diff --git a/src/tls/mod.mk b/src/tls/mod.mk
new file mode 100644
index 0000000..f653395
--- /dev/null
+++ b/src/tls/mod.mk
@@ -0,0 +1,11 @@
+#
+# mod.mk
+#
+# Copyright (C) 2010 Creytiv.com
+#
+
+ifneq ($(USE_OPENSSL),)
+SRCS	+= tls/openssl/tls.c
+SRCS	+= tls/openssl/tls_tcp.c
+SRCS	+= tls/openssl/tls_udp.c
+endif
diff --git a/src/tls/openssl/tls.c b/src/tls/openssl/tls.c
new file mode 100644
index 0000000..d84e65f
--- /dev/null
+++ b/src/tls/openssl/tls.c
@@ -0,0 +1,904 @@
+/**
+ * @file openssl/tls.c TLS backend using OpenSSL
+ *
+ * Copyright (C) 2010 Creytiv.com
+ */
+#include <string.h>
+#include <openssl/ssl.h>
+#include <openssl/err.h>
+#include <openssl/rsa.h>
+#include <openssl/bn.h>
+#include <openssl/evp.h>
+#include <openssl/x509.h>
+#include <re_types.h>
+#include <re_fmt.h>
+#include <re_mem.h>
+#include <re_mbuf.h>
+#include <re_main.h>
+#include <re_sa.h>
+#include <re_net.h>
+#include <re_srtp.h>
+#include <re_sys.h>
+#include <re_tcp.h>
+#include <re_tls.h>
+#include "tls.h"
+
+
+/* also defined by wincrypt.h */
+#ifdef WIN32
+#undef X509_NAME
+#endif
+
+
+#define DEBUG_MODULE "tls"
+#define DEBUG_LEVEL 5
+#include <re_dbg.h>
+
+
+/* NOTE: shadow struct defined in tls_*.c */
+struct tls_conn {
+	SSL *ssl;
+};
+
+
+static void destructor(void *data)
+{
+	struct tls *tls = data;
+
+	if (tls->ctx)
+		SSL_CTX_free(tls->ctx);
+
+	if (tls->cert)
+		X509_free(tls->cert);
+
+	mem_deref(tls->pass);
+}
+
+
+/*The password code is not thread safe*/
+static int password_cb(char *buf, int size, int rwflag, void *userdata)
+{
+	struct tls *tls = userdata;
+
+	(void)rwflag;
+
+	DEBUG_NOTICE("password callback\n");
+
+	if (size < (int)strlen(tls->pass)+1)
+		return 0;
+
+	strncpy(buf, tls->pass, size);
+
+	return (int)strlen(tls->pass);
+}
+
+
+static int keytype2int(enum tls_keytype type)
+{
+	switch (type) {
+	case TLS_KEYTYPE_EC:
+		return EVP_PKEY_EC;
+	case TLS_KEYTYPE_RSA:
+		return EVP_PKEY_RSA;
+	default:
+		return EVP_PKEY_NONE;
+	}
+}
+
+
+/**
+ * Allocate a new TLS context
+ *
+ * @param tlsp    Pointer to allocated TLS context
+ * @param method  TLS method
+ * @param keyfile Optional private key file
+ * @param pwd     Optional password
+ *
+ * @return 0 if success, otherwise errorcode
+ */
+int tls_alloc(struct tls **tlsp, enum tls_method method, const char *keyfile,
+	      const char *pwd)
+{
+	struct tls *tls;
+	int r, err;
+
+	if (!tlsp)
+		return EINVAL;
+
+	tls = mem_zalloc(sizeof(*tls), destructor);
+	if (!tls)
+		return ENOMEM;
+
+	switch (method) {
+
+	case TLS_METHOD_SSLV23:
+		tls->ctx = SSL_CTX_new(SSLv23_method());
+		break;
+
+#ifdef USE_OPENSSL_DTLS
+	case TLS_METHOD_DTLSV1:
+#if OPENSSL_VERSION_NUMBER >= 0x10100000L && \
+	!defined(LIBRESSL_VERSION_NUMBER)
+
+		tls->ctx = SSL_CTX_new(DTLS_method());
+#else
+		tls->ctx = SSL_CTX_new(DTLSv1_method());
+#endif
+		break;
+
+#ifdef SSL_OP_NO_DTLSv1_2
+		/* DTLS v1.2 is available in OpenSSL 1.0.2 and later */
+
+	case TLS_METHOD_DTLS:
+		tls->ctx = SSL_CTX_new(DTLS_method());
+		break;
+
+	case TLS_METHOD_DTLSV1_2:
+#if OPENSSL_VERSION_NUMBER >= 0x10100000L && \
+	!defined(LIBRESSL_VERSION_NUMBER)
+
+		tls->ctx = SSL_CTX_new(DTLS_method());
+#else
+		tls->ctx = SSL_CTX_new(DTLSv1_2_method());
+#endif
+		break;
+#endif
+
+#endif
+
+	default:
