Merge branch 'merges'

[unleashed.git] / bin / openssl / ts.c

/* $OpenBSD: ts.c,v 1.15 2018/02/07 05:47:55 jsing Exp $ */
/* Written by Zoltan Glozik (zglozik@stones.com) for the OpenSSL
 * project 2002.
 */
/* ====================================================================
 * Copyright (c) 2001 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    licensing@OpenSSL.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "apps.h"

#include <openssl/bio.h>
#include <openssl/bn.h>
#include <openssl/err.h>
#include <openssl/pem.h>
#include <openssl/ts.h>

/* Length of the nonce of the request in bits (must be a multiple of 8). */
#define NONCE_LENGTH            64

/* Macro definitions for the configuration file. */
#define ENV_OID_FILE            "oid_file"

/* Local function declarations. */

static ASN1_OBJECT *txt2obj(const char *oid);
static CONF *load_config_file(const char *configfile);

/* Query related functions. */
static int query_command(const char *data, char *digest,
    const EVP_MD * md, const char *policy, int no_nonce,
    int cert, const char *in, const char *out, int text);
static BIO *BIO_open_with_default(const char *file, const char *mode,
    FILE * default_fp);
static TS_REQ *create_query(BIO * data_bio, char *digest, const EVP_MD * md,
    const char *policy, int no_nonce, int cert);
static int create_digest(BIO * input, char *digest,
    const EVP_MD * md, unsigned char **md_value);
static ASN1_INTEGER *create_nonce(int bits);

/* Reply related functions. */
static int reply_command(CONF * conf, char *section,
    char *queryfile, char *passin, char *inkey,
    char *signer, char *chain, const char *policy,
    char *in, int token_in, char *out, int token_out,
    int text);
static TS_RESP *read_PKCS7(BIO * in_bio);
static TS_RESP *create_response(CONF * conf, const char *section,
    char *queryfile, char *passin, char *inkey,
    char *signer, char *chain, const char *policy);
static ASN1_INTEGER *serial_cb(TS_RESP_CTX * ctx, void *data);
static ASN1_INTEGER *next_serial(const char *serialfile);
static int save_ts_serial(const char *serialfile, ASN1_INTEGER * serial);

/* Verify related functions. */
static int verify_command(char *data, char *digest, char *queryfile,
    char *in, int token_in,
    char *ca_path, char *ca_file, char *untrusted);
static TS_VERIFY_CTX *create_verify_ctx(char *data, char *digest,
    char *queryfile,
    char *ca_path, char *ca_file,
    char *untrusted);
static X509_STORE *create_cert_store(char *ca_path, char *ca_file);
static int verify_cb(int ok, X509_STORE_CTX * ctx);

int
ts_main(int argc, char **argv)
{
        int ret = 1;
        char *configfile = NULL;
        char *section = NULL;
        CONF *conf = NULL;
        enum mode {
                CMD_NONE, CMD_QUERY, CMD_REPLY, CMD_VERIFY
        } mode = CMD_NONE;
        char *data = NULL;
        char *digest = NULL;
        const EVP_MD *md = NULL;
        char *policy = NULL;
        int no_nonce = 0;
        int cert = 0;
        char *in = NULL;
        char *out = NULL;
        int text = 0;
        char *queryfile = NULL;
        char *passin = NULL;    /* Password source. */
        char *password = NULL;  /* Password itself. */
        char *inkey = NULL;
        char *signer = NULL;
        char *chain = NULL;
        char *ca_path = NULL;
        char *ca_file = NULL;
        char *untrusted = NULL;
        /* Input is ContentInfo instead of TimeStampResp. */
        int token_in = 0;
        /* Output is ContentInfo instead of TimeStampResp. */
        int token_out = 0;

        if (single_execution) {
                if (pledge("stdio cpath wpath rpath tty", NULL) == -1) {
                        perror("pledge");
                        exit(1);
                }
        }

