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third-party-mirror / openvpn / ac2da300dcd4eb79b146e91455cca2c610f394fa / . / src / openvpn / ssl_openssl.c
blob: 7b06beb7c7dd34072de681d1f5d8f0247466c559 [file] [log] [blame]
/*
* OpenVPN -- An application to securely tunnel IP networks
* over a single TCP/UDP port, with support for SSL/TLS-based
* session authentication and key exchange,
* packet encryption, packet authentication, and
* packet compression.
*
* Copyright (C) 2002-2018 OpenVPN Inc <sales@openvpn.net>
* Copyright (C) 2010-2018 Fox Crypto B.V. <openvpn@fox-it.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
/**
* @file Control Channel OpenSSL Backend
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#elif defined(_MSC_VER)
#include "config-msvc.h"
#endif
#include "syshead.h"
#if defined(ENABLE_CRYPTO_OPENSSL)
#include "errlevel.h"
#include "buffer.h"
#include "misc.h"
#include "manage.h"
#include "memdbg.h"
#include "ssl_backend.h"
#include "ssl_common.h"
#include "base64.h"
#include "openssl_compat.h"
#ifdef ENABLE_CRYPTOAPI
#include "cryptoapi.h"
#endif
#include "ssl_verify_openssl.h"
#include <openssl/bn.h>
#include <openssl/crypto.h>
#include <openssl/dh.h>
#include <openssl/dsa.h>
#include <openssl/err.h>
#include <openssl/pkcs12.h>
#include <openssl/rsa.h>
#include <openssl/x509.h>
#include <openssl/ssl.h>
#ifndef OPENSSL_NO_EC
#include <openssl/ec.h>
#endif
/*
* Allocate space in SSL objects in which to store a struct tls_session
* pointer back to parent.
*
*/
int mydata_index; /* GLOBAL */
void
tls_init_lib(void)
{
#if (OPENSSL_VERSION_NUMBER < 0x10100000L && !defined(LIBRESSL_VERSION_NUMBER))
SSL_library_init();
#ifndef ENABLE_SMALL
SSL_load_error_strings();
#endif
OpenSSL_add_all_algorithms();
#endif
mydata_index = SSL_get_ex_new_index(0, "struct session *", NULL, NULL, NULL);
ASSERT(mydata_index >= 0);
}
void
tls_free_lib(void)
{
#if (OPENSSL_VERSION_NUMBER < 0x10100000L && !defined(LIBRESSL_VERSION_NUMBER))
EVP_cleanup();
#ifndef ENABLE_SMALL
ERR_free_strings();
#endif
#endif
}
void
tls_clear_error(void)
{
ERR_clear_error();
}
void
tls_ctx_server_new(struct tls_root_ctx *ctx)
{
ASSERT(NULL != ctx);
ctx->ctx = SSL_CTX_new(SSLv23_server_method());
if (ctx->ctx == NULL)
{
crypto_msg(M_FATAL, "SSL_CTX_new SSLv23_server_method");
}
if (ERR_peek_error() != 0)
{
crypto_msg(M_WARN, "Warning: TLS server context initialisation "
"has warnings.");
}
}
void
tls_ctx_client_new(struct tls_root_ctx *ctx)
{
ASSERT(NULL != ctx);
ctx->ctx = SSL_CTX_new(SSLv23_client_method());
if (ctx->ctx == NULL)
{
crypto_msg(M_FATAL, "SSL_CTX_new SSLv23_client_method");
}
if (ERR_peek_error() != 0)
{
crypto_msg(M_WARN, "Warning: TLS client context initialisation "
"has warnings.");
}
}
void
tls_ctx_free(struct tls_root_ctx *ctx)
{
ASSERT(NULL != ctx);
if (NULL != ctx->ctx)
{
SSL_CTX_free(ctx->ctx);
}
ctx->ctx = NULL;
}
bool
tls_ctx_initialised(struct tls_root_ctx *ctx)
{
ASSERT(NULL != ctx);
return NULL != ctx->ctx;
}
void
key_state_export_keying_material(struct key_state_ssl *ssl,
struct tls_session *session)
{
if (session->opt->ekm_size > 0)
{
unsigned int size = session->opt->ekm_size;
struct gc_arena gc = gc_new();
unsigned char *ekm = (unsigned char *) gc_malloc(size, true, &gc);
if (SSL_export_keying_material(ssl->ssl, ekm, size,
session->opt->ekm_label,
session->opt->ekm_label_size,
NULL, 0, 0))
{
unsigned int len = (size * 2) + 2;
const char *key = format_hex_ex(ekm, size, len, 0, NULL, &gc);
setenv_str(session->opt->es, "exported_keying_material", key);
dmsg(D_TLS_DEBUG_MED, "%s: exported keying material: %s",
__func__, key);
}
else
{
msg(M_WARN, "WARNING: Export keying material failed!");
setenv_del(session->opt->es, "exported_keying_material");
}
gc_free(&gc);
}
}
/*
* Print debugging information on SSL/TLS session negotiation.
*/
#ifndef INFO_CALLBACK_SSL_CONST
#define INFO_CALLBACK_SSL_CONST const
#endif
static void
info_callback(INFO_CALLBACK_SSL_CONST SSL *s, int where, int ret)
{
if (where & SSL_CB_LOOP)
{
dmsg(D_HANDSHAKE_VERBOSE, "SSL state (%s): %s",
where & SSL_ST_CONNECT ? "connect" :
where &SSL_ST_ACCEPT ? "accept" :
"undefined", SSL_state_string_long(s));
}
else if (where & SSL_CB_ALERT)
{
dmsg(D_HANDSHAKE_VERBOSE, "SSL alert (%s): %s: %s",
where & SSL_CB_READ ? "read" : "write",
SSL_alert_type_string_long(ret),
SSL_alert_desc_string_long(ret));
}
}
/*
* Return maximum TLS version supported by local OpenSSL library.
* Assume that presence of SSL_OP_NO_TLSvX macro indicates that
* TLSvX is supported.
*/
int
tls_version_max(void)
{
#if defined(TLS1_3_VERSION)
/* If this is defined we can safely assume TLS 1.3 support */
return TLS_VER_1_3;
#elif OPENSSL_VERSION_NUMBER >= 0x10100000L
/*
* If TLS_VER_1_3 is not defined, we were compiled against a version that
* did not support TLS 1.3.
*
* However, the library we are *linked* against might be OpenSSL 1.1.1
* and therefore supports TLS 1.3. This needs to be checked at runtime
* since we can be compiled against 1.1.0 and then the library can be
* upgraded to 1.1.1.
