summaryrefslogtreecommitdiff
path: root/src/openvpn/ssl_mbedtls.c
diff options
context:
space:
mode:
authorAlberto Gonzalez Iniesta <agi@inittab.org>2016-11-21 09:37:33 +0100
committerAlberto Gonzalez Iniesta <agi@inittab.org>2016-11-21 09:37:33 +0100
commit20c8675ba46bda97330a4117c459a59a9f1c465e (patch)
treed888c714fb61947dd79dc44b64a4aaae2f70bfb7 /src/openvpn/ssl_mbedtls.c
parentffca24bed7a03d95585ad02278667abe75d8b272 (diff)
New upstream version 2.4~beta1upstream/2.4_beta1
Diffstat (limited to 'src/openvpn/ssl_mbedtls.c')
-rw-r--r--src/openvpn/ssl_mbedtls.c1226
1 files changed, 1226 insertions, 0 deletions
diff --git a/src/openvpn/ssl_mbedtls.c b/src/openvpn/ssl_mbedtls.c
new file mode 100644
index 0000000..7fa35a7
--- /dev/null
+++ b/src/openvpn/ssl_mbedtls.c
@@ -0,0 +1,1226 @@
+/*
+ * 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) 2002-2010 OpenVPN Technologies, Inc. <sales@openvpn.net>
+ * Copyright (C) 2010 Fox Crypto B.V. <openvpn@fox-it.com>
+ * Copyright (C) 2006-2010, Brainspark B.V.
+ *
+ * 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 (see the file COPYING included with this
+ * distribution); if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+/**
+ * @file Control Channel mbed TLS Backend
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#elif defined(_MSC_VER)
+#include "config-msvc.h"
+#endif
+
+#include "syshead.h"
+
+#if defined(ENABLE_CRYPTO) && defined(ENABLE_CRYPTO_MBEDTLS)
+
+#include "errlevel.h"
+#include "ssl_backend.h"
+#include "base64.h"
+#include "buffer.h"
+#include "misc.h"
+#include "manage.h"
+#include "ssl_common.h"
+
+#include <mbedtls/havege.h>
+
+#include "ssl_verify_mbedtls.h"
+#include <mbedtls/debug.h>
+#include <mbedtls/error.h>
+#include <mbedtls/net.h>
+#include <mbedtls/oid.h>
+#include <mbedtls/pem.h>
+#include <mbedtls/sha256.h>
+#include <mbedtls/version.h>
+
+void
+tls_init_lib()
+{
+}
+
+void
+tls_free_lib()
+{
+}
+
+void
+tls_clear_error()
+{
+}
+
+void
+tls_ctx_server_new(struct tls_root_ctx *ctx)
+{
+ ASSERT(NULL != ctx);
+ CLEAR(*ctx);
+
+ ALLOC_OBJ_CLEAR(ctx->dhm_ctx, mbedtls_dhm_context);
+
+ ALLOC_OBJ_CLEAR(ctx->ca_chain, mbedtls_x509_crt);
+
+ ctx->endpoint = MBEDTLS_SSL_IS_SERVER;
+ ctx->initialised = true;
+}
+
+void
+tls_ctx_client_new(struct tls_root_ctx *ctx)
+{
+ ASSERT(NULL != ctx);
+ CLEAR(*ctx);
+
+ ALLOC_OBJ_CLEAR(ctx->dhm_ctx, mbedtls_dhm_context);
+ ALLOC_OBJ_CLEAR(ctx->ca_chain, mbedtls_x509_crt);
+
+ ctx->endpoint = MBEDTLS_SSL_IS_CLIENT;
+ ctx->initialised = true;
+}
+
+void
+tls_ctx_free(struct tls_root_ctx *ctx)
+{
+ if (ctx)
+ {
+ mbedtls_pk_free(ctx->priv_key);
+ if (ctx->priv_key)
+ free(ctx->priv_key);
+
+ mbedtls_x509_crt_free(ctx->ca_chain);
+ if (ctx->ca_chain)
+ free(ctx->ca_chain);
+
+ mbedtls_x509_crt_free(ctx->crt_chain);
+ if (ctx->crt_chain)
+ free(ctx->crt_chain);
+
+ mbedtls_dhm_free(ctx->dhm_ctx);
+ if (ctx->dhm_ctx)
+ free(ctx->dhm_ctx);
+
+ mbedtls_x509_crl_free(ctx->crl);
+ if (ctx->crl)
+ {
+ free(ctx->crl);
+ }
+
+#if defined(ENABLE_PKCS11)
+ if (ctx->priv_key_pkcs11 != NULL) {
+ mbedtls_pkcs11_priv_key_free(ctx->priv_key_pkcs11);
+ free(ctx->priv_key_pkcs11);
+ }
+#endif
+#if defined(MANAGMENT_EXTERNAL_KEY)
+ if (ctx->external_key != NULL)
+ free(ctx->external_key);
+#endif
+
+ if (ctx->allowed_ciphers)
+ free(ctx->allowed_ciphers);
+
+ CLEAR(*ctx);
+
+ ctx->initialised = false;
+
+ }
+}
+
+bool
+tls_ctx_initialised(struct tls_root_ctx *ctx)
+{
+ ASSERT(NULL != ctx);
+ return ctx->initialised;
+}
+
+void
+key_state_export_keying_material(struct key_state_ssl *ssl,
+ struct tls_session *session)
+{
+}
+