        for (argc--, argv++; argc > 0; argc--, argv++) {
                if (strcmp(*argv, "-config") == 0) {
                        if (argc-- < 1)
                                goto usage;
                        configfile = *++argv;
                } else if (strcmp(*argv, "-section") == 0) {
                        if (argc-- < 1)
                                goto usage;
                        section = *++argv;
                } else if (strcmp(*argv, "-query") == 0) {
                        if (mode != CMD_NONE)
                                goto usage;
                        mode = CMD_QUERY;
                } else if (strcmp(*argv, "-data") == 0) {
                        if (argc-- < 1)
                                goto usage;
                        data = *++argv;
                } else if (strcmp(*argv, "-digest") == 0) {
                        if (argc-- < 1)
                                goto usage;
                        digest = *++argv;
                } else if (strcmp(*argv, "-policy") == 0) {
                        if (argc-- < 1)
                                goto usage;
                        policy = *++argv;
                } else if (strcmp(*argv, "-no_nonce") == 0) {
                        no_nonce = 1;
                } else if (strcmp(*argv, "-cert") == 0) {
                        cert = 1;
                } else if (strcmp(*argv, "-in") == 0) {
                        if (argc-- < 1)
                                goto usage;
                        in = *++argv;
                } else if (strcmp(*argv, "-token_in") == 0) {
                        token_in = 1;
                } else if (strcmp(*argv, "-out") == 0) {
                        if (argc-- < 1)
                                goto usage;
                        out = *++argv;
                } else if (strcmp(*argv, "-token_out") == 0) {
                        token_out = 1;
                } else if (strcmp(*argv, "-text") == 0) {
                        text = 1;
                } else if (strcmp(*argv, "-reply") == 0) {
                        if (mode != CMD_NONE)
                                goto usage;
                        mode = CMD_REPLY;
                } else if (strcmp(*argv, "-queryfile") == 0) {
                        if (argc-- < 1)
                                goto usage;
                        queryfile = *++argv;
                } else if (strcmp(*argv, "-passin") == 0) {
                        if (argc-- < 1)
                                goto usage;
                        passin = *++argv;
                } else if (strcmp(*argv, "-inkey") == 0) {
                        if (argc-- < 1)
                                goto usage;
                        inkey = *++argv;
                } else if (strcmp(*argv, "-signer") == 0) {
                        if (argc-- < 1)
                                goto usage;
                        signer = *++argv;
                } else if (strcmp(*argv, "-chain") == 0) {
                        if (argc-- < 1)
                                goto usage;
                        chain = *++argv;
                } else if (strcmp(*argv, "-verify") == 0) {
                        if (mode != CMD_NONE)
                                goto usage;
                        mode = CMD_VERIFY;
                } else if (strcmp(*argv, "-CApath") == 0) {
                        if (argc-- < 1)
                                goto usage;
                        ca_path = *++argv;
                } else if (strcmp(*argv, "-CAfile") == 0) {
                        if (argc-- < 1)
                                goto usage;
                        ca_file = *++argv;
                } else if (strcmp(*argv, "-untrusted") == 0) {
                        if (argc-- < 1)
                                goto usage;
                        untrusted = *++argv;
                } else if ((md = EVP_get_digestbyname(*argv + 1)) != NULL) {
                        /* empty. */
                } else
                        goto usage;
        }

        /* Get the password if required. */
        if (mode == CMD_REPLY && passin &&
            !app_passwd(bio_err, passin, NULL, &password, NULL)) {
                BIO_printf(bio_err, "Error getting password.\n");
                goto cleanup;
        }
        /*
         * Check consistency of parameters and execute the appropriate
         * function.
         */
        switch (mode) {
        case CMD_NONE:
                goto usage;
        case CMD_QUERY:
                /*
                 * Data file and message imprint cannot be specified at the
                 * same time.
                 */
                ret = data != NULL && digest != NULL;
                if (ret)
                        goto usage;
                /* Load the config file for possible policy OIDs. */
                conf = load_config_file(configfile);
                ret = !query_command(data, digest, md, policy, no_nonce, cert,
                    in, out, text);
                break;
        case CMD_REPLY:
                conf = load_config_file(configfile);
                if (in == NULL) {
                        ret = !(queryfile != NULL && conf != NULL && !token_in);
                        if (ret)
                                goto usage;
                } else {
                        /* 'in' and 'queryfile' are exclusive. */
                        ret = !(queryfile == NULL);
                        if (ret)
                                goto usage;
                }