* We only need to check this for OpenSSL versions that can be
* upgraded to 1.1.1 without recompile (>= 1.1.0)
*/
if (OpenSSL_version_num() >= 0x1010100fL)
{
return TLS_VER_1_3;
}
else
{
return TLS_VER_1_2;
}
#elif defined(TLS1_2_VERSION) || defined(SSL_OP_NO_TLSv1_2)
return TLS_VER_1_2;
#elif defined(TLS1_1_VERSION) || defined(SSL_OP_NO_TLSv1_1)
return TLS_VER_1_1;
#else /* if defined(TLS1_3_VERSION) */
return TLS_VER_1_0;
#endif
}
/** Convert internal version number to openssl version number */
static int
openssl_tls_version(int ver)
{
if (ver == TLS_VER_1_0)
{
return TLS1_VERSION;
}
else if (ver == TLS_VER_1_1)
{
return TLS1_1_VERSION;
}
else if (ver == TLS_VER_1_2)
{
return TLS1_2_VERSION;
}
else if (ver == TLS_VER_1_3)
{
/*
* Supporting the library upgraded to TLS1.3 without recompile
* is enough to support here with a simple constant that the same
* as in the TLS 1.3, so spec it is very unlikely that OpenSSL
* will change this constant
*/
#ifndef TLS1_3_VERSION
/*
* We do not want to define TLS_VER_1_3 if not defined
* since other parts of the code use the existance of this macro
* as proxy for TLS 1.3 support
*/
return 0x0304;
#else
return TLS1_3_VERSION;
#endif
}
return 0;
}
static bool
tls_ctx_set_tls_versions(struct tls_root_ctx *ctx, unsigned int ssl_flags)
{
int tls_ver_min = openssl_tls_version(
(ssl_flags >> SSLF_TLS_VERSION_MIN_SHIFT) & SSLF_TLS_VERSION_MIN_MASK);
int tls_ver_max = openssl_tls_version(
(ssl_flags >> SSLF_TLS_VERSION_MAX_SHIFT) & SSLF_TLS_VERSION_MAX_MASK);
if (!tls_ver_min)
{
/* Enforce at least TLS 1.0 */
int cur_min = SSL_CTX_get_min_proto_version(ctx->ctx);
tls_ver_min = cur_min < TLS1_VERSION ? TLS1_VERSION : cur_min;
}
if (!SSL_CTX_set_min_proto_version(ctx->ctx, tls_ver_min))
{
msg(D_TLS_ERRORS, "%s: failed to set minimum TLS version", __func__);
return false;
}
if (tls_ver_max && !SSL_CTX_set_max_proto_version(ctx->ctx, tls_ver_max))
{
msg(D_TLS_ERRORS, "%s: failed to set maximum TLS version", __func__);
return false;
}
return true;
}
bool
tls_ctx_set_options(struct tls_root_ctx *ctx, unsigned int ssl_flags)
{
ASSERT(NULL != ctx);
/* process SSL options */
long sslopt = SSL_OP_SINGLE_DH_USE | SSL_OP_NO_TICKET;
#ifdef SSL_OP_CIPHER_SERVER_PREFERENCE
sslopt |= SSL_OP_CIPHER_SERVER_PREFERENCE;
#endif
sslopt |= SSL_OP_NO_COMPRESSION;
/* Disable TLS renegotiations. OpenVPN's renegotiation creates new SSL
* session and does not depend on this feature. And TLS renegotiations have
* been problematic in the past */
#ifdef SSL_OP_NO_RENEGOTIATION
sslopt |= SSL_OP_NO_RENEGOTIATION;
#endif
SSL_CTX_set_options(ctx->ctx, sslopt);
if (!tls_ctx_set_tls_versions(ctx, ssl_flags))
{
return false;
}
#ifdef SSL_MODE_RELEASE_BUFFERS
SSL_CTX_set_mode(ctx->ctx, SSL_MODE_RELEASE_BUFFERS);
#endif
SSL_CTX_set_session_cache_mode(ctx->ctx, SSL_SESS_CACHE_OFF);
SSL_CTX_set_default_passwd_cb(ctx->ctx, pem_password_callback);
/* Require peer certificate verification */
int verify_flags = SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT;
if (ssl_flags & SSLF_CLIENT_CERT_NOT_REQUIRED)
{
verify_flags = 0;
}
else if (ssl_flags & SSLF_CLIENT_CERT_OPTIONAL)
{
verify_flags = SSL_VERIFY_PEER;
}
SSL_CTX_set_verify(ctx->ctx, verify_flags, verify_callback);
SSL_CTX_set_info_callback(ctx->ctx, info_callback);
return true;
}
void
convert_tls_list_to_openssl(char *openssl_ciphers, size_t len,const char *ciphers)
{
/* Parse supplied cipher list and pass on to OpenSSL */
size_t begin_of_cipher, end_of_cipher;
const char *current_cipher;
size_t current_cipher_len;
const tls_cipher_name_pair *cipher_pair;
size_t openssl_ciphers_len = 0;
openssl_ciphers[0] = '\0';
/* Translate IANA cipher suite names to OpenSSL names */
begin_of_cipher = end_of_cipher = 0;
for (; begin_of_cipher < strlen(ciphers); begin_of_cipher = end_of_cipher)
{
end_of_cipher += strcspn(&ciphers[begin_of_cipher], ":");
cipher_pair = tls_get_cipher_name_pair(&ciphers[begin_of_cipher], end_of_cipher - begin_of_cipher);
if (NULL == cipher_pair)
{
/* No translation found, use original */
current_cipher = &ciphers[begin_of_cipher];
current_cipher_len = end_of_cipher - begin_of_cipher;
/* Issue warning on missing translation */
/* %.*s format specifier expects length of type int, so guarantee */
/* that length is small enough and cast to int. */
msg(D_LOW, "No valid translation found for TLS cipher '%.*s'",
constrain_int(current_cipher_len, 0, 256), current_cipher);
}
else
{
/* Use OpenSSL name */
current_cipher = cipher_pair->openssl_name;
current_cipher_len = strlen(current_cipher);
if (end_of_cipher - begin_of_cipher == current_cipher_len
&& 0 != memcmp(&ciphers[begin_of_cipher], cipher_pair->iana_name,
end_of_cipher - begin_of_cipher))
{
/* Non-IANA name used, show warning */
msg(M_WARN, "Deprecated TLS cipher name '%s', please use IANA name '%s'", cipher_pair->openssl_name, cipher_pair->iana_name);
}
}
/* Make sure new cipher name fits in cipher string */
if ((SIZE_MAX - openssl_ciphers_len) < current_cipher_len
|| (len - 1) < (openssl_ciphers_len + current_cipher_len))
{
msg(M_FATAL,
"Failed to set restricted TLS cipher list, too long (>%d).",
(int)(len - 1));
}
/* Concatenate cipher name to OpenSSL cipher string */
memcpy(&openssl_ciphers[openssl_ciphers_len], current_cipher, current_cipher_len);
openssl_ciphers_len += current_cipher_len;
openssl_ciphers[openssl_ciphers_len] = ':';
openssl_ciphers_len++;
end_of_cipher++;
}
if (openssl_ciphers_len > 0)
{
openssl_ciphers[openssl_ciphers_len-1] = '\0';
}
}
void
tls_ctx_restrict_ciphers(struct tls_root_ctx *ctx, const char *ciphers)
{
if (ciphers == NULL)
{
/* Use sane default TLS cipher list */
if (!SSL_CTX_set_cipher_list(ctx->ctx,
/* Use openssl's default list as a basis */
"DEFAULT"
/* Disable export ciphers and openssl's 'low' and 'medium' ciphers */
":!EXP:!LOW:!MEDIUM"
/* Disable static (EC)DH keys (no forward secrecy) */
":!kDH:!kECDH"
/* Disable DSA private keys */
":!DSS"
/* Disable unsupported TLS modes */
":!PSK:!SRP:!kRSA"))
{
crypto_msg(M_FATAL, "Failed to set default TLS cipher list.");
}
return;
}
char openssl_ciphers[4096];
convert_tls_list_to_openssl(openssl_ciphers, sizeof(openssl_ciphers), ciphers);
ASSERT(NULL != ctx);
/* Set OpenSSL cipher list */
if (!SSL_CTX_set_cipher_list(ctx->ctx, openssl_ciphers))
{
crypto_msg(M_FATAL, "Failed to set restricted TLS cipher list: %s", openssl_ciphers);
}
}
void
convert_tls13_list_to_openssl(char *openssl_ciphers, size_t len,
const char *ciphers)
{
/*
* OpenSSL (and official IANA) cipher names have _ in them. We
* historically used names with - in them. Silently convert names
* with - to names with _ to support both
*/
if (strlen(ciphers) >= (len - 1))
{
msg(M_FATAL,
"Failed to set restricted TLS 1.3 cipher list, too long (>%d).",
(int) (len - 1));
}
strncpy(openssl_ciphers, ciphers, len);
for (size_t i = 0; i < strlen(openssl_ciphers); i++)
{
if (openssl_ciphers[i] == '-')
{
openssl_ciphers[i] = '_';
}
}
}
void
tls_ctx_restrict_ciphers_tls13(struct tls_root_ctx *ctx, const char *ciphers)
{
if (ciphers == NULL)
{
/* default cipher list of OpenSSL 1.1.1 is sane, do not set own
* default as we do with tls-cipher */
return;
}
#if !defined(TLS1_3_VERSION)
crypto_msg(M_WARN, "Not compiled with OpenSSL 1.1.1 or higher. "
"Ignoring TLS 1.3 only tls-ciphersuites '%s' setting.",
ciphers);
#else
ASSERT(NULL != ctx);
char openssl_ciphers[4096];
convert_tls13_list_to_openssl(openssl_ciphers, sizeof(openssl_ciphers),
ciphers);
if (!SSL_CTX_set_ciphersuites(ctx->ctx, openssl_ciphers))
{
crypto_msg(M_FATAL, "Failed to set restricted TLS 1.3 cipher list: %s",
openssl_ciphers);
}
#endif
}
void
tls_ctx_set_cert_profile(struct tls_root_ctx *ctx, const char *profile)
{
#ifdef HAVE_SSL_CTX_SET_SECURITY_LEVEL
/* OpenSSL does not have certificate profiles, but a complex set of
* callbacks that we could try to implement to achieve something similar.
