Convert dtls_write_records to use standard record layer functions

We have standard functions for most of the work that dtls_write_records
does - so we convert it to use those functions instead.

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Hugo Landau <hlandau@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/19424)

1 files changed, 21 insertions, 26 deletions

diff --git a/ssl/statem/statem_dtls.c b/ssl/statem/statem_dtls.c
index 93c49011a2..b673c860ab 100644
--- a/ssl/statem/statem_dtls.c
+++ b/ssl/statem/statem_dtls.c
@@ -94,9 +94,12 @@ void dtls1_hm_fragment_free(hm_fragment *frag)
     if (!frag)
         return;
     if (frag->msg_header.is_ccs) {
-        EVP_CIPHER_CTX_free(frag->msg_header.
-                            saved_retransmit_state.enc_write_ctx);
-        EVP_MD_CTX_free(frag->msg_header.saved_retransmit_state.write_hash);
+        /*
+         * If we're freeing the CCS then we're done with the old wrl and it
+         * can bee freed
+         */
+        if (frag->msg_header.saved_retransmit_state.wrlmethod != NULL)
+            frag->msg_header.saved_retransmit_state.wrlmethod->free(frag->msg_header.saved_retransmit_state.wrl);
     }
     OPENSSL_free(frag->fragment);
     OPENSSL_free(frag->reassembly);
@@ -1161,12 +1164,9 @@ int dtls1_buffer_message(SSL_CONNECTION *s, int is_ccs)
     frag->msg_header.is_ccs = is_ccs;
 
     /* save current state */
-    frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
-    frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
-    frag->msg_header.saved_retransmit_state.compress = s->compress;
-    frag->msg_header.saved_retransmit_state.session = s->session;
-    frag->msg_header.saved_retransmit_state.epoch =
-        DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer);
+    frag->msg_header.saved_retransmit_state.wrlmethod = s->rlayer.wrlmethod;
+    frag->msg_header.saved_retransmit_state.wrl = s->rlayer.wrl;
+
 
     memset(seq64be, 0, sizeof(seq64be));
     seq64be[6] =
@@ -1228,32 +1228,27 @@ int dtls1_retransmit_message(SSL_CONNECTION *s, unsigned short seq, int *found)
                                  frag->msg_header.frag_len);
 
     /* save current state */
-    saved_state.enc_write_ctx = s->enc_write_ctx;
-    saved_state.write_hash = s->write_hash;
-    saved_state.compress = s->compress;
-    saved_state.session = s->session;
-    saved_state.epoch = DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer);
+    saved_state.wrlmethod = s->rlayer.wrlmethod;
+    saved_state.wrl = s->rlayer.wrl;
 
     s->d1->retransmitting = 1;
 
     /* restore state in which the message was originally sent */
-    s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
-    s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
-    s->compress = frag->msg_header.saved_retransmit_state.compress;
-    s->session = frag->msg_header.saved_retransmit_state.session;
-    DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer,
-                                        frag->msg_header.
-                                        saved_retransmit_state.epoch);
+    s->rlayer.wrlmethod = frag->msg_header.saved_retransmit_state.wrlmethod;
+    s->rlayer.wrl = frag->msg_header.saved_retransmit_state.wrl;
+
+    /*
+     * The old wrl may be still pointing at an old BIO. Update it to what we're
+     * using now.
+     */
+    s->rlayer.wrlmethod->set1_bio(s->rlayer.wrl, s->wbio);
 
     ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
                          SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
 
     /* restore current state */
-    s->enc_write_ctx = saved_state.enc_write_ctx;
-    s->write_hash = saved_state.write_hash;
-    s->compress = saved_state.compress;
-    s->session = saved_state.session;
-    DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer, saved_state.epoch);
+    s->rlayer.wrlmethod = saved_state.wrlmethod;
+    s->rlayer.wrl = saved_state.wrl;
 
     s->d1->retransmitting = 0;