1 files changed, 29 insertions, 8 deletions

diff --git a/src/lib/libcrypto/x509/x509_vfy.c b/src/lib/libcrypto/x509/x509_vfy.c
index ea35ce791d..126e0f3000 100644
--- a/src/lib/libcrypto/x509/x509_vfy.c
+++ b/src/lib/libcrypto/x509/x509_vfy.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: x509_vfy.c,v 1.72 2019/03/06 05:06:58 tb Exp $ */
+/* $OpenBSD: x509_vfy.c,v 1.73 2020/05/31 17:23:39 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -117,7 +117,8 @@
 
 static int null_callback(int ok, X509_STORE_CTX *e);
 static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer);
-static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x);
+static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x,
+    int allow_expired);
 static int check_chain_extensions(X509_STORE_CTX *ctx);
 static int check_name_constraints(X509_STORE_CTX *ctx);
 static int check_trust(X509_STORE_CTX *ctx);
@@ -324,7 +325,25 @@ X509_verify_cert(X509_STORE_CTX *ctx)
                 }
                 /* If we were passed a cert chain, use it first */
                 if (ctx->untrusted != NULL) {
-                        xtmp = find_issuer(ctx, sktmp, x);
+                        /*
+                         * If we do not find a non-expired untrusted cert, peek
+                         * ahead and see if we can satisify this from the trusted
+                         * store. If not, see if we have an expired untrusted cert.
+                         */
+                        xtmp = find_issuer(ctx, sktmp, x, 0);
+                        if (xtmp == NULL &&
+                            !(ctx->param->flags & X509_V_FLAG_TRUSTED_FIRST)) {
+                                ok = ctx->get_issuer(&xtmp, ctx, x);
+                                if (ok < 0) {
+                                        ctx->error = X509_V_ERR_STORE_LOOKUP;
+                                        goto end;
+                                }
+                                if (ok > 0) {
+                                        X509_free(xtmp);
+                                        break;
+                                }
+                                xtmp = find_issuer(ctx, sktmp, x, 1);
+                        }
                         if (xtmp != NULL) {
                                 if (!sk_X509_push(ctx->chain, xtmp)) {
                                         X509error(ERR_R_MALLOC_FAILURE);
@@ -562,7 +581,8 @@ X509_verify_cert(X509_STORE_CTX *ctx)
  */
 
 static X509 *
-find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x)
+find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x,
+    int allow_expired)
 {
         int i;
         X509 *issuer, *rv = NULL;
@@ -570,9 +590,10 @@ find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x)
         for (i = 0; i < sk_X509_num(sk); i++) {
                 issuer = sk_X509_value(sk, i);
                 if (ctx->check_issued(ctx, x, issuer)) {
-                        rv = issuer;
-                        if (x509_check_cert_time(ctx, rv, -1))
-                                break;
+                        if (x509_check_cert_time(ctx, issuer, -1))
+                                return issuer;
+                        if (allow_expired)
+                                rv = issuer;
                 }
         }
         return rv;
@@ -603,7 +624,7 @@ check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer)
 static int
 get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x)
 {
-        *issuer = find_issuer(ctx, ctx->other_ctx, x);
+        *issuer = find_issuer(ctx, ctx->other_ctx, x, 1);
         if (*issuer) {
                 CRYPTO_add(&(*issuer)->references, 1, CRYPTO_LOCK_X509);
                 return 1;