* For now, use OpenSSL's security levels to achieve similar (but not equal)
* behaviour. */
if (!profile || 0 == strcmp(profile, "legacy"))
{
SSL_CTX_set_security_level(ctx->ctx, 1);
}
else if (0 == strcmp(profile, "preferred"))
{
SSL_CTX_set_security_level(ctx->ctx, 2);
}
else if (0 == strcmp(profile, "suiteb"))
{
SSL_CTX_set_security_level(ctx->ctx, 3);
SSL_CTX_set_cipher_list(ctx->ctx, "SUITEB128");
}
else
{
msg(M_FATAL, "ERROR: Invalid cert profile: %s", profile);
}
#else /* ifdef HAVE_SSL_CTX_SET_SECURITY_LEVEL */
if (profile)
{
msg(M_WARN, "WARNING: OpenSSL 1.0.2 does not support --tls-cert-profile"
", ignoring user-set profile: '%s'", profile);
}
#endif /* ifdef HAVE_SSL_CTX_SET_SECURITY_LEVEL */
}
void
tls_ctx_set_tls_groups(struct tls_root_ctx *ctx, const char *groups)
{
ASSERT(ctx);
struct gc_arena gc = gc_new();
/* This method could be as easy as
* SSL_CTX_set1_groups_list(ctx->ctx, groups)
* but OpenSSL does not like the name secp256r1 for prime256v1
* This is one of the important curves.
* To support the same name for OpenSSL and mbedTLS, we do
* this dance.
*/
int groups_count = get_num_elements(groups, ':');
int *glist;
/* Allocate an array for them */
ALLOC_ARRAY_CLEAR_GC(glist, int, groups_count, &gc);
/* Parse allowed ciphers, getting IDs */
int glistlen = 0;
char *tmp_groups = string_alloc(groups, &gc);
const char *token;
while ((token = strsep(&tmp_groups, ":")))
{
if (streq(token, "secp256r1"))
{
token = "prime256v1";
}
int nid = OBJ_sn2nid(token);
if (nid == 0)
{
msg(M_WARN, "Warning unknown curve/group specified: %s", token);
}
else
{
glist[glistlen] = nid;
glistlen++;
}
}
if (!SSL_CTX_set1_groups(ctx->ctx, glist, glistlen))
{
crypto_msg(M_FATAL, "Failed to set allowed TLS group list: %s",
groups);
}
gc_free(&gc);
}
void
tls_ctx_check_cert_time(const struct tls_root_ctx *ctx)
{
int ret;
const X509 *cert;
ASSERT(ctx);
cert = SSL_CTX_get0_certificate(ctx->ctx);
if (cert == NULL)
{
return; /* Nothing to check if there is no certificate */
}
ret = X509_cmp_time(X509_get0_notBefore(cert), NULL);
if (ret == 0)
{
msg(D_TLS_DEBUG_MED, "Failed to read certificate notBefore field.");
}
if (ret > 0)
{
msg(M_WARN, "WARNING: Your certificate is not yet valid!");
}
ret = X509_cmp_time(X509_get0_notAfter(cert), NULL);
if (ret == 0)
{
msg(D_TLS_DEBUG_MED, "Failed to read certificate notAfter field.");
}
if (ret < 0)
{
msg(M_WARN, "WARNING: Your certificate has expired!");
}
}
void
tls_ctx_load_dh_params(struct tls_root_ctx *ctx, const char *dh_file,
bool dh_file_inline)
{
DH *dh;
BIO *bio;
ASSERT(NULL != ctx);
if (dh_file_inline)
{
if (!(bio = BIO_new_mem_buf((char *)dh_file, -1)))
{
crypto_msg(M_FATAL, "Cannot open memory BIO for inline DH parameters");
}
}
else
{
/* Get Diffie Hellman Parameters */
if (!(bio = BIO_new_file(dh_file, "r")))
{
crypto_msg(M_FATAL, "Cannot open %s for DH parameters", dh_file);
}
}
dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL);
BIO_free(bio);
if (!dh)
{
crypto_msg(M_FATAL, "Cannot load DH parameters from %s",
print_key_filename(dh_file, dh_file_inline));
}
if (!SSL_CTX_set_tmp_dh(ctx->ctx, dh))
{
crypto_msg(M_FATAL, "SSL_CTX_set_tmp_dh");
}
msg(D_TLS_DEBUG_LOW, "Diffie-Hellman initialized with %d bit key",
8 * DH_size(dh));
DH_free(dh);
}
void
tls_ctx_load_ecdh_params(struct tls_root_ctx *ctx, const char *curve_name
)
{
#ifndef OPENSSL_NO_EC
int nid = NID_undef;
EC_KEY *ecdh = NULL;
const char *sname = NULL;
/* Generate a new ECDH key for each SSL session (for non-ephemeral ECDH) */
SSL_CTX_set_options(ctx->ctx, SSL_OP_SINGLE_ECDH_USE);
if (curve_name != NULL)
{
/* Use user supplied curve if given */
msg(D_TLS_DEBUG, "Using user specified ECDH curve (%s)", curve_name);
nid = OBJ_sn2nid(curve_name);
}
else
{
#if (OPENSSL_VERSION_NUMBER < 0x10100000L && !defined(LIBRESSL_VERSION_NUMBER))
/* OpenSSL 1.0.2 and newer can automatically handle ECDH parameter
* loading */
SSL_CTX_set_ecdh_auto(ctx->ctx, 1);
/* OpenSSL 1.1.0 and newer have always ecdh auto loading enabled,
* so do nothing */
#endif
return;
}
/* Translate NID back to name , just for kicks */
sname = OBJ_nid2sn(nid);
if (sname == NULL)
{
sname = "(Unknown)";
}
/* Create new EC key and set as ECDH key */
if (NID_undef == nid || NULL == (ecdh = EC_KEY_new_by_curve_name(nid)))
{
/* Creating key failed, fall back on sane default */
ecdh = EC_KEY_new_by_curve_name(NID_secp384r1);
const char *source = (NULL == curve_name) ?
"extract curve from certificate" : "use supplied curve";
msg(D_TLS_DEBUG_LOW,
"Failed to %s (%s), using secp384r1 instead.", source, sname);
sname = OBJ_nid2sn(NID_secp384r1);
}
if (!SSL_CTX_set_tmp_ecdh(ctx->ctx, ecdh))
{
crypto_msg(M_FATAL, "SSL_CTX_set_tmp_ecdh: cannot add curve");
}
msg(D_TLS_DEBUG_LOW, "ECDH curve %s added", sname);
EC_KEY_free(ecdh);
#else /* ifndef OPENSSL_NO_EC */
msg(D_LOW, "Your OpenSSL library was built without elliptic curve support."
" Skipping ECDH parameter loading.");
#endif /* OPENSSL_NO_EC */
}
int
tls_ctx_load_pkcs12(struct tls_root_ctx *ctx, const char *pkcs12_file,
bool pkcs12_file_inline, bool load_ca_file)
{
FILE *fp;
EVP_PKEY *pkey;
X509 *cert;
STACK_OF(X509) *ca = NULL;
PKCS12 *p12;
int i;
char password[256];
ASSERT(NULL != ctx);
if (pkcs12_file_inline)
{
BIO *b64 = BIO_new(BIO_f_base64());
BIO *bio = BIO_new_mem_buf((void *) pkcs12_file,
(int) strlen(pkcs12_file));
ASSERT(b64 && bio);
BIO_push(b64, bio);
p12 = d2i_PKCS12_bio(b64, NULL);
if (!p12)
{
crypto_msg(M_FATAL, "Error reading inline PKCS#12 file");
}
BIO_free(b64);
BIO_free(bio);
}
else
{
/* Load the PKCS #12 file */
if (!(fp = platform_fopen(pkcs12_file, "rb")))
{
crypto_msg(M_FATAL, "Error opening file %s", pkcs12_file);
}
p12 = d2i_PKCS12_fp(fp, NULL);
fclose(fp);
if (!p12)
{
crypto_msg(M_FATAL, "Error reading PKCS#12 file %s", pkcs12_file);
}
}
/* Parse the PKCS #12 file */
if (!PKCS12_parse(p12, "", &pkey, &cert, &ca))
{
pem_password_callback(password, sizeof(password) - 1, 0, NULL);
/* Reparse the PKCS #12 file with password */
ca = NULL;
if (!PKCS12_parse(p12, password, &pkey, &cert, &ca))
{
#ifdef ENABLE_MANAGEMENT
if (management && (ERR_GET_REASON(ERR_peek_error()) == PKCS12_R_MAC_VERIFY_FAILURE))
{
management_auth_failure(management, UP_TYPE_PRIVATE_KEY, NULL);
}
#endif
PKCS12_free(p12);
return 1;
}
}
PKCS12_free(p12);
/* Load Certificate */
if (!SSL_CTX_use_certificate(ctx->ctx, cert))
{
crypto_msg(M_FATAL, "Cannot use certificate");
}
/* Load Private Key */
if (!SSL_CTX_use_PrivateKey(ctx->ctx, pkey))
{
crypto_msg(M_FATAL, "Cannot use private key");
}
/* Check Private Key */
if (!SSL_CTX_check_private_key(ctx->ctx))
{
crypto_msg(M_FATAL, "Private key does not match the certificate");
}
/* Set Certificate Verification chain */
if (load_ca_file)
{
/* Add CAs from PKCS12 to the cert store and mark them as trusted.
