU3 (v2) support
"https://ieb9oopo.mooo.com/" // Only HTTPS and SU3 (v2) support
};
//TODO: Implement v2 reseeding. Lightweight zip library is needed.
//TODO: Implement SU3, utils.
Reseeder::Reseeder()
{
}
Reseeder::~Reseeder()
{
}
bool Reseeder::reseedNow()
{
try
{
// Seems like the best place to try to intercept with SSL
/*ssl_server = true;
try {
// SSL
}
catch (std::exception& e)
{
LogPrint("Exception in SSL: ", e.what());
}*/
std::string reseedHost = httpReseedHostList[(rand() % httpReseedHostList.size())];
LogPrint("Reseeding from ", reseedHost);
std::string content = i2p::util::http::httpRequest(reseedHost);
if (content == "")
{
LogPrint("Reseed failed");
return false;
}
boost::regex e("<\\s*A\\s+[^>]*href\\s*=\\s*\"([^\"]*)\"", boost::regex::normal | boost::regbase::icase);
boost::sregex_token_iterator i(content.begin(), content.end(), e, 1);
boost::sregex_token_iterator j;
//TODO: Ugly code, try to clean up.
//TODO: Try to reduce N number of variables
std::string name;
std::string routerInfo;
std::string tmpUrl;
std::string filename;
std::string ignoreFileSuffix = ".su3";
boost::filesystem::path root = i2p::util::filesystem::GetDataDir();
while (i != j)
{
name = *i++;
if (name.find(ignoreFileSuffix)!=std::string::npos)
continue;
LogPrint("Downloading ", name);
tmpUrl = reseedHost;
tmpUrl.append(name);
routerInfo = i2p::util::http::httpRequest(tmpUrl);
if (routerInfo.size()==0)
continue;
filename = root.string();
#ifndef _WIN32
filename += "/netDb/r";
#else
filename += "\\netDb\\r";
#endif
filename += name.at(11); // first char in id
#ifndef _WIN32
filename.append("/");
#else
filename.append("\\");
#endif
filename.append(name.c_str());
std::ofstream outfile (filename, std::ios::binary);
outfile << routerInfo;
outfile.close();
}
return true;
}
catch (std::exception& ex)
{
//TODO: error reporting
return false;
}
return false;
}
int Reseeder::ReseedNowSU3 ()
{
CryptoPP::AutoSeededRandomPool rnd;
auto ind = rnd.GenerateWord32 (0, httpReseedHostList.size() - 1);
std::string reseedHost = httpReseedHostList[ind];
return ReseedFromSU3 (reseedHost);
}
int Reseeder::ReseedFromSU3 (const std::string& host)
{
std::string url = host + "i2pseeds.su3";
LogPrint (eLogInfo, "Dowloading SU3 from ", host);
std::string su3 = i2p::util::http::httpRequest (url);
if (su3.length () > 0)
{
std::stringstream s(su3);
return ProcessSU3Stream (s);
}
else
{
LogPrint (eLogWarning, "SU3 download failed");
return 0;
}
}
int Reseeder::ProcessSU3File (const char * filename)
{
std::ifstream s(filename, std::ifstream::binary);
if (s.is_open ())
return ProcessSU3Stream (s);
else
{
LogPrint (eLogError, "Can't open file ", filename);
return 0;
}
}
const char SU3_MAGIC_NUMBER[]="I2Psu3";
const uint32_t ZIP_HEADER_SIGNATURE = 0x04034B50;
const uint32_t ZIP_CENTRAL_DIRECTORY_HEADER_SIGNATURE = 0x02014B50;
const uint16_t ZIP_BIT_FLAG_DATA_DESCRIPTOR = 0x0008;
int Reseeder::ProcessSU3Stream (std::istream& s)
{
char magicNumber[7];
s.read (magicNumber, 7); // magic number and zero byte 6
if (strcmp (magicNumber, SU3_MAGIC_NUMBER))
{
LogPrint (eLogError, "Unexpected SU3 magic number");
return 0;
}
s.seekg (1, std::ios::cur); // su3 file format version
SigningKeyType signatureType;
s.read ((char *)&signatureType, 2); // signature type
signatureType = be16toh (signatureType);
uint16_t signatureLength;
s.read ((char *)&signatureLength, 2); // signature length
signatureLength = be16toh (signatureLength);
s.seekg (1, std::ios::cur); // unused
