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#include "integrity_algo.hpp"
#include "message_parsers.hpp"
#include <openssl/evp.h>
#include <openssl/hmac.h>
#include <openssl/sha.h>
namespace cipher
{
namespace integrity
{
AlgoSHA1::AlgoSHA1(const std::vector<uint8_t>& sik) :
Interface(SHA1_96_AUTHCODE_LENGTH)
{
k1 = generateKn(sik, rmcp::const_1);
}
std::vector<uint8_t> AlgoSHA1::generateHMAC(const uint8_t* input,
const size_t len) const
{
std::vector<uint8_t> output(SHA_DIGEST_LENGTH);
unsigned int mdLen = 0;
if (HMAC(EVP_sha1(), k1.data(), k1.size(), input, len, output.data(),
&mdLen) == NULL)
{
throw std::runtime_error("Generating integrity data failed");
}
// HMAC generates Message Digest to the size of SHA_DIGEST_LENGTH, the
// AuthCode field length is based on the integrity algorithm. So we are
// interested only in the AuthCode field length of the generated Message
// digest.
output.resize(authCodeLength);
return output;
}
bool AlgoSHA1::verifyIntegrityData(
const std::vector<uint8_t>& packet, const size_t length,
std::vector<uint8_t>::const_iterator integrityData) const
{
auto output = generateHMAC(
packet.data() + message::parser::RMCP_SESSION_HEADER_SIZE, length);
// Verify if the generated integrity data for the packet and the received
// integrity data matches.
return (std::equal(output.begin(), output.end(), integrityData));
}
std::vector<uint8_t>
AlgoSHA1::generateIntegrityData(const std::vector<uint8_t>& packet) const
{
return generateHMAC(
packet.data() + message::parser::RMCP_SESSION_HEADER_SIZE,
packet.size() - message::parser::RMCP_SESSION_HEADER_SIZE);
}
std::vector<uint8_t> AlgoSHA1::generateKn(const std::vector<uint8_t>& sik,
const rmcp::Const_n& const_n) const
{
unsigned int mdLen = 0;
std::vector<uint8_t> Kn(sik.size());
// Generated Kn for the integrity algorithm with the additional key keyed
// with SIK.
if (HMAC(EVP_sha1(), sik.data(), sik.size(), const_n.data(), const_n.size(),
Kn.data(), &mdLen) == NULL)
{
throw std::runtime_error("Generating KeyN for integrity "
"algorithm failed");
}
return Kn;
}
AlgoSHA256::AlgoSHA256(const std::vector<uint8_t>& sik) :
Interface(SHA256_128_AUTHCODE_LENGTH)
{
k1 = generateKn(sik, rmcp::const_1);
}
std::vector<uint8_t> AlgoSHA256::generateHMAC(const uint8_t* input,
const size_t len) const
{
std::vector<uint8_t> output(SHA256_DIGEST_LENGTH);
unsigned int mdLen = 0;
if (HMAC(EVP_sha256(), k1.data(), k1.size(), input, len, output.data(),
&mdLen) == NULL)
{
throw std::runtime_error("Generating HMAC_SHA256_128 failed");
}
// HMAC generates Message Digest to the size of SHA256_DIGEST_LENGTH, the
// AuthCode field length is based on the integrity algorithm. So we are
// interested only in the AuthCode field length of the generated Message
// digest.
output.resize(authCodeLength);
return output;
}
bool AlgoSHA256::verifyIntegrityData(
const std::vector<uint8_t>& packet, const size_t length,
std::vector<uint8_t>::const_iterator integrityData) const
{
auto output = generateHMAC(
packet.data() + message::parser::RMCP_SESSION_HEADER_SIZE, length);
// Verify if the generated integrity data for the packet and the received
// integrity data matches.
return (std::equal(output.begin(), output.end(), integrityData));
}
std::vector<uint8_t>
AlgoSHA256::generateIntegrityData(const std::vector<uint8_t>& packet) const
{
return generateHMAC(
packet.data() + message::parser::RMCP_SESSION_HEADER_SIZE,
packet.size() - message::parser::RMCP_SESSION_HEADER_SIZE);
}
std::vector<uint8_t> AlgoSHA256::generateKn(const std::vector<uint8_t>& sik,
const rmcp::Const_n& const_n) const
{
unsigned int mdLen = 0;
std::vector<uint8_t> Kn(sik.size());
// Generated Kn for the integrity algorithm with the additional key keyed
// with SIK.
if (HMAC(EVP_sha256(), sik.data(), sik.size(), const_n.data(),
const_n.size(), Kn.data(), &mdLen) == NULL)
{
throw std::runtime_error("Generating KeyN for integrity "
"algorithm HMAC_SHA256 failed");
}
return Kn;
}
} // namespace integrity
} // namespace cipher
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