+void
+tls_ctx_set_options (struct tls_root_ctx *ctx, unsigned int ssl_flags)
+{
+}
+
+static const char *
+tls_translate_cipher_name (const char * cipher_name) {
+ const tls_cipher_name_pair * pair = tls_get_cipher_name_pair(cipher_name, strlen(cipher_name));
+
+ if (NULL == pair)
+ {
+ // No translation found, return original
+ return cipher_name;
+ }
+
+ if (0 != strcmp(cipher_name, pair->iana_name))
+ {
+ // Deprecated name found, notify user
+ msg(M_WARN, "Deprecated cipher suite name '%s', please use IANA name '%s'", pair->openssl_name, pair->iana_name);
+ }
+
+ return pair->iana_name;
+}
+
+void
+tls_ctx_restrict_ciphers(struct tls_root_ctx *ctx, const char *ciphers)
+{
+ char *tmp_ciphers, *tmp_ciphers_orig, *token;
+ int i, cipher_count;
+ int ciphers_len;
+
+ if (NULL == ciphers)
+ return; /* Nothing to do */
+
+ ciphers_len = strlen (ciphers);
+
+ ASSERT (NULL != ctx);
+ ASSERT (0 != ciphers_len);
+
+ /* Get number of ciphers */
+ for (i = 0, cipher_count = 1; i < ciphers_len; i++)
+ if (ciphers[i] == ':')
+ cipher_count++;
+
+ /* Allocate an array for them */
+ ALLOC_ARRAY_CLEAR(ctx->allowed_ciphers, int, cipher_count+1)
+
+ /* Parse allowed ciphers, getting IDs */
+ i = 0;
+ tmp_ciphers_orig = tmp_ciphers = string_alloc (ciphers, NULL);
+
+ token = strtok (tmp_ciphers, ":");
+ while(token)
+ {
+ ctx->allowed_ciphers[i] = mbedtls_ssl_get_ciphersuite_id (
+ tls_translate_cipher_name (token));
+ if (0 != ctx->allowed_ciphers[i])
+ i++;
+ token = strtok (NULL, ":");
+ }
+ free(tmp_ciphers_orig);
+}
+
+void
+tls_ctx_check_cert_time (const struct tls_root_ctx *ctx)
+{
+ ASSERT (ctx);
+ if (ctx->crt_chain == NULL)
+ {
+ return; /* Nothing to check if there is no certificate */
+ }
+
+ if (mbedtls_x509_time_is_future (&ctx->crt_chain->valid_from))
+ {
+ msg (M_WARN, "WARNING: Your certificate is not yet valid!");
+ }
+
+ if (mbedtls_x509_time_is_past (&ctx->crt_chain->valid_to))
+ {
+ msg (M_WARN, "WARNING: Your certificate has expired!");
+ }
+}
+
+void
+tls_ctx_load_dh_params (struct tls_root_ctx *ctx, const char *dh_file,
+ const char *dh_inline
+ )
+{
+ if (!strcmp (dh_file, INLINE_FILE_TAG) && dh_inline)
+ {
+ if (!mbed_ok(mbedtls_dhm_parse_dhm(ctx->dhm_ctx,
+ (const unsigned char *) dh_inline, strlen(dh_inline)+1)))
+ msg (M_FATAL, "Cannot read inline DH parameters");
+ }
+else
+ {
+ if (!mbed_ok(mbedtls_dhm_parse_dhmfile(ctx->dhm_ctx, dh_file)))
+ msg (M_FATAL, "Cannot read DH parameters from file %s", dh_file);
+ }
+
+ msg (D_TLS_DEBUG_LOW, "Diffie-Hellman initialized with " counter_format " bit key",
+ (counter_type) 8 * mbedtls_mpi_size(&ctx->dhm_ctx->P));
+}
+
+void
+tls_ctx_load_ecdh_params (struct tls_root_ctx *ctx, const char *curve_name
+ )
+{
+ if (NULL != curve_name)
+ msg(M_WARN, "WARNING: mbed TLS builds do not support specifying an ECDH "
+ "curve, using default curves.");
+}
+
+int
+tls_ctx_load_pkcs12(struct tls_root_ctx *ctx, const char *pkcs12_file,
+ const char *pkcs12_file_inline,
+ bool load_ca_file
+ )
+{
+ msg(M_FATAL, "PKCS #12 files not yet supported for mbed TLS.");
+ return 0;
+}
+
+#ifdef ENABLE_CRYPTOAPI
+void
+tls_ctx_load_cryptoapi(struct tls_root_ctx *ctx, const char *cryptoapi_cert)
+{
+ msg(M_FATAL, "Windows CryptoAPI not yet supported for mbed TLS.");
+}
+#endif /* _WIN32 */
+
+void
+tls_ctx_load_cert_file (struct tls_root_ctx *ctx, const char *cert_file,
+ const char *cert_inline
+ )
+{
+ ASSERT(NULL != ctx);
+
+ if (!ctx->crt_chain)
+ {
+ ALLOC_OBJ_CLEAR(ctx->crt_chain, mbedtls_x509_crt);
+ }
+
+ if (!strcmp (cert_file, INLINE_FILE_TAG) && cert_inline)
+ {