uint8_t versionLength;
s.read ((char *)&versionLength, 1); // version length
s.seekg (1, std::ios::cur); // unused
uint8_t signerIDLength;
s.read ((char *)&signerIDLength, 1); // signer ID length
uint64_t contentLength;
s.read ((char *)&contentLength, 8); // content length
contentLength = be64toh (contentLength);
s.seekg (1, std::ios::cur); // unused
uint8_t fileType;
s.read ((char *)&fileType, 1); // file type
if (fileType != 0x00) // zip file
{
LogPrint (eLogError, "Can't handle file type ", (int)fileType);
return 0;
}
s.seekg (1, std::ios::cur); // unused
uint8_t contentType;
s.read ((char *)&contentType, 1); // content type
if (contentType != 0x03) // reseed data
{
LogPrint (eLogError, "Unexpected content type ", (int)contentType);
return 0;
}
s.seekg (12, std::ios::cur); // unused
s.seekg (versionLength, std::ios::cur); // skip version
char signerID[256];
s.read (signerID, signerIDLength); // signerID
signerID[signerIDLength] = 0;
//try to verify signature
auto it = m_SigningKeys.find (signerID);
if (it != m_SigningKeys.end ())
{
// TODO: implement all signature types
if (signatureType == SIGNING_KEY_TYPE_RSA_SHA512_4096)
{
size_t pos = s.tellg ();
size_t tbsLen = pos + contentLength;
uint8_t * tbs = new uint8_t[tbsLen];
s.seekg (0, std::ios::beg);
s.read ((char *)tbs, tbsLen);
uint8_t * signature = new uint8_t[signatureLength];
s.read ((char *)signature, signatureLength);
// RSA-raw
i2p::crypto::RSASHA5124096RawVerifier verifier(it->second);
verifier.Update (tbs, tbsLen);
if (!verifier.Verify (signature))
LogPrint (eLogWarning, "SU3 signature verification failed");
delete[] signature;
delete[] tbs;
s.seekg (pos, std::ios::beg);
}
else
LogPrint (eLogWarning, "Signature type ", signatureType, " is not supported");
}
else
LogPrint (eLogWarning, "Certificate for ", signerID, " not loaded");
// handle content
int numFiles = 0;
size_t contentPos = s.tellg ();
while (!s.eof ())
{
uint32_t signature;
s.read ((char *)&signature, 4);
signature = le32toh (signature);
if (signature == ZIP_HEADER_SIGNATURE)
{
// next local file
s.seekg (2, std::ios::cur); // version
uint16_t bitFlag;
s.read ((char *)&bitFlag, 2);
bitFlag = le16toh (bitFlag);
uint16_t compressionMethod;
s.read ((char *)&compressionMethod, 2);
compressionMethod = le16toh (compressionMethod);
s.seekg (4, std::ios::cur); // skip fields we don't care about
uint32_t compressedSize, uncompressedSize;
uint8_t crc32[4];
s.read ((char *)crc32, 4);
s.read ((char *)&compressedSize, 4);
compressedSize = le32toh (compressedSize);
s.read ((char *)&uncompressedSize, 4);
uncompressedSize = le32toh (uncompressedSize);
uint16_t fileNameLength, extraFieldLength;
s.read ((char *)&fileNameLength, 2);
fileNameLength = le16toh (fileNameLength);
s.read ((char *)&extraFieldLength, 2);
extraFieldLength = le16toh (extraFieldLength);
char localFileName[255];
s.read (localFileName, fileNameLength);
localFileName[fileNameLength] = 0;
s.seekg (extraFieldLength, std::ios::cur);
// take care about data desriptor if presented
if (bitFlag & ZIP_BIT_FLAG_DATA_DESCRIPTOR)
{
size_t pos = s.tellg ();
if (!FindZipDataDescriptor (s))
{
LogPrint (eLogError, "SU3 archive data descriptor not found");
return numFiles;
}
s.read ((char *)crc32, 4);
s.read ((char *)&compressedSize, 4);
compressedSize = le32toh (compressedSize) + 4; // ??? we must consider signature as part of compressed data
s.read ((char *)&uncompressedSize, 4);
uncompressedSize = le32toh (uncompressedSize);
// now we know compressed and uncompressed size
