lib-ssl-iostream: Add get_compression accessor

This is needed by login-common

src/lib-ssl-iostream/iostream-openssl.c

@@ -710,6 +710,19 @@ static const char *openssl_iostream_get_server_name(struct ssl_iostream *ssl_io)
 	return ssl_io->host;
 }
 
+static const char *
+openssl_iostream_get_compression(struct ssl_iostream *ssl_io)
+{
+#if defined(HAVE_SSL_COMPRESSION) && !defined(OPENSSL_NO_COMP)
+	const COMP_METHOD *comp;
+
+	comp = SSL_get_current_compression(ssl_io->ssl);
+	return comp == NULL ? NULL : SSL_COMP_get_name(comp);
+#else
+	return NULL;
+#endif
+}
+
 static const char *
 openssl_iostream_get_security_string(struct ssl_iostream *ssl_io)
 {
@@ -764,6 +777,7 @@ static const struct iostream_ssl_vfuncs ssl_vfuncs = {
 	openssl_iostream_cert_match_name,
 	openssl_iostream_get_peer_name,
 	openssl_iostream_get_server_name,
+	openssl_iostream_get_compression,
 	openssl_iostream_get_security_string,
 	openssl_iostream_get_last_error
 };

src/lib-ssl-iostream/iostream-ssl-private.h

@@ -32,6 +32,7 @@ struct iostream_ssl_vfuncs {
 	int (*cert_match_name)(struct ssl_iostream *ssl_io, const char *name);
 	const char *(*get_peer_name)(struct ssl_iostream *ssl_io);
 	const char *(*get_server_name)(struct ssl_iostream *ssl_io);
+	const char *(*get_compression)(struct ssl_iostream *ssl_io);
 	const char *(*get_security_string)(struct ssl_iostream *ssl_io);
 	const char *(*get_last_error)(struct ssl_iostream *ssl_io);
 };

src/lib-ssl-iostream/iostream-ssl.c

@@ -200,6 +200,11 @@ const char *ssl_iostream_get_server_name(struct ssl_iostream *ssl_io)
 	return ssl_vfuncs->get_server_name(ssl_io);
 }
 
+const char *ssl_iostream_get_compression(struct ssl_iostream *ssl_io)
+{
+	return ssl_vfuncs->get_compression(ssl_io);
+}
+
 const char *ssl_iostream_get_security_string(struct ssl_iostream *ssl_io)
 {
 	return ssl_vfuncs->get_security_string(ssl_io);

src/lib-ssl-iostream/iostream-ssl.h

@@ -71,6 +71,7 @@ int ssl_iostream_check_cert_validity(struct ssl_iostream *ssl_io,
 				     const char *host, const char **error_r);
 int ssl_iostream_cert_match_name(struct ssl_iostream *ssl_io, const char *name);
 const char *ssl_iostream_get_peer_name(struct ssl_iostream *ssl_io);
+const char *ssl_iostream_get_compression(struct ssl_iostream *ssl_io);
 const char *ssl_iostream_get_server_name(struct ssl_iostream *ssl_io);
 const char *ssl_iostream_get_security_string(struct ssl_iostream *ssl_io);
 const char *ssl_iostream_get_last_error(struct ssl_iostream *ssl_io);