+ if (!mbed_ok(mbedtls_x509_crt_parse(ctx->crt_chain,
+ (const unsigned char *) cert_inline, strlen(cert_inline)+1)))
+ msg (M_FATAL, "Cannot load inline certificate file");
+ }
+ else
+ {
+ if (!mbed_ok(mbedtls_x509_crt_parse_file(ctx->crt_chain, cert_file)))
+ {
+ msg (M_FATAL, "Cannot load certificate file %s", cert_file);
+ }
+ }
+}
+
+int
+tls_ctx_load_priv_file (struct tls_root_ctx *ctx, const char *priv_key_file,
+ const char *priv_key_inline
+ )
+{
+ int status;
+ ASSERT(NULL != ctx);
+
+ if (!ctx->priv_key)
+ {
+ ALLOC_OBJ_CLEAR(ctx->priv_key, mbedtls_pk_context);
+ }
+
+ if (!strcmp (priv_key_file, INLINE_FILE_TAG) && priv_key_inline)
+ {
+ status = mbedtls_pk_parse_key(ctx->priv_key,
+ (const unsigned char *) priv_key_inline, strlen(priv_key_inline)+1,
+ NULL, 0);
+
+ if (MBEDTLS_ERR_PK_PASSWORD_REQUIRED == status)
+ {
+ char passbuf[512] = {0};
+ pem_password_callback(passbuf, 512, 0, NULL);
+ status = mbedtls_pk_parse_key(ctx->priv_key,
+ (const unsigned char *) priv_key_inline,
+ strlen(priv_key_inline)+1, (unsigned char *) passbuf,
+ strlen(passbuf));
+ }
+ }
+ else
+ {
+ status = mbedtls_pk_parse_keyfile(ctx->priv_key, priv_key_file, NULL);
+ if (MBEDTLS_ERR_PK_PASSWORD_REQUIRED == status)
+ {
+ char passbuf[512] = {0};
+ pem_password_callback(passbuf, 512, 0, NULL);
+ status = mbedtls_pk_parse_keyfile(ctx->priv_key, priv_key_file, passbuf);
+ }
+ }
+ if (!mbed_ok(status))
+ {
+#ifdef ENABLE_MANAGEMENT
+ if (management && (MBEDTLS_ERR_PK_PASSWORD_MISMATCH == status))
+ management_auth_failure (management, UP_TYPE_PRIVATE_KEY, NULL);
+#endif
+ msg (M_WARN, "Cannot load private key file %s", priv_key_file);
+ return 1;
+ }
+
+ if (!mbed_ok(mbedtls_pk_check_pair(&ctx->crt_chain->pk, ctx->priv_key)))
+ {
+ msg (M_WARN, "Private key does not match the certificate");
+ return 1;
+ }
+
+ return 0;
+}
+
+#ifdef MANAGMENT_EXTERNAL_KEY
+
+
+struct external_context {
+ size_t signature_length;
+};
+
+/**
+ * external_pkcs1_sign implements a mbed TLS rsa_sign_func callback, that uses
+ * the management interface to request an RSA signature for the supplied hash.
+ *
+ * @param ctx_voidptr Management external key context.
+ * @param f_rng (Unused)
+ * @param p_rng (Unused)
+ * @param mode RSA mode (should be RSA_PRIVATE).
+ * @param md_alg Message digest ('hash') algorithm type.
+ * @param hashlen Length of hash (overridden by length specified by md_alg
+ * if md_alg != MBEDTLS_MD_NONE).
+ * @param hash The digest ('hash') to sign. Should have a size
+ * matching the length of md_alg (if != MBEDTLS_MD_NONE),
+ * or hashlen otherwise.
+ * @param sig Buffer that returns the signature. Should be at least of
+ * size ctx->signature_length.
+ *
+ * @return 0 on success, non-zero mbed TLS error code on failure.
+ */
+static inline int external_pkcs1_sign( void *ctx_voidptr,
+ int (*f_rng)(void *, unsigned char *, size_t), void *p_rng, int mode,
+ mbedtls_md_type_t md_alg, unsigned int hashlen, const unsigned char *hash,
+ unsigned char *sig )
+{
+ struct external_context * const ctx = ctx_voidptr;
+ char *in_b64 = NULL;
+ char *out_b64 = NULL;
+ int rv;
+ unsigned char *p = sig;
+ size_t asn_len = 0, oid_size = 0, sig_len = 0;
+ const char *oid = NULL;
+
+ if( NULL == ctx )
+ return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
+
+ if( MBEDTLS_RSA_PRIVATE != mode )
+ return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
+
+ /*
+ * Support a wide range of hashes. TLSv1.1 and before only need SIG_RSA_RAW,
+ * but TLSv1.2 needs the full suite of hashes.
+ *
+ * This code has been taken from mbed TLS pkcs11_sign(), under the GPLv2.0+.
