Use EXFLAG_INVALID to handle out of memory and parse errors in

x509v3_cache_extensions().

ok tb@

2 files changed, 45 insertions, 11 deletions

diff --git a/src/lib/libcrypto/x509/x509_purp.c b/src/lib/libcrypto/x509/x509_purp.c
index f2d46658f6..3b8bd6b81c 100644
--- a/src/lib/libcrypto/x509/x509_purp.c
+++ b/src/lib/libcrypto/x509/x509_purp.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: x509_purp.c,v 1.2 2020/09/13 15:06:17 beck Exp $ */
+/* $OpenBSD: x509_purp.c,v 1.3 2021/03/13 23:01:49 tobhe Exp $ */
 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
  * project 2001.
  */
@@ -132,6 +132,8 @@ X509_check_purpose(X509 *x, int id, int ca)
                 CRYPTO_w_lock(CRYPTO_LOCK_X509);
                 x509v3_cache_extensions(x);
                 CRYPTO_w_unlock(CRYPTO_LOCK_X509);
+                if (x->ex_flags & EXFLAG_INVALID)
+                        return X509_V_ERR_UNSPECIFIED;
         }
         if (id == -1)
                 return 1;
@@ -421,7 +423,12 @@ setup_crldp(X509 *x)
 {
         int i;
 
-        x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, NULL, NULL);
+        x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, &i, NULL);
+        if (x->crldp == NULL && i != -1) {
+                x->ex_flags |= EXFLAG_INVALID;
+                return;
+        }
+
         for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++)
                 setup_dp(x, sk_DIST_POINT_value(x->crldp, i));
 }
@@ -449,7 +456,7 @@ x509v3_cache_extensions(X509 *x)
                 x->ex_flags |= EXFLAG_V1;
 
         /* Handle basic constraints */
-        if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, NULL, NULL))) {
+        if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, &i, NULL))) {
                 if (bs->ca)
                         x->ex_flags |= EXFLAG_CA;
                 if (bs->pathlen) {
@@ -463,10 +470,12 @@ x509v3_cache_extensions(X509 *x)
                         x->ex_pathlen = -1;
                 BASIC_CONSTRAINTS_free(bs);
                 x->ex_flags |= EXFLAG_BCONS;
+        } else if (i != -1) {
+                x->ex_flags |= EXFLAG_INVALID;
         }
 
         /* Handle proxy certificates */
-        if ((pci = X509_get_ext_d2i(x, NID_proxyCertInfo, NULL, NULL))) {
+        if ((pci = X509_get_ext_d2i(x, NID_proxyCertInfo, &i, NULL))) {
                 if (x->ex_flags & EXFLAG_CA ||
                     X509_get_ext_by_NID(x, NID_subject_alt_name, -1) >= 0 ||
                     X509_get_ext_by_NID(x, NID_issuer_alt_name, -1) >= 0) {
@@ -485,10 +494,12 @@ x509v3_cache_extensions(X509 *x)
                         x->ex_pcpathlen = -1;
                 PROXY_CERT_INFO_EXTENSION_free(pci);
                 x->ex_flags |= EXFLAG_PROXY;
+        } else if (i != -1) {
+                x->ex_flags |= EXFLAG_INVALID;
         }
 
         /* Handle key usage */
-        if ((usage = X509_get_ext_d2i(x, NID_key_usage, NULL, NULL))) {
+        if ((usage = X509_get_ext_d2i(x, NID_key_usage, &i, NULL))) {
                 if (usage->length > 0) {
                         x->ex_kusage = usage->data[0];
                         if (usage->length > 1)
@@ -497,9 +508,12 @@ x509v3_cache_extensions(X509 *x)
                         x->ex_kusage = 0;
                 x->ex_flags |= EXFLAG_KUSAGE;
                 ASN1_BIT_STRING_free(usage);
+        } else if (i != -1) {
+                x->ex_flags |= EXFLAG_INVALID;
         }
+
         x->ex_xkusage = 0;
-        if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, NULL, NULL))) {
+        if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, &i, NULL))) {
                 x->ex_flags |= EXFLAG_XKUSAGE;
                 for (i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
                         switch (OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage, i))) {
@@ -538,19 +552,27 @@ x509v3_cache_extensions(X509 *x)
                         }
                 }
                 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
+        } else if (i != -1) {
+                x->ex_flags |= EXFLAG_INVALID;
         }
 
