Adding iOS OpenSSL Implementation

This adds the OpenSSL-specific implementations for iOS, using SecTrustEvaluate in order to determine the validity of the certificate chain.

(Relanding without nist-pkits dependency)

[email protected],[email protected]
BUG=591545

Review URL: https://codereview.chromium.org/1833183002

Cr-Commit-Position: refs/heads/master@{#383348}
8 files changed