process functions
Access to process functions is needed to reduce possible timing attacks
on SSL MAC checks. As SSL is set to move to using the dynamic MD layer,
the MD layer needs access to these process functions as well.
The real peer certificate is copied into a x509_buf in the
ssl_cache_entry and reinstated upon cache retrieval. The information
about the rest of the certificate chain is lost in the process.
As the handshake (and certificate verification) has already been
performed, no issue is foreseen.
If the define POLARSSL_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO is enabled,
the SSL Server module can handle the old SSLv2 Client Hello messages.
It has been updated to deny SSLv2 Client Hello messages during
renegotiation.
Split rsa_pkcs1_encrypt() into rsa_rsaes_oaep_encrypt() and
rsa_rsaes_pkcs1_v15_encrypt()
Split rsa_pkcs1_decrypt() into rsa_rsaes_oaep_decrypt() and
rsa_rsaes_pkcs1_v15_decrypt()
Split rsa_pkcs1_sign() into rsa_rsassa_pss_sign() and
rsa_rsassa_pkcs1_v15_sign()
Split rsa_pkcs1_verify() into rsa_rsassa_pss_verify() and
rsa_rsassa_pkcs1_v15_verify()
The original functions exist as generic wrappers to these functions.
New padding checking is unbiased on correct or incorrect padding and
has no branch prediction timing differences.
The additional MAC checks further straighten out the timing differences.
The flag POLARSSL_SSL_ALERT_MESSAGES switched between enabling and
disabling the sending of alert messages that give adversaries intel
about the result of their action. PolarSSL can still communicate with
other parties if they are disabled, but debugging of issues might be
harder.
Enable a dummy error function to make use of error_strerror() in
third party libraries easier.
Disable if you run into name conflicts and want to really remove the
error_strerror()
process
Single stepping the handshake process allows for better support of
non-blocking network stacks and for getting information from specific
handshake messages if wanted.
