This is errata/6.8/013_libressl.patch.siglibressl-v3.2.4

Various interoperability issues and memory leaks were discovered in
libcrypto and libssl.

The new verifier is not bug compatible with the old verifier and caused
many issues by failing to propagate errors correctly, returning different
error codes than some software was trained to expect and otherwise failing
when it shouldn't. While much of this is fixed in -current, it's still not
perfect, so switching back to the legacy verifier is preferable at this
point.

Other included fixes:

* Unbreak DTLS retransmissions for flights that include a CCS
* Only check BIO_should_read() on read and BIO_should_write() on write
* Implement autochain for the TLSv1.3 server
* Use the legacy verifier for AUTO_CHAIN
* Implement exporter for TLSv1.3
* Free alert_data and phh_data in tls13_record_layer_free()
* Plug leak in x509_verify_chain_dup()
* Free the policy tree in x509_vfy_check_policy()

Original commits by jsing and tb

ok inoguchi jsing

1 files changed, 25 insertions, 1 deletions

diff --git a/src/lib/libssl/tls13_server.c b/src/lib/libssl/tls13_server.c
index a5c03b610c..f9b557d2ac 100644
--- a/src/lib/libssl/tls13_server.c
+++ b/src/lib/libssl/tls13_server.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tls13_server.c,v 1.61 2020/07/03 04:12:51 tb Exp $ */
+/* $OpenBSD: tls13_server.c,v 1.61.4.1 2021/02/03 07:06:14 tb Exp $ */
 /*
  * Copyright (c) 2019, 2020 Joel Sing <jsing@openbsd.org>
  * Copyright (c) 2020 Bob Beck <beck@openbsd.org>
@@ -611,6 +611,7 @@ tls13_server_certificate_send(struct tls13_ctx *ctx, CBB *cbb)
         SSL *s = ctx->ssl;
         CBB cert_request_context, cert_list;
         const struct ssl_sigalg *sigalg;
+        X509_STORE_CTX *xsc = NULL;
         STACK_OF(X509) *chain;
         CERT_PKEY *cpk;
         X509 *cert;
@@ -633,6 +634,18 @@ tls13_server_certificate_send(struct tls13_ctx *ctx, CBB *cbb)
         if ((chain = cpk->chain) == NULL)
                 chain = s->ctx->extra_certs;
 
+        if (chain == NULL && !(s->internal->mode & SSL_MODE_NO_AUTO_CHAIN)) {
+                if ((xsc = X509_STORE_CTX_new()) == NULL)
+                        goto err;
+                if (!X509_STORE_CTX_init(xsc, s->ctx->cert_store, cpk->x509, NULL))
+                        goto err;
+                X509_VERIFY_PARAM_set_flags(X509_STORE_CTX_get0_param(xsc),
+                    X509_V_FLAG_LEGACY_VERIFY);
+                X509_verify_cert(xsc);
+                ERR_clear_error();
+                chain = xsc->chain;
+        }
+
         if (!CBB_add_u8_length_prefixed(cbb, &cert_request_context))
                 goto err;
         if (!CBB_add_u24_length_prefixed(cbb, &cert_list))
@@ -643,6 +656,15 @@ tls13_server_certificate_send(struct tls13_ctx *ctx, CBB *cbb)
 
         for (i = 0; i < sk_X509_num(chain); i++) {
                 cert = sk_X509_value(chain, i);
+
+                /*
+                 * In the case of auto chain, the leaf certificate will be at
+                 * the top of the chain - skip over it as we've already added
+                 * it earlier.
+                 */
+                if (i == 0 && cert == cpk->x509)
+                        continue;
+
                 /*
                  * XXX we don't send extensions with chain certs to avoid sending
                  * a leaf ocsp stape with the chain certs.  This needs to get
@@ -658,6 +680,8 @@ tls13_server_certificate_send(struct tls13_ctx *ctx, CBB *cbb)
         ret = 1;
 
  err:
+        X509_STORE_CTX_free(xsc);
+
         return ret;
 }