From 22b88fc9c0e22545401c0b34d24843883ea73fec Mon Sep 17 00:00:00 2001
From: Matt Caswell <matt@openssl.org>
Date: Mon, 30 Nov 2020 14:46:47 +0000
Subject: [PATCH] Add a test for encoding/decoding using an invalid ASN.1
 Template

If you have a CHOICE type that it must use explicit tagging - otherwise
the template is invalid. We add tests for this.

Reviewed-by: Tomas Mraz <tmraz@fedoraproject.org>
---
 test/asn1_decode_test.c | 36 ++++++++++++++++++++++++++++++++++++
 test/asn1_encode_test.c | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 69 insertions(+)

diff --git a/test/asn1_decode_test.c b/test/asn1_decode_test.c
index b0c031a5a2..c6e1501fa1 100644
--- a/test/asn1_decode_test.c
+++ b/test/asn1_decode_test.c
@@ -160,6 +160,41 @@ static int test_uint64(void)
     return 1;
 }
 
+typedef struct {
+    ASN1_STRING *invalidDirString;
+} INVALIDTEMPLATE;
+
+ASN1_SEQUENCE(INVALIDTEMPLATE) = {
+    /*
+     * DirectoryString is a CHOICE type so it must use explicit tagging -
+     * but we deliberately use implicit here, which makes this template invalid.
+     */
+    ASN1_IMP(INVALIDTEMPLATE, invalidDirString, DIRECTORYSTRING, 12)
+} static_ASN1_SEQUENCE_END(INVALIDTEMPLATE)
+
+IMPLEMENT_STATIC_ASN1_ENCODE_FUNCTIONS(INVALIDTEMPLATE)
+IMPLEMENT_STATIC_ASN1_ALLOC_FUNCTIONS(INVALIDTEMPLATE)
+
+/* Empty sequence for invalid template test */
+static unsigned char t_invalid_template[] = {
+    0x30, 0x03,                  /* SEQUENCE tag + length */
+    0x0c, 0x01, 0x41             /* UTF8String, length 1, "A" */
+};
+
+static int test_invalid_template(void)
+{
+    const unsigned char *p = t_invalid_template;
+    INVALIDTEMPLATE *tmp = d2i_INVALIDTEMPLATE(NULL, &p,
+                                               sizeof(t_invalid_template));
+
+    /* We expect a NULL pointer return */
+    if (TEST_ptr_null(tmp))
+        return 1;
+
+    INVALIDTEMPLATE_free(tmp);
+    return 0;
+}
+
 int setup_tests(void)
 {
 #ifndef OPENSSL_NO_DEPRECATED_3_0
@@ -169,5 +204,6 @@ int setup_tests(void)
     ADD_TEST(test_uint32);
     ADD_TEST(test_int64);
     ADD_TEST(test_uint64);
+    ADD_TEST(test_invalid_template);
     return 1;
 }
diff --git a/test/asn1_encode_test.c b/test/asn1_encode_test.c
index 4ff8a20ff4..27f522b222 100644
--- a/test/asn1_encode_test.c
+++ b/test/asn1_encode_test.c
@@ -856,6 +856,38 @@ static int test_uint64(void)
     return test_intern(&uint64_test_package);
 }
 
+typedef struct {
+    ASN1_STRING *invalidDirString;
+} INVALIDTEMPLATE;
+
+ASN1_SEQUENCE(INVALIDTEMPLATE) = {
+    /*
+     * DirectoryString is a CHOICE type so it must use explicit tagging -
+     * but we deliberately use implicit here, which makes this template invalid.
+     */
+    ASN1_IMP(INVALIDTEMPLATE, invalidDirString, DIRECTORYSTRING, 12)
+} static_ASN1_SEQUENCE_END(INVALIDTEMPLATE)
+
+IMPLEMENT_STATIC_ASN1_ENCODE_FUNCTIONS(INVALIDTEMPLATE)
+IMPLEMENT_STATIC_ASN1_ALLOC_FUNCTIONS(INVALIDTEMPLATE)
+
+static int test_invalid_template(void)
+{
+    INVALIDTEMPLATE *temp = INVALIDTEMPLATE_new();
+    int ret;
+
+    if (!TEST_ptr(temp))
+        return 0;
+
+    ret = i2d_INVALIDTEMPLATE(temp, NULL);
+
+    INVALIDTEMPLATE_free(temp);
+
+    /* We expect the i2d operation to fail */
+    return ret < 0;
+}
+
+
 int setup_tests(void)
 {
 #ifndef OPENSSL_NO_DEPRECATED_3_0
@@ -866,5 +898,6 @@ int setup_tests(void)
     ADD_TEST(test_uint32);
     ADD_TEST(test_int64);
     ADD_TEST(test_uint64);
+    ADD_TEST(test_invalid_template);
     return 1;
 }