+ */
+ if( md_alg != MBEDTLS_MD_NONE )
+ {
+ const mbedtls_md_info_t *md_info = mbedtls_md_info_from_type( md_alg );
+ if( md_info == NULL )
+ return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
+
+ if (!mbed_ok(mbedtls_oid_get_oid_by_md( md_alg, &oid, &oid_size )))
+ return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
+
+ hashlen = mbedtls_md_get_size( md_info );
+ asn_len = 10 + oid_size;
+ }
+
+ sig_len = ctx->signature_length;
+ if ( (SIZE_MAX - hashlen) < asn_len || (hashlen + asn_len) > sig_len )
+ return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
+
+ if( md_alg != MBEDTLS_MD_NONE )
+ {
+ /*
+ * DigestInfo ::= SEQUENCE {
+ * digestAlgorithm DigestAlgorithmIdentifier,
+ * digest Digest }
+ *
+ * DigestAlgorithmIdentifier ::= AlgorithmIdentifier
+ *
+ * Digest ::= OCTET STRING
+ */
+ *p++ = MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED;
+ *p++ = (unsigned char) ( 0x08 + oid_size + hashlen );
+ *p++ = MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED;
+ *p++ = (unsigned char) ( 0x04 + oid_size );
+ *p++ = MBEDTLS_ASN1_OID;
+ *p++ = oid_size & 0xFF;
+ memcpy( p, oid, oid_size );
+ p += oid_size;
+ *p++ = MBEDTLS_ASN1_NULL;
+ *p++ = 0x00;
+ *p++ = MBEDTLS_ASN1_OCTET_STRING;
+ *p++ = hashlen;
+
+ /* Determine added ASN length */
+ asn_len = p - sig;
+ }
+
+ /* Copy the hash to be signed */
+ memcpy( p, hash, hashlen );
+
+ /* convert 'from' to base64 */
+ if (openvpn_base64_encode (sig, asn_len + hashlen, &in_b64) <= 0)
+ {
+ rv = MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
+ goto done;
+ }
+
+ /* call MI for signature */
+ if (management)
+ out_b64 = management_query_rsa_sig (management, in_b64);
+ if (!out_b64)
+ {
+ rv = MBEDTLS_ERR_RSA_PRIVATE_FAILED;
+ goto done;
+ }
+
+ /* decode base64 signature to binary and verify length */
+ if ( openvpn_base64_decode (out_b64, sig, ctx->signature_length) !=
+ ctx->signature_length )
+ {
+ rv = MBEDTLS_ERR_RSA_PRIVATE_FAILED;
+ goto done;
+ }
+
+ rv = 0;
+
+done:
+ if (in_b64)
+ free (in_b64);
+ if (out_b64)
+ free (out_b64);
+ return rv;
+}
+
+static inline size_t external_key_len(void *vctx)
+{
+ struct external_context * const ctx = vctx;
+
+ return ctx->signature_length;
+}
+
+int
+tls_ctx_use_external_private_key (struct tls_root_ctx *ctx,
+ const char *cert_file, const char *cert_file_inline)
+{
+ ASSERT(NULL != ctx);
+
+ tls_ctx_load_cert_file(ctx, cert_file, cert_file_inline);
+
+ if (ctx->crt_chain == NULL)
+ return 0;
+
+ ALLOC_OBJ_CLEAR (ctx->external_key, struct external_context);
+ ctx->external_key->signature_length = mbedtls_pk_get_len (&ctx->crt_chain->pk);
+
+ ALLOC_OBJ_CLEAR (ctx->priv_key, mbedtls_pk_context);
+ if (!mbed_ok (mbedtls_pk_setup_rsa_alt (ctx->priv_key, ctx->external_key,
+ NULL, external_pkcs1_sign, external_key_len)))
+ return 0;
+
+ return 1;
+}
+#endif
+
+void tls_ctx_load_ca (struct tls_root_ctx *ctx, const char *ca_file,
+ const char *ca_inline, const char *ca_path, bool tls_server
+ )
+{
+ if (ca_path)
+ msg(M_FATAL, "ERROR: mbed TLS cannot handle the capath directive");
+
+ if (ca_file && !strcmp (ca_file, INLINE_FILE_TAG) && ca_inline)
+ {
+ if (!mbed_ok (mbedtls_x509_crt_parse (ctx->ca_chain,
+ (const unsigned char *) ca_inline, strlen(ca_inline)+1)))
+ msg (M_FATAL, "Cannot load inline CA certificates");
+ }
+ else
+ {
+ /* Load CA file for verifying peer supplied certificate */
+ if (!mbed_ok (mbedtls_x509_crt_parse_file (ctx->ca_chain, ca_file)))
+ msg (M_FATAL, "Cannot load CA certificate file %s", ca_file);
+ }
+}
+
+void
+tls_ctx_load_extra_certs (struct tls_root_ctx *ctx, const char *extra_certs_file,
+ const char *extra_certs_inline
+ )
+{
+ ASSERT(NULL != ctx);
+
+ if (!ctx->crt_chain)
+ {
+ ALLOC_OBJ_CLEAR (ctx->crt_chain, mbedtls_x509_crt);
+ }
+
+ if (!strcmp (extra_certs_file, INLINE_FILE_TAG) && extra_certs_inline)
+ {
+ if (!mbed_ok(mbedtls_x509_crt_parse(ctx->crt_chain,
+ (const unsigned char *) extra_certs_inline,
+ strlen(extra_certs_inline)+1)))
+ msg (M_FATAL, "Cannot load inline extra-certs file");
+ }