-        if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, NULL, NULL))) {
+        if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, &i, NULL))) {
                 if (ns->length > 0)
                         x->ex_nscert = ns->data[0];
                 else
                         x->ex_nscert = 0;
                 x->ex_flags |= EXFLAG_NSCERT;
                 ASN1_BIT_STRING_free(ns);
+        } else if (i != -1) {
+                x->ex_flags |= EXFLAG_INVALID;
         }
 
-        x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, NULL, NULL);
-        x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, NULL, NULL);
+        x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, &i, NULL);
+        if (x->skid == NULL && i != -1)
+                x->ex_flags |= EXFLAG_INVALID;
+        x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, &i, NULL);
+        if (x->skid == NULL && i != -1)
+                x->ex_flags |= EXFLAG_INVALID;
 
         /* Does subject name match issuer? */
         if (!X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x))) {
@@ -561,7 +583,9 @@ x509v3_cache_extensions(X509 *x)
                         x->ex_flags |= EXFLAG_SS;
         }
 
-        x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL);
+        x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, &i, NULL);
+        if (x->altname == NULL && i != -1)
+                x->ex_flags |= EXFLAG_INVALID;
         x->nc = X509_get_ext_d2i(x, NID_name_constraints, &i, NULL);
         if (!x->nc && (i != -1))
                 x->ex_flags |= EXFLAG_INVALID;
@@ -626,6 +650,8 @@ X509_check_ca(X509 *x)
                 CRYPTO_w_lock(CRYPTO_LOCK_X509);
                 x509v3_cache_extensions(x);
                 CRYPTO_w_unlock(CRYPTO_LOCK_X509);
+                if (x->ex_flags & EXFLAG_INVALID)
+                        return X509_V_ERR_UNSPECIFIED;
         }
 
         return check_ca(x);
@@ -837,7 +863,11 @@ X509_check_issued(X509 *issuer, X509 *subject)
             X509_get_issuer_name(subject)))
                 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH;
         x509v3_cache_extensions(issuer);
+        if (issuer->ex_flags & EXFLAG_INVALID)
+                return X509_V_ERR_UNSPECIFIED;
         x509v3_cache_extensions(subject);
+        if (subject->ex_flags & EXFLAG_INVALID)
+                return X509_V_ERR_UNSPECIFIED;
 
         if (subject->akid) {
                 int ret = X509_check_akid(issuer, subject->akid);
diff --git a/src/lib/libcrypto/x509/x509_verify.c b/src/lib/libcrypto/x509/x509_verify.c
index 3c8369f1f9..9c34e31ee3 100644
--- a/src/lib/libcrypto/x509/x509_verify.c
+++ b/src/lib/libcrypto/x509/x509_verify.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: x509_verify.c,v 1.35 2021/03/12 15:53:38 tb Exp $ */
+/* $OpenBSD: x509_verify.c,v 1.36 2021/03/13 23:01:49 tobhe Exp $ */
 /*
  * Copyright (c) 2020-2021 Bob Beck <beck@openbsd.org>
  *
@@ -756,6 +756,10 @@ x509_verify_cert_extensions(struct x509_verify_ctx *ctx, X509 *cert, int need_ca
                 CRYPTO_w_lock(CRYPTO_LOCK_X509);
                 x509v3_cache_extensions(cert);
                 CRYPTO_w_unlock(CRYPTO_LOCK_X509);
+                if (cert->ex_flags & EXFLAG_INVALID) {
+                        ctx->error = X509_V_ERR_UNSPECIFIED;
+                        return 0;
+                }
         }
 
         if (ctx->xsc != NULL)