Modify the DtlsMsgPoolSend() function to keep track of the last message
retransmit. If a write would block, it allows the retransmit pick up
where it left off.
Do not allow the DTLS message flight be retransmit without being
finished. This can happen if a non-blocking transmit times out the
response and the application tries to retransmit.
1. Add error code for trying to retransmit a flight when transmitting
the flight hasn't finished.
2. Add function to retransmit the stored flight without updating the
timeout count.
1. In DTLS, when transmitting the Change Cipher Spec message increment the
sequence number.
2. In DTLS, when client receives the CCS message, sanity check that the
server hello has been received in the case of resume.
1. In the client, check the return code on wolfSSL_CTX_SetMinDhKey_Sz() as it is checked in the server. (Resolves issue #2037.)
2. In HashOutput(), check that the hsHashes exists for the session before hashing. (Resolves issue #2038.)
Fixed a potential bug with respect to processing fragmented handshake
messages. If a handshake message is fragmented across multiple TLS
records and the last fragment's record has the next handshake message in
it, we would throw a buffer error instead of processing the next
message. Changed this so it will finish the handshake message and return
out to process the next message. Also changed the handling of the
handshake message to follow the calling pattern.
* Fix with `WOLFSSL_ALT_CERT_CHAINS` to resolve issue with using a trusted intermediate to validate a partial chain. With the alt cert chain enabled a CA may fail with only `ASN_NO_SIGNER_E` and the connection is allowed if the peer's certificate validates to a trusted CA. Eliminates overly complex 1 deep error alternate chain detection logic. Resolves ZD 4525.
* Refactor and cleanup of ProcessPeerPerts to combine duplicate code and improve code commenting.
* Fix for CA path len check in `ParseCertRelative` to always check for self-signed case (was previously only in NO_SKID case).
* Improvement to include self-signed flag in the DecodedCert struct.
