On 02/08/2019 18:24, Neptune wrote: > I am in the process of migrating our code from the 1.0.2 library to 1.1 and > have run across a situation that I am struggling to reconcile: > > The existing code utilizes the verify_callback() function in order to > perform validation measures against a peer certificate. This callback > performs validation such as checking the certificate against a CRL and doing > wildcard matching. The reason we need to define our own callback and > validation code is because, as I understand it, the built-in OpenSSL > wildcard matching will only process one wildcard field prefix (*.domain.com) > whereas our requirements allow for wildcard patterns beyond just a prefix > (FOO.*.domain.com, FOO.B*R.domain.com, etc.). > > The problem arises when I attempt to access 'ssl->tlsext_hostname' which is > understood because this structure is now opaque. I believe the accessor > function for this is '__owur const char *SSL_SESSION_get0_hostname(const > SSL_SESSION *s);' in ssl.h. However, within the context of the callback > function I only have two arguments to work with: > > int verify_callback(int ok, X509_STORE_CTX *ctx) > > This does not provide me with a SSL_SESSION object to pass into the > SSL_SESSION_get0_hostname accessor function, so... >From within your callback you can do this to get hold of the SSL object: SSL *s = (SSL *)X509_STORE_CTX_get_ex_data(ctx, SSL_get_ex_data_X509_STORE_CTX_idx()); And then this to get hold of the hostname requested: const char *hostname = SSL_get_servername(s, TLSEXT_NAMETYPE_host_name); Hope that helps, Matt
