crypto/cmp/cmp_util.c - third_party/openssl - Git at Google

 /*
  * Copyright 2007-2020 The OpenSSL Project Authors. All Rights Reserved.
  * Copyright Nokia 2007-2019
  * Copyright Siemens AG 2015-2019
  *
  * Licensed under the Apache License 2.0 (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 <string.h>
 #include <openssl/cmp_util.h>
 #include "cmp_local.h" /* just for decls of internal functions defined here */
 #include <openssl/cmperr.h>
 #include <openssl/err.h> /* should be implied by cmperr.h */
 #include <openssl/x509v3.h>

 DEFINE_STACK_OF(X509_OBJECT)
 DEFINE_STACK_OF(ASN1_UTF8STRING)

 /*
  * use trace API for CMP-specific logging, prefixed by "CMP " and severity
  */

 int OSSL_CMP_log_open(void) /* is designed to be idempotent */
 {
 #ifndef OPENSSL_NO_STDIO
     BIO *bio = BIO_new_fp(stdout, BIO_NOCLOSE);

     if (bio != NULL && OSSL_trace_set_channel(OSSL_TRACE_CATEGORY_CMP, bio))
         return 1;
     BIO_free(bio);
 #endif
     CMPerr(0, CMP_R_NO_STDIO);
     return 0;
 }

 void OSSL_CMP_log_close(void) /* is designed to be idempotent */
 {
     (void)OSSL_trace_set_channel(OSSL_TRACE_CATEGORY_CMP, NULL);
 }

 /* return >= 0 if level contains logging level, possibly preceded by "CMP " */
 #define max_level_len 5 /* = max length of the below strings, e.g., "EMERG" */
 static OSSL_CMP_severity parse_level(const char *level)
 {
     const char *end_level = strchr(level, ':');
     int len;
     char level_copy[max_level_len + 1];

     if (end_level == NULL)
         return -1;

     if (strncmp(level, OSSL_CMP_LOG_PREFIX,
                 strlen(OSSL_CMP_LOG_PREFIX)) == 0)
         level += strlen(OSSL_CMP_LOG_PREFIX);
     len = end_level - level;
     if (len > max_level_len)
         return -1;
     OPENSSL_strlcpy(level_copy, level, len + 1);
     return
         strcmp(level_copy, "EMERG") == 0 ? OSSL_CMP_LOG_EMERG :
         strcmp(level_copy, "ALERT") == 0 ? OSSL_CMP_LOG_ALERT :
         strcmp(level_copy, "CRIT") == 0 ? OSSL_CMP_LOG_CRIT :
         strcmp(level_copy, "ERROR") == 0 ? OSSL_CMP_LOG_ERR :
         strcmp(level_copy, "WARN") == 0 ? OSSL_CMP_LOG_WARNING :
         strcmp(level_copy, "NOTE") == 0 ? OSSL_CMP_LOG_NOTICE :
         strcmp(level_copy, "INFO") == 0 ? OSSL_CMP_LOG_INFO :
         strcmp(level_copy, "DEBUG") == 0 ? OSSL_CMP_LOG_DEBUG :
         -1;
 }

 const char *ossl_cmp_log_parse_metadata(const char *buf,
                                         OSSL_CMP_severity *level,
                                         char **func, char **file, int *line)
 {
     const char *p_func = buf;
     const char *p_file = buf == NULL ? NULL : strchr(buf, ':');
     const char *p_level = buf;
     const char *msg = buf;

     *level = -1;
     *func = NULL;
     *file = NULL;
     *line = 0;

     if (p_file != NULL) {
         const char *p_line = strchr(++p_file, ':');

         if ((*level = parse_level(buf)) < 0 && p_line != NULL) {
             /* check if buf contains location info and logging level */
             char *p_level_tmp = (char *)p_level;
             const long line_number = strtol(++p_line, &p_level_tmp, 10);

             p_level = p_level_tmp;
             if (p_level > p_line && *(p_level++) == ':') {
                 if ((*level = parse_level(p_level)) >= 0) {
                     *func = OPENSSL_strndup(p_func, p_file - 1 - p_func);
                     *file = OPENSSL_strndup(p_file, p_line - 1 - p_file);
                     /* no real problem if OPENSSL_strndup() returns NULL */
                     *line = (int)line_number;
                     msg = strchr(p_level, ':') + 1;
                     if (*msg == ' ')
                         msg++;
                 }
             }
         }
     }
     return msg;
 }

