/* $OpenBSD: apitest.c,v 1.3 2024/09/07 16:39:29 tb Exp $ */
/*
 * Copyright (c) 2020, 2021 Joel Sing <jsing@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <err.h>

#include <openssl/bio.h>
#include <openssl/err.h>
#include <openssl/ssl.h>

#ifndef CERTSDIR
#define CERTSDIR "."
#endif

const char *certs_path = CERTSDIR;

int debug = 0;

static int
ssl_ctx_use_ca_file(SSL_CTX *ssl_ctx, const char *ca_file)
{
        char *ca_path = NULL;
        int ret = 0;

        if (asprintf(&ca_path, "%s/%s", certs_path, ca_file) == -1)
                goto err;
        if (!SSL_CTX_load_verify_locations(ssl_ctx, ca_path, NULL)) {
                fprintf(stderr, "load_verify_locations(%s) failed\n", ca_path);
                goto err;
        }

        ret = 1;

 err:
        free(ca_path);

        return ret;
}

static int
ssl_ctx_use_keypair(SSL_CTX *ssl_ctx, const char *chain_file,
    const char *key_file)
{
        char *chain_path = NULL, *key_path = NULL;
        int ret = 0;

        if (asprintf(&chain_path, "%s/%s", certs_path, chain_file) == -1)
                goto err;
        if (SSL_CTX_use_certificate_chain_file(ssl_ctx, chain_path) != 1) {
                fprintf(stderr, "FAIL: Failed to load certificates\n");
                goto err;
        }
        if (asprintf(&key_path, "%s/%s", certs_path, key_file) == -1)
                goto err;
        if (SSL_CTX_use_PrivateKey_file(ssl_ctx, key_path,
            SSL_FILETYPE_PEM) != 1) {
                fprintf(stderr, "FAIL: Failed to load private key\n");
                goto err;
        }

        ret = 1;

 err:
        free(chain_path);
        free(key_path);

        return ret;
}

static SSL *
tls_client(BIO *rbio, BIO *wbio)
{
        SSL_CTX *ssl_ctx = NULL;
        SSL *ssl = NULL;

        if ((ssl_ctx = SSL_CTX_new(TLS_method())) == NULL)
                errx(1, "client context");

        SSL_CTX_set_verify(ssl_ctx, SSL_VERIFY_PEER, NULL);

        if (!ssl_ctx_use_ca_file(ssl_ctx, "ca-root-rsa.pem"))
                goto failure;
        if (!ssl_ctx_use_keypair(ssl_ctx, "client1-rsa-chain.pem",
            "client1-rsa.pem"))
                goto failure;

        if ((ssl = SSL_new(ssl_ctx)) == NULL)
                errx(1, "client ssl");

        BIO_up_ref(rbio);
        BIO_up_ref(wbio);

        SSL_set_bio(ssl, rbio, wbio);

 failure:
        SSL_CTX_free(ssl_ctx);

        return ssl;
}

static SSL *
tls_server(BIO *rbio, BIO *wbio)
{
        SSL_CTX *ssl_ctx = NULL;
        SSL *ssl = NULL;

        if ((ssl_ctx = SSL_CTX_new(TLS_method())) == NULL)
                errx(1, "server context");

        SSL_CTX_set_dh_auto(ssl_ctx, 2);

        SSL_CTX_set_verify(ssl_ctx,
            SSL_VERIFY_PEER|SSL_VERIFY_FAIL_IF_NO_PEER_CERT, NULL);

        if (!ssl_ctx_use_ca_file(ssl_ctx, "ca-root-rsa.pem"))
                goto failure;
        if (!ssl_ctx_use_keypair(ssl_ctx, "server1-rsa-chain.pem",
            "server1-rsa.pem"))
                goto failure;

        if ((ssl = SSL_new(ssl_ctx)) == NULL)
                errx(1, "server ssl");

        BIO_up_ref(rbio);
        BIO_up_ref(wbio);

        SSL_set_bio(ssl, rbio, wbio);

 failure:
        SSL_CTX_free(ssl_ctx);

        return ssl;
}

static int
ssl_error(SSL *ssl, const char *name, const char *desc, int ssl_ret)
{
        int ssl_err;

        ssl_err = SSL_get_error(ssl, ssl_ret);

        if (ssl_err == SSL_ERROR_WANT_READ) {
                return 1;
        } else if (ssl_err == SSL_ERROR_WANT_WRITE) {
                return 1;
        } else if (ssl_err == SSL_ERROR_SYSCALL && errno == 0) {
                /* Yup, this is apparently a thing... */
        } else {
                fprintf(stderr, "FAIL: %s %s failed - ssl err = %d, errno = %d\n",
                    name, desc, ssl_err, errno);
                ERR_print_errors_fp(stderr);
                return 0;
        }

        return 1;
}

static int
do_connect(SSL *ssl, const char *name, int *done)
{
        int ssl_ret;

        if ((ssl_ret = SSL_connect(ssl)) == 1) {
                fprintf(stderr, "INFO: %s connect done\n", name);
                *done = 1;
                return 1;
        }

        return ssl_error(ssl, name, "connect", ssl_ret);
}

static int
do_accept(SSL *ssl, const char *name, int *done)
{
        int ssl_ret;

        if ((ssl_ret = SSL_accept(ssl)) == 1) {
                fprintf(stderr, "INFO: %s accept done\n", name);
                *done = 1;
                return 1;
        }

        return ssl_error(ssl, name, "accept", ssl_ret);
}

typedef int (*ssl_func)(SSL *ssl, const char *name, int *done);