+		DEBUG_WARNING("tls method %d not supported\n", method);
+		err = ENOSYS;
+		goto out;
+	}
+
+	if (!tls->ctx) {
+		ERR_clear_error();
+		err = ENOMEM;
+		goto out;
+	}
+
+#if (OPENSSL_VERSION_NUMBER < 0x00905100L)
+	SSL_CTX_set_verify_depth(tls->ctx, 1);
+#endif
+
+	/* Load our keys and certificates */
+	if (keyfile) {
+		if (pwd) {
+			err = str_dup(&tls->pass, pwd);
+			if (err)
+				goto out;
+
+			SSL_CTX_set_default_passwd_cb(tls->ctx, password_cb);
+			SSL_CTX_set_default_passwd_cb_userdata(tls->ctx, tls);
+		}
+
+		r = SSL_CTX_use_certificate_chain_file(tls->ctx, keyfile);
+		if (r <= 0) {
+			DEBUG_WARNING("Can't read certificate file: %s (%d)\n",
+				      keyfile, r);
+			ERR_clear_error();
+			err = EINVAL;
+			goto out;
+		}
+
+		r = SSL_CTX_use_PrivateKey_file(tls->ctx, keyfile,
+						SSL_FILETYPE_PEM);
+		if (r <= 0) {
+			DEBUG_WARNING("Can't read key file: %s (%d)\n",
+				      keyfile, r);
+			ERR_clear_error();
+			err = EINVAL;
+			goto out;
+		}
+	}
+
+	err = 0;
+ out:
+	if (err)
+		mem_deref(tls);
+	else
+		*tlsp = tls;
+
+	return err;
+}
+
+
+/**
+ * Set default locations for trusted CA certificates
+ *
+ * @param tls    TLS Context
+ * @param cafile PEM file with CA certificates
+ *
+ * @return 0 if success, otherwise errorcode
+ */
+int tls_add_ca(struct tls *tls, const char *cafile)
+{
+	if (!tls || !cafile)
+		return EINVAL;
+
+	/* Load the CAs we trust */
+	if (!(SSL_CTX_load_verify_locations(tls->ctx, cafile, NULL))) {
+		DEBUG_WARNING("Can't read CA file: %s\n", cafile);
+		ERR_clear_error();
+		return EINVAL;
+	}
+
+	return 0;
+}
+
+
+/**
+ * Generate and set selfsigned certificate on TLS context
+ *
+ * @param tls TLS Context
+ * @param cn  Common Name
+ *
+ * @return 0 if success, otherwise errorcode
+ */
+int tls_set_selfsigned(struct tls *tls, const char *cn)
+{
+	X509_NAME *subj = NULL;
+	EVP_PKEY *key = NULL;
+	X509 *cert = NULL;
+	BIGNUM *bn = NULL;
+	RSA *rsa = NULL;
+	int r, err = ENOMEM;
+
+	if (!tls || !cn)
+		return EINVAL;
+
+	rsa = RSA_new();
+	if (!rsa)
+		goto out;
+
+	bn = BN_new();
+	if (!bn)
+		goto out;
+
+	BN_set_word(bn, RSA_F4);
+	if (!RSA_generate_key_ex(rsa, 1024, bn, NULL))
+		goto out;
+
+	key = EVP_PKEY_new();
+	if (!key)
+		goto out;
+
+	if (!EVP_PKEY_set1_RSA(key, rsa))
+		goto out;
+
+	cert = X509_new();
+	if (!cert)
+		goto out;
+
+	if (!X509_set_version(cert, 2))
+		goto out;
+
+	if (!ASN1_INTEGER_set(X509_get_serialNumber(cert), rand_u32()))
+		goto out;
+
+	subj = X509_NAME_new();
+	if (!subj)
+		goto out;
+
+	if (!X509_NAME_add_entry_by_txt(subj, "CN", MBSTRING_ASC,
+					(unsigned char *)cn,
+					(int)strlen(cn), -1, 0))
+		goto out;
+
+	if (!X509_set_issuer_name(cert, subj) ||
+	    !X509_set_subject_name(cert, subj))
+		goto out;
+
+	if (!X509_gmtime_adj(X509_get_notBefore(cert), -3600*24*365) ||
+	    !X509_gmtime_adj(X509_get_notAfter(cert),   3600*24*365*10))
+		goto out;
+
+	if (!X509_set_pubkey(cert, key))
+		goto out;
+
+	if (!X509_sign(cert, key, EVP_sha1()))
+		goto out;
+
+	r = SSL_CTX_use_certificate(tls->ctx, cert);
+	if (r != 1)
+		goto out;
+
+	r = SSL_CTX_use_PrivateKey(tls->ctx, key);
+	if (r != 1)
+		goto out;
+
+	if (tls->cert)
+		X509_free(tls->cert);
+
+	tls->cert = cert;
+	cert = NULL;
+
+	err = 0;
+
+ out:
+	if (subj)
+		X509_NAME_free(subj);
