/* * DTLS Hello Verify Request * (C) 2012 Jack Lloyd * * Botan is released under the Simplified BSD License (see license.txt) */ #include #include #include namespace Botan { namespace TLS { Hello_Verify_Request::Hello_Verify_Request(const std::vector& buf) { if(buf.size() < 3) throw Decoding_Error("Hello verify request too small"); Protocol_Version version(buf[0], buf[1]); if(version != Protocol_Version::DTLS_V10 && version != Protocol_Version::DTLS_V12) { throw Decoding_Error("Unknown version from server in hello verify request"); } if(static_cast(buf[2]) + 3 != buf.size()) throw Decoding_Error("Bad length in hello verify request"); m_cookie.assign(&buf[3], &buf[buf.size()]); } Hello_Verify_Request::Hello_Verify_Request(const std::vector& client_hello_bits, const std::string& client_identity, const SymmetricKey& secret_key) { std::unique_ptr hmac(get_mac("HMAC(SHA-256)")); hmac->set_key(secret_key); hmac->update_be(client_hello_bits.size()); hmac->update(client_hello_bits); hmac->update_be(client_identity.size()); hmac->update(client_identity); m_cookie = unlock(hmac->final()); } std::vector Hello_Verify_Request::serialize() const { /* DTLS 1.2 server implementations SHOULD use DTLS version 1.0 regardless of the version of TLS that is expected to be negotiated (RFC 6347, section 4.2.1) */ Protocol_Version format_version(Protocol_Version::DTLS_V10); std::vector bits; bits.push_back(format_version.major_version()); bits.push_back(format_version.minor_version()); bits.push_back(static_cast(m_cookie.size())); bits += m_cookie; return bits; } } }