/*

 * Copyright 1995-2019 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 <stdlib.h>

#include <string.h>

#include "apps.h"

#include "progs.h"

#include <openssl/bio.h>

#include <openssl/err.h>

#include <openssl/x509.h>

#include <openssl/x509v3.h>

#include <openssl/pem.h>

static int cb(int ok, X509_STORE_CTX *ctx);

static int check(X509_STORE *ctx, const char *file,

                 STACK_OF(X509) *uchain, STACK_OF(X509) *tchain,

                 STACK_OF(X509_CRL) *crls, int show_chain);

static int v_verbose = 0, vflags = 0;

typedef enum OPTION_choice {

    OPT_ERR = -1, OPT_EOF = 0, OPT_HELP,

    OPT_ENGINE, OPT_CAPATH, OPT_CAFILE, OPT_NOCAPATH, OPT_NOCAFILE,

    OPT_UNTRUSTED, OPT_TRUSTED, OPT_CRLFILE, OPT_CRL_DOWNLOAD, OPT_SHOW_CHAIN,

    OPT_V_ENUM, OPT_NAMEOPT,

    OPT_VERBOSE

} OPTION_CHOICE;

const OPTIONS verify_options[] = {

    {OPT_HELP_STR, 1, '-', "Usage: %s [options] cert.pem...\n"},

    {OPT_HELP_STR, 1, '-', "Valid options are:\n"},

    {"help", OPT_HELP, '-', "Display this summary"},

    {"verbose", OPT_VERBOSE, '-',

        "Print extra information about the operations being performed."},

    {"CApath", OPT_CAPATH, '/', "A directory of trusted certificates"},

    {"CAfile", OPT_CAFILE, '<', "A file of trusted certificates"},

    {"no-CAfile", OPT_NOCAFILE, '-',

     "Do not load the default certificates file"},

    {"no-CApath", OPT_NOCAPATH, '-',

     "Do not load certificates from the default certificates directory"},

    {"untrusted", OPT_UNTRUSTED, '<', "A file of untrusted certificates"},

    {"trusted", OPT_TRUSTED, '<', "A file of trusted certificates"},

    {"CRLfile", OPT_CRLFILE, '<',

        "File containing one or more CRL's (in PEM format) to load"},

    {"crl_download", OPT_CRL_DOWNLOAD, '-',

        "Attempt to download CRL information for this certificate"},

    {"show_chain", OPT_SHOW_CHAIN, '-',

        "Display information about the certificate chain"},

    {"nameopt", OPT_NAMEOPT, 's', "Various certificate name options"},

    OPT_V_OPTIONS,

#ifndef OPENSSL_NO_ENGINE

    {"engine", OPT_ENGINE, 's', "Use engine, possibly a hardware device"},

#endif

    {NULL}

};

int verify_main(int argc, char **argv)

{

    ENGINE *e = NULL;

    STACK_OF(X509) *untrusted = NULL, *trusted = NULL;

    STACK_OF(X509_CRL) *crls = NULL;

    X509_STORE *store = NULL;

    X509_VERIFY_PARAM *vpm = NULL;

    const char *prog, *CApath = NULL, *CAfile = NULL;

    int noCApath = 0, noCAfile = 0;

    int vpmtouched = 0, crl_download = 0, show_chain = 0, i = 0, ret = 1;

    OPTION_CHOICE o;

    if ((vpm = X509_VERIFY_PARAM_new()) == NULL)

        goto end;

    prog = opt_init(argc, argv, verify_options);

    while ((o = opt_next()) != OPT_EOF) {

        switch (o) {

        case OPT_EOF:

        case OPT_ERR:

            BIO_printf(bio_err, "%s: Use -help for summary.\n", prog);

            goto end;

        case OPT_HELP:

            opt_help(verify_options);

            BIO_printf(bio_err, "Recognized usages:\n");

            for (i = 0; i < X509_PURPOSE_get_count(); i++) {

                X509_PURPOSE *ptmp;

                ptmp = X509_PURPOSE_get0(i);