+ else
+ {
+ if (!mbed_ok(mbedtls_x509_crt_parse_file(ctx->crt_chain, extra_certs_file)))
+ msg (M_FATAL, "Cannot load extra-certs file: %s", extra_certs_file);
+ }
+}
+
+/* **************************************
+ *
+ * Key-state specific functions
+ *
+ ***************************************/
+
+/*
+ * "Endless buffer"
+ */
+
+static inline void buf_free_entry(buffer_entry *entry)
+{
+ if (NULL != entry)
+ {
+ free(entry->data);
+ free(entry);
+ }
+}
+
+static void buf_free_entries(endless_buffer *buf)
+{
+ while(buf->first_block)
+ {
+ buffer_entry *cur_block = buf->first_block;
+ buf->first_block = cur_block->next_block;
+ buf_free_entry(cur_block);
+ }
+ buf->last_block = NULL;
+}
+
+static int endless_buf_read( endless_buffer *in, unsigned char * out, size_t out_len )
+{
+ size_t read_len = 0;
+
+ if (in->first_block == NULL)
+ return MBEDTLS_ERR_SSL_WANT_READ;
+
+ while (in->first_block != NULL && read_len < out_len)
+ {
+ int block_len = in->first_block->length - in->data_start;
+ if (block_len <= out_len - read_len)
+ {
+ buffer_entry *cur_entry = in->first_block;
+ memcpy(out + read_len, cur_entry->data + in->data_start,
+ block_len);
+
+ read_len += block_len;
+
+ in->first_block = cur_entry->next_block;
+ in->data_start = 0;
+
+ if (in->first_block == NULL)
+ in->last_block = NULL;
+
+ buf_free_entry(cur_entry);
+ }
+ else
+ {
+ memcpy(out + read_len, in->first_block->data + in->data_start,
+ out_len - read_len);
+ in->data_start += out_len - read_len;
+ read_len = out_len;
+ }
+ }
+
+ return read_len;
+}
+
+static int endless_buf_write( endless_buffer *out, const unsigned char *in, size_t len )
+{
+ buffer_entry *new_block = malloc(sizeof(buffer_entry));
+ if (NULL == new_block)
+ return MBEDTLS_ERR_NET_SEND_FAILED;
+
+ new_block->data = malloc(len);
+ if (NULL == new_block->data)
+ {
+ free(new_block);
+ return MBEDTLS_ERR_NET_SEND_FAILED;
+ }
+
+ new_block->length = len;
+ new_block->next_block = NULL;
+
+ memcpy(new_block->data, in, len);
+
+ if (NULL == out->first_block)
+ out->first_block = new_block;
+
+ if (NULL != out->last_block)
+ out->last_block->next_block = new_block;
+
+ out->last_block = new_block;
+
+ return len;
+}
+
+static int ssl_bio_read( void *ctx, unsigned char *out, size_t out_len)
+{
+ bio_ctx *my_ctx = (bio_ctx *) ctx;
+ return endless_buf_read (&my_ctx->in, out, out_len);
+}
+
+static int ssl_bio_write( void *ctx, const unsigned char *in, size_t in_len)
+{
+ bio_ctx *my_ctx = (bio_ctx *) ctx;
+ return endless_buf_write (&my_ctx->out, in, in_len);
+}
+
+static void my_debug( void *ctx, int level, const char *file, int line,
+ const char *str )
+{
+ int my_loglevel = (level < 3) ? D_TLS_DEBUG_MED : D_TLS_DEBUG;
+ msg (my_loglevel, "mbed TLS msg (%s:%d): %s", file, line, str);
+}
+
+/*
+ * Further personalise the RNG using a hash of the public key
+ */
+void tls_ctx_personalise_random(struct tls_root_ctx *ctx)
+{
+ static char old_sha256_hash[32] = {0};
+ unsigned char sha256_hash[32] = {0};
+ mbedtls_ctr_drbg_context *cd_ctx = rand_ctx_get();
+
+ if (NULL != ctx->crt_chain)
+ {
+ mbedtls_x509_crt *cert = ctx->crt_chain;
+
+ mbedtls_sha256(cert->tbs.p, cert->tbs.len, sha256_hash, false);
+ if ( 0 != memcmp(old_sha256_hash, sha256_hash, sizeof(sha256_hash)))
+ {
+ mbedtls_ctr_drbg_update(cd_ctx, sha256_hash, 32);
+ memcpy(old_sha256_hash, sha256_hash, sizeof(old_sha256_hash));
+ }
+ }
+}
+
+int
+tls_version_max(void)
+{
+#if defined(MBEDTLS_SSL_MAJOR_VERSION_3) && defined(MBEDTLS_SSL_MINOR_VERSION_3)
+ return TLS_VER_1_2;
+#elif defined(MBEDTLS_SSL_MAJOR_VERSION_3) && defined(MBEDTLS_SSL_MINOR_VERSION_2)
+ return TLS_VER_1_1;
+#else
+ return TLS_VER_1_0;
+#endif
+}
+
+/**
+ * Convert an OpenVPN tls-version variable to mbed TLS format (i.e. a major and
+ * minor ssl version number).
+ *
+ * @param tls_ver The tls-version variable to convert.
+ * @param major Returns the TLS major version in mbed TLS format.
+ * Must be a valid pointer.
+ * @param minor Returns the TLS minor version in mbed TLS format.
+ * Must be a valid pointer.