* They're also used to fill in the chain of intermediate certs as
* necessary.
*/
if (ca && sk_X509_num(ca))
{
for (i = 0; i < sk_X509_num(ca); i++)
{
X509_STORE *cert_store = SSL_CTX_get_cert_store(ctx->ctx);
if (!X509_STORE_add_cert(cert_store,sk_X509_value(ca, i)))
{
crypto_msg(M_FATAL,"Cannot add certificate to certificate chain (X509_STORE_add_cert)");
}
if (!SSL_CTX_add_client_CA(ctx->ctx, sk_X509_value(ca, i)))
{
crypto_msg(M_FATAL,"Cannot add certificate to client CA list (SSL_CTX_add_client_CA)");
}
}
}
}
else
{
/* If trusted CA certs were loaded from a PEM file, and we ignore the
* ones in PKCS12, do load PKCS12-provided certs to the client extra
* certs chain just in case they include intermediate CAs needed to
* prove my identity to the other end. This does not make them trusted.
*/
if (ca && sk_X509_num(ca))
{
for (i = 0; i < sk_X509_num(ca); i++)
{
if (!SSL_CTX_add_extra_chain_cert(ctx->ctx,sk_X509_value(ca, i)))
{
crypto_msg(M_FATAL, "Cannot add extra certificate to chain (SSL_CTX_add_extra_chain_cert)");
}
}
}
}
return 0;
}
#ifdef ENABLE_CRYPTOAPI
void
tls_ctx_load_cryptoapi(struct tls_root_ctx *ctx, const char *cryptoapi_cert)
{
ASSERT(NULL != ctx);
/* Load Certificate and Private Key */
if (!SSL_CTX_use_CryptoAPI_certificate(ctx->ctx, cryptoapi_cert))
{
crypto_msg(M_FATAL, "Cannot load certificate \"%s\" from Microsoft Certificate Store", cryptoapi_cert);
}
}
#endif /* ENABLE_CRYPTOAPI */
static void
tls_ctx_add_extra_certs(struct tls_root_ctx *ctx, BIO *bio, bool optional)
{
X509 *cert;
while (true)
{
cert = NULL;
if (!PEM_read_bio_X509(bio, &cert, NULL, NULL))
{
/* a PEM_R_NO_START_LINE "Error" indicates that no certificate
* is found in the buffer. If loading more certificates is
* optional, break without raising an error
*/
if (optional
&& ERR_GET_REASON(ERR_peek_error()) == PEM_R_NO_START_LINE)
{
/* remove that error from error stack */
(void)ERR_get_error();
break;
}
/* Otherwise, bail out with error */
crypto_msg(M_FATAL, "Error reading extra certificate");
}
/* takes ownership of cert like a set1 method */
if (SSL_CTX_add_extra_chain_cert(ctx->ctx, cert) != 1)
{
crypto_msg(M_FATAL, "Error adding extra certificate");
}
/* We loaded at least one certificate, so loading more is optional */
optional = true;
}
}
void
tls_ctx_load_cert_file(struct tls_root_ctx *ctx, const char *cert_file,
bool cert_file_inline)
{
BIO *in = NULL;
X509 *x = NULL;
int ret = 0;
ASSERT(NULL != ctx);
if (cert_file_inline)
{
in = BIO_new_mem_buf((char *) cert_file, -1);
}
else
{
in = BIO_new_file(cert_file, "r");
}
if (in == NULL)
{
SSLerr(SSL_F_SSL_CTX_USE_CERTIFICATE_FILE, ERR_R_SYS_LIB);
goto end;
}
x = PEM_read_bio_X509(in, NULL,
SSL_CTX_get_default_passwd_cb(ctx->ctx),
SSL_CTX_get_default_passwd_cb_userdata(ctx->ctx));
if (x == NULL)
{
SSLerr(SSL_F_SSL_CTX_USE_CERTIFICATE_FILE, ERR_R_PEM_LIB);
goto end;
}
ret = SSL_CTX_use_certificate(ctx->ctx, x);
if (ret)
{
tls_ctx_add_extra_certs(ctx, in, true);
}
end:
if (!ret)
{
if (cert_file_inline)
{
crypto_msg(M_FATAL, "Cannot load inline certificate file");
}
else
{
crypto_msg(M_FATAL, "Cannot load certificate file %s", cert_file);
}
}
else
{
crypto_print_openssl_errors(M_DEBUG);
}
if (in != NULL)
{
BIO_free(in);
}
if (x)
{
X509_free(x);
}
}
int
tls_ctx_load_priv_file(struct tls_root_ctx *ctx, const char *priv_key_file,
bool priv_key_file_inline)
{
SSL_CTX *ssl_ctx = NULL;
BIO *in = NULL;
EVP_PKEY *pkey = NULL;
int ret = 1;
ASSERT(NULL != ctx);
ssl_ctx = ctx->ctx;
if (priv_key_file_inline)
{
in = BIO_new_mem_buf((char *) priv_key_file, -1);
}
else
{
in = BIO_new_file(priv_key_file, "r");
}
if (!in)
{
goto end;
}
pkey = PEM_read_bio_PrivateKey(in, NULL,
SSL_CTX_get_default_passwd_cb(ctx->ctx),
SSL_CTX_get_default_passwd_cb_userdata(ctx->ctx));
if (!pkey)
{
pkey = engine_load_key(priv_key_file, ctx->ctx);
}
if (!pkey || !SSL_CTX_use_PrivateKey(ssl_ctx, pkey))
{
#ifdef ENABLE_MANAGEMENT
if (management && (ERR_GET_REASON(ERR_peek_error()) == EVP_R_BAD_DECRYPT))
{
management_auth_failure(management, UP_TYPE_PRIVATE_KEY, NULL);
}
#endif
crypto_msg(M_WARN, "Cannot load private key file %s",
print_key_filename(priv_key_file, priv_key_file_inline));
goto end;
}
/* Check Private Key */
if (!SSL_CTX_check_private_key(ssl_ctx))
{
crypto_msg(M_FATAL, "Private key does not match the certificate");
}
ret = 0;
end:
if (pkey)
{
EVP_PKEY_free(pkey);
}
if (in)
{
BIO_free(in);
}
return ret;
}
void
backend_tls_ctx_reload_crl(struct tls_root_ctx *ssl_ctx, const char *crl_file,
bool crl_inline)
{
BIO *in = NULL;
X509_STORE *store = SSL_CTX_get_cert_store(ssl_ctx->ctx);
if (!store)
{
crypto_msg(M_FATAL, "Cannot get certificate store");
}
/* Always start with a cleared CRL list, for that we
* we need to manually find the CRL object from the stack
* and remove it */
STACK_OF(X509_OBJECT) *objs = X509_STORE_get0_objects(store);
for (int i = 0; i < sk_X509_OBJECT_num(objs); i++)
{
X509_OBJECT *obj = sk_X509_OBJECT_value(objs, i);
ASSERT(obj);
if (X509_OBJECT_get_type(obj) == X509_LU_CRL)
{
sk_X509_OBJECT_delete(objs, i);
X509_OBJECT_free(obj);
}
}
X509_STORE_set_flags(store, X509_V_FLAG_CRL_CHECK | X509_V_FLAG_CRL_CHECK_ALL);
if (crl_inline)
{
in = BIO_new_mem_buf((char *) crl_file, -1);
}
else
{
in = BIO_new_file(crl_file, "r");
}
if (in == NULL)
{
msg(M_WARN, "CRL: cannot read: %s",
print_key_filename(crl_file, crl_inline));
goto end;
}
int num_crls_loaded = 0;
while (true)
{
X509_CRL *crl = PEM_read_bio_X509_CRL(in, NULL, NULL, NULL);
if (crl == NULL)
{
/*
* PEM_R_NO_START_LINE can be considered equivalent to EOF.
