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IABSD.fr/src/lib/libtls/tls_config.c

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  • Author : tb
    Date : 2021-10-21 08:33:07
    Hash : ac45a079
    Message : Print uid with %u instead of %i. Prompted by a diff by Jonas Termansen, discussed with deraadt, millert ok jsing

  • lib/libtls/tls_config.c
  • /* $OpenBSD: tls_config.c,v 1.64 2021/10/21 08:33:07 tb Exp $ */
    /*
     * Copyright (c) 2014 Joel Sing <jsing@openbsd.org>
     *
     * Permission to use, copy, modify, and distribute this software for any
     * purpose with or without fee is hereby granted, provided that the above
     * copyright notice and this permission notice appear in all copies.
     *
     * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
     * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
     * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
     * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
     * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
     * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
     * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
     */
    
    #include <sys/stat.h>
    
    #include <ctype.h>
    #include <errno.h>
    #include <fcntl.h>
    #include <pthread.h>
    #include <stdlib.h>
    #include <unistd.h>
    
    #include <tls.h>
    
    #include "tls_internal.h"
    
    static const char default_ca_file[] = TLS_DEFAULT_CA_FILE;
    
    const char *
    tls_default_ca_cert_file(void)
    {
    	return default_ca_file;
    }
    
    int
    tls_config_load_file(struct tls_error *error, const char *filetype,
        const char *filename, char **buf, size_t *len)
    {
    	struct stat st;
    	int fd = -1;
    	ssize_t n;
    
    	free(*buf);
    	*buf = NULL;
    	*len = 0;
    
    	if ((fd = open(filename, O_RDONLY)) == -1) {
    		tls_error_set(error, "failed to open %s file '%s'",
    		    filetype, filename);
    		goto err;
    	}
    	if (fstat(fd, &st) != 0) {
    		tls_error_set(error, "failed to stat %s file '%s'",
    		    filetype, filename);
    		goto err;
    	}
    	if (st.st_size < 0)
    		goto err;
    	*len = (size_t)st.st_size;
    	if ((*buf = malloc(*len)) == NULL) {
    		tls_error_set(error, "failed to allocate buffer for "
    		    "%s file", filetype);
    		goto err;
    	}
    	n = read(fd, *buf, *len);
    	if (n < 0 || (size_t)n != *len) {
    		tls_error_set(error, "failed to read %s file '%s'",
    		    filetype, filename);
    		goto err;
    	}
    	close(fd);
    	return 0;
    
     err:
    	if (fd != -1)
    		close(fd);
    	freezero(*buf, *len);
    	*buf = NULL;
    	*len = 0;
    
    	return -1;
    }
    
    struct tls_config *
    tls_config_new_internal(void)
    {
    	struct tls_config *config;
    	unsigned char sid[TLS_MAX_SESSION_ID_LENGTH];
    
    	if ((config = calloc(1, sizeof(*config))) == NULL)
    		return (NULL);
    
    	if (pthread_mutex_init(&config->mutex, NULL) != 0)
    		goto err;
    
    	config->refcount = 1;
    	config->session_fd = -1;
    
    	if ((config->keypair = tls_keypair_new()) == NULL)
    		goto err;
    
    	/*
    	 * Default configuration.
    	 */
    	if (tls_config_set_dheparams(config, "none") != 0)
    		goto err;
    	if (tls_config_set_ecdhecurves(config, "default") != 0)
    		goto err;
    	if (tls_config_set_ciphers(config, "secure") != 0)
    		goto err;
    
    	if (tls_config_set_protocols(config, TLS_PROTOCOLS_DEFAULT) != 0)
    		goto err;
    	if (tls_config_set_verify_depth(config, 6) != 0)
    		goto err;
    
