1 files changed, 153 insertions, 0 deletions
diff --git a/fuzz/x509.c b/fuzz/x509.c
new file mode 100644
index 000000000000..e2d2639164c0
--- /dev/null
+++ b/fuzz/x509.c
@@ -0,0 +1,153 @@
+/*
+ * Copyright 2016-2023 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the Apache License 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * https://www.openssl.org/source/license.html
+ * or in the file LICENSE in the source distribution.
+ */
+
+#include <openssl/x509.h>
+#include <openssl/ocsp.h>
+#include <openssl/bio.h>
+#include <openssl/err.h>
+#include <openssl/rand.h>
+#include "fuzzer.h"
+
+int FuzzerInitialize(int *argc, char ***argv)
+{
+    FuzzerSetRand();
+    OPENSSL_init_crypto(OPENSSL_INIT_LOAD_CRYPTO_STRINGS
+       | OPENSSL_INIT_ADD_ALL_CIPHERS | OPENSSL_INIT_ADD_ALL_DIGESTS, NULL);
+    ERR_clear_error();
+    CRYPTO_free_ex_index(0, -1);
+    return 1;
+}
+
+static int cb(int ok, X509_STORE_CTX *ctx)
+{
+    return 1;
+}
+
+int FuzzerTestOneInput(const uint8_t *buf, size_t len)
+{
+    const unsigned char *p = buf;
+    size_t orig_len = len;
+    unsigned char *der = NULL;
+    BIO *bio = NULL;
+    X509 *x509_1 = NULL, *x509_2 = NULL;
+    X509_STORE *store = NULL;
+    X509_VERIFY_PARAM *param = NULL;
+    X509_STORE_CTX *ctx = NULL;
+    X509_CRL *crl = NULL;
+    STACK_OF(X509_CRL) *crls = NULL;
+    STACK_OF(X509) *certs = NULL;
+    OCSP_RESPONSE *resp = NULL;
+    OCSP_BASICRESP *bs = NULL;
+    OCSP_CERTID *id = NULL;
+
+    x509_1 = d2i_X509(NULL, &p, len);
+    if (x509_1 == NULL)
+        goto err;
+
+    bio = BIO_new(BIO_s_null());
+    if (bio == NULL)
+        goto err;
+
+    /* This will load and print the public key as well as extensions */
+    X509_print(bio, x509_1);
+    BIO_free(bio);
+
+    X509_issuer_and_serial_hash(x509_1);
+
+    i2d_X509(x509_1, &der);
+    OPENSSL_free(der);
+
+    len = orig_len - (p - buf);
+    x509_2 = d2i_X509(NULL, &p, len);
+    if (x509_2 == NULL)
+        goto err;
+
+    len = orig_len - (p - buf);
+    crl = d2i_X509_CRL(NULL, &p, len);
+    if (crl == NULL)
+        goto err;
+
+    len = orig_len - (p - buf);
+    resp = d2i_OCSP_RESPONSE(NULL, &p, len);
+
+    store = X509_STORE_new();
+    X509_STORE_add_cert(store, x509_2);
+
+    param = X509_VERIFY_PARAM_new();
+    X509_VERIFY_PARAM_set_flags(param, X509_V_FLAG_NO_CHECK_TIME);
+    X509_VERIFY_PARAM_set_flags(param, X509_V_FLAG_X509_STRICT);
+    X509_VERIFY_PARAM_set_flags(param, X509_V_FLAG_PARTIAL_CHAIN);
+    X509_VERIFY_PARAM_set_flags(param, X509_V_FLAG_CRL_CHECK);
+
+    X509_STORE_set1_param(store, param);
+
+    X509_STORE_set_verify_cb(store, cb);
+
+    ctx = X509_STORE_CTX_new();
+    if (ctx == NULL)
+        goto err;
+
+    X509_STORE_CTX_init(ctx, store, x509_1, NULL);
+
+    if (crl != NULL) {
+        crls = sk_X509_CRL_new_null();
+        if (crls == NULL)
+            goto err;
+
+        sk_X509_CRL_push(crls, crl);
+        X509_STORE_CTX_set0_crls(ctx, crls);
+    }
+
+    X509_verify_cert(ctx);
+
+    if (resp != NULL)
+        bs = OCSP_response_get1_basic(resp);
+
+    if (bs != NULL) {
+        int status, reason;
+        ASN1_GENERALIZEDTIME *revtime, *thisupd, *nextupd;
+
+        certs = sk_X509_new_null();
+        if (certs == NULL)
+            goto err;
+
+        sk_X509_push(certs, x509_1);
+        sk_X509_push(certs, x509_2);
+
+        OCSP_basic_verify(bs, certs, store, OCSP_PARTIAL_CHAIN);
+
+        id = OCSP_cert_to_id(NULL, x509_1, x509_2);
+        if (id == NULL)
+            goto err;
+        OCSP_resp_find_status(bs, id, &status, &reason, &revtime, &thisupd,
+                              &nextupd);
+    }
+
+err:
+    X509_STORE_CTX_free(ctx);
+    X509_VERIFY_PARAM_free(param);
+    X509_STORE_free(store);
+    X509_free(x509_1);
+    X509_free(x509_2);
+    X509_CRL_free(crl);
+    OCSP_CERTID_free(id);
+    OCSP_BASICRESP_free(bs);
+    OCSP_RESPONSE_free(resp);
+    sk_X509_CRL_free(crls);
+    sk_X509_free(certs);
+
+    ERR_clear_error();
+    return 0;
+}
+
+void FuzzerCleanup(void)
+{
+    FuzzerClearRand();
+}