Allow configuring QUIC method per-connection

This allows sharing SSL_CTX between TCP and QUIC connections, such that
common settings can be configured without having to duplicate the
context.

Change-Id: Ie920e7f2a772dd6c6c7b63fdac243914ac5b7b26
Reviewed-on: https://boringssl-review.googlesource.com/c/33904
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>

ssl/ssl_lib.cc

diff --git a/ssl/ssl_lib.cc b/ssl/ssl_lib.cc
index bbc3758..f3d92a6 100644
--- a/ssl/ssl_lib.cc
+++ b/ssl/ssl_lib.cc
@@ -714,6 +714,7 @@
   ssl->config->ocsp_stapling_enabled = ctx->ocsp_stapling_enabled;
   ssl->config->handoff = ctx->handoff;
   ssl->config->ignore_tls13_downgrade = ctx->ignore_tls13_downgrade;
+  ssl->quic_method = ctx->quic_method;
 
   if (!ssl->method->ssl_new(ssl.get()) ||
       !ssl->ctx->x509_method->ssl_new(ssl->s3->hs.get())) {
@@ -850,7 +851,7 @@
 
 int SSL_provide_quic_data(SSL *ssl, enum ssl_encryption_level_t level,
                           const uint8_t *data, size_t len) {
-  if (ssl->ctx->quic_method == nullptr) {
+  if (ssl->quic_method == nullptr) {
     OPENSSL_PUT_ERROR(SSL, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
     return 0;
   }
@@ -1077,7 +1078,7 @@
 }
 
 int SSL_peek(SSL *ssl, void *buf, int num) {
-  if (ssl->ctx->quic_method != nullptr) {
+  if (ssl->quic_method != nullptr) {
     OPENSSL_PUT_ERROR(SSL, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
     return 0;
   }
@@ -1098,7 +1099,7 @@
 int SSL_write(SSL *ssl, const void *buf, int num) {
   ssl_reset_error_state(ssl);
 
-  if (ssl->ctx->quic_method != nullptr) {
+  if (ssl->quic_method != nullptr) {
     OPENSSL_PUT_ERROR(SSL, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
     return 0;
   }
@@ -1342,7 +1343,7 @@
       return SSL_ERROR_HANDBACK;
 
     case SSL_READING: {
-      if (ssl->ctx->quic_method) {
+      if (ssl->quic_method) {
         return SSL_ERROR_WANT_READ;
       }
       BIO *bio = SSL_get_rbio(ssl);
@@ -2459,6 +2460,14 @@
   return 1;
 }
 
+int SSL_set_quic_method(SSL *ssl, const SSL_QUIC_METHOD *quic_method) {
+  if (ssl->method->is_dtls) {
+    return 0;
+  }
+  ssl->quic_method = quic_method;
+  return 1;
+}
+
 int SSL_get_ex_new_index(long argl, void *argp, CRYPTO_EX_unused *unused,
                          CRYPTO_EX_dup *dup_unused, CRYPTO_EX_free *free_func) {
   int index;