 #define UNKNOWN_FUNC "(unknown function)" /* the default for OPENSSL_FUNC */
 /*
  * substitute fallback if component/function name is NULL or empty or contains
  * just pseudo-information "(unknown function)" due to -pedantic and macros.h
  */
 static const char *improve_location_name(const char *func, const char *fallback)
 {
     if (fallback == NULL)
         return func == NULL ? UNKNOWN_FUNC : func;

     return func == NULL || *func == '\0' || strcmp(func, UNKNOWN_FUNC) == 0
         ? fallback : func;
 }

 int OSSL_CMP_print_to_bio(BIO *bio, const char *component, const char *file,
                           int line, OSSL_CMP_severity level, const char *msg)
 {
     const char *level_string =
         level == OSSL_CMP_LOG_EMERG ? "EMERG" :
         level == OSSL_CMP_LOG_ALERT ? "ALERT" :
         level == OSSL_CMP_LOG_CRIT ? "CRIT" :
         level == OSSL_CMP_LOG_ERR ? "error" :
         level == OSSL_CMP_LOG_WARNING ? "warning" :
         level == OSSL_CMP_LOG_NOTICE ? "NOTE" :
         level == OSSL_CMP_LOG_INFO ? "info" :
         level == OSSL_CMP_LOG_DEBUG ? "DEBUG" : "(unknown level)";

 #ifndef NDEBUG
     if (BIO_printf(bio, "%s:%s:%d:", improve_location_name(component, "CMP"),
                    file, line) < 0)
         return 0;
 #endif
     return BIO_printf(bio, OSSL_CMP_LOG_PREFIX"%s: %s\n",
                       level_string, msg) >= 0;
 }

 #define ERR_PRINT_BUF_SIZE 4096
 /* this is similar to ERR_print_errors_cb, but uses the CMP-specific cb type */
 void OSSL_CMP_print_errors_cb(OSSL_CMP_log_cb_t log_fn)
 {
     unsigned long err;
     char msg[ERR_PRINT_BUF_SIZE];
     const char *file = NULL, *func = NULL, *data = NULL;
     int line, flags;

     while ((err = ERR_get_error_all(&file, &line, &func, &data, &flags)) != 0) {
         const char *component =
             improve_location_name(func, ERR_lib_error_string(err));

         if (!(flags & ERR_TXT_STRING))
             data = NULL;
         BIO_snprintf(msg, sizeof(msg), "%s%s%s", ERR_reason_error_string(err),
                      data == NULL || *data == '\0' ? "" : " : ",
                      data == NULL ? "" : data);
         if (log_fn == NULL) {
 #ifndef OPENSSL_NO_STDIO
             BIO *bio = BIO_new_fp(stderr, BIO_NOCLOSE);

             if (bio != NULL) {
                 OSSL_CMP_print_to_bio(bio, component, file, line,
                                       OSSL_CMP_LOG_ERR, msg);
                 BIO_free(bio);
             }
 #else
             /* CMPerr(0, CMP_R_NO_STDIO) makes no sense during error printing */
 #endif
         } else {
             if (log_fn(component, file, line, OSSL_CMP_LOG_ERR, msg) <= 0)
                 break; /* abort outputting the error report */
         }
     }
 }

 int ossl_cmp_X509_STORE_add1_certs(X509_STORE *store, STACK_OF(X509) *certs,
                                    int only_self_signed)
 {
     int i;

     if (store == NULL) {
         CMPerr(0, CMP_R_NULL_ARGUMENT);
         return 0;
     }
     if (certs == NULL)
         return 1;
     for (i = 0; i < sk_X509_num(certs); i++) {
         X509 *cert = sk_X509_value(certs, i);

         if (!only_self_signed || X509_self_signed(cert, 0) == 1)
             if (!X509_STORE_add_cert(store, cert)) /* ups cert ref counter */
                 return 0;
     }
     return 1;
 }