    	/*
    	 * Set session ID context to a random value.  For the simple case
    	 * of a single process server this is good enough. For multiprocess
    	 * servers the session ID needs to be set by the caller.
    	 */
    	arc4random_buf(sid, sizeof(sid));
    	if (tls_config_set_session_id(config, sid, sizeof(sid)) != 0)
    		goto err;
    	config->ticket_keyrev = arc4random();
    	config->ticket_autorekey = 1;
    
    	tls_config_prefer_ciphers_server(config);
    
    	tls_config_verify(config);
    
    	return (config);
    
     err:
    	tls_config_free(config);
    	return (NULL);
    }
    
    struct tls_config *
    tls_config_new(void)
    {
    	if (tls_init() == -1)
    		return (NULL);
    
    	return tls_config_new_internal();
    }
    
    void
    tls_config_free(struct tls_config *config)
    {
    	struct tls_keypair *kp, *nkp;
    	int refcount;
    
    	if (config == NULL)
    		return;
    
    	pthread_mutex_lock(&config->mutex);
    	refcount = --config->refcount;
    	pthread_mutex_unlock(&config->mutex);
    
    	if (refcount > 0)
    		return;
    
    	for (kp = config->keypair; kp != NULL; kp = nkp) {
    		nkp = kp->next;
    		tls_keypair_free(kp);
    	}
    
    	free(config->error.msg);
    
    	free(config->alpn);
    	free((char *)config->ca_mem);
    	free((char *)config->ca_path);
    	free((char *)config->ciphers);
    	free((char *)config->crl_mem);
    	free(config->ecdhecurves);
    
    	pthread_mutex_destroy(&config->mutex);
    
    	free(config);
    }
    
    static void
    tls_config_keypair_add(struct tls_config *config, struct tls_keypair *keypair)
    {
    	struct tls_keypair *kp;
    
    	kp = config->keypair;
    	while (kp->next != NULL)
    		kp = kp->next;
    
    	kp->next = keypair;
    }
    
    const char *
    tls_config_error(struct tls_config *config)
    {
    	return config->error.msg;
    }
    
    void
    tls_config_clear_keys(struct tls_config *config)
    {
    	struct tls_keypair *kp;
    
    	for (kp = config->keypair; kp != NULL; kp = kp->next)
    		tls_keypair_clear_key(kp);
    }
    
    int
    tls_config_parse_protocols(uint32_t *protocols, const char *protostr)
    {
    	uint32_t proto, protos = 0;
    	char *s, *p, *q;
    	int negate;
    
    	if (protostr == NULL) {
    		*protocols = TLS_PROTOCOLS_DEFAULT;
    		return (0);
    	}
    
    	if ((s = strdup(protostr)) == NULL)
    		return (-1);
    
    	q = s;
    	while ((p = strsep(&q, ",:")) != NULL) {
    		while (*p == ' ' || *p == '\t')
    			p++;
    
    		negate = 0;
    		if (*p == '!') {
    			negate = 1;
    			p++;
    		}
    
    		if (negate && protos == 0)
    			protos = TLS_PROTOCOLS_ALL;
    
    		proto = 0;
    		if (strcasecmp(p, "all") == 0 ||
    		    strcasecmp(p, "legacy") == 0)
    			proto = TLS_PROTOCOLS_ALL;
    		else if (strcasecmp(p, "default") == 0 ||
    		    strcasecmp(p, "secure") == 0)
    			proto = TLS_PROTOCOLS_DEFAULT;
    		if (strcasecmp(p, "tlsv1") == 0)
    			proto = TLS_PROTOCOL_TLSv1;
    		else if (strcasecmp(p, "tlsv1.0") == 0)
    			proto = TLS_PROTOCOL_TLSv1_0;
    		else if (strcasecmp(p, "tlsv1.1") == 0)
    			proto = TLS_PROTOCOL_TLSv1_1;
    		else if (strcasecmp(p, "tlsv1.2") == 0)
    			proto = TLS_PROTOCOL_TLSv1_2;
    		else if (strcasecmp(p, "tlsv1.3") == 0)
    			proto = TLS_PROTOCOL_TLSv1_3;
    
    		if (proto == 0) {
    			free(s);
    			return (-1);
    		}
    
    		if (negate)
    			protos &= ~proto;
    		else
    			protos |= proto;
    	}
    
    	*protocols = protos;
    
    	free(s);
    