+ */
+static void tls_version_to_major_minor(int tls_ver, int *major, int *minor) {
+ ASSERT(major);
+ ASSERT(minor);
+
+ switch (tls_ver)
+ {
+ case TLS_VER_1_0:
+ *major = MBEDTLS_SSL_MAJOR_VERSION_3;
+ *minor = MBEDTLS_SSL_MINOR_VERSION_1;
+ break;
+ case TLS_VER_1_1:
+ *major = MBEDTLS_SSL_MAJOR_VERSION_3;
+ *minor = MBEDTLS_SSL_MINOR_VERSION_2;
+ break;
+ case TLS_VER_1_2:
+ *major = MBEDTLS_SSL_MAJOR_VERSION_3;
+ *minor = MBEDTLS_SSL_MINOR_VERSION_3;
+ break;
+ default:
+ msg(M_FATAL, "%s: invalid TLS version %d", __func__, tls_ver);
+ break;
+ }
+}
+
+void
+tls_ctx_reload_crl(struct tls_root_ctx *ctx, const char *crl_file,
+ const char *crl_inline)
+{
+ ASSERT (crl_file);
+
+ if (ctx->crl == NULL)
+ {
+ ALLOC_OBJ_CLEAR(ctx->crl, mbedtls_x509_crl);
+ }
+ mbedtls_x509_crl_free(ctx->crl);
+
+ if (!strcmp (crl_file, INLINE_FILE_TAG) && crl_inline)
+ {
+ if (!mbed_ok(mbedtls_x509_crl_parse(ctx->crl,
+ (const unsigned char *)crl_inline, strlen(crl_inline)+1)))
+ {
+ msg (M_WARN, "CRL: cannot parse inline CRL");
+ goto err;
+ }
+ }
+ else
+ {
+ if (!mbed_ok(mbedtls_x509_crl_parse_file(ctx->crl, crl_file)))
+ {
+ msg (M_WARN, "CRL: cannot read CRL from file %s", crl_file);
+ goto err;
+ }
+ }
+ return;
+
+err:
+ mbedtls_x509_crl_free(ctx->crl);
+}
+
+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);
+
+ /* Initialise SSL config */
+ mbedtls_ssl_config_init(&ks_ssl->ssl_config);
+ mbedtls_ssl_config_defaults(&ks_ssl->ssl_config, ssl_ctx->endpoint,
+ MBEDTLS_SSL_TRANSPORT_STREAM, MBEDTLS_SSL_PRESET_DEFAULT);
+#ifdef MBEDTLS_DEBUG_C
+ mbedtls_debug_set_threshold(3);
+#endif
+ mbedtls_ssl_conf_dbg (&ks_ssl->ssl_config, my_debug, NULL);
+ mbedtls_ssl_conf_rng (&ks_ssl->ssl_config, mbedtls_ctr_drbg_random,
+ rand_ctx_get());
+
+ if (ssl_ctx->allowed_ciphers)
+ mbedtls_ssl_conf_ciphersuites (&ks_ssl->ssl_config, ssl_ctx->allowed_ciphers);
+
+ /* Disable record splitting (for now). OpenVPN assumes records are sent
+ * unfragmented, and changing that will require thorough review and
+ * testing. Since OpenVPN is not susceptible to BEAST, we can just
+ * disable record splitting as a quick fix. */
+#if defined(MBEDTLS_SSL_CBC_RECORD_SPLITTING)
+ mbedtls_ssl_conf_cbc_record_splitting (&ks_ssl->ssl_config,
+ MBEDTLS_SSL_CBC_RECORD_SPLITTING_DISABLED);
+#endif /* MBEDTLS_SSL_CBC_RECORD_SPLITTING */
+
+ /* Initialise authentication information */
+ if (is_server)
+ mbed_ok (mbedtls_ssl_conf_dh_param_ctx(&ks_ssl->ssl_config,
+ ssl_ctx->dhm_ctx));
+
+ mbed_ok (mbedtls_ssl_conf_own_cert(&ks_ssl->ssl_config, ssl_ctx->crt_chain,
+ ssl_ctx->priv_key));
+
+ /* Initialise SSL verification */
+#if P2MP_SERVER
+ if (session->opt->ssl_flags & SSLF_CLIENT_CERT_OPTIONAL)
+ {
+ mbedtls_ssl_conf_authmode(&ks_ssl->ssl_config, MBEDTLS_SSL_VERIFY_OPTIONAL);
+ }
+ else if (!(session->opt->ssl_flags & SSLF_CLIENT_CERT_NOT_REQUIRED))
+#endif
+ {
+ mbedtls_ssl_conf_authmode (&ks_ssl->ssl_config, MBEDTLS_SSL_VERIFY_REQUIRED);
+ }
+ mbedtls_ssl_conf_verify (&ks_ssl->ssl_config, verify_callback, session);
+
+ /* TODO: mbed TLS does not currently support sending the CA chain to the client */
+ mbedtls_ssl_conf_ca_chain (&ks_ssl->ssl_config, ssl_ctx->ca_chain, ssl_ctx->crl);
+
+ /* Initialize minimum TLS version */
+ {
+ const int tls_version_min =
+ (session->opt->ssl_flags >> SSLF_TLS_VERSION_MIN_SHIFT) &
+ SSLF_TLS_VERSION_MIN_MASK;
+
+ /* default to TLS 1.0 */
+ int major = MBEDTLS_SSL_MAJOR_VERSION_3;
+ int minor = MBEDTLS_SSL_MINOR_VERSION_1;
+
+ if (tls_version_min > TLS_VER_UNSPEC)
+ tls_version_to_major_minor(tls_version_min, &major, &minor);
+
+ mbedtls_ssl_conf_min_version(&ks_ssl->ssl_config, major, minor);
+ }
+
+ /* Initialize maximum TLS version */
+ {
+ const int tls_version_max =