                ret = !reply_command(conf, section, queryfile,
                    password, inkey, signer, chain, policy,
                    in, token_in, out, token_out, text);
                break;
        case CMD_VERIFY:
                ret = !(((queryfile && !data && !digest) ||
                    (!queryfile && data && !digest) ||
                    (!queryfile && !data && digest)) && in != NULL);
                if (ret)
                        goto usage;

                ret = !verify_command(data, digest, queryfile, in, token_in,
                    ca_path, ca_file, untrusted);
        }

        goto cleanup;

 usage:
        BIO_printf(bio_err, "usage:\n"
            "ts -query [-config configfile] "
            "[-data file_to_hash] [-digest digest_bytes]"
            "[-md4|-md5|-sha1|-ripemd160] "
            "[-policy object_id] [-no_nonce] [-cert] "
            "[-in request.tsq] [-out request.tsq] [-text]\n");
        BIO_printf(bio_err, "or\n"
            "ts -reply [-config configfile] [-section tsa_section] "
            "[-queryfile request.tsq] [-passin password] "
            "[-signer tsa_cert.pem] [-inkey private_key.pem] "
            "[-chain certs_file.pem] [-policy object_id] "
            "[-in response.tsr] [-token_in] "
            "[-out response.tsr] [-token_out] [-text]\n");
        BIO_printf(bio_err, "or\n"
            "ts -verify [-data file_to_hash] [-digest digest_bytes] "
            "[-queryfile request.tsq] "
            "-in response.tsr [-token_in] "
            "-CApath ca_path -CAfile ca_file.pem "
            "-untrusted cert_file.pem\n");

 cleanup:
        /* Clean up. */
        NCONF_free(conf);
        free(password);
        OBJ_cleanup();

        return (ret);
}

/*
 * Configuration file-related function definitions.
 */

static ASN1_OBJECT *
txt2obj(const char *oid)
{
        ASN1_OBJECT *oid_obj = NULL;

        if (!(oid_obj = OBJ_txt2obj(oid, 0)))
                BIO_printf(bio_err, "cannot convert %s to OID\n", oid);

        return oid_obj;
}

static CONF *
load_config_file(const char *configfile)
{
        CONF *conf = NULL;
        long errorline = -1;

        if (!configfile)
                configfile = getenv("OPENSSL_CONF");

        if (configfile &&
            (!(conf = NCONF_new(NULL)) ||
            NCONF_load(conf, configfile, &errorline) <= 0)) {
                if (errorline <= 0)
                        BIO_printf(bio_err, "error loading the config file "
                            "'%s'\n", configfile);
                else
                        BIO_printf(bio_err, "error on line %ld of config file "
                            "'%s'\n", errorline, configfile);
        }
        if (conf != NULL) {
                const char *p;

                BIO_printf(bio_err, "Using configuration from %s\n",
                    configfile);
                p = NCONF_get_string(conf, NULL, ENV_OID_FILE);
                if (p != NULL) {
                        BIO *oid_bio = BIO_new_file(p, "r");
                        if (!oid_bio)
                                ERR_print_errors(bio_err);
                        else {
                                OBJ_create_objects(oid_bio);
                                BIO_free_all(oid_bio);
                        }
                } else
                        ERR_clear_error();
                if (!add_oid_section(bio_err, conf))
                        ERR_print_errors(bio_err);
        }
        return conf;
}

/*
 * Query-related method definitions.
 */

static int
query_command(const char *data, char *digest, const EVP_MD * md,
    const char *policy, int no_nonce, int cert, const char *in,
    const char *out, int text)
{
        int ret = 0;
        TS_REQ *query = NULL;
        BIO *in_bio = NULL;
        BIO *data_bio = NULL;
        BIO *out_bio = NULL;

        /* Build query object either from file or from scratch. */
        if (in != NULL) {
                if ((in_bio = BIO_new_file(in, "rb")) == NULL)
                        goto end;
                query = d2i_TS_REQ_bio(in_bio, NULL);
        } else {
                /* Open the file if no explicit digest bytes were specified. */
                if (!digest &&
                    !(data_bio = BIO_open_with_default(data, "rb", stdin)))
                        goto end;
                /* Creating the query object. */
                query = create_query(data_bio, digest, md,
                    policy, no_nonce, cert);
                /* Saving the random number generator state. */
        }
        if (query == NULL)
                goto end;