    	return (0);
    }
    
    static int
    tls_config_parse_alpn(struct tls_config *config, const char *alpn,
        char **alpn_data, size_t *alpn_len)
    {
    	size_t buf_len, i, len;
    	char *buf = NULL;
    	char *s = NULL;
    	char *p, *q;
    
    	free(*alpn_data);
    	*alpn_data = NULL;
    	*alpn_len = 0;
    
    	if ((buf_len = strlen(alpn) + 1) > 65535) {
    		tls_config_set_errorx(config, "alpn too large");
    		goto err;
    	}
    
    	if ((buf = malloc(buf_len)) == NULL) {
    		tls_config_set_errorx(config, "out of memory");
    		goto err;
    	}
    
    	if ((s = strdup(alpn)) == NULL) {
    		tls_config_set_errorx(config, "out of memory");
    		goto err;
    	}
    
    	i = 0;
    	q = s;
    	while ((p = strsep(&q, ",")) != NULL) {
    		if ((len = strlen(p)) == 0) {
    			tls_config_set_errorx(config,
    			    "alpn protocol with zero length");
    			goto err;
    		}
    		if (len > 255) {
    			tls_config_set_errorx(config,
    			    "alpn protocol too long");
    			goto err;
    		}
    		buf[i++] = len & 0xff;
    		memcpy(&buf[i], p, len);
    		i += len;
    	}
    
    	free(s);
    
    	*alpn_data = buf;
    	*alpn_len = buf_len;
    
    	return (0);
    
     err:
    	free(buf);
    	free(s);
    
    	return (-1);
    }
    
    int
    tls_config_set_alpn(struct tls_config *config, const char *alpn)
    {
    	return tls_config_parse_alpn(config, alpn, &config->alpn,
    	    &config->alpn_len);
    }
    
    static int
    tls_config_add_keypair_file_internal(struct tls_config *config,
        const char *cert_file, const char *key_file, const char *ocsp_file)
    {
    	struct tls_keypair *keypair;
    
    	if ((keypair = tls_keypair_new()) == NULL)
    		return (-1);
    	if (tls_keypair_set_cert_file(keypair, &config->error, cert_file) != 0)
    		goto err;
    	if (key_file != NULL &&
    	    tls_keypair_set_key_file(keypair, &config->error, key_file) != 0)
    		goto err;
    	if (ocsp_file != NULL &&
    	    tls_keypair_set_ocsp_staple_file(keypair, &config->error,
    		ocsp_file) != 0)
    		goto err;
    
    	tls_config_keypair_add(config, keypair);
    
    	return (0);
    
     err:
    	tls_keypair_free(keypair);
    	return (-1);
    }
    
    static int
    tls_config_add_keypair_mem_internal(struct tls_config *config, const uint8_t *cert,
        size_t cert_len, const uint8_t *key, size_t key_len,
        const uint8_t *staple, size_t staple_len)
    {
    	struct tls_keypair *keypair;
    
    	if ((keypair = tls_keypair_new()) == NULL)
    		return (-1);
    	if (tls_keypair_set_cert_mem(keypair, &config->error, cert, cert_len) != 0)
    		goto err;
    	if (key != NULL &&
    	    tls_keypair_set_key_mem(keypair, &config->error, key, key_len) != 0)
    		goto err;
    	if (staple != NULL &&
    	    tls_keypair_set_ocsp_staple_mem(keypair, &config->error, staple,
    		staple_len) != 0)
    		goto err;
    
    	tls_config_keypair_add(config, keypair);
    
    	return (0);
    
     err:
    	tls_keypair_free(keypair);
    	return (-1);
    }
    
    int
    tls_config_add_keypair_mem(struct tls_config *config, const uint8_t *cert,
        size_t cert_len, const uint8_t *key, size_t key_len)
    {
    	return tls_config_add_keypair_mem_internal(config, cert, cert_len, key,
    	    key_len, NULL, 0);
    }
    
    int
    tls_config_add_keypair_file(struct tls_config *config,
        const char *cert_file, const char *key_file)
    {
    	return tls_config_add_keypair_file_internal(config, cert_file,
    	    key_file, NULL);
    }
    