+
+	if (cert)
+		X509_free(cert);
+
+	if (key)
+		EVP_PKEY_free(key);
+
+	if (rsa)
+		RSA_free(rsa);
+
+	if (bn)
+		BN_free(bn);
+
+	if (err)
+		ERR_clear_error();
+
+	return err;
+}
+
+
+/**
+ * Set the certificate and private key on a TLS context
+ *
+ * @param tls      TLS Context
+ * @param cert     Certificate in PEM format
+ * @param len_cert Length of certificate PEM string
+ * @param key      Private key in PEM format, will be read from cert if NULL
+ * @param len_key  Length of private key PEM string
+ *
+ * @return 0 if success, otherwise errorcode
+ */
+int tls_set_certificate_pem(struct tls *tls, const char *cert, size_t len_cert,
+			    const char *key, size_t len_key)
+{
+	BIO *bio = NULL, *kbio = NULL;
+	X509 *x509 = NULL;
+	EVP_PKEY *pkey = NULL;
+	int r, err = ENOMEM;
+
+	if (!tls || !cert || !len_cert || (key && !len_key))
+		return EINVAL;
+
+	if (!key) {
+		key = cert;
+		len_key = len_cert;
+	}
+
+	bio  = BIO_new_mem_buf((char *)cert, (int)len_cert);
+	kbio = BIO_new_mem_buf((char *)key, (int)len_key);
+	if (!bio || !kbio)
+		goto out;
+
+	x509 = PEM_read_bio_X509(bio, NULL, 0, NULL);
+	pkey = PEM_read_bio_PrivateKey(kbio, NULL, 0, NULL);
+	if (!x509 || !pkey)
+		goto out;
+
+	r = SSL_CTX_use_certificate(tls->ctx, x509);
+	if (r != 1)
+		goto out;
+
+	r = SSL_CTX_use_PrivateKey(tls->ctx, pkey);
+	if (r != 1) {
+		DEBUG_WARNING("set_certificate_pem: use_PrivateKey failed\n");
+		goto out;
+	}
+
+	if (tls->cert)
+		X509_free(tls->cert);
+
+	tls->cert = x509;
+	x509 = NULL;
+
+	err = 0;
+
+ out:
+	if (x509)
+		X509_free(x509);
+	if (pkey)
+		EVP_PKEY_free(pkey);
+	if (bio)
+		BIO_free(bio);
+	if (kbio)
+		BIO_free(kbio);
+	if (err)
+		ERR_clear_error();
+
+	return err;
+}
+
+
+/**
+ * Set the certificate and private key on a TLS context
+ *
+ * @param tls      TLS Context
+ * @param keytype  Private key type
+ * @param cert     Certificate in DER format
+ * @param len_cert Length of certificate DER bytes
+ * @param key      Private key in DER format, will be read from cert if NULL
+ * @param len_key  Length of private key DER bytes
+ *
+ * @return 0 if success, otherwise errorcode
+ */
+int tls_set_certificate_der(struct tls *tls, enum tls_keytype keytype,
+			    const uint8_t *cert, size_t len_cert,
+			    const uint8_t *key, size_t len_key)
+{
+	const uint8_t *buf_cert;
+	X509 *x509 = NULL;
+	EVP_PKEY *pkey = NULL;
+	int r, type, err = ENOMEM;
+
+	if (!tls || !cert || !len_cert || (key && !len_key))
+		return EINVAL;
+
+	type = keytype2int(keytype);
+	if (type == EVP_PKEY_NONE)
+		return EINVAL;
+
+	buf_cert = cert;
+
+	x509 = d2i_X509(NULL, &buf_cert, len_cert);
+	if (!x509)
+		goto out;
+
+	if (!key) {
+		key = buf_cert;
+		len_key = len_cert - (buf_cert - cert);
+	}
+
+	pkey = d2i_PrivateKey(type, NULL, &key, len_key);
+	if (!pkey)
+		goto out;
+
+	r = SSL_CTX_use_certificate(tls->ctx, x509);
+	if (r != 1)
+		goto out;
+
+	r = SSL_CTX_use_PrivateKey(tls->ctx, pkey);
+	if (r != 1) {
+		DEBUG_WARNING("set_certificate_der: use_PrivateKey failed\n");
+		goto out;
+	}
+
+	if (tls->cert)
+		X509_free(tls->cert);
+
+	tls->cert = x509;
+	x509 = NULL;
+
+	err = 0;
+
+ out:
+	if (x509)
+		X509_free(x509);
+	if (pkey)
+		EVP_PKEY_free(pkey);
+	if (err)
+		ERR_clear_error();
+
+	return err;
+}
+
+
+/**
