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/*
* Copyright 2015-2016 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <stdio.h>
#include <openssl/crypto.h>
#include <openssl/bio.h>
#include <openssl/x509.h>
#include <openssl/pem.h>
#include <openssl/err.h>
static STACK_OF(X509) *load_certs_from_file(const char *filename)
{
STACK_OF(X509) *certs;
BIO *bio;
X509 *x;
bio = BIO_new_file(filename, "r");
if (bio == NULL) {
return NULL;
}
certs = sk_X509_new_null();
if (certs == NULL) {
BIO_free(bio);
return NULL;
}
ERR_set_mark();
do {
x = PEM_read_bio_X509(bio, NULL, 0, NULL);
if (x != NULL && !sk_X509_push(certs, x)) {
sk_X509_pop_free(certs, X509_free);
BIO_free(bio);
return NULL;
} else if (x == NULL) {
/*
* We probably just ran out of certs, so ignore any errors
* generated
*/
ERR_pop_to_mark();
}
} while (x != NULL);
BIO_free(bio);
return certs;
}
/*
* Test for CVE-2015-1793 (Alternate Chains Certificate Forgery)
*
* Chain is as follows:
*
* rootCA (self-signed)
* |
* interCA
* |
* subinterCA subinterCA (self-signed)
* | |
* leaf ------------------
* |
* bad
*
* rootCA, interCA, subinterCA, subinterCA (ss) all have CA=TRUE
* leaf and bad have CA=FALSE
*
* subinterCA and subinterCA (ss) have the same subject name and keys
*
* interCA (but not rootCA) and subinterCA (ss) are in the trusted store
* (roots.pem)
* leaf and subinterCA are in the untrusted list (untrusted.pem)
* bad is the certificate being verified (bad.pem)
*
* Versions vulnerable to CVE-2015-1793 will fail to detect that leaf has
* CA=FALSE, and will therefore incorrectly verify bad
*
*/
static int test_alt_chains_cert_forgery(const char *roots_f,
const char *untrusted_f,
const char *bad_f)
{
int ret = 0;
int i;
X509 *x = NULL;
STACK_OF(X509) *untrusted = NULL;
BIO *bio = NULL;
X509_STORE_CTX *sctx = NULL;
X509_STORE *store = NULL;
X509_LOOKUP *lookup = NULL;
store = X509_STORE_new();
if (store == NULL)
goto err;
lookup = X509_STORE_add_lookup(store, X509_LOOKUP_file());
if (lookup == NULL)
goto err;
if (!X509_LOOKUP_load_file(lookup, roots_f, X509_FILETYPE_PEM))
goto err;
untrusted = load_certs_from_file(untrusted_f);
if ((bio = BIO_new_file(bad_f, "r")) == NULL)
goto err;
if ((x = PEM_read_bio_X509(bio, NULL, 0, NULL)) == NULL)
goto err;
sctx = X509_STORE_CTX_new();
if (sctx == NULL)
goto err;
if (!X509_STORE_CTX_init(sctx, store, x, untrusted))
goto err;
i = X509_verify_cert(sctx);
if (i == 0 && X509_STORE_CTX_get_error(sctx) == X509_V_ERR_INVALID_CA) {
/* This is the result we were expecting: Test passed */
ret = 1;
}
err:
X509_STORE_CTX_free(sctx);
X509_free(x);
BIO_free(bio);
sk_X509_pop_free(untrusted, X509_free);
X509_STORE_free(store);
if (ret != 1)
ERR_print_errors_fp(stderr);
return ret;
}
int main(int argc, char **argv)
{
CRYPTO_set_mem_debug(1);
CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ON);
if (argc != 4) {
fprintf(stderr, "usage: verify_extra_test roots.pem untrusted.pem bad.pem\n");
return 1;
}
if (!test_alt_chains_cert_forgery(argv[1], argv[2], argv[3])) {
fprintf(stderr, "Test alt chains cert forgery failed\n");
return 1;
}
#ifndef OPENSSL_NO_CRYPTO_MDEBUG
if (CRYPTO_mem_leaks_fp(stderr) <= 0)
return 1;
#endif
printf("PASS\n");
return 0;
}
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