s.seekg (pos, std::ios::beg); // back to compressed data
}
LogPrint (eLogDebug, "Proccessing file ", localFileName, " ", compressedSize, " bytes");
if (!compressedSize)
{
LogPrint (eLogWarning, "Unexpected size 0. Skipped");
continue;
}
uint8_t * compressed = new uint8_t[compressedSize];
s.read ((char *)compressed, compressedSize);
if (compressionMethod) // we assume Deflate
{
CryptoPP::Inflator decompressor;
decompressor.Put (compressed, compressedSize);
decompressor.MessageEnd();
if (decompressor.MaxRetrievable () <= uncompressedSize)
{
uint8_t * uncompressed = new uint8_t[uncompressedSize];
decompressor.Get (uncompressed, uncompressedSize);
if (CryptoPP::CRC32().VerifyDigest (crc32, uncompressed, uncompressedSize))
{
i2p::data::netdb.AddRouterInfo (uncompressed, uncompressedSize);
numFiles++;
}
else
LogPrint (eLogError, "CRC32 verification failed");
delete[] uncompressed;
}
else
LogPrint (eLogError, "Actual uncompressed size ", decompressor.MaxRetrievable (), " exceed ", uncompressedSize, " from header");
}
else // no compression
{
i2p::data::netdb.AddRouterInfo (compressed, compressedSize);
numFiles++;
}
delete[] compressed;
if (bitFlag & ZIP_BIT_FLAG_DATA_DESCRIPTOR)
s.seekg (12, std::ios::cur); // skip data descriptor section if presented (12 = 16 - 4)
}
else
{
if (signature != ZIP_CENTRAL_DIRECTORY_HEADER_SIGNATURE)
LogPrint (eLogWarning, "Missing zip central directory header");
break; // no more files
}
size_t end = s.tellg ();
if (end - contentPos >= contentLength)
break; // we are beyond contentLength
}
return numFiles;
}
const uint8_t ZIP_DATA_DESCRIPTOR_SIGNATURE[] = { 0x50, 0x4B, 0x07, 0x08 };
bool Reseeder::FindZipDataDescriptor (std::istream& s)
{
size_t nextInd = 0;
while (!s.eof ())
{
uint8_t nextByte;
s.read ((char *)&nextByte, 1);
if (nextByte == ZIP_DATA_DESCRIPTOR_SIGNATURE[nextInd])
{
nextInd++;
if (nextInd >= sizeof (ZIP_DATA_DESCRIPTOR_SIGNATURE))
return true;
}
else
nextInd = 0;
}
return false;
}
const char CERTIFICATE_HEADER[] = "-----BEGIN CERTIFICATE-----";
const char CERTIFICATE_FOOTER[] = "-----END CERTIFICATE-----";
void Reseeder::LoadCertificate (const std::string& filename)
{
std::ifstream s(filename, std::ifstream::binary);
if (s.is_open ())
{
s.seekg (0, std::ios::end);
size_t len = s.tellg ();
s.seekg (0, std::ios::beg);
char buf[2048];
s.read (buf, len);
std::string cert (buf, len);
// assume file in pem format
auto pos1 = cert.find (CERTIFICATE_HEADER);
auto pos2 = cert.find (CERTIFICATE_FOOTER);
if (pos1 == std::string::npos || pos2 == std::string::npos)
{
LogPrint (eLogError, "Malformed certificate file");
return;
}
pos1 += strlen (CERTIFICATE_HEADER);
pos2 -= pos1;
std::string base64 = cert.substr (pos1, pos2);
CryptoPP::ByteQueue queue;
CryptoPP::Base64Decoder decoder; // regular base64 rather than I2P
decoder.Attach (new CryptoPP::Redirector (queue));
decoder.Put ((const uint8_t *)base64.data(), base64.length());
decoder.MessageEnd ();
LoadCertificate (queue);
}
else
LogPrint (eLogError, "Can't open certificate file ", filename);
}
std::string Reseeder::LoadCertificate (CryptoPP::ByteQueue& queue)
{
// extract X.509
CryptoPP::BERSequenceDecoder x509Cert (queue);
CryptoPP::BERSequenceDecoder tbsCert (x509Cert);
// version
uint32_t ver;
CryptoPP::BERGeneralDecoder context (tbsCert, CryptoPP::CONTEXT_SPECIFIC | CryptoPP::CONSTRUCTED);
CryptoPP::BERDecodeUnsigned<uint32_t>(context, ver, CryptoPP::INTEGER);
// serial
CryptoPP::Integer serial;