        /* Write query either in ASN.1 or in text format. */
        if ((out_bio = BIO_open_with_default(out, "wb", stdout)) == NULL)
                goto end;
        if (text) {
                /* Text output. */
                if (!TS_REQ_print_bio(out_bio, query))
                        goto end;
        } else {
                /* ASN.1 output. */
                if (!i2d_TS_REQ_bio(out_bio, query))
                        goto end;
        }

        ret = 1;

 end:
        ERR_print_errors(bio_err);

        /* Clean up. */
        BIO_free_all(in_bio);
        BIO_free_all(data_bio);
        BIO_free_all(out_bio);
        TS_REQ_free(query);

        return ret;
}

static BIO *
BIO_open_with_default(const char *file, const char *mode, FILE * default_fp)
{
        return file == NULL ? BIO_new_fp(default_fp, BIO_NOCLOSE) :
            BIO_new_file(file, mode);
}

static TS_REQ *
create_query(BIO * data_bio, char *digest, const EVP_MD * md,
    const char *policy, int no_nonce, int cert)
{
        int ret = 0;
        TS_REQ *ts_req = NULL;
        int len;
        TS_MSG_IMPRINT *msg_imprint = NULL;
        X509_ALGOR *algo = NULL;
        unsigned char *data = NULL;
        ASN1_OBJECT *policy_obj = NULL;
        ASN1_INTEGER *nonce_asn1 = NULL;

        /* Setting default message digest. */
        if (!md && !(md = EVP_get_digestbyname("sha1")))
                goto err;

        /* Creating request object. */
        if (!(ts_req = TS_REQ_new()))
                goto err;

        /* Setting version. */
        if (!TS_REQ_set_version(ts_req, 1))
                goto err;

        /* Creating and adding MSG_IMPRINT object. */
        if (!(msg_imprint = TS_MSG_IMPRINT_new()))
                goto err;

        /* Adding algorithm. */
        if (!(algo = X509_ALGOR_new()))
                goto err;
        if (!(algo->algorithm = OBJ_nid2obj(EVP_MD_type(md))))
                goto err;
        if (!(algo->parameter = ASN1_TYPE_new()))
                goto err;
        algo->parameter->type = V_ASN1_NULL;
        if (!TS_MSG_IMPRINT_set_algo(msg_imprint, algo))
                goto err;

        /* Adding message digest. */
        if ((len = create_digest(data_bio, digest, md, &data)) == 0)
                goto err;
        if (!TS_MSG_IMPRINT_set_msg(msg_imprint, data, len))
                goto err;

        if (!TS_REQ_set_msg_imprint(ts_req, msg_imprint))
                goto err;

        /* Setting policy if requested. */
        if (policy && !(policy_obj = txt2obj(policy)))
                goto err;
        if (policy_obj && !TS_REQ_set_policy_id(ts_req, policy_obj))
                goto err;

        /* Setting nonce if requested. */
        if (!no_nonce && !(nonce_asn1 = create_nonce(NONCE_LENGTH)))
                goto err;
        if (nonce_asn1 && !TS_REQ_set_nonce(ts_req, nonce_asn1))
                goto err;

        /* Setting certificate request flag if requested. */
        if (!TS_REQ_set_cert_req(ts_req, cert))
                goto err;

        ret = 1;

 err:
        if (!ret) {
                TS_REQ_free(ts_req);
                ts_req = NULL;
                BIO_printf(bio_err, "could not create query\n");
        }
        TS_MSG_IMPRINT_free(msg_imprint);
        X509_ALGOR_free(algo);
        free(data);
        ASN1_OBJECT_free(policy_obj);
        ASN1_INTEGER_free(nonce_asn1);

        return ts_req;
}

static int
create_digest(BIO * input, char *digest, const EVP_MD * md,
    unsigned char **md_value)
{
        int md_value_len;

        md_value_len = EVP_MD_size(md);
        if (md_value_len < 0)
                goto err;
        if (input) {
                /* Digest must be computed from an input file. */
                EVP_MD_CTX md_ctx;
                unsigned char buffer[4096];
                int length;