 /*-
  * Builds a certificate chain starting from <cert>
  * using the optional list of intermediate CA certificates <certs>.
  * If <store> is NULL builds the chain as far down as possible, ignoring errors.
  * Else the chain must reach a trust anchor contained in <store>.
  *
  * Returns NULL on error, else a pointer to a stack of (up_ref'ed) certificates
  * starting with given EE certificate and followed by all available intermediate
  * certificates down towards any trust anchor but without including the latter.
  *
  * NOTE: If a non-NULL stack is returned the caller is responsible for freeing.
  * NOTE: In case there is more than one possibility for the chain,
  * OpenSSL seems to take the first one; check X509_verify_cert() for details.
  */
 /* TODO this should be of more general interest and thus be exported. */
 STACK_OF(X509)
     *ossl_cmp_build_cert_chain(OPENSSL_CTX *libctx, const char *propq,
                                X509_STORE *store,
                                STACK_OF(X509) *certs, X509 *cert)
 {
     STACK_OF(X509) *chain = NULL, *result = NULL;
     X509_STORE *ts = store == NULL ? X509_STORE_new() : store;
     X509_STORE_CTX *csc = NULL;

     if (ts == NULL || cert == NULL) {
         CMPerr(0, CMP_R_NULL_ARGUMENT);
         goto err;
     }

     if ((csc = X509_STORE_CTX_new_with_libctx(libctx, propq)) == NULL)
         goto err;
     if (store == NULL && certs != NULL
             && !ossl_cmp_X509_STORE_add1_certs(ts, certs, 0))
         goto err;
     if (!X509_STORE_CTX_init(csc, ts, cert,
                              store == NULL ? NULL : certs))
         goto err;
     /* disable any cert status/revocation checking etc. */
     X509_VERIFY_PARAM_clear_flags(X509_STORE_CTX_get0_param(csc),
                                   ~(X509_V_FLAG_USE_CHECK_TIME
                                     | X509_V_FLAG_NO_CHECK_TIME));

     if (X509_verify_cert(csc) <= 0 && store != NULL)
         goto err;
     chain = X509_STORE_CTX_get0_chain(csc);

     /* result list to store the up_ref'ed not self-signed certificates */
     if ((result = sk_X509_new_null()) == NULL)
         goto err;
     if (!X509_add_certs(result, chain,
                         X509_ADD_FLAG_UP_REF | X509_ADD_FLAG_NO_DUP
                         | X509_ADD_FLAG_NO_SS)) {
         sk_X509_free(result);
         result = NULL;
     }

  err:
     if (store == NULL)
         X509_STORE_free(ts);
     X509_STORE_CTX_free(csc);
     return result;
 }

 int ossl_cmp_sk_ASN1_UTF8STRING_push_str(STACK_OF(ASN1_UTF8STRING) *sk,
                                          const char *text)
 {
     ASN1_UTF8STRING *utf8string;

     if (!ossl_assert(sk != NULL && text != NULL))
         return 0;
     if ((utf8string = ASN1_UTF8STRING_new()) == NULL)
         return 0;
     if (!ASN1_STRING_set(utf8string, text, -1))
         goto err;
     if (!sk_ASN1_UTF8STRING_push(sk, utf8string))
         goto err;
     return 1;

  err:
     ASN1_UTF8STRING_free(utf8string);
     return 0;
 }

 int ossl_cmp_asn1_octet_string_set1(ASN1_OCTET_STRING **tgt,
                                     const ASN1_OCTET_STRING *src)
 {
     ASN1_OCTET_STRING *new;
     if (tgt == NULL) {
         CMPerr(0, CMP_R_NULL_ARGUMENT);
         return 0;
     }
     if (*tgt == src) /* self-assignment */
         return 1;

     if (src != NULL) {
         if ((new = ASN1_OCTET_STRING_dup(src)) == NULL)
             return 0;
     } else {
         new = NULL;
     }

     ASN1_OCTET_STRING_free(*tgt);
     *tgt = new;
     return 1;
 }

 int ossl_cmp_asn1_octet_string_set1_bytes(ASN1_OCTET_STRING **tgt,
                                           const unsigned char *bytes, int len)
 {
     ASN1_OCTET_STRING *new = NULL;

     if (tgt == NULL) {
         CMPerr(0, CMP_R_NULL_ARGUMENT);
         return 0;
     }
     if (bytes != NULL) {
         if ((new = ASN1_OCTET_STRING_new()) == NULL
                 || !(ASN1_OCTET_STRING_set(new, bytes, len))) {
             ASN1_OCTET_STRING_free(new);
             return 0;
         }
     }