*/
bool eof = ERR_GET_REASON(ERR_peek_error()) == PEM_R_NO_START_LINE;
/* but warn if no CRLs have been loaded */
if (num_crls_loaded > 0 && eof)
{
/* remove that error from error stack */
(void)ERR_get_error();
break;
}
crypto_msg(M_WARN, "CRL: cannot read CRL from file %s",
print_key_filename(crl_file, crl_inline));
break;
}
if (!X509_STORE_add_crl(store, crl))
{
X509_CRL_free(crl);
crypto_msg(M_WARN, "CRL: cannot add %s to store",
print_key_filename(crl_file, crl_inline));
break;
}
X509_CRL_free(crl);
num_crls_loaded++;
}
msg(M_INFO, "CRL: loaded %d CRLs from file %s", num_crls_loaded, crl_file);
end:
BIO_free(in);
}
#ifdef ENABLE_MANAGEMENT
/* encrypt */
static int
rsa_pub_enc(int flen, const unsigned char *from, unsigned char *to, RSA *rsa, int padding)
{
ASSERT(0);
return -1;
}
/* verify arbitrary data */
static int
rsa_pub_dec(int flen, const unsigned char *from, unsigned char *to, RSA *rsa, int padding)
{
ASSERT(0);
return -1;
}
/* decrypt */
static int
rsa_priv_dec(int flen, const unsigned char *from, unsigned char *to, RSA *rsa, int padding)
{
ASSERT(0);
return -1;
}
/* called at RSA_free */
static int
openvpn_extkey_rsa_finish(RSA *rsa)
{
/* meth was allocated in tls_ctx_use_management_external_key() ; since
* this function is called when the parent RSA object is destroyed,
* it is no longer used after this point so kill it. */
const RSA_METHOD *meth = RSA_get_method(rsa);
RSA_meth_free((RSA_METHOD *)meth);
return 1;
}
/*
* Convert OpenSSL's constant to the strings used in the management
* interface query
*/
const char *
get_rsa_padding_name(const int padding)
{
switch (padding)
{
case RSA_PKCS1_PADDING:
return "RSA_PKCS1_PADDING";
case RSA_NO_PADDING:
return "RSA_NO_PADDING";
default:
return "UNKNOWN";
}
}
/**
* Pass the input hash in 'dgst' to management and get the signature back.
*
* @param dgst hash to be signed
* @param dgstlen len of data in dgst
* @param sig On successful return signature is in sig.
* @param siglen length of buffer sig
* @param algorithm padding/hashing algorithm for the signature
*
* @return signature length or -1 on error.
*/
static int
get_sig_from_man(const unsigned char *dgst, unsigned int dgstlen,
unsigned char *sig, unsigned int siglen,
const char *algorithm)
{
char *in_b64 = NULL;
char *out_b64 = NULL;
int len = -1;
int bencret = openvpn_base64_encode(dgst, dgstlen, &in_b64);
if (management && bencret > 0)
{
out_b64 = management_query_pk_sig(management, in_b64, algorithm);
}
if (out_b64)
{
len = openvpn_base64_decode(out_b64, sig, siglen);
}
free(in_b64);
free(out_b64);
return len;
}
/* sign arbitrary data */
static int
rsa_priv_enc(int flen, const unsigned char *from, unsigned char *to, RSA *rsa,
int padding)
{
unsigned int len = RSA_size(rsa);
int ret = -1;
if (padding != RSA_PKCS1_PADDING && padding != RSA_NO_PADDING)
{
RSAerr(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
return -1;
}
ret = get_sig_from_man(from, flen, to, len, get_rsa_padding_name(padding));
return (ret == len) ? ret : -1;
}
static int
tls_ctx_use_external_rsa_key(struct tls_root_ctx *ctx, EVP_PKEY *pkey)
{
RSA *rsa = NULL;
RSA *pub_rsa;
RSA_METHOD *rsa_meth;
ASSERT(NULL != ctx);
pub_rsa = EVP_PKEY_get0_RSA(pkey);
ASSERT(NULL != pub_rsa);
/* allocate custom RSA method object */
rsa_meth = RSA_meth_new("OpenVPN external private key RSA Method",
RSA_METHOD_FLAG_NO_CHECK);
check_malloc_return(rsa_meth);
RSA_meth_set_pub_enc(rsa_meth, rsa_pub_enc);
RSA_meth_set_pub_dec(rsa_meth, rsa_pub_dec);
RSA_meth_set_priv_enc(rsa_meth, rsa_priv_enc);
RSA_meth_set_priv_dec(rsa_meth, rsa_priv_dec);
RSA_meth_set_init(rsa_meth, NULL);
RSA_meth_set_finish(rsa_meth, openvpn_extkey_rsa_finish);
RSA_meth_set0_app_data(rsa_meth, NULL);
/* allocate RSA object */
rsa = RSA_new();
if (rsa == NULL)
{
SSLerr(SSL_F_SSL_USE_PRIVATEKEY, ERR_R_MALLOC_FAILURE);
goto err;
}
/* initialize RSA object */
const BIGNUM *n = NULL;
const BIGNUM *e = NULL;
RSA_get0_key(pub_rsa, &n, &e, NULL);
RSA_set0_key(rsa, BN_dup(n), BN_dup(e), NULL);
RSA_set_flags(rsa, RSA_flags(rsa) | RSA_FLAG_EXT_PKEY);
if (!RSA_set_method(rsa, rsa_meth))
{
RSA_meth_free(rsa_meth);
goto err;
}
/* from this point rsa_meth will get freed with rsa */
/* bind our custom RSA object to ssl_ctx */
if (!SSL_CTX_use_RSAPrivateKey(ctx->ctx, rsa))
{
goto err;
}
RSA_free(rsa); /* doesn't necessarily free, just decrements refcount */
return 1;
err:
if (rsa)
{
RSA_free(rsa);
}
else
{
if (rsa_meth)
{
RSA_meth_free(rsa_meth);
}
}
return 0;
}
#if ((OPENSSL_VERSION_NUMBER > 0x10100000L && !defined(LIBRESSL_VERSION_NUMBER)) \
|| LIBRESSL_VERSION_NUMBER > 0x2090000fL) \
&& !defined(OPENSSL_NO_EC)
/* called when EC_KEY is destroyed */
static void
openvpn_extkey_ec_finish(EC_KEY *ec)
{
/* release the method structure */
const EC_KEY_METHOD *ec_meth = EC_KEY_get_method(ec);
EC_KEY_METHOD_free((EC_KEY_METHOD *) ec_meth);
}
/* EC_KEY_METHOD callback: sign().
* Sign the hash using EC key and return DER encoded signature in sig,
* its length in siglen. Return value is 1 on success, 0 on error.
*/
static int
ecdsa_sign(int type, const unsigned char *dgst, int dgstlen, unsigned char *sig,
unsigned int *siglen, const BIGNUM *kinv, const BIGNUM *r, EC_KEY *ec)
{
int capacity = ECDSA_size(ec);
/*
* ECDSA does not seem to have proper constants for paddings since
* there are only signatures without padding at the moment, use
* a generic ECDSA for the moment
*/
int len = get_sig_from_man(dgst, dgstlen, sig, capacity, "ECDSA");
if (len > 0)
{
*siglen = len;
return 1;
}
return 0;
}
/* EC_KEY_METHOD callback: sign_setup(). We do no precomputations */
static int
ecdsa_sign_setup(EC_KEY *ec, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp)
{
return 1;
}
/* EC_KEY_METHOD callback: sign_sig().
* Sign the hash and return the result as a newly allocated ECDS_SIG
* struct or NULL on error.