                *md_value = malloc(md_value_len);
                if (*md_value == 0)
                        goto err;

                EVP_DigestInit(&md_ctx, md);
                while ((length = BIO_read(input, buffer, sizeof(buffer))) > 0) {
                        EVP_DigestUpdate(&md_ctx, buffer, length);
                }
                EVP_DigestFinal(&md_ctx, *md_value, NULL);
        } else {
                /* Digest bytes are specified with digest. */
                long digest_len;
                *md_value = string_to_hex(digest, &digest_len);
                if (!*md_value || md_value_len != digest_len) {
                        free(*md_value);
                        *md_value = NULL;
                        BIO_printf(bio_err, "bad digest, %d bytes "
                            "must be specified\n", md_value_len);
                        goto err;
                }
        }

        return md_value_len;
 err:
        return 0;
}

static ASN1_INTEGER *
create_nonce(int bits)
{
        unsigned char buf[20];
        ASN1_INTEGER *nonce = NULL;
        int len = (bits - 1) / 8 + 1;
        int i;

        /* Generating random byte sequence. */
        if (len > (int) sizeof(buf))
                goto err;
        arc4random_buf(buf, len);

        /* Find the first non-zero byte and creating ASN1_INTEGER object. */
        for (i = 0; i < len && !buf[i]; ++i)
                ;
        if (!(nonce = ASN1_INTEGER_new()))
                goto err;
        free(nonce->data);
        /* Allocate at least one byte. */
        nonce->length = len - i;
        if (!(nonce->data = malloc(nonce->length + 1)))
                goto err;
        memcpy(nonce->data, buf + i, nonce->length);

        return nonce;

 err:
        BIO_printf(bio_err, "could not create nonce\n");
        ASN1_INTEGER_free(nonce);
        return NULL;
}
/*
 * Reply-related method definitions.
 */

static int
reply_command(CONF * conf, char *section, char *queryfile,
    char *passin, char *inkey, char *signer, char *chain, const char *policy,
    char *in, int token_in, char *out, int token_out, int text)
{
        int ret = 0;
        TS_RESP *response = NULL;
        BIO *in_bio = NULL;
        BIO *query_bio = NULL;
        BIO *inkey_bio = NULL;
        BIO *signer_bio = NULL;
        BIO *out_bio = NULL;

        /* Build response object either from response or query. */
        if (in != NULL) {
                if ((in_bio = BIO_new_file(in, "rb")) == NULL)
                        goto end;
                if (token_in) {
                        /*
                         * We have a ContentInfo (PKCS7) object, add
                         * 'granted' status info around it.
                         */
                        response = read_PKCS7(in_bio);
                } else {
                        /* We have a ready-made TS_RESP object. */
                        response = d2i_TS_RESP_bio(in_bio, NULL);
                }
        } else {
                response = create_response(conf, section, queryfile,
                    passin, inkey, signer, chain,
                    policy);
                if (response)
                        BIO_printf(bio_err, "Response has been generated.\n");
                else
                        BIO_printf(bio_err, "Response is not generated.\n");
        }
        if (response == NULL)
                goto end;

        /* Write response either in ASN.1 or text format. */
        if ((out_bio = BIO_open_with_default(out, "wb", stdout)) == NULL)
                goto end;
        if (text) {
                /* Text output. */
                if (token_out) {
                        TS_TST_INFO *tst_info = TS_RESP_get_tst_info(response);
                        if (!TS_TST_INFO_print_bio(out_bio, tst_info))
                                goto end;
                } else {
                        if (!TS_RESP_print_bio(out_bio, response))
                                goto end;
                }
        } else {
                /* ASN.1 DER output. */
                if (token_out) {
                        PKCS7 *token = TS_RESP_get_token(response);
                        if (!i2d_PKCS7_bio(out_bio, token))
                                goto end;
                } else {
                        if (!i2d_TS_RESP_bio(out_bio, response))
                                goto end;
                }
        }

        ret = 1;

 end:
        ERR_print_errors(bio_err);

