text: /* $OpenBSD: ts.c,v 1.13 2015/10/17 15:00:11 doug 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 rpath wpath cpath 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;
  }
  