Implement proper verification for server certificate chain,
with refactoring of the certificate stuff.
If custom CA and CRL certs are given, load them into in-memory store, and
use CertVerifyCertificateChainPolicy() to verify the certificate chain.
There are minor errors fixed, such as
- now there is a support for private keys encoded as BEGIN/END PRIVATE KEY
in PEM, instead of only BEGIN/END RSA PRIVATE KEY
- memory leak around CryptAcquireContext() is fixed i.e when client loads
private key, it previously did never released it, not even when connection
ended.
The handling of certificates moved into schannel_certs.c from various places