        /* Clean up. */
        BIO_free_all(in_bio);
        BIO_free_all(query_bio);
        BIO_free_all(inkey_bio);
        BIO_free_all(signer_bio);
        BIO_free_all(out_bio);
        TS_RESP_free(response);

        return ret;
}

/* Reads a PKCS7 token and adds default 'granted' status info to it. */
static TS_RESP *
read_PKCS7(BIO * in_bio)
{
        int ret = 0;
        PKCS7 *token = NULL;
        TS_TST_INFO *tst_info = NULL;
        TS_RESP *resp = NULL;
        TS_STATUS_INFO *si = NULL;

        /* Read PKCS7 object and extract the signed time stamp info. */
        if (!(token = d2i_PKCS7_bio(in_bio, NULL)))
                goto end;
        if (!(tst_info = PKCS7_to_TS_TST_INFO(token)))
                goto end;

        /* Creating response object. */
        if (!(resp = TS_RESP_new()))
                goto end;

        /* Create granted status info. */
        if (!(si = TS_STATUS_INFO_new()))
                goto end;
        if (!(ASN1_INTEGER_set(si->status, TS_STATUS_GRANTED)))
                goto end;
        if (!TS_RESP_set_status_info(resp, si))
                goto end;

        /* Setting encapsulated token. */
        TS_RESP_set_tst_info(resp, token, tst_info);
        token = NULL;           /* Ownership is lost. */
        tst_info = NULL;        /* Ownership is lost. */

        ret = 1;
 end:
        PKCS7_free(token);
        TS_TST_INFO_free(tst_info);
        if (!ret) {
                TS_RESP_free(resp);
                resp = NULL;
        }
        TS_STATUS_INFO_free(si);
        return resp;
}

static TS_RESP *
create_response(CONF * conf, const char *section,
    char *queryfile, char *passin, char *inkey,
    char *signer, char *chain, const char *policy)
{
        int ret = 0;
        TS_RESP *response = NULL;
        BIO *query_bio = NULL;
        TS_RESP_CTX *resp_ctx = NULL;

        if (!(query_bio = BIO_new_file(queryfile, "rb")))
                goto end;

        /* Getting TSA configuration section. */
        if (!(section = TS_CONF_get_tsa_section(conf, section)))
                goto end;

        /* Setting up response generation context. */
        if (!(resp_ctx = TS_RESP_CTX_new()))
                goto end;

        /* Setting serial number provider callback. */
        if (!TS_CONF_set_serial(conf, section, serial_cb, resp_ctx))
                goto end;

        /* Setting TSA signer certificate. */
        if (!TS_CONF_set_signer_cert(conf, section, signer, resp_ctx))
                goto end;

        /* Setting TSA signer certificate chain. */
        if (!TS_CONF_set_certs(conf, section, chain, resp_ctx))
                goto end;

        /* Setting TSA signer private key. */
        if (!TS_CONF_set_signer_key(conf, section, inkey, passin, resp_ctx))
                goto end;

        /* Setting default policy OID. */
        if (!TS_CONF_set_def_policy(conf, section, policy, resp_ctx))
                goto end;

        /* Setting acceptable policy OIDs. */
        if (!TS_CONF_set_policies(conf, section, resp_ctx))
                goto end;

        /* Setting the acceptable one-way hash algorithms. */
        if (!TS_CONF_set_digests(conf, section, resp_ctx))
                goto end;

        /* Setting guaranteed time stamp accuracy. */
        if (!TS_CONF_set_accuracy(conf, section, resp_ctx))
                goto end;

        /* Setting the precision of the time. */
        if (!TS_CONF_set_clock_precision_digits(conf, section, resp_ctx))
                goto end;

        /* Setting the ordering flaf if requested. */
        if (!TS_CONF_set_ordering(conf, section, resp_ctx))
                goto end;

        /* Setting the TSA name required flag if requested. */
        if (!TS_CONF_set_tsa_name(conf, section, resp_ctx))
                goto end;

        /* Setting the ESS cert id chain flag if requested. */
        if (!TS_CONF_set_ess_cert_id_chain(conf, section, resp_ctx))
                goto end;

