Validate config options during x509 extension creation

There are several points during x509 extension creation which rely on
configuration options which may have been incorrectly parsed due to
invalid settings.  Preform a value check for null in those locations to
avoid various crashes/undefined behaviors

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/23183)

(cherry picked from commit bac7e687d7)

crypto/x509/v3_addr.c

@@ -972,6 +972,10 @@ static void *v2i_IPAddrBlocks(const struct v3_ext_method *method,
          * the other input values.
          */
         if (safi != NULL) {
+            if (val->value == NULL) {
+                ERR_raise(ERR_LIB_X509V3, X509V3_R_MISSING_VALUE);
+                goto err;
+            }
             *safi = strtoul(val->value, &t, 0);
             t += strspn(t, " \t");
             if (*safi > 0xFF || *t++ != ':') {

crypto/x509/v3_asid.c

@@ -547,6 +547,11 @@ static void *v2i_ASIdentifiers(const struct v3_ext_method *method,
             goto err;
         }
 
+        if (val->value == NULL) {
+            ERR_raise(ERR_LIB_X509V3, X509V3_R_EXTENSION_VALUE_ERROR);
+            goto err;
+        }
+
         /*
          * Handle inheritance.
          */

crypto/x509/v3_crld.c

@@ -70,6 +70,11 @@ static int set_dist_point_name(DIST_POINT_NAME **pdp, X509V3_CTX *ctx,
     STACK_OF(GENERAL_NAME) *fnm = NULL;
     STACK_OF(X509_NAME_ENTRY) *rnm = NULL;
 
+    if (cnf->value == NULL) {
+        ERR_raise(ERR_LIB_X509V3, X509V3_R_MISSING_VALUE);
+        goto err;
+    }
+
     if (strncmp(cnf->name, "fullname", 9) == 0) {
         fnm = gnames_from_sectname(ctx, cnf->value);
         if (!fnm)

crypto/x509/v3_ist.c

@@ -50,25 +50,33 @@ static ISSUER_SIGN_TOOL *v2i_issuer_sign_tool(X509V3_EXT_METHOD *method, X509V3_
         }
         if (strcmp(cnf->name, "signTool") == 0) {
             ist->signTool = ASN1_UTF8STRING_new();
-            if (ist->signTool == NULL || !ASN1_STRING_set(ist->signTool, cnf->value, strlen(cnf->value))) {
+            if (ist->signTool == NULL
+                || cnf->value == NULL
+                || !ASN1_STRING_set(ist->signTool, cnf->value, strlen(cnf->value))) {
                 ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
                 goto err;
             }
         } else if (strcmp(cnf->name, "cATool") == 0) {
             ist->cATool = ASN1_UTF8STRING_new();
-            if (ist->cATool == NULL || !ASN1_STRING_set(ist->cATool, cnf->value, strlen(cnf->value))) {
+            if (ist->cATool == NULL
+                || cnf->value == NULL
+                || !ASN1_STRING_set(ist->cATool, cnf->value, strlen(cnf->value))) {
                 ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
                 goto err;
             }
         } else if (strcmp(cnf->name, "signToolCert") == 0) {
             ist->signToolCert = ASN1_UTF8STRING_new();
-            if (ist->signToolCert == NULL || !ASN1_STRING_set(ist->signToolCert, cnf->value, strlen(cnf->value))) {
+            if (ist->signToolCert == NULL
+                || cnf->value == NULL
+                || !ASN1_STRING_set(ist->signToolCert, cnf->value, strlen(cnf->value))) {
                 ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
                 goto err;
             }
         } else if (strcmp(cnf->name, "cAToolCert") == 0) {
             ist->cAToolCert = ASN1_UTF8STRING_new();
-            if (ist->cAToolCert == NULL || !ASN1_STRING_set(ist->cAToolCert, cnf->value, strlen(cnf->value))) {
+            if (ist->cAToolCert == NULL
+                || cnf->value == NULL
+                || !ASN1_STRING_set(ist->cAToolCert, cnf->value, strlen(cnf->value))) {
                 ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
                 goto err;
             }

test/invalid-x509.cnf

@@ -0,0 +1,6 @@
+[ext]
+issuerSignTool = signTool
+sbgp-autonomousSysNum = AS
+issuingDistributionPoint = fullname
+sbgp-ipAddrBlock = IPv4-SAFI
+

test/recipes/25-test_x509.t

@@ -16,7 +16,7 @@ use OpenSSL::Test qw/:DEFAULT srctop_file/;
 
 setup("test_x509");
 
-plan tests => 28;
+plan tests => 29;
 
 # Prevent MSys2 filename munging for arguments that look like file paths but
 # aren't
@@ -186,6 +186,14 @@ ok(run(app(["openssl", "x509", "-in", $a_cert, "-CA", $ca_cert,
 # verify issuer is CA
 ok (get_issuer($a2_cert) =~ /CN = ca.example.com/);
 
+my $in_csr = srctop_file('test', 'certs', 'x509-check.csr');
+my $in_key = srctop_file('test', 'certs', 'x509-check-key.pem');
+my $invextfile = srctop_file('test', 'invalid-x509.cnf');
+# Test that invalid extensions settings fail
+ok(!run(app(["openssl", "x509", "-req", "-in", $in_csr, "-signkey", $in_key,
+            "-out", "/dev/null", "-days", "3650" , "-extensions", "ext",
+            "-extfile", $invextfile])));
+
 # Tests for issue #16080 (fixed in 1.1.1o)
 my $b_key = "b-key.pem";
 my $b_csr = "b-cert.csr";