*/
static ECDSA_SIG *
ecdsa_sign_sig(const unsigned char *dgst, int dgstlen, const BIGNUM *in_kinv,
const BIGNUM *in_r, EC_KEY *ec)
{
ECDSA_SIG *ecsig = NULL;
unsigned int len = ECDSA_size(ec);
struct gc_arena gc = gc_new();
unsigned char *buf = gc_malloc(len, false, &gc);
if (ecdsa_sign(0, dgst, dgstlen, buf, &len, NULL, NULL, ec) != 1)
{
goto out;
}
/* const char ** should be avoided: not up to us, so we cast our way through */
ecsig = d2i_ECDSA_SIG(NULL, (const unsigned char **)&buf, len);
out:
gc_free(&gc);
return ecsig;
}
static int
tls_ctx_use_external_ec_key(struct tls_root_ctx *ctx, EVP_PKEY *pkey)
{
EC_KEY *ec = NULL;
EVP_PKEY *privkey = NULL;
EC_KEY_METHOD *ec_method;
ASSERT(ctx);
ec_method = EC_KEY_METHOD_new(EC_KEY_OpenSSL());
if (!ec_method)
{
goto err;
}
/* Among init methods, we only need the finish method */
EC_KEY_METHOD_set_init(ec_method, NULL, openvpn_extkey_ec_finish, NULL, NULL, NULL, NULL);
EC_KEY_METHOD_set_sign(ec_method, ecdsa_sign, ecdsa_sign_setup, ecdsa_sign_sig);
ec = EC_KEY_dup(EVP_PKEY_get0_EC_KEY(pkey));
if (!ec)
{
EC_KEY_METHOD_free(ec_method);
goto err;
}
if (!EC_KEY_set_method(ec, ec_method))
{
EC_KEY_METHOD_free(ec_method);
goto err;
}
/* from this point ec_method will get freed when ec is freed */
privkey = EVP_PKEY_new();
if (!EVP_PKEY_assign_EC_KEY(privkey, ec))
{
goto err;
}
/* from this point ec will get freed when privkey is freed */
if (!SSL_CTX_use_PrivateKey(ctx->ctx, privkey))
{
ec = NULL; /* avoid double freeing it below */
goto err;
}
EVP_PKEY_free(privkey); /* this will down ref privkey and ec */
return 1;
err:
/* Reach here only when ec and privkey can be independenly freed */
if (privkey)
{
EVP_PKEY_free(privkey);
}
if (ec)
{
EC_KEY_free(ec);
}
return 0;
}
#endif /* OPENSSL_VERSION_NUMBER > 1.1.0 dev && !defined(OPENSSL_NO_EC) */
int
tls_ctx_use_management_external_key(struct tls_root_ctx *ctx)
{
int ret = 1;
ASSERT(NULL != ctx);
X509 *cert = SSL_CTX_get0_certificate(ctx->ctx);
ASSERT(NULL != cert);
/* get the public key */
EVP_PKEY *pkey = X509_get0_pubkey(cert);
ASSERT(pkey); /* NULL before SSL_CTX_use_certificate() is called */
if (EVP_PKEY_id(pkey) == EVP_PKEY_RSA)
{
if (!tls_ctx_use_external_rsa_key(ctx, pkey))
{
goto cleanup;
}
}
#if ((OPENSSL_VERSION_NUMBER > 0x10100000L && !defined(LIBRESSL_VERSION_NUMBER)) \
|| LIBRESSL_VERSION_NUMBER > 0x2090000fL) \
&& !defined(OPENSSL_NO_EC)
else if (EVP_PKEY_id(pkey) == EVP_PKEY_EC)
{
if (!tls_ctx_use_external_ec_key(ctx, pkey))
{
goto cleanup;
}
}
else
{
crypto_msg(M_WARN, "management-external-key requires an RSA or EC certificate");
goto cleanup;
}
#else /* OPENSSL_VERSION_NUMBER > 1.1.0 dev && !defined(OPENSSL_NO_EC) */
else
{
crypto_msg(M_WARN, "management-external-key requires an RSA certificate");
goto cleanup;
}
#endif /* OPENSSL_VERSION_NUMBER > 1.1.0 dev && !defined(OPENSSL_NO_EC) */
ret = 0;
cleanup:
if (ret)
{
crypto_msg(M_FATAL, "Cannot enable SSL external private key capability");
}
return ret;
}
#endif /* ifdef ENABLE_MANAGEMENT */
static int
sk_x509_name_cmp(const X509_NAME *const *a, const X509_NAME *const *b)
{
return X509_NAME_cmp(*a, *b);
}
void
tls_ctx_load_ca(struct tls_root_ctx *ctx, const char *ca_file,
bool ca_file_inline, const char *ca_path, bool tls_server)
{
STACK_OF(X509_INFO) *info_stack = NULL;
STACK_OF(X509_NAME) *cert_names = NULL;
X509_LOOKUP *lookup = NULL;
X509_STORE *store = NULL;
X509_NAME *xn = NULL;
BIO *in = NULL;
int i, added = 0, prev = 0;
ASSERT(NULL != ctx);
store = SSL_CTX_get_cert_store(ctx->ctx);
if (!store)
{
crypto_msg(M_FATAL, "Cannot get certificate store");
}
/* Try to add certificates and CRLs from ca_file */
if (ca_file)
{
if (ca_file_inline)
{
in = BIO_new_mem_buf((char *)ca_file, -1);
}
else
{
in = BIO_new_file(ca_file, "r");
}
if (in)
{
info_stack = PEM_X509_INFO_read_bio(in, NULL, NULL, NULL);
}
if (info_stack)
{
for (i = 0; i < sk_X509_INFO_num(info_stack); i++)
{
X509_INFO *info = sk_X509_INFO_value(info_stack, i);
if (info->crl)
{
X509_STORE_add_crl(store, info->crl);
}
if (tls_server && !info->x509)
{
crypto_msg(M_FATAL, "X509 name was missing in TLS mode");
}
if (info->x509)
{
X509_STORE_add_cert(store, info->x509);
added++;
if (!tls_server)
{
continue;
}
/* Use names of CAs as a client CA list */
if (cert_names == NULL)
{
cert_names = sk_X509_NAME_new(sk_x509_name_cmp);
if (!cert_names)
{
continue;
}
}
xn = X509_get_subject_name(info->x509);
if (!xn)
{
continue;
}
/* Don't add duplicate CA names */
if (sk_X509_NAME_find(cert_names, xn) == -1)
{
xn = X509_NAME_dup(xn);
if (!xn)
{
continue;
}
sk_X509_NAME_push(cert_names, xn);
}
}
if (tls_server)
{
int cnum = sk_X509_NAME_num(cert_names);
if (cnum != (prev + 1))
{
crypto_msg(M_WARN,
"Cannot load CA certificate file %s (entry %d did not validate)",
print_key_filename(ca_file, ca_file_inline),
added);
}
prev = cnum;
}
}
sk_X509_INFO_pop_free(info_stack, X509_INFO_free);
}
if (tls_server)
{
SSL_CTX_set_client_CA_list(ctx->ctx, cert_names);
}
if (!added)
{
crypto_msg(M_FATAL,
"Cannot load CA certificate file %s (no entries were read)",
print_key_filename(ca_file, ca_file_inline));
}
if (tls_server)
{
int cnum = sk_X509_NAME_num(cert_names);
if (cnum != added)
{
crypto_msg(M_FATAL, "Cannot load CA certificate file %s (only %d "
"of %d entries were valid X509 names)",
print_key_filename(ca_file, ca_file_inline), cnum,
added);
}
}
if (in)
{
BIO_free(in);
}
}
/* Set a store for certs (CA & CRL) with a lookup on the "capath" hash directory */
if (ca_path)
{
lookup = X509_STORE_add_lookup(store, X509_LOOKUP_hash_dir());
if (lookup && X509_LOOKUP_add_dir(lookup, ca_path, X509_FILETYPE_PEM))
{
msg(M_WARN, "WARNING: experimental option --capath %s", ca_path);
}
else
{
crypto_msg(M_FATAL, "Cannot add lookup at --capath %s", ca_path);
}
X509_STORE_set_flags(store, X509_V_FLAG_CRL_CHECK | X509_V_FLAG_CRL_CHECK_ALL);
}
}
void