+ (session->opt->ssl_flags >> SSLF_TLS_VERSION_MAX_SHIFT) &
+ SSLF_TLS_VERSION_MAX_MASK;
+
+ if (tls_version_max > TLS_VER_UNSPEC)
+ {
+ int major, minor;
+ tls_version_to_major_minor(tls_version_max, &major, &minor);
+ mbedtls_ssl_conf_max_version(&ks_ssl->ssl_config, major, minor);
+ }
+ }
+
+ /* Initialise SSL context */
+ ALLOC_OBJ_CLEAR(ks_ssl->ctx, mbedtls_ssl_context);
+ mbedtls_ssl_init(ks_ssl->ctx);
+ mbedtls_ssl_setup(ks_ssl->ctx, &ks_ssl->ssl_config);
+
+ /* Initialise BIOs */
+ CLEAR (ks_ssl->bio_ctx);
+ mbedtls_ssl_set_bio (ks_ssl->ctx, &ks_ssl->bio_ctx, ssl_bio_write,
+ ssl_bio_read, NULL);
+}
+
+void
+key_state_ssl_free(struct key_state_ssl *ks_ssl)
+{
+ if (ks_ssl) {
+ if (ks_ssl->ctx)
+ {
+ mbedtls_ssl_free(ks_ssl->ctx);
+ free(ks_ssl->ctx);
+ }
+ mbedtls_ssl_config_free(&ks_ssl->ssl_config);
+ buf_free_entries(&ks_ssl->bio_ctx.in);
+ buf_free_entries(&ks_ssl->bio_ctx.out);
+ CLEAR(*ks_ssl);
+ }
+}
+
+int
+key_state_write_plaintext (struct key_state_ssl *ks, struct buffer *buf)
+{
+ int retval = 0;
+
+ ASSERT (buf);
+
+ retval = key_state_write_plaintext_const(ks, BPTR(buf), BLEN(buf));
+
+ if (1 == retval)
+ {
+ memset (BPTR (buf), 0, BLEN (buf)); /* erase data just written */
+ buf->len = 0;
+ }
+
+ return retval;
+}
+
+int
+key_state_write_plaintext_const (struct key_state_ssl *ks, const uint8_t *data, int len)
+{
+ int retval = 0;
+ perf_push (PERF_BIO_WRITE_PLAINTEXT);
+
+ ASSERT (NULL != ks);
+ ASSERT (len >= 0);
+
+ if (0 == len)
+ {
+ perf_pop ();
+ return 0;
+ }
+
+ ASSERT (data);
+
+ retval = mbedtls_ssl_write(ks->ctx, data, len);
+
+ if (retval < 0)
+ {
+ perf_pop ();
+ if (MBEDTLS_ERR_SSL_WANT_WRITE == retval || MBEDTLS_ERR_SSL_WANT_READ == retval)
+ return 0;
+ mbed_log_err (D_TLS_ERRORS, retval,
+ "TLS ERROR: write tls_write_plaintext_const error");
+ return -1;
+ }
+
+ if (retval != len)
+ {
+ msg (D_TLS_ERRORS,
+ "TLS ERROR: write tls_write_plaintext_const incomplete %d/%d",
+ retval, len);
+ perf_pop ();
+ return -1;
+ }
+
+ /* successful write */
+ dmsg (D_HANDSHAKE_VERBOSE, "write tls_write_plaintext_const %d bytes", retval);
+
+ perf_pop ();
+ return 1;
+}
+
+int
+key_state_read_ciphertext (struct key_state_ssl *ks, struct buffer *buf,
+ int maxlen)
+{
+ int retval = 0;
+ int len = 0;
+
+ perf_push (PERF_BIO_READ_CIPHERTEXT);
+
+ ASSERT (NULL != ks);
+ ASSERT (buf);
+ ASSERT (buf->len >= 0);
+
+ if (buf->len)
+ {
+ perf_pop ();
+ return 0;
+ }
+
+ len = buf_forward_capacity (buf);
+ if (maxlen < len)
+ len = maxlen;
+
+ retval = endless_buf_read(&ks->bio_ctx.out, BPTR(buf), len);
+
+ /* Error during read, check for retry error */
+ if (retval < 0)
+ {
+ perf_pop ();
+ if (MBEDTLS_ERR_SSL_WANT_WRITE == retval || MBEDTLS_ERR_SSL_WANT_READ == retval)
+ return 0;
+ mbed_log_err (D_TLS_ERRORS, retval, "TLS_ERROR: read tls_read_ciphertext error");
+ buf->len = 0;
+ return -1;
+ }
+ /* Nothing read, try again */
+ if (0 == retval)
+ {
+ buf->len = 0;
+ perf_pop ();
+ return 0;
+ }
+
+ /* successful read */
+ dmsg (D_HANDSHAKE_VERBOSE, "read tls_read_ciphertext %d bytes", retval);
+ buf->len = retval;
+ perf_pop ();
+ return 1;
+}
+
+int
+key_state_write_ciphertext (struct key_state_ssl *ks, struct buffer *buf)
+{
+ int retval = 0;
+ perf_push (PERF_BIO_WRITE_CIPHERTEXT);
+
+ ASSERT (NULL != ks);
+ ASSERT (buf);
+ ASSERT (buf->len >= 0);
+
+ if (0 == buf->len)
+ {
+ perf_pop ();
+ return 0;
+ }
+
+ retval = endless_buf_write(&ks->bio_ctx.in, BPTR(buf), buf->len);
+
+ if (retval < 0)
+ {
+ perf_pop ();
+
+ if (MBEDTLS_ERR_SSL_WANT_WRITE == retval || MBEDTLS_ERR_SSL_WANT_READ == retval)
+ return 0;
+ mbed_log_err (D_TLS_ERRORS, retval,
+ "TLS ERROR: write tls_write_ciphertext error");
+ return -1;
+ }
+
+ if (retval != buf->len)
+ {