     ASN1_OCTET_STRING_free(*tgt);
     *tgt = new;
     return 1;
 }
	/*
	* Copyright 2007-2020 The OpenSSL Project Authors. All Rights Reserved.
	* Copyright Nokia 2007-2019
	* Copyright Siemens AG 2015-2019
	*
	* Licensed under the Apache License 2.0 (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 <string.h>
	#include <openssl/cmp_util.h>
	#include "cmp_local.h" /* just for decls of internal functions defined here */
	#include <openssl/cmperr.h>
	#include <openssl/err.h> /* should be implied by cmperr.h */
	#include <openssl/x509v3.h>

	DEFINE_STACK_OF(X509_OBJECT)
	DEFINE_STACK_OF(ASN1_UTF8STRING)

	/*
	* use trace API for CMP-specific logging, prefixed by "CMP " and severity
	*/

	int OSSL_CMP_log_open(void) /* is designed to be idempotent */
	{
	#ifndef OPENSSL_NO_STDIO
	BIO *bio = BIO_new_fp(stdout, BIO_NOCLOSE);

	if (bio != NULL && OSSL_trace_set_channel(OSSL_TRACE_CATEGORY_CMP, bio))
	return 1;
	BIO_free(bio);
	#endif
	CMPerr(0, CMP_R_NO_STDIO);
	return 0;
	}

	void OSSL_CMP_log_close(void) /* is designed to be idempotent */
	{
	(void)OSSL_trace_set_channel(OSSL_TRACE_CATEGORY_CMP, NULL);
	}

	/* return >= 0 if level contains logging level, possibly preceded by "CMP " */
	#define max_level_len 5 /* = max length of the below strings, e.g., "EMERG" */
	static OSSL_CMP_severity parse_level(const char *level)
	{
	const char *end_level = strchr(level, ':');
	int len;
	char level_copy[max_level_len + 1];

	if (end_level == NULL)
	return -1;

	if (strncmp(level, OSSL_CMP_LOG_PREFIX,
	strlen(OSSL_CMP_LOG_PREFIX)) == 0)
	level += strlen(OSSL_CMP_LOG_PREFIX);
	len = end_level - level;
	if (len > max_level_len)
	return -1;
	OPENSSL_strlcpy(level_copy, level, len + 1);
	return
	strcmp(level_copy, "EMERG") == 0 ? OSSL_CMP_LOG_EMERG :
	strcmp(level_copy, "ALERT") == 0 ? OSSL_CMP_LOG_ALERT :
	strcmp(level_copy, "CRIT") == 0 ? OSSL_CMP_LOG_CRIT :
	strcmp(level_copy, "ERROR") == 0 ? OSSL_CMP_LOG_ERR :
	strcmp(level_copy, "WARN") == 0 ? OSSL_CMP_LOG_WARNING :
	strcmp(level_copy, "NOTE") == 0 ? OSSL_CMP_LOG_NOTICE :
	strcmp(level_copy, "INFO") == 0 ? OSSL_CMP_LOG_INFO :
	strcmp(level_copy, "DEBUG") == 0 ? OSSL_CMP_LOG_DEBUG :
	-1;
	}

	const char ossl_cmp_log_parse_metadata(const char buf,
	OSSL_CMP_severity *level,
	char func, char file, int *line)
	{
	const char *p_func = buf;
	const char *p_file = buf == NULL ? NULL : strchr(buf, ':');
	const char *p_level = buf;
	const char *msg = buf;

	*level = -1;
	*func = NULL;
	*file = NULL;
	*line = 0;

	if (p_file != NULL) {
	const char *p_line = strchr(++p_file, ':');

	if ((*level = parse_level(buf)) < 0 && p_line != NULL) {
	/* check if buf contains location info and logging level */
	char p_level_tmp = (char )p_level;
	const long line_number = strtol(++p_line, &p_level_tmp, 10);

	p_level = p_level_tmp;
	if (p_level > p_line && *(p_level++) == ':') {
	if ((*level = parse_level(p_level)) >= 0) {
	*func = OPENSSL_strndup(p_func, p_file - 1 - p_func);
	*file = OPENSSL_strndup(p_file, p_line - 1 - p_file);
	/* no real problem if OPENSSL_strndup() returns NULL */
	*line = (int)line_number;
	msg = strchr(p_level, ':') + 1;
	if (*msg == ' ')
	msg++;
	}
	}
	}
	}
	return msg;
	}