        /* Creating the response. */
        if (!(response = TS_RESP_create_response(resp_ctx, query_bio)))
                goto end;

        ret = 1;
 end:
        if (!ret) {
                TS_RESP_free(response);
                response = NULL;
        }
        TS_RESP_CTX_free(resp_ctx);
        BIO_free_all(query_bio);

        return response;
}

static ASN1_INTEGER *
serial_cb(TS_RESP_CTX * ctx, void *data)
{
        const char *serial_file = (const char *) data;
        ASN1_INTEGER *serial = next_serial(serial_file);

        if (!serial) {
                TS_RESP_CTX_set_status_info(ctx, TS_STATUS_REJECTION,
                    "Error during serial number "
                    "generation.");
                TS_RESP_CTX_add_failure_info(ctx,
                    TS_INFO_ADD_INFO_NOT_AVAILABLE);
        } else
                save_ts_serial(serial_file, serial);

        return serial;
}

static ASN1_INTEGER *
next_serial(const char *serialfile)
{
        int ret = 0;
        BIO *in = NULL;
        ASN1_INTEGER *serial = NULL;
        BIGNUM *bn = NULL;

        if (!(serial = ASN1_INTEGER_new()))
                goto err;

        if (!(in = BIO_new_file(serialfile, "r"))) {
                ERR_clear_error();
                BIO_printf(bio_err, "Warning: could not open file %s for "
                    "reading, using serial number: 1\n", serialfile);
                if (!ASN1_INTEGER_set(serial, 1))
                        goto err;
        } else {
                char buf[1024];
                if (!a2i_ASN1_INTEGER(in, serial, buf, sizeof(buf))) {
                        BIO_printf(bio_err, "unable to load number from %s\n",
                            serialfile);
                        goto err;
                }
                if (!(bn = ASN1_INTEGER_to_BN(serial, NULL)))
                        goto err;
                ASN1_INTEGER_free(serial);
                serial = NULL;
                if (!BN_add_word(bn, 1))
                        goto err;
                if (!(serial = BN_to_ASN1_INTEGER(bn, NULL)))
                        goto err;
        }
        ret = 1;
 err:
        if (!ret) {
                ASN1_INTEGER_free(serial);
                serial = NULL;
        }
        BIO_free_all(in);
        BN_free(bn);
        return serial;
}

static int
save_ts_serial(const char *serialfile, ASN1_INTEGER * serial)
{
        int ret = 0;
        BIO *out = NULL;

        if (!(out = BIO_new_file(serialfile, "w")))
                goto err;
        if (i2a_ASN1_INTEGER(out, serial) <= 0)
                goto err;
        if (BIO_puts(out, "\n") <= 0)
                goto err;
        ret = 1;
 err:
        if (!ret)
                BIO_printf(bio_err, "could not save serial number to %s\n",
                    serialfile);
        BIO_free_all(out);
        return ret;
}

/*
 * Verify-related method definitions.
 */

static int
verify_command(char *data, char *digest, char *queryfile, char *in,
    int token_in, char *ca_path, char *ca_file, char *untrusted)
{
        BIO *in_bio = NULL;
        PKCS7 *token = NULL;
        TS_RESP *response = NULL;
        TS_VERIFY_CTX *verify_ctx = NULL;
        int ret = 0;

        /* Decode the token (PKCS7) or response (TS_RESP) files. */
        if (!(in_bio = BIO_new_file(in, "rb")))
                goto end;
        if (token_in) {
                if (!(token = d2i_PKCS7_bio(in_bio, NULL)))
                        goto end;
        } else {
                if (!(response = d2i_TS_RESP_bio(in_bio, NULL)))
                        goto end;
        }

        if (!(verify_ctx = create_verify_ctx(data, digest, queryfile,
            ca_path, ca_file, untrusted)))
                goto end;

        /* Checking the token or response against the request. */
        ret = token_in ?
            TS_RESP_verify_token(verify_ctx, token) :
            TS_RESP_verify_response(verify_ctx, response);

 end:
        printf("Verification: ");
        if (ret)
                printf("OK\n");
        else {
                printf("FAILED\n");
                /* Print errors, if there are any. */
                ERR_print_errors(bio_err);
        }