static int
do_client_server_loop(SSL *client, ssl_func client_func, SSL *server,
    ssl_func server_func)
{
        int client_done = 0, server_done = 0;
        int i = 0;

        do {
                if (!client_done) {
                        if (debug)
                                fprintf(stderr, "DEBUG: client loop\n");
                        if (!client_func(client, "client", &client_done))
                                return 0;
                }
                if (!server_done) {
                        if (debug)
                                fprintf(stderr, "DEBUG: server loop\n");
                        if (!server_func(server, "server", &server_done))
                                return 0;
                }
        } while (i++ < 100 && (!client_done || !server_done));

        if (!client_done || !server_done)
                fprintf(stderr, "FAIL: gave up\n");

        return client_done && server_done;
}

static int
ssl_get_peer_cert_chain_test(uint16_t tls_version)
{
        STACK_OF(X509) *peer_chain;
        X509 *peer_cert;
        BIO *client_wbio = NULL, *server_wbio = NULL;
        SSL *client = NULL, *server = NULL;
        int failed = 1;

        if ((client_wbio = BIO_new(BIO_s_mem())) == NULL)
                goto failure;
        if (BIO_set_mem_eof_return(client_wbio, -1) <= 0)
                goto failure;

        if ((server_wbio = BIO_new(BIO_s_mem())) == NULL)
                goto failure;
        if (BIO_set_mem_eof_return(server_wbio, -1) <= 0)
                goto failure;

        if ((client = tls_client(server_wbio, client_wbio)) == NULL)
                goto failure;
        if (tls_version != 0) {
                if (!SSL_set_min_proto_version(client, tls_version))
                        goto failure;
                if (!SSL_set_max_proto_version(client, tls_version))
                        goto failure;
        }

        if ((server = tls_server(client_wbio, server_wbio)) == NULL)
                goto failure;
        if (tls_version != 0) {
                if (!SSL_set_min_proto_version(server, tls_version))
                        goto failure;
                if (!SSL_set_max_proto_version(server, tls_version))
                        goto failure;
        }

        if (!do_client_server_loop(client, do_connect, server, do_accept)) {
                fprintf(stderr, "FAIL: client and server handshake failed\n");
                goto failure;
        }

        if (tls_version != 0) {
                if (SSL_version(client) != tls_version) {
                        fprintf(stderr, "FAIL: client got TLS version %x, "
                            "want %x\n", SSL_version(client), tls_version);
                        goto failure;
                }
                if (SSL_version(server) != tls_version) {
                        fprintf(stderr, "FAIL: server got TLS version %x, "
                            "want %x\n", SSL_version(server), tls_version);
                        goto failure;
                }
        }

        /*
         * Due to the wonders of API inconsistency, SSL_get_peer_cert_chain()
         * includes the peer's leaf certificate when called by the client,
         * however it does not when called by the server. Furthermore, the
         * certificate returned by SSL_get_peer_certificate() has already
         * had its reference count incremented and must be freed, where as
         * the certificates returned from SSL_get_peer_cert_chain() must
         * not be freed... *sigh*
         */
        peer_cert = SSL_get_peer_certificate(client);
        peer_chain = SSL_get_peer_cert_chain(client);
        X509_free(peer_cert);

        if (peer_cert == NULL) {
                fprintf(stderr, "FAIL: client got no peer cert\n");
                goto failure;
        }
        if (sk_X509_num(peer_chain) != 2) {
                fprintf(stderr, "FAIL: client got peer cert chain with %d "
                    "certificates, want 2\n", sk_X509_num(peer_chain));
                goto failure;
        }
        if (X509_cmp(peer_cert, sk_X509_value(peer_chain, 0)) != 0) {
                fprintf(stderr, "FAIL: client got peer cert chain without peer "
                    "certificate\n");
                goto failure;
        }

        peer_cert = SSL_get_peer_certificate(server);
        peer_chain = SSL_get_peer_cert_chain(server);
        X509_free(peer_cert);

        if (peer_cert == NULL) {
                fprintf(stderr, "FAIL: server got no peer cert\n");
                goto failure;
        }
        if (sk_X509_num(peer_chain) != 1) {
                fprintf(stderr, "FAIL: server got peer cert chain with %d "
                    "certificates, want 1\n", sk_X509_num(peer_chain));
                goto failure;
        }
        if (X509_cmp(peer_cert, sk_X509_value(peer_chain, 0)) == 0) {
                fprintf(stderr, "FAIL: server got peer cert chain with peer "
                    "certificate\n");
                goto failure;
        }

        fprintf(stderr, "INFO: Done!\n");

        failed = 0;

 failure:
        BIO_free(client_wbio);
        BIO_free(server_wbio);

        SSL_free(client);
        SSL_free(server);

        return failed;
}

static int
ssl_get_peer_cert_chain_tests(void)
{
        int failed = 0;

        fprintf(stderr, "\n== Testing SSL_get_peer_cert_chain()... ==\n");

        failed |= ssl_get_peer_cert_chain_test(0);
        failed |= ssl_get_peer_cert_chain_test(TLS1_3_VERSION);
        failed |= ssl_get_peer_cert_chain_test(TLS1_2_VERSION);

        return failed;
}

int
main(int argc, char **argv)
{
        int failed = 0;

        if (argc > 2) {
                fprintf(stderr, "usage: %s [certspath]\n", argv[0]);
                exit(1);
        }
        if (argc == 2)
                certs_path = argv[1];

        failed |= ssl_get_peer_cert_chain_tests();

        return failed;
}