serial.BERDecode(tbsCert);
// signature
CryptoPP::BERSequenceDecoder signature (tbsCert);
signature.SkipAll();
// issuer
std::string name;
CryptoPP::BERSequenceDecoder issuer (tbsCert);
{
CryptoPP::BERSetDecoder c (issuer); c.SkipAll();
CryptoPP::BERSetDecoder st (issuer); st.SkipAll();
CryptoPP::BERSetDecoder l (issuer); l.SkipAll();
CryptoPP::BERSetDecoder o (issuer); o.SkipAll();
CryptoPP::BERSetDecoder ou (issuer); ou.SkipAll();
CryptoPP::BERSetDecoder cn (issuer);
{
CryptoPP::BERSequenceDecoder attributes (cn);
{
CryptoPP::BERGeneralDecoder ident(attributes, CryptoPP::OBJECT_IDENTIFIER);
ident.SkipAll ();
CryptoPP::BERDecodeTextString (attributes, name, CryptoPP::UTF8_STRING);
}
}
}
issuer.SkipAll();
// validity
CryptoPP::BERSequenceDecoder validity (tbsCert);
validity.SkipAll();
// subject
CryptoPP::BERSequenceDecoder subject (tbsCert);
subject.SkipAll();
// public key
CryptoPP::BERSequenceDecoder publicKey (tbsCert);
{
CryptoPP::BERSequenceDecoder ident (publicKey);
ident.SkipAll ();
CryptoPP::BERGeneralDecoder key (publicKey, CryptoPP::BIT_STRING);
key.Skip (1); // FIXME: probably bug in crypto++
CryptoPP::BERSequenceDecoder keyPair (key);
CryptoPP::Integer n;
n.BERDecode (keyPair);
if (name.length () > 0)
{
PublicKey value;
n.Encode (value, 512);
m_SigningKeys[name] = value;
}
else
LogPrint (eLogWarning, "Unknown issuer. Skipped");
}
publicKey.SkipAll();
tbsCert.SkipAll();
x509Cert.SkipAll();
return name;
}
void Reseeder::LoadCertificates ()
{
boost::filesystem::path reseedDir = i2p::util::filesystem::GetCertificatesDir() / "reseed";
if (!boost::filesystem::exists (reseedDir))
{
LogPrint (eLogWarning, "Reseed certificates not loaded. ", reseedDir, " doesn't exist");
return;
}
int numCertificates = 0;
boost::filesystem::directory_iterator end; // empty
for (boost::filesystem::directory_iterator it (reseedDir); it != end; ++it)
{
if (boost::filesystem::is_regular_file (it->status()) && it->path ().extension () == ".crt")
{
LoadCertificate (it->path ().string ());
numCertificates++;
}
}
LogPrint (eLogInfo, numCertificates, " certificates loaded");
}
std::string Reseeder::HttpsRequest (const std::string& address)
{
static uint8_t clientHello[] =
{
0x16, // handshake
0x03, 0x02, // version (TSL 1.2)
0x00, 0x2F, // length of handshake
// handshake
0x01, // handshake type (client hello)
0x00, 0x00, 0x2B, // length of handshake payload
// client hello
0x03, 0x02, // highest version supported (TSL 1.2)
0x01, 0x01, 0x01, 0x01, // date, can be anything
0x74, 0x55, 0x18, 0x36, 0x42, 0x05, 0xC1, 0xDD, 0x4A, 0x21, 0x80, 0x80, 0xEC, 0x37,
0x11, 0x93, 0x16, 0xF4, 0x66, 0x00, 0x12, 0x67, 0xAB, 0xBA, 0xFF, 0x29, 0x13, 0x9E, // 28 random bytes
0x00, // session id length
0x00, 0x04, // chiper suites length
0x00, 0x00, // NULL_WITH_NULL_NULL
0x00, 0x3D, // RSA_WITH_AES_256_CBC_SHA256
0x01, // compression methods length
0x00 // no compression
};
static uint8_t clientKeyExchange[] =
{
0x16, // handshake
0x03, 0x02, // version (TSL 1.2)
0x02, 0x04, // length of handshake
// handshake
0x10, // handshake type (client key exchange)
0x00, 0x02, 0x00, // length of handshake payload
// client key exchange RSA
// 512 RSA encrypted 48 bytes ( 2 bytes version + 46 random bytes)
};
i2p::util::http::url u(address);
boost::asio::ip::tcp::iostream site;
site.connect(u.host_, "443");
if (site.good ())
{
// send ClientHello
site.write ((char *)clientHello, sizeof (clientHello));
// read ServerHello
uint8_t type;
site.read ((char *)&type, 1);