	#define UNKNOWN_FUNC "(unknown function)" /* the default for OPENSSL_FUNC */
	/*
	* substitute fallback if component/function name is NULL or empty or contains
	* just pseudo-information "(unknown function)" due to -pedantic and macros.h
	*/
	static const char improve_location_name(const char func, const char *fallback)
	{
	if (fallback == NULL)
	return func == NULL ? UNKNOWN_FUNC : func;

	return func == NULL \|\| *func == '\0' \|\| strcmp(func, UNKNOWN_FUNC) == 0
	? fallback : func;
	}

	int OSSL_CMP_print_to_bio(BIO bio, const char component, const char *file,
	int line, OSSL_CMP_severity level, const char *msg)
	{
	const char *level_string =
	level == OSSL_CMP_LOG_EMERG ? "EMERG" :
	level == OSSL_CMP_LOG_ALERT ? "ALERT" :
	level == OSSL_CMP_LOG_CRIT ? "CRIT" :
	level == OSSL_CMP_LOG_ERR ? "error" :
	level == OSSL_CMP_LOG_WARNING ? "warning" :
	level == OSSL_CMP_LOG_NOTICE ? "NOTE" :
	level == OSSL_CMP_LOG_INFO ? "info" :
	level == OSSL_CMP_LOG_DEBUG ? "DEBUG" : "(unknown level)";

	#ifndef NDEBUG
	if (BIO_printf(bio, "%s:%s:%d:", improve_location_name(component, "CMP"),
	file, line) < 0)
	return 0;
	#endif
	return BIO_printf(bio, OSSL_CMP_LOG_PREFIX"%s: %s\n",
	level_string, msg) >= 0;
	}

	#define ERR_PRINT_BUF_SIZE 4096
	/* this is similar to ERR_print_errors_cb, but uses the CMP-specific cb type */
	void OSSL_CMP_print_errors_cb(OSSL_CMP_log_cb_t log_fn)
	{
	unsigned long err;
	char msg[ERR_PRINT_BUF_SIZE];
	const char file = NULL, func = NULL, *data = NULL;
	int line, flags;

	while ((err = ERR_get_error_all(&file, &line, &func, &data, &flags)) != 0) {
	const char *component =
	improve_location_name(func, ERR_lib_error_string(err));

	if (!(flags & ERR_TXT_STRING))
	data = NULL;
	BIO_snprintf(msg, sizeof(msg), "%s%s%s", ERR_reason_error_string(err),
	data == NULL \|\| *data == '\0' ? "" : " : ",
	data == NULL ? "" : data);
	if (log_fn == NULL) {
	#ifndef OPENSSL_NO_STDIO
	BIO *bio = BIO_new_fp(stderr, BIO_NOCLOSE);

	if (bio != NULL) {
	OSSL_CMP_print_to_bio(bio, component, file, line,
	OSSL_CMP_LOG_ERR, msg);
	BIO_free(bio);
	}
	#else
	/* CMPerr(0, CMP_R_NO_STDIO) makes no sense during error printing */
	#endif
	} else {
	if (log_fn(component, file, line, OSSL_CMP_LOG_ERR, msg) <= 0)
	break; /* abort outputting the error report */
	}
	}
	}

	int ossl_cmp_X509_STORE_add1_certs(X509_STORE store, STACK_OF(X509) certs,
	int only_self_signed)
	{
	int i;

	if (store == NULL) {
	CMPerr(0, CMP_R_NULL_ARGUMENT);
	return 0;
	}
	if (certs == NULL)
	return 1;
	for (i = 0; i < sk_X509_num(certs); i++) {
	X509 *cert = sk_X509_value(certs, i);

	if (!only_self_signed \|\| X509_self_signed(cert, 0) == 1)
	if (!X509_STORE_add_cert(store, cert)) /* ups cert ref counter */
	return 0;
	}
	return 1;
	}