+ msg (D_TLS_ERRORS, "TLS ERROR: write tls_write_ciphertext incomplete %d/%d",
+ retval, buf->len);
+ perf_pop ();
+ return -1;
+ }
+
+ /* successful write */
+ dmsg (D_HANDSHAKE_VERBOSE, "write tls_write_ciphertext %d bytes", retval);
+
+ memset (BPTR (buf), 0, BLEN (buf)); /* erase data just written */
+ buf->len = 0;
+
+ perf_pop ();
+ return 1;
+}
+
+int
+key_state_read_plaintext (struct key_state_ssl *ks, struct buffer *buf,
+ int maxlen)
+{
+ int retval = 0;
+ int len = 0;
+
+ perf_push (PERF_BIO_READ_PLAINTEXT);
+
+ ASSERT (NULL != ks);
+ ASSERT (buf);
+ ASSERT (buf->len >= 0);
+
+ if (buf->len)
+ {
+ perf_pop ();
+ return 0;
+ }
+
+ len = buf_forward_capacity (buf);
+ if (maxlen < len)
+ len = maxlen;
+
+ retval = mbedtls_ssl_read(ks->ctx, BPTR(buf), len);
+
+ /* Error during read, check for retry error */
+ if (retval < 0)
+ {
+ if (MBEDTLS_ERR_SSL_WANT_WRITE == retval || MBEDTLS_ERR_SSL_WANT_READ == retval)
+ return 0;
+ mbed_log_err (D_TLS_ERRORS, retval, "TLS_ERROR: read tls_read_plaintext error");
+ buf->len = 0;
+ perf_pop ();
+ return -1;
+ }
+ /* Nothing read, try again */
+ if (0 == retval)
+ {
+ buf->len = 0;
+ perf_pop ();
+ return 0;
+ }
+
+ /* successful read */
+ dmsg (D_HANDSHAKE_VERBOSE, "read tls_read_plaintext %d bytes", retval);
+ buf->len = retval;
+
+ perf_pop ();
+ return 1;
+}
+
+/* **************************************
+ *
+ * Information functions
+ *
+ * Print information for the end user.
+ *
+ ***************************************/
+void
+print_details (struct key_state_ssl * ks_ssl, const char *prefix)
+{
+ const mbedtls_x509_crt *cert;
+ char s1[256];
+ char s2[256];
+
+ s1[0] = s2[0] = 0;
+ openvpn_snprintf (s1, sizeof (s1), "%s %s, cipher %s",
+ prefix,
+ mbedtls_ssl_get_version (ks_ssl->ctx),
+ mbedtls_ssl_get_ciphersuite (ks_ssl->ctx));
+
+ cert = mbedtls_ssl_get_peer_cert (ks_ssl->ctx);
+ if (cert != NULL)
+ {
+ openvpn_snprintf (s2, sizeof (s2), ", %u bit key",
+ (unsigned int) mbedtls_pk_get_bitlen (&cert->pk));
+ }
+
+ msg (D_HANDSHAKE, "%s%s", s1, s2);
+}
+
+void
+show_available_tls_ciphers (const char *cipher_list)
+{
+ struct tls_root_ctx tls_ctx;
+ const int *ciphers = mbedtls_ssl_list_ciphersuites ();
+
+ tls_ctx_server_new(&tls_ctx);
+ tls_ctx_restrict_ciphers(&tls_ctx, cipher_list);
+
+ if (tls_ctx.allowed_ciphers)
+ ciphers = tls_ctx.allowed_ciphers;
+
+#ifndef ENABLE_SMALL
+ printf ("Available TLS Ciphers,\n");
+ printf ("listed in order of preference:\n\n");
+#endif
+
+ while (*ciphers != 0)
+ {
+ printf ("%s\n", mbedtls_ssl_get_ciphersuite_name (*ciphers));
+ ciphers++;
+ }
+ printf ("\n" SHOW_TLS_CIPHER_LIST_WARNING);
+
+ tls_ctx_free(&tls_ctx);
+}
+
+void
+show_available_curves (void)
+{
+ const mbedtls_ecp_curve_info *pcurve = mbedtls_ecp_curve_list ();
+
+ if (NULL == pcurve)
+ msg (M_FATAL, "Cannot retrieve curve list from mbed TLS");
+
+ /* Print curve list */
+ printf ("Available Elliptic curves, listed in order of preference:\n\n");
+ while (MBEDTLS_ECP_DP_NONE != pcurve->grp_id)
+ {
+ printf("%s\n", pcurve->name);
+ pcurve++;
+ }
+}
+
+void
+get_highest_preference_tls_cipher (char *buf, int size)
+{
+ const char *cipher_name;
+ const int *ciphers = mbedtls_ssl_list_ciphersuites();
+ if (*ciphers == 0)
+ msg (M_FATAL, "Cannot retrieve list of supported SSL ciphers.");
+
+ cipher_name = mbedtls_ssl_get_ciphersuite_name(*ciphers);
+ strncpynt (buf, cipher_name, size);
+}
+
+const char *
+get_ssl_library_version(void)
+{
+ static char mbedtls_version[30];
+ unsigned int pv = mbedtls_version_get_number();
+ sprintf( mbedtls_version, "mbed TLS %d.%d.%d",
+ (pv>>24)&0xff, (pv>>16)&0xff, (pv>>8)&0xff );
+ return mbedtls_version;
+}
+
+#endif /* defined(ENABLE_CRYPTO) && defined(ENABLE_CRYPTO_MBEDTLS) */