/*

 * Copyright 2015-2018 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>

#include "testutil.h"

static const char *roots_f;

static const char *untrusted_f;

static const char *bad_f;

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(void)

{

    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);

    return ret;

}

static int test_store_ctx(void)

{

    X509_STORE_CTX *sctx = NULL;

    X509 *x = NULL;

    BIO *bio = NULL;

    int testresult = 0, ret;

    bio = BIO_new_file(bad_f, "r");

    if (bio == NULL)

        goto err;

    x = PEM_read_bio_X509(bio, NULL, 0, NULL);

    if (x == NULL)

        goto err;

    sctx = X509_STORE_CTX_new();

    if (sctx == NULL)

        goto err;

    if (!X509_STORE_CTX_init(sctx, NULL, x, NULL))

        goto err;

    /* Verifying a cert where we have no trusted certs should fail */

    ret = X509_verify_cert(sctx);

    if (ret == 0) {

        /* This is the result we were expecting: Test passed */

        testresult = 1;

    }

 err:

    X509_STORE_CTX_free(sctx);

    X509_free(x);

    BIO_free(bio);

    return testresult;

}

int setup_tests(void)

{

    if (!TEST_ptr(roots_f = test_get_argument(0))

            || !TEST_ptr(untrusted_f = test_get_argument(1))

            || !TEST_ptr(bad_f = test_get_argument(2))) {

        TEST_error("usage: verify_extra_test roots.pem untrusted.pem bad.pem\n");

        return 0;

    }

    ADD_TEST(test_alt_chains_cert_forgery);

    ADD_TEST(test_store_ctx);

    return 1;

}