	/*-
	* Builds a certificate chain starting from <cert>
	* using the optional list of intermediate CA certificates <certs>.
	* If <store> is NULL builds the chain as far down as possible, ignoring errors.
	* Else the chain must reach a trust anchor contained in <store>.
	*
	* Returns NULL on error, else a pointer to a stack of (up_ref'ed) certificates
	* starting with given EE certificate and followed by all available intermediate
	* certificates down towards any trust anchor but without including the latter.
	*
	* NOTE: If a non-NULL stack is returned the caller is responsible for freeing.
	* NOTE: In case there is more than one possibility for the chain,
	* OpenSSL seems to take the first one; check X509_verify_cert() for details.
	*/
	/* TODO this should be of more general interest and thus be exported. */
	STACK_OF(X509)
	ossl_cmp_build_cert_chain(OPENSSL_CTX libctx, const char *propq,
	X509_STORE *store,
	STACK_OF(X509) certs, X509 cert)
	{
	STACK_OF(X509) chain = NULL, result = NULL;
	X509_STORE *ts = store == NULL ? X509_STORE_new() : store;
	X509_STORE_CTX *csc = NULL;

	if (ts == NULL \|\| cert == NULL) {
	CMPerr(0, CMP_R_NULL_ARGUMENT);
	goto err;
	}

	if ((csc = X509_STORE_CTX_new_with_libctx(libctx, propq)) == NULL)
	goto err;
	if (store == NULL && certs != NULL
	&& !ossl_cmp_X509_STORE_add1_certs(ts, certs, 0))
	goto err;
	if (!X509_STORE_CTX_init(csc, ts, cert,
	store == NULL ? NULL : certs))
	goto err;
	/* disable any cert status/revocation checking etc. */
	X509_VERIFY_PARAM_clear_flags(X509_STORE_CTX_get0_param(csc),
	~(X509_V_FLAG_USE_CHECK_TIME
	\| X509_V_FLAG_NO_CHECK_TIME));

	if (X509_verify_cert(csc) <= 0 && store != NULL)
	goto err;
	chain = X509_STORE_CTX_get0_chain(csc);

	/* result list to store the up_ref'ed not self-signed certificates */
	if ((result = sk_X509_new_null()) == NULL)
	goto err;
	if (!X509_add_certs(result, chain,
	X509_ADD_FLAG_UP_REF \| X509_ADD_FLAG_NO_DUP
	\| X509_ADD_FLAG_NO_SS)) {
	sk_X509_free(result);
	result = NULL;
	}

	err:
	if (store == NULL)
	X509_STORE_free(ts);
	X509_STORE_CTX_free(csc);
	return result;
	}

	int ossl_cmp_sk_ASN1_UTF8STRING_push_str(STACK_OF(ASN1_UTF8STRING) *sk,
	const char *text)
	{
	ASN1_UTF8STRING *utf8string;

	if (!ossl_assert(sk != NULL && text != NULL))
	return 0;
	if ((utf8string = ASN1_UTF8STRING_new()) == NULL)
	return 0;
	if (!ASN1_STRING_set(utf8string, text, -1))
	goto err;
	if (!sk_ASN1_UTF8STRING_push(sk, utf8string))
	goto err;
	return 1;

	err:
	ASN1_UTF8STRING_free(utf8string);
	return 0;
	}

	int ossl_cmp_asn1_octet_string_set1(ASN1_OCTET_STRING **tgt,
	const ASN1_OCTET_STRING *src)
	{
	ASN1_OCTET_STRING *new;
	if (tgt == NULL) {
	CMPerr(0, CMP_R_NULL_ARGUMENT);
	return 0;
	}
	if (tgt == src) / self-assignment */
	return 1;

	if (src != NULL) {
	if ((new = ASN1_OCTET_STRING_dup(src)) == NULL)
	return 0;
	} else {
	new = NULL;
	}

	ASN1_OCTET_STRING_free(*tgt);
	*tgt = new;
	return 1;
	}

	int ossl_cmp_asn1_octet_string_set1_bytes(ASN1_OCTET_STRING **tgt,
	const unsigned char *bytes, int len)
	{
	ASN1_OCTET_STRING *new = NULL;

	if (tgt == NULL) {
	CMPerr(0, CMP_R_NULL_ARGUMENT);
	return 0;
	}
	if (bytes != NULL) {
	if ((new = ASN1_OCTET_STRING_new()) == NULL
	\|\| !(ASN1_OCTET_STRING_set(new, bytes, len))) {
	ASN1_OCTET_STRING_free(new);
	return 0;
	}
	}

	ASN1_OCTET_STRING_free(*tgt);
	*tgt = new;
	return 1;
	}