                BIO_printf(bio_err, "\t%-10s\t%s\n",

                        X509_PURPOSE_get0_sname(ptmp),

                        X509_PURPOSE_get0_name(ptmp));

            }

            BIO_printf(bio_err, "Recognized verify names:\n");

            for (i = 0; i < X509_VERIFY_PARAM_get_count(); i++) {

                const X509_VERIFY_PARAM *vptmp;

                vptmp = X509_VERIFY_PARAM_get0(i);

                BIO_printf(bio_err, "\t%-10s\n",

                        X509_VERIFY_PARAM_get0_name(vptmp));

            }

            ret = 0;

            goto end;

        case OPT_V_CASES:

            if (!opt_verify(o, vpm))

                goto end;

            vpmtouched++;

            break;

        case OPT_CAPATH:

            CApath = opt_arg();

            break;

        case OPT_CAFILE:

            CAfile = opt_arg();

            break;

        case OPT_NOCAPATH:

            noCApath = 1;

            break;

        case OPT_NOCAFILE:

            noCAfile = 1;

            break;

        case OPT_UNTRUSTED:

            /* Zero or more times */

            if (!load_certs(opt_arg(), &untrusted, FORMAT_PEM, NULL,

                            "untrusted certificates"))

                goto end;

            break;

        case OPT_TRUSTED:

            /* Zero or more times */

            noCAfile = 1;

            noCApath = 1;

            if (!load_certs(opt_arg(), &trusted, FORMAT_PEM, NULL,

                            "trusted certificates"))

                goto end;

            break;

        case OPT_CRLFILE:

            /* Zero or more times */

            if (!load_crls(opt_arg(), &crls, FORMAT_PEM, NULL,

                           "other CRLs"))

                goto end;

            break;

        case OPT_CRL_DOWNLOAD:

            crl_download = 1;

            break;

        case OPT_ENGINE:

            if ((e = setup_engine(opt_arg(), 0)) == NULL) {

                /* Failure message already displayed */

                goto end;

            }

            break;

        case OPT_SHOW_CHAIN:

            show_chain = 1;

            break;

        case OPT_NAMEOPT:

            if (!set_nameopt(opt_arg()))

                goto end;

            break;

        case OPT_VERBOSE:

            v_verbose = 1;

            break;

        }

    }

    argc = opt_num_rest();

    argv = opt_rest();

    if (trusted != NULL && (CAfile || CApath)) {

        BIO_printf(bio_err,

                   "%s: Cannot use -trusted with -CAfile or -CApath\n",

                   prog);

        goto end;

    }

    if ((store = setup_verify(CAfile, CApath, noCAfile, noCApath)) == NULL)

        goto end;

    X509_STORE_set_verify_cb(store, cb);

    if (vpmtouched)

        X509_STORE_set1_param(store, vpm);

    ERR_clear_error();

    if (crl_download)

        store_setup_crl_download(store);

    ret = 0;

    if (argc < 1) {

        if (check(store, NULL, untrusted, trusted, crls, show_chain) != 1)

            ret = -1;

    } else {

        for (i = 0; i < argc; i++)

            if (check(store, argv[i], untrusted, trusted, crls,

                      show_chain) != 1)

                ret = -1;

    }

 end:

    X509_VERIFY_PARAM_free(vpm);

    X509_STORE_free(store);

    sk_X509_pop_free(untrusted, X509_free);

    sk_X509_pop_free(trusted, X509_free);

    sk_X509_CRL_pop_free(crls, X509_CRL_free);

    release_engine(e);

    return (ret < 0 ? 2 : ret);

}

static int check(X509_STORE *ctx, const char *file,

                 STACK_OF(X509) *uchain, STACK_OF(X509) *tchain,

                 STACK_OF(X509_CRL) *crls, int show_chain)

{

    X509 *x = NULL;

    int i = 0, ret = 0;

    X509_STORE_CTX *csc;