tls_ctx_load_extra_certs(struct tls_root_ctx *ctx, const char *extra_certs_file,
bool extra_certs_file_inline)
{
BIO *in;
if (extra_certs_file_inline)
{
in = BIO_new_mem_buf((char *)extra_certs_file, -1);
}
else
{
in = BIO_new_file(extra_certs_file, "r");
}
if (in == NULL)
{
crypto_msg(M_FATAL, "Cannot load extra-certs file: %s",
print_key_filename(extra_certs_file,
extra_certs_file_inline));
}
else
{
tls_ctx_add_extra_certs(ctx, in, false);
}
BIO_free(in);
}
/* **************************************
*
* Key-state specific functions
*
***************************************/
/*
*
* BIO functions
*
*/
#ifdef BIO_DEBUG
#warning BIO_DEBUG defined
static FILE *biofp; /* GLOBAL */
static bool biofp_toggle; /* GLOBAL */
static time_t biofp_last_open; /* GLOBAL */
static const int biofp_reopen_interval = 600; /* GLOBAL */
static void
close_biofp(void)
{
if (biofp)
{
ASSERT(!fclose(biofp));
biofp = NULL;
}
}
static void
open_biofp(void)
{
const time_t current = time(NULL);
const pid_t pid = getpid();
if (biofp_last_open + biofp_reopen_interval < current)
{
close_biofp();
}
if (!biofp)
{
char fn[256];
openvpn_snprintf(fn, sizeof(fn), "bio/%d-%d.log", pid, biofp_toggle);
biofp = fopen(fn, "w");
ASSERT(biofp);
biofp_last_open = time(NULL);
biofp_toggle ^= 1;
}
}
static void
bio_debug_data(const char *mode, BIO *bio, const uint8_t *buf, int len, const char *desc)
{
struct gc_arena gc = gc_new();
if (len > 0)
{
open_biofp();
fprintf(biofp, "BIO_%s %s time=%" PRIi64 " bio=" ptr_format " len=%d data=%s\n",
mode, desc, (int64_t)time(NULL), (ptr_type)bio, len, format_hex(buf, len, 0, &gc));
fflush(biofp);
}
gc_free(&gc);
}
static void
bio_debug_oc(const char *mode, BIO *bio)
{
open_biofp();
fprintf(biofp, "BIO %s time=%" PRIi64 " bio=" ptr_format "\n",
mode, (int64_t)time(NULL), (ptr_type)bio);
fflush(biofp);
}
#endif /* ifdef BIO_DEBUG */
/*
* Write to an OpenSSL BIO in non-blocking mode.
*/
static int
bio_write(BIO *bio, const uint8_t *data, int size, const char *desc)
{
int i;
int ret = 0;
ASSERT(size >= 0);
if (size)
{
/*
* Free the L_TLS lock prior to calling BIO routines
* so that foreground thread can still call
* tls_pre_decrypt or tls_pre_encrypt,
* allowing tunnel packet forwarding to continue.
*/
#ifdef BIO_DEBUG
bio_debug_data("write", bio, data, size, desc);
#endif
i = BIO_write(bio, data, size);
if (i < 0)
{
if (BIO_should_retry(bio))
{
}
else
{
crypto_msg(D_TLS_ERRORS, "TLS ERROR: BIO write %s error", desc);
ret = -1;
ERR_clear_error();
}
}
else if (i != size)
{
crypto_msg(D_TLS_ERRORS, "TLS ERROR: BIO write %s incomplete %d/%d",
desc, i, size);
ret = -1;
ERR_clear_error();
}
else
{ /* successful write */
dmsg(D_HANDSHAKE_VERBOSE, "BIO write %s %d bytes", desc, i);
ret = 1;
}
}
return ret;
}
/*
* Inline functions for reading from and writing
* to BIOs.
*/
static void
bio_write_post(const int status, struct buffer *buf)
{
if (status == 1) /* success status return from bio_write? */
{
memset(BPTR(buf), 0, BLEN(buf)); /* erase data just written */
buf->len = 0;
}
}
/*
* Read from an OpenSSL BIO in non-blocking mode.
*/
static int
bio_read(BIO *bio, struct buffer *buf, int maxlen, const char *desc)
{
int i;
int ret = 0;
ASSERT(buf->len >= 0);
if (buf->len)
{
}
else
{
int len = buf_forward_capacity(buf);
if (maxlen < len)
{
len = maxlen;
}
/*
* BIO_read brackets most of the serious RSA
* key negotiation number crunching.
*/
i = BIO_read(bio, BPTR(buf), len);
VALGRIND_MAKE_READABLE((void *) &i, sizeof(i));
#ifdef BIO_DEBUG
bio_debug_data("read", bio, BPTR(buf), i, desc);
#endif
if (i < 0)
{
if (BIO_should_retry(bio))
{
}
else
{
crypto_msg(D_TLS_ERRORS, "TLS_ERROR: BIO read %s error", desc);
buf->len = 0;
ret = -1;
ERR_clear_error();
}
}
else if (!i)
{
buf->len = 0;
}
else
{ /* successful read */
dmsg(D_HANDSHAKE_VERBOSE, "BIO read %s %d bytes", desc, i);
buf->len = i;
ret = 1;
VALGRIND_MAKE_READABLE((void *) BPTR(buf), BLEN(buf));
}
}
return ret;
}
void
key_state_ssl_init(struct key_state_ssl *ks_ssl, const struct tls_root_ctx *ssl_ctx, bool is_server, struct tls_session *session)
{
ASSERT(NULL != ssl_ctx);
ASSERT(ks_ssl);
CLEAR(*ks_ssl);
ks_ssl->ssl = SSL_new(ssl_ctx->ctx);
if (!ks_ssl->ssl)
{
crypto_msg(M_FATAL, "SSL_new failed");
}
/* put session * in ssl object so we can access it
* from verify callback*/
SSL_set_ex_data(ks_ssl->ssl, mydata_index, session);
ASSERT((ks_ssl->ssl_bio = BIO_new(BIO_f_ssl())));
ASSERT((ks_ssl->ct_in = BIO_new(BIO_s_mem())));
ASSERT((ks_ssl->ct_out = BIO_new(BIO_s_mem())));
#ifdef BIO_DEBUG
bio_debug_oc("open ssl_bio", ks_ssl->ssl_bio);
bio_debug_oc("open ct_in", ks_ssl->ct_in);
bio_debug_oc("open ct_out", ks_ssl->ct_out);
#endif
if (is_server)
{
SSL_set_accept_state(ks_ssl->ssl);
}
else
{
SSL_set_connect_state(ks_ssl->ssl);
}
SSL_set_bio(ks_ssl->ssl, ks_ssl->ct_in, ks_ssl->ct_out);
BIO_set_ssl(ks_ssl->ssl_bio, ks_ssl->ssl, BIO_NOCLOSE);
}
void
key_state_ssl_free(struct key_state_ssl *ks_ssl)
{
if (ks_ssl->ssl)
{
#ifdef BIO_DEBUG
bio_debug_oc("close ssl_bio", ks_ssl->ssl_bio);
bio_debug_oc("close ct_in", ks_ssl->ct_in);
bio_debug_oc("close ct_out", ks_ssl->ct_out);
#endif
BIO_free_all(ks_ssl->ssl_bio);
SSL_free(ks_ssl->ssl);
}
}
int
key_state_write_plaintext(struct key_state_ssl *ks_ssl, struct buffer *buf)
{
int ret = 0;
perf_push(PERF_BIO_WRITE_PLAINTEXT);
#ifdef ENABLE_CRYPTO_OPENSSL
ASSERT(NULL != ks_ssl);
ret = bio_write(ks_ssl->ssl_bio, BPTR(buf), BLEN(buf),
"tls_write_plaintext");
bio_write_post(ret, buf);
#endif /* ENABLE_CRYPTO_OPENSSL */
perf_pop();
return ret;
}
int
key_state_write_plaintext_const(struct key_state_ssl *ks_ssl, const uint8_t *data, int len)
{
int ret = 0;
perf_push(PERF_BIO_WRITE_PLAINTEXT);
ASSERT(NULL != ks_ssl);
ret = bio_write(ks_ssl->ssl_bio, data, len, "tls_write_plaintext_const");
perf_pop();
return ret;
}
int
key_state_read_ciphertext(struct key_state_ssl *ks_ssl, struct buffer *buf,
int maxlen)
{
int ret = 0;