    int
    tls_config_add_keypair_ocsp_mem(struct tls_config *config, const uint8_t *cert,
        size_t cert_len, const uint8_t *key, size_t key_len, const uint8_t *staple,
        size_t staple_len)
    {
    	return tls_config_add_keypair_mem_internal(config, cert, cert_len, key,
    	    key_len, staple, staple_len);
    }
    
    int
    tls_config_add_keypair_ocsp_file(struct tls_config *config,
        const char *cert_file, const char *key_file, const char *ocsp_file)
    {
    	return tls_config_add_keypair_file_internal(config, cert_file,
    	    key_file, ocsp_file);
    }
    
    int
    tls_config_set_ca_file(struct tls_config *config, const char *ca_file)
    {
    	return tls_config_load_file(&config->error, "CA", ca_file,
    	    &config->ca_mem, &config->ca_len);
    }
    
    int
    tls_config_set_ca_path(struct tls_config *config, const char *ca_path)
    {
    	return tls_set_string(&config->ca_path, ca_path);
    }
    
    int
    tls_config_set_ca_mem(struct tls_config *config, const uint8_t *ca, size_t len)
    {
    	return tls_set_mem(&config->ca_mem, &config->ca_len, ca, len);
    }
    
    int
    tls_config_set_cert_file(struct tls_config *config, const char *cert_file)
    {
    	return tls_keypair_set_cert_file(config->keypair, &config->error,
    	    cert_file);
    }
    
    int
    tls_config_set_cert_mem(struct tls_config *config, const uint8_t *cert,
        size_t len)
    {
    	return tls_keypair_set_cert_mem(config->keypair, &config->error,
    	    cert, len);
    }
    
    int
    tls_config_set_ciphers(struct tls_config *config, const char *ciphers)
    {
    	SSL_CTX *ssl_ctx = NULL;
    
    	if (ciphers == NULL ||
    	    strcasecmp(ciphers, "default") == 0 ||
    	    strcasecmp(ciphers, "secure") == 0)
    		ciphers = TLS_CIPHERS_DEFAULT;
    	else if (strcasecmp(ciphers, "compat") == 0)
    		ciphers = TLS_CIPHERS_COMPAT;
    	else if (strcasecmp(ciphers, "legacy") == 0)
    		ciphers = TLS_CIPHERS_LEGACY;
    	else if (strcasecmp(ciphers, "all") == 0 ||
    	    strcasecmp(ciphers, "insecure") == 0)
    		ciphers = TLS_CIPHERS_ALL;
    
    	if ((ssl_ctx = SSL_CTX_new(SSLv23_method())) == NULL) {
    		tls_config_set_errorx(config, "out of memory");
    		goto err;
    	}
    	if (SSL_CTX_set_cipher_list(ssl_ctx, ciphers) != 1) {
    		tls_config_set_errorx(config, "no ciphers for '%s'", ciphers);
    		goto err;
    	}
    
    	SSL_CTX_free(ssl_ctx);
    	return tls_set_string(&config->ciphers, ciphers);
    
     err:
    	SSL_CTX_free(ssl_ctx);
    	return -1;
    }
    
    int
    tls_config_set_crl_file(struct tls_config *config, const char *crl_file)
    {
    	return tls_config_load_file(&config->error, "CRL", crl_file,
    	    &config->crl_mem, &config->crl_len);
    }
    
    int
    tls_config_set_crl_mem(struct tls_config *config, const uint8_t *crl,
        size_t len)
    {
    	return tls_set_mem(&config->crl_mem, &config->crl_len, crl, len);
    }
    
    int
    tls_config_set_dheparams(struct tls_config *config, const char *params)
    {
    	int keylen;
    
    	if (params == NULL || strcasecmp(params, "none") == 0)
    		keylen = 0;
    	else if (strcasecmp(params, "auto") == 0)
    		keylen = -1;
    	else if (strcasecmp(params, "legacy") == 0)
    		keylen = 1024;
    	else {
    		tls_config_set_errorx(config, "invalid dhe param '%s'", params);
    		return (-1);
    	}
    