        /* Clean up. */
        BIO_free_all(in_bio);
        PKCS7_free(token);
        TS_RESP_free(response);
        TS_VERIFY_CTX_free(verify_ctx);
        return ret;
}

static TS_VERIFY_CTX *
create_verify_ctx(char *data, char *digest, char *queryfile, char *ca_path,
    char *ca_file, char *untrusted)
{
        TS_VERIFY_CTX *ctx = NULL;
        BIO *input = NULL;
        TS_REQ *request = NULL;
        int ret = 0;

        if (data != NULL || digest != NULL) {
                if (!(ctx = TS_VERIFY_CTX_new()))
                        goto err;
                ctx->flags = TS_VFY_VERSION | TS_VFY_SIGNER;
                if (data != NULL) {
                        ctx->flags |= TS_VFY_DATA;
                        if (!(ctx->data = BIO_new_file(data, "rb")))
                                goto err;
                } else if (digest != NULL) {
                        long imprint_len;
                        ctx->flags |= TS_VFY_IMPRINT;
                        if (!(ctx->imprint = string_to_hex(digest,
                                    &imprint_len))) {
                                BIO_printf(bio_err, "invalid digest string\n");
                                goto err;
                        }
                        ctx->imprint_len = imprint_len;
                }
        } else if (queryfile != NULL) {
                /*
                 * The request has just to be read, decoded and converted to
                 * a verify context object.
                 */
                if (!(input = BIO_new_file(queryfile, "rb")))
                        goto err;
                if (!(request = d2i_TS_REQ_bio(input, NULL)))
                        goto err;
                if (!(ctx = TS_REQ_to_TS_VERIFY_CTX(request, NULL)))
                        goto err;
        } else
                return NULL;

        /* Add the signature verification flag and arguments. */
        ctx->flags |= TS_VFY_SIGNATURE;

        /* Initialising the X509_STORE object. */
        if (!(ctx->store = create_cert_store(ca_path, ca_file)))
                goto err;

        /* Loading untrusted certificates. */
        if (untrusted && !(ctx->certs = TS_CONF_load_certs(untrusted)))
                goto err;

        ret = 1;
 err:
        if (!ret) {
                TS_VERIFY_CTX_free(ctx);
                ctx = NULL;
        }
        BIO_free_all(input);
        TS_REQ_free(request);
        return ctx;
}

static X509_STORE *
create_cert_store(char *ca_path, char *ca_file)
{
        X509_STORE *cert_ctx = NULL;
        X509_LOOKUP *lookup = NULL;
        int i;

        /* Creating the X509_STORE object. */
        cert_ctx = X509_STORE_new();

        /* Setting the callback for certificate chain verification. */
        X509_STORE_set_verify_cb(cert_ctx, verify_cb);

        /* Adding a trusted certificate directory source. */
        if (ca_path) {
                lookup = X509_STORE_add_lookup(cert_ctx,
                    X509_LOOKUP_hash_dir());
                if (lookup == NULL) {
                        BIO_printf(bio_err, "memory allocation failure\n");
                        goto err;
                }
                i = X509_LOOKUP_add_dir(lookup, ca_path, X509_FILETYPE_PEM);
                if (!i) {
                        BIO_printf(bio_err, "Error loading directory %s\n",
                            ca_path);
                        goto err;
                }
        }
        /* Adding a trusted certificate file source. */
        if (ca_file) {
                lookup = X509_STORE_add_lookup(cert_ctx, X509_LOOKUP_file());
                if (lookup == NULL) {
                        BIO_printf(bio_err, "memory allocation failure\n");
                        goto err;
                }
                i = X509_LOOKUP_load_file(lookup, ca_file, X509_FILETYPE_PEM);
                if (!i) {
                        BIO_printf(bio_err, "Error loading file %s\n", ca_file);
                        goto err;
                }
        }
        return cert_ctx;
 err:
        X509_STORE_free(cert_ctx);
        return NULL;
}

static int
verify_cb(int ok, X509_STORE_CTX * ctx)
{
        /*
        char buf[256];

        if (!ok)
                {
                X509_NAME_oneline(X509_get_subject_name(ctx->current_cert),
                                  buf, sizeof(buf));
                printf("%s\n", buf);
                printf("error %d at %d depth lookup: %s\n",
                       ctx->error, ctx->error_depth,
                        X509_verify_cert_error_string(ctx->error));
                }
        */

        return ok;
}