perf_push(PERF_BIO_READ_CIPHERTEXT);
ASSERT(NULL != ks_ssl);
ret = bio_read(ks_ssl->ct_out, buf, maxlen, "tls_read_ciphertext");
perf_pop();
return ret;
}
int
key_state_write_ciphertext(struct key_state_ssl *ks_ssl, struct buffer *buf)
{
int ret = 0;
perf_push(PERF_BIO_WRITE_CIPHERTEXT);
ASSERT(NULL != ks_ssl);
ret = bio_write(ks_ssl->ct_in, BPTR(buf), BLEN(buf), "tls_write_ciphertext");
bio_write_post(ret, buf);
perf_pop();
return ret;
}
int
key_state_read_plaintext(struct key_state_ssl *ks_ssl, struct buffer *buf,
int maxlen)
{
int ret = 0;
perf_push(PERF_BIO_READ_PLAINTEXT);
ASSERT(NULL != ks_ssl);
ret = bio_read(ks_ssl->ssl_bio, buf, maxlen, "tls_read_plaintext");
perf_pop();
return ret;
}
/**
* Print human readable information about the certifcate into buf
* @param cert the certificate being used
* @param buf output buffer
* @param buflen output buffer length
*/
static void
print_cert_details(X509 *cert, char *buf, size_t buflen)
{
const char *curve = "";
const char *type = "(error getting type)";
EVP_PKEY *pkey = X509_get_pubkey(cert);
if (pkey == NULL)
{
buf[0] = 0;
return;
}
int typeid = EVP_PKEY_id(pkey);
#ifndef OPENSSL_NO_EC
if (typeid == EVP_PKEY_EC && EVP_PKEY_get0_EC_KEY(pkey) != NULL)
{
EC_KEY *ec = EVP_PKEY_get0_EC_KEY(pkey);
const EC_GROUP *group = EC_KEY_get0_group(ec);
int nid = EC_GROUP_get_curve_name(group);
if (nid == 0 || (curve = OBJ_nid2sn(nid)) == NULL)
{
curve = "(error getting curve name)";
}
}
#endif
if (EVP_PKEY_id(pkey) != 0)
{
int typeid = EVP_PKEY_id(pkey);
type = OBJ_nid2sn(typeid);
/* OpenSSL reports rsaEncryption, dsaEncryption and
* id-ecPublicKey, map these values to nicer ones */
if (typeid == EVP_PKEY_RSA)
{
type = "RSA";
}
else if (typeid == EVP_PKEY_DSA)
{
type = "DSA";
}
else if (typeid == EVP_PKEY_EC)
{
/* EC gets the curve appended after the type */
type = "EC, curve ";
}
else if (type == NULL)
{
type = "unknown type";
}
}
char sig[128] = { 0 };
int signature_nid = X509_get_signature_nid(cert);
if (signature_nid != 0)
{
openvpn_snprintf(sig, sizeof(sig), ", signature: %s",
OBJ_nid2sn(signature_nid));
}
openvpn_snprintf(buf, buflen, ", peer certificate: %d bit %s%s%s",
EVP_PKEY_bits(pkey), type, curve, sig);
EVP_PKEY_free(pkey);
}
/* **************************************
*
* Information functions
*
* Print information for the end user.
*
***************************************/
void
print_details(struct key_state_ssl *ks_ssl, const char *prefix)
{
const SSL_CIPHER *ciph;
char s1[256];
char s2[256];
s1[0] = s2[0] = 0;
ciph = SSL_get_current_cipher(ks_ssl->ssl);
openvpn_snprintf(s1, sizeof(s1), "%s %s, cipher %s %s",
prefix,
SSL_get_version(ks_ssl->ssl),
SSL_CIPHER_get_version(ciph),
SSL_CIPHER_get_name(ciph));
X509 *cert = SSL_get_peer_certificate(ks_ssl->ssl);
if (cert)
{
print_cert_details(cert, s2, sizeof(s2));
X509_free(cert);
}
msg(D_HANDSHAKE, "%s%s", s1, s2);
}
void
show_available_tls_ciphers_list(const char *cipher_list,
const char *tls_cert_profile,
bool tls13)
{
struct tls_root_ctx tls_ctx;
tls_ctx.ctx = SSL_CTX_new(SSLv23_method());
if (!tls_ctx.ctx)
{
crypto_msg(M_FATAL, "Cannot create SSL_CTX object");
}
#if defined(TLS1_3_VERSION)
if (tls13)
{
SSL_CTX_set_min_proto_version(tls_ctx.ctx,
openssl_tls_version(TLS_VER_1_3));
tls_ctx_restrict_ciphers_tls13(&tls_ctx, cipher_list);
}
else
#endif
{
SSL_CTX_set_max_proto_version(tls_ctx.ctx, TLS1_2_VERSION);
tls_ctx_restrict_ciphers(&tls_ctx, cipher_list);
}
tls_ctx_set_cert_profile(&tls_ctx, tls_cert_profile);
SSL *ssl = SSL_new(tls_ctx.ctx);
if (!ssl)
{
crypto_msg(M_FATAL, "Cannot create SSL object");
}
#if (OPENSSL_VERSION_NUMBER < 0x1010000fL) \
|| (defined(LIBRESSL_VERSION_NUMBER) && LIBRESSL_VERSION_NUMBER <= 0x2090000fL)
STACK_OF(SSL_CIPHER) *sk = SSL_get_ciphers(ssl);
#else
STACK_OF(SSL_CIPHER) *sk = SSL_get1_supported_ciphers(ssl);
#endif
for (int i = 0; i < sk_SSL_CIPHER_num(sk); i++)
{
const SSL_CIPHER *c = sk_SSL_CIPHER_value(sk, i);
const char *cipher_name = SSL_CIPHER_get_name(c);
const tls_cipher_name_pair *pair =
tls_get_cipher_name_pair(cipher_name, strlen(cipher_name));
if (tls13)
{
printf("%s\n", cipher_name);
}
else if (NULL == pair)
{
/* No translation found, print warning */
printf("%s (No IANA name known to OpenVPN, use OpenSSL name.)\n",
cipher_name);
}
else
{
printf("%s\n", pair->iana_name);
}
}
#if (OPENSSL_VERSION_NUMBER >= 0x1010000fL)
sk_SSL_CIPHER_free(sk);
#endif
SSL_free(ssl);
SSL_CTX_free(tls_ctx.ctx);
}
/*
* Show the Elliptic curves that are available for us to use
* in the OpenSSL library.
*/
void
show_available_curves(void)
{
printf("Consider using openssl 'ecparam -list_curves' as\n"
"alternative to running this command.\n");
#ifndef OPENSSL_NO_EC
EC_builtin_curve *curves = NULL;
size_t crv_len = 0;
size_t n = 0;
crv_len = EC_get_builtin_curves(NULL, 0);
ALLOC_ARRAY(curves, EC_builtin_curve, crv_len);
if (EC_get_builtin_curves(curves, crv_len))
{
printf("\nAvailable Elliptic curves/groups:\n");
for (n = 0; n < crv_len; n++)
{
const char *sname;
sname = OBJ_nid2sn(curves[n].nid);
if (sname == NULL)
{
sname = "";
}
printf("%s\n", sname);
}
}
else
{
crypto_msg(M_FATAL, "Cannot get list of builtin curves");
}
free(curves);
#else /* ifndef OPENSSL_NO_EC */
msg(M_WARN, "Your OpenSSL library was built without elliptic curve support. "
"No curves available.");
#endif /* ifndef OPENSSL_NO_EC */
}
void
get_highest_preference_tls_cipher(char *buf, int size)
{
SSL_CTX *ctx;
SSL *ssl;
const char *cipher_name;
ctx = SSL_CTX_new(SSLv23_method());
if (!ctx)
{
crypto_msg(M_FATAL, "Cannot create SSL_CTX object");
}
ssl = SSL_new(ctx);
if (!ssl)
{
crypto_msg(M_FATAL, "Cannot create SSL object");
}
cipher_name = SSL_get_cipher_list(ssl, 0);
strncpynt(buf, cipher_name, size);
SSL_free(ssl);
SSL_CTX_free(ctx);
}
const char *
get_ssl_library_version(void)
{
return OpenSSL_version(OPENSSL_VERSION);
}
#endif /* defined(ENABLE_CRYPTO_OPENSSL) */