    	config->dheparams = keylen;
    
    	return (0);
    }
    
    int
    tls_config_set_ecdhecurve(struct tls_config *config, const char *curve)
    {
    	if (curve == NULL ||
    	    strcasecmp(curve, "none") == 0 ||
    	    strcasecmp(curve, "auto") == 0) {
    		curve = TLS_ECDHE_CURVES;
    	} else if (strchr(curve, ',') != NULL || strchr(curve, ':') != NULL) {
    		tls_config_set_errorx(config, "invalid ecdhe curve '%s'",
    		    curve);
    		return (-1);
    	}
    
    	return tls_config_set_ecdhecurves(config, curve);
    }
    
    int
    tls_config_set_ecdhecurves(struct tls_config *config, const char *curves)
    {
    	int *curves_list = NULL, *curves_new;
    	size_t curves_num = 0;
    	char *cs = NULL;
    	char *p, *q;
    	int rv = -1;
    	int nid;
    
    	free(config->ecdhecurves);
    	config->ecdhecurves = NULL;
    	config->ecdhecurves_len = 0;
    
    	if (curves == NULL || strcasecmp(curves, "default") == 0)
    		curves = TLS_ECDHE_CURVES;
    
    	if ((cs = strdup(curves)) == NULL) {
    		tls_config_set_errorx(config, "out of memory");
    		goto err;
    	}
    
    	q = cs;
    	while ((p = strsep(&q, ",:")) != NULL) {
    		while (*p == ' ' || *p == '\t')
    			p++;
    
    		nid = OBJ_sn2nid(p);
    		if (nid == NID_undef)
    			nid = OBJ_ln2nid(p);
    		if (nid == NID_undef)
    			nid = EC_curve_nist2nid(p);
    		if (nid == NID_undef) {
    			tls_config_set_errorx(config,
    			    "invalid ecdhe curve '%s'", p);
    			goto err;
    		}
    
    		if ((curves_new = reallocarray(curves_list, curves_num + 1,
    		    sizeof(int))) == NULL) {
    			tls_config_set_errorx(config, "out of memory");
    			goto err;
    		}
    		curves_list = curves_new;
    		curves_list[curves_num] = nid;
    		curves_num++;
    	}
    
    	config->ecdhecurves = curves_list;
    	config->ecdhecurves_len = curves_num;
    	curves_list = NULL;
    
    	rv = 0;
    
     err:
    	free(cs);
    	free(curves_list);
    
    	return (rv);
    }
    
    int
    tls_config_set_key_file(struct tls_config *config, const char *key_file)
    {
    	return tls_keypair_set_key_file(config->keypair, &config->error,
    	    key_file);
    }
    
    int
    tls_config_set_key_mem(struct tls_config *config, const uint8_t *key,
        size_t len)
    {
    	return tls_keypair_set_key_mem(config->keypair, &config->error,
    	    key, len);
    }
    
    static int
    tls_config_set_keypair_file_internal(struct tls_config *config,
        const char *cert_file, const char *key_file, const char *ocsp_file)
    {
    	if (tls_config_set_cert_file(config, cert_file) != 0)
    		return (-1);
    	if (tls_config_set_key_file(config, key_file) != 0)
    		return (-1);
    	if (ocsp_file != NULL &&
    	    tls_config_set_ocsp_staple_file(config, ocsp_file) != 0)
    		return (-1);
    
    	return (0);
    }
    
    static int
    tls_config_set_keypair_mem_internal(struct tls_config *config, const uint8_t *cert,
        size_t cert_len, const uint8_t *key, size_t key_len,
        const uint8_t *staple, size_t staple_len)
    {
    	if (tls_config_set_cert_mem(config, cert, cert_len) != 0)
    		return (-1);
    	if (tls_config_set_key_mem(config, key, key_len) != 0)
    		return (-1);
    	if ((staple != NULL) &&
    	    (tls_config_set_ocsp_staple_mem(config, staple, staple_len) != 0))
    		return (-1);
    
