Add support for DTLS handshake timeouts and retransmissions.

1 files changed, 15 insertions, 7 deletions

diff --git a/src/lib/tls/tls_seq_numbers.h b/src/lib/tls/tls_seq_numbers.h
index 87edf3130..d7b8c919c 100644
--- a/src/lib/tls/tls_seq_numbers.h
+++ b/src/lib/tls/tls_seq_numbers.h
@@ -24,7 +24,7 @@ class Connection_Sequence_Numbers
       virtual u16bit current_read_epoch() const = 0;
       virtual u16bit current_write_epoch() const = 0;
 
-      virtual u64bit next_write_sequence() = 0;
+      virtual u64bit next_write_sequence(u16bit) = 0;
       virtual u64bit next_read_sequence() = 0;
 
       virtual bool already_seen(u64bit seq) const = 0;
@@ -40,7 +40,7 @@ class Stream_Sequence_Numbers : public Connection_Sequence_Numbers
       u16bit current_read_epoch() const override { return m_read_epoch; }
       u16bit current_write_epoch() const override { return m_write_epoch; }
 
-      u64bit next_write_sequence() override { return m_write_seq_no++; }
+      u64bit next_write_sequence(u16bit) override { return m_write_seq_no++; }
       u64bit next_read_sequence() override { return m_read_seq_no; }
 
       bool already_seen(u64bit) const override { return false; }
@@ -55,18 +55,25 @@ class Stream_Sequence_Numbers : public Connection_Sequence_Numbers
 class Datagram_Sequence_Numbers : public Connection_Sequence_Numbers
    {
    public:
+      Datagram_Sequence_Numbers() { m_write_seqs[0] = 0; }
+
       void new_read_cipher_state() override { m_read_epoch += 1; }
 
       void new_write_cipher_state() override
          {
-         // increment epoch
-         m_write_seq_no = ((m_write_seq_no >> 48) + 1) << 48;
+         m_write_epoch += 1;
+         m_write_seqs[m_write_epoch] = 0;
          }
 
       u16bit current_read_epoch() const override { return m_read_epoch; }
-      u16bit current_write_epoch() const override { return (m_write_seq_no >> 48); }
+      u16bit current_write_epoch() const override { return m_write_epoch; }
 
-      u64bit next_write_sequence() override { return m_write_seq_no++; }
+      u64bit next_write_sequence(u16bit epoch) override
+         {
+         auto i = m_write_seqs.find(epoch);
+         BOTAN_ASSERT(i != m_write_seqs.end(), "Found epoch");
+         return (static_cast<u64bit>(epoch) << 48) | i->second++;
+         }
 
       u64bit next_read_sequence() override
          {
@@ -112,7 +119,8 @@ class Datagram_Sequence_Numbers : public Connection_Sequence_Numbers
          }
 
    private:
-      u64bit m_write_seq_no = 0;
+      std::map<u16bit, u64bit> m_write_seqs;
+      u16bit m_write_epoch = 0;
       u16bit m_read_epoch = 0;
       u64bit m_window_highest = 0;
       u64bit m_window_bits = 0;