uint16_t version;
site.read ((char *)&version, 2);
uint16_t length;
site.read ((char *)&length, 2);
length = be16toh (length);
char * serverHello = new char[length];
site.read (serverHello, length);
uint8_t serverRandom[32];
if (serverHello[0] == 0x02) // handshake type server hello
memcpy (serverRandom, serverHello + 6, 32);
else
LogPrint (eLogError, "Unexpected handshake type ", (int)serverHello[0]);
delete[] serverHello;
// read Certificate
site.read ((char *)&type, 1);
site.read ((char *)&version, 2);
site.read ((char *)&length, 2);
length = be16toh (length);
char * certificate = new char[length];
site.read (certificate, length);
CryptoPP::RSA::PublicKey publicKey;
// 0 - handshake type
// 1 - 3 - handshake payload length
// 4 - 6 - length of array of certificates
// 7 - 9 - length of certificate
if (certificate[0] == 0x0B) // handshake type certificate
{
CryptoPP::ByteQueue queue;
queue.Put ((uint8_t *)certificate + 10, length - 10);
queue.MessageEnd ();
auto issuer = LoadCertificate (queue);
auto it = m_SigningKeys.find (issuer);
if (it != m_SigningKeys.end ())
publicKey.Initialize (CryptoPP::Integer (it->second, 512), CryptoPP::Integer (i2p::crypto::rsae));
else
LogPrint (eLogError, "Can't find public key for ", issuer);
}
else
LogPrint (eLogError, "Unexpected handshake type ", (int)certificate[0]);
delete[] certificate;
// read ServerHelloDone
site.read ((char *)&type, 1);
site.read ((char *)&version, 2);
site.read ((char *)&length, 2);
length = be16toh (length);
char * serverHelloDone = new char[length];
site.read (serverHelloDone, length);
if (serverHelloDone[0] != 0x0E) // handshake type hello done
LogPrint (eLogError, "Unexpected handshake type ", (int)serverHelloDone[0]);
delete[] serverHelloDone;
// our turn now
// generate secret key
CryptoPP::AutoSeededRandomPool rnd;
CryptoPP::RSAES_PKCS1v15_Encryptor encryptor(publicKey);
// encryptor.CiphertextLength (48);
uint8_t secret[48], encrypted[512];
secret[0] = clientKeyExchange[1]; secret[1] = clientKeyExchange[2]; // version
rnd.GenerateBlock (secret + 2, 46); // 46 random bytes
encryptor.Encrypt (rnd, secret, 48, encrypted);
// send ClientKeyExchange
site.write ((char *)clientKeyExchange, sizeof (clientKeyExchange));
site.write ((char *)encrypted, 512);
uint8_t masterSecret[48], random[64];
memcpy (random, clientHello + 11, 32);
memcpy (random + 32, serverRandom, 32);
PRF (secret, "master secret", random, 48, masterSecret);
struct
{
uint8_t clientMACKey[32];
uint8_t serverMACKey[32];
uint8_t clientKey[32];
uint8_t serverKey[32];
} keys;
memcpy (random, serverRandom, 32);
memcpy (random + 32, clientHello + 11, 32);
PRF (masterSecret, "key expansion", random, 128, (uint8_t *)&keys);
}
else
LogPrint (eLogError, "Can't connect to ", address);
return "";
}
void Reseeder::PRF (const uint8_t * secret, const char * label, const uint8_t * random, size_t len, uint8_t * buf)
{
// secret is assumed 48 bytes
// random is 64 bytes
// output is 48 bytes (buffer size should be 64)
CryptoPP::HMAC<CryptoPP::SHA256> hmac (secret, 48);
uint8_t seed[96]; size_t seedLen;
seedLen = strlen (label);
memcpy (seed, label, seedLen);
memcpy (seed + seedLen, random, 64);
seedLen += 64;
size_t offset = 0;
uint8_t a[128];
hmac.CalculateDigest (a, seed, seedLen);
while (offset < len)
{
memcpy (a + 32, seed, seedLen);
hmac.CalculateDigest (buf + offset, a, seedLen + 32);
offset += 32;
hmac.CalculateDigest (a, a, 32);
}
}
}
}
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