gmid/compat/libtls/tls_config.c
Omar Polo f9ab77a898 bundle libtls
gmid (like all other daemons that want to do privsep crypto) has a
very close relationship with libtls and need to stay in sync with
it.

OpenBSD' libtls was recently changed to use OpenSSL' EC_KEY_METHOD
instead of the older ECDSA_METHOD, on the gmid side we have to do
the same otherwise failures happens at runtime.  In a similar manner,
privsep crypto is silently broken in the current libretls (next
version should fix it.)

The proper solution would be to complete the signer APIs so that
applications don't need to dive into the library' internals, but
that's a mid-term goal, for the immediate bundling the 'little'
libtls is the lesser evil.

The configure script has gained a new (undocumented for the time
being) flag `--with-libtls=bundled|system' to control which libtls
to use.  It defaults to `bundled' except for OpenBSD where it uses
the `system' one.  Note that OpenBSD versions before 7.3 (inclusive)
ought to use --with-libtls=bundled too since they still do ECDSA_METHOD.
2023-08-23 17:38:49 +00:00

916 lines
20 KiB
C

/* $OpenBSD: tls_config.c,v 1.66 2023/05/14 07:26:25 op 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 "config.h"
#include <sys/stat.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <tls.h>
#include "tls_internal.h"
const char *
tls_default_ca_cert_file(void)
{
#ifdef OPENSMTPD_CA_FILE
return OPENSMTPD_CA_FILE;
#else
return X509_get_default_cert_file();
#endif
}
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);
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;
refcount = --config->refcount;
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);
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);
}