    STACK_OF(X509) *chain = NULL;

    int num_untrusted;

    x = load_cert(file, FORMAT_PEM, "certificate file");

    if (x == NULL)

        goto end;

    csc = X509_STORE_CTX_new();

    if (csc == NULL) {

        printf("error %s: X.509 store context allocation failed\n",

               (file == NULL) ? "stdin" : file);

        goto end;

    }

    X509_STORE_set_flags(ctx, vflags);

    if (!X509_STORE_CTX_init(csc, ctx, x, uchain)) {

        X509_STORE_CTX_free(csc);

        printf("error %s: X.509 store context initialization failed\n",

               (file == NULL) ? "stdin" : file);

        goto end;

    }

    if (tchain != NULL)

        X509_STORE_CTX_set0_trusted_stack(csc, tchain);

    if (crls != NULL)

        X509_STORE_CTX_set0_crls(csc, crls);

    i = X509_verify_cert(csc);

    if (i > 0 && X509_STORE_CTX_get_error(csc) == X509_V_OK) {

        printf("%s: OK\n", (file == NULL) ? "stdin" : file);

        ret = 1;

        if (show_chain) {

            int j;

            chain = X509_STORE_CTX_get1_chain(csc);

            num_untrusted = X509_STORE_CTX_get_num_untrusted(csc);

            printf("Chain:\n");

            for (j = 0; j < sk_X509_num(chain); j++) {

                X509 *cert = sk_X509_value(chain, j);

                printf("depth=%d: ", j);

                X509_NAME_print_ex_fp(stdout,

                                      X509_get_subject_name(cert),

                                      0, get_nameopt());

                if (j < num_untrusted)

                    printf(" (untrusted)");

                printf("\n");

            }

            sk_X509_pop_free(chain, X509_free);

        }

    } else {

        printf("error %s: verification failed\n", (file == NULL) ? "stdin" : file);

    }

    X509_STORE_CTX_free(csc);

 end:

    if (i <= 0)

        ERR_print_errors(bio_err);

    X509_free(x);

    return ret;

}

static int cb(int ok, X509_STORE_CTX *ctx)

{

    int cert_error = X509_STORE_CTX_get_error(ctx);

    X509 *current_cert = X509_STORE_CTX_get_current_cert(ctx);

    if (!ok) {

        if (current_cert != NULL) {

            X509_NAME_print_ex(bio_err,

                            X509_get_subject_name(current_cert),

                            0, get_nameopt());

            BIO_printf(bio_err, "\n");

        }

        BIO_printf(bio_err, "%serror %d at %d depth lookup: %s\n",

               X509_STORE_CTX_get0_parent_ctx(ctx) ? "[CRL path] " : "",

               cert_error,

               X509_STORE_CTX_get_error_depth(ctx),

               X509_verify_cert_error_string(cert_error));

        /*

         * Pretend that some errors are ok, so they don't stop further

         * processing of the certificate chain.  Setting ok = 1 does this.

         * After X509_verify_cert() is done, we verify that there were

         * no actual errors, even if the returned value was positive.

         */

        switch (cert_error) {

        case X509_V_ERR_NO_EXPLICIT_POLICY:

            policies_print(ctx);

            /* fall thru */

        case X509_V_ERR_CERT_HAS_EXPIRED:

            /* Continue even if the leaf is a self signed cert */

        case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT:

            /* Continue after extension errors too */

        case X509_V_ERR_INVALID_CA:

        case X509_V_ERR_INVALID_NON_CA:

        case X509_V_ERR_PATH_LENGTH_EXCEEDED:

        case X509_V_ERR_INVALID_PURPOSE:

        case X509_V_ERR_CRL_HAS_EXPIRED:

        case X509_V_ERR_CRL_NOT_YET_VALID:

        case X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION:

            ok = 1;

        }

        return ok;

    }

    if (cert_error == X509_V_OK && ok == 2)

        policies_print(ctx);

    if (!v_verbose)

        ERR_clear_error();

    return ok;

}