    	return (0);
    }
    
    int
    tls_config_set_keypair_file(struct tls_config *config,
        const char *cert_file, const char *key_file)
    {
    	return tls_config_set_keypair_file_internal(config, cert_file, key_file,
    	    NULL);
    }
    
    int
    tls_config_set_keypair_mem(struct tls_config *config, const uint8_t *cert,
        size_t cert_len, const uint8_t *key, size_t key_len)
    {
    	return tls_config_set_keypair_mem_internal(config, cert, cert_len,
    	    key, key_len, NULL, 0);
    }
    
    int
    tls_config_set_keypair_ocsp_file(struct tls_config *config,
        const char *cert_file, const char *key_file, const char *ocsp_file)
    {
    	return tls_config_set_keypair_file_internal(config, cert_file, key_file,
    	    ocsp_file);
    }
    
    int
    tls_config_set_keypair_ocsp_mem(struct tls_config *config, const uint8_t *cert,
        size_t cert_len, const uint8_t *key, size_t key_len,
        const uint8_t *staple, size_t staple_len)
    {
    	return tls_config_set_keypair_mem_internal(config, cert, cert_len,
    	    key, key_len, staple, staple_len);
    }
    
    
    int
    tls_config_set_protocols(struct tls_config *config, uint32_t protocols)
    {
    	config->protocols = protocols;
    
    	return (0);
    }
    
    int
    tls_config_set_session_fd(struct tls_config *config, int session_fd)
    {
    	struct stat sb;
    	mode_t mugo;
    
    	if (session_fd == -1) {
    		config->session_fd = session_fd;
    		return (0);
    	}
    
    	if (fstat(session_fd, &sb) == -1) {
    		tls_config_set_error(config, "failed to stat session file");
    		return (-1);
    	}
    	if (!S_ISREG(sb.st_mode)) {
    		tls_config_set_errorx(config,
    		    "session file is not a regular file");
    		return (-1);
    	}
    
    	if (sb.st_uid != getuid()) {
    		tls_config_set_errorx(config, "session file has incorrect "
    		    "owner (uid %u != %u)", sb.st_uid, getuid());
    		return (-1);
    	}
    	mugo = sb.st_mode & (S_IRWXU|S_IRWXG|S_IRWXO);
    	if (mugo != (S_IRUSR|S_IWUSR)) {
    		tls_config_set_errorx(config, "session file has incorrect "
    		    "permissions (%o != 600)", mugo);
    		return (-1);
    	}
    
    	config->session_fd = session_fd;
    
    	return (0);
    }
    
    int
    tls_config_set_verify_depth(struct tls_config *config, int verify_depth)
    {
    	config->verify_depth = verify_depth;
    
    	return (0);
    }
    
    void
    tls_config_prefer_ciphers_client(struct tls_config *config)
    {
    	config->ciphers_server = 0;
    }
    
    void
    tls_config_prefer_ciphers_server(struct tls_config *config)
    {
    	config->ciphers_server = 1;
    }
    
    void
    tls_config_insecure_noverifycert(struct tls_config *config)
    {
    	config->verify_cert = 0;
    }
    
    void
    tls_config_insecure_noverifyname(struct tls_config *config)
    {
    	config->verify_name = 0;
    }
    
    void
    tls_config_insecure_noverifytime(struct tls_config *config)
    {
    	config->verify_time = 0;
    }
    
    void
    tls_config_verify(struct tls_config *config)
    {
    	config->verify_cert = 1;
    	config->verify_name = 1;
    	config->verify_time = 1;
    }
    
    void
    tls_config_ocsp_require_stapling(struct tls_config *config)
    {
    	config->ocsp_require_stapling = 1;
    }
    
    void
    tls_config_verify_client(struct tls_config *config)
    {
    	config->verify_client = 1;
    }
    
    void
    tls_config_verify_client_optional(struct tls_config *config)
    {
    	config->verify_client = 2;
    }
    
