1 files changed, 69 insertions, 0 deletions
diff --git a/comm/third_party/botan/src/lib/tls/msg_hello_verify.cpp b/comm/third_party/botan/src/lib/tls/msg_hello_verify.cpp
new file mode 100644
index 0000000000..bc93af9d62
--- /dev/null
+++ b/comm/third_party/botan/src/lib/tls/msg_hello_verify.cpp
@@ -0,0 +1,69 @@
+/*
+* DTLS Hello Verify Request
+* (C) 2012 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#include <botan/tls_messages.h>
+#include <botan/mac.h>
+
+namespace Botan {
+
+namespace TLS {
+
+Hello_Verify_Request::Hello_Verify_Request(const std::vector<uint8_t>& 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<size_t>(buf[2]) + 3 != buf.size())
+      throw Decoding_Error("Bad length in hello verify request");
+
+   m_cookie.assign(buf.begin() + 3, buf.end());
+   }
+
+Hello_Verify_Request::Hello_Verify_Request(const std::vector<uint8_t>& client_hello_bits,
+                                           const std::string& client_identity,
+                                           const SymmetricKey& secret_key)
+   {
+   std::unique_ptr<MessageAuthenticationCode> hmac = MessageAuthenticationCode::create_or_throw("HMAC(SHA-256)");
+   hmac->set_key(secret_key);
+
+   hmac->update_be(static_cast<uint64_t>(client_hello_bits.size()));
+   hmac->update(client_hello_bits);
+   hmac->update_be(static_cast<uint64_t>(client_identity.size()));
+   hmac->update(client_identity);
+
+   m_cookie.resize(hmac->output_length());
+   hmac->final(m_cookie.data());
+   }
+
+std::vector<uint8_t> 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<uint8_t> bits;
+   bits.push_back(format_version.major_version());
+   bits.push_back(format_version.minor_version());
+   bits.push_back(static_cast<uint8_t>(m_cookie.size()));
+   bits += m_cookie;
+   return bits;
+   }
+
+}
+
+}