    void
    tls_config_skip_private_key_check(struct tls_config *config)
    {
    	config->skip_private_key_check = 1;
    }
    
    void
    tls_config_use_fake_private_key(struct tls_config *config)
    {
    	config->use_fake_private_key = 1;
    	config->skip_private_key_check = 1;
    }
    
    int
    tls_config_set_ocsp_staple_file(struct tls_config *config, const char *staple_file)
    {
    	return tls_keypair_set_ocsp_staple_file(config->keypair, &config->error,
    	    staple_file);
    }
    
    int
    tls_config_set_ocsp_staple_mem(struct tls_config *config, const uint8_t *staple,
        size_t len)
    {
    	return tls_keypair_set_ocsp_staple_mem(config->keypair, &config->error,
    	    staple, len);
    }
    
    int
    tls_config_set_session_id(struct tls_config *config,
        const unsigned char *session_id, size_t len)
    {
    	if (len > TLS_MAX_SESSION_ID_LENGTH) {
    		tls_config_set_errorx(config, "session ID too large");
    		return (-1);
    	}
    	memset(config->session_id, 0, sizeof(config->session_id));
    	memcpy(config->session_id, session_id, len);
    	return (0);
    }
    
    int
    tls_config_set_session_lifetime(struct tls_config *config, int lifetime)
    {
    	if (lifetime > TLS_MAX_SESSION_TIMEOUT) {
    		tls_config_set_errorx(config, "session lifetime too large");
    		return (-1);
    	}
    	if (lifetime != 0 && lifetime < TLS_MIN_SESSION_TIMEOUT) {
    		tls_config_set_errorx(config, "session lifetime too small");
    		return (-1);
    	}
    
    	config->session_lifetime = lifetime;
    	return (0);
    }
    
    int
    tls_config_add_ticket_key(struct tls_config *config, uint32_t keyrev,
        unsigned char *key, size_t keylen)
    {
    	struct tls_ticket_key newkey;
    	int i;
    
    	if (TLS_TICKET_KEY_SIZE != keylen ||
    	    sizeof(newkey.aes_key) + sizeof(newkey.hmac_key) > keylen) {
    		tls_config_set_errorx(config,
    		    "wrong amount of ticket key data");
    		return (-1);
    	}
    
    	keyrev = htonl(keyrev);
    	memset(&newkey, 0, sizeof(newkey));
    	memcpy(newkey.key_name, &keyrev, sizeof(keyrev));
    	memcpy(newkey.aes_key, key, sizeof(newkey.aes_key));
    	memcpy(newkey.hmac_key, key + sizeof(newkey.aes_key),
    	    sizeof(newkey.hmac_key));
    	newkey.time = time(NULL);
    
    	for (i = 0; i < TLS_NUM_TICKETS; i++) {
    		struct tls_ticket_key *tk = &config->ticket_keys[i];
    		if (memcmp(newkey.key_name, tk->key_name,
    		    sizeof(tk->key_name)) != 0)
    			continue;
    
    		/* allow re-entry of most recent key */
    		if (i == 0 && memcmp(newkey.aes_key, tk->aes_key,
    		    sizeof(tk->aes_key)) == 0 && memcmp(newkey.hmac_key,
    		    tk->hmac_key, sizeof(tk->hmac_key)) == 0)
    			return (0);
    		tls_config_set_errorx(config, "ticket key already present");
    		return (-1);
    	}
    
    	memmove(&config->ticket_keys[1], &config->ticket_keys[0],
    	    sizeof(config->ticket_keys) - sizeof(config->ticket_keys[0]));
    	config->ticket_keys[0] = newkey;
    
    	config->ticket_autorekey = 0;
    
    	return (0);
    }
    
    int
    tls_config_ticket_autorekey(struct tls_config *config)
    {
    	unsigned char key[TLS_TICKET_KEY_SIZE];
    	int rv;
    
    	arc4random_buf(key, sizeof(key));
    	rv = tls_config_add_ticket_key(config, config->ticket_keyrev++, key,
    	    sizeof(key));
    	config->ticket_autorekey = 1;
    	return (rv);
    }