+ * Set the certificate and private key on a TLS context
+ *
+ * @param tls TLS Context
+ * @param pem Certificate and private key in PEM format
+ * @param len Length of PEM string
+ *
+ * @return 0 if success, otherwise errorcode
+ */
+int tls_set_certificate(struct tls *tls, const char *pem, size_t len)
+{
+	return tls_set_certificate_pem(tls, pem, len, NULL, 0);
+}
+
+
+static int verify_handler(int ok, X509_STORE_CTX *ctx)
+{
+	(void)ok;
+	(void)ctx;
+
+	return 1;    /* We trust the certificate from peer */
+}
+
+
+/**
+ * Set TLS server context to request certificate from client
+ *
+ * @param tls    TLS Context
+ */
+void tls_set_verify_client(struct tls *tls)
+{
+	if (!tls)
+		return;
+
+	SSL_CTX_set_verify_depth(tls->ctx, 0);
+	SSL_CTX_set_verify(tls->ctx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE,
+			   verify_handler);
+}
+
+
+/**
+ * Set SRTP suites on TLS context
+ *
+ * @param tls    TLS Context
+ * @param suites Secure-RTP Profiles
+ *
+ * @return 0 if success, otherwise errorcode
+ */
+int tls_set_srtp(struct tls *tls, const char *suites)
+{
+#ifdef USE_OPENSSL_SRTP
+	if (!tls || !suites)
+		return EINVAL;
+
+	if (0 != SSL_CTX_set_tlsext_use_srtp(tls->ctx, suites)) {
+		ERR_clear_error();
+		return ENOSYS;
+	}
+
+	return 0;
+#else
+	(void)tls;
+	(void)suites;
+
+	return ENOSYS;
+#endif
+}
+
+
+static int cert_fingerprint(X509 *cert, enum tls_fingerprint type,
+			    uint8_t *md, size_t size)
+{
+	unsigned int len = (unsigned int)size;
+	int n;
+
+	switch (type) {
+
+	case TLS_FINGERPRINT_SHA1:
+		if (size < 20)
+			return EOVERFLOW;
+
+		n = X509_digest(cert, EVP_sha1(), md, &len);
+		break;
+
+	case TLS_FINGERPRINT_SHA256:
+		if (size < 32)
+			return EOVERFLOW;
+
+		n = X509_digest(cert, EVP_sha256(), md, &len);
+		break;
+
+	default:
+		return ENOSYS;
+	}
+
+	if (n != 1) {
+		ERR_clear_error();
+		return ENOENT;
+	}
+
+	return 0;
+}
+
+
+/**
+ * Get fingerprint of local certificate
+ *
+ * @param tls  TLS Context
+ * @param type Digest type
+ * @param md   Buffer for fingerprint digest
+ * @param size Buffer size
+ *
+ * @return 0 if success, otherwise errorcode
+ */
+int tls_fingerprint(const struct tls *tls, enum tls_fingerprint type,
+		    uint8_t *md, size_t size)
+{
+	if (!tls || !tls->cert || !md)
+		return EINVAL;
+
+	return cert_fingerprint(tls->cert, type, md, size);
+}
+
+
+/**
+ * Get fingerprint of peer certificate of a TLS connection
+ *
+ * @param tc   TLS Connection
+ * @param type Digest type
+ * @param md   Buffer for fingerprint digest
+ * @param size Buffer size
+ *
+ * @return 0 if success, otherwise errorcode
+ */
+int tls_peer_fingerprint(const struct tls_conn *tc, enum tls_fingerprint type,
+			 uint8_t *md, size_t size)
+{
+	X509 *cert;
+	int err;
+
+	if (!tc || !md)
+		return EINVAL;
+
+	cert = SSL_get_peer_certificate(tc->ssl);
+	if (!cert)
+		return ENOENT;
+
+	err = cert_fingerprint(cert, type, md, size);
+
+	X509_free(cert);
+
+	return err;
+}
+
+
+/**
+ * Get common name of peer certificate of a TLS connection
+ *
+ * @param tc   TLS Connection
+ * @param cn   Returned common name
+ * @param size Size of common name
+ *
+ * @return 0 if success, otherwise errorcode
+ */
+int tls_peer_common_name(const struct tls_conn *tc, char *cn, size_t size)
+{
+	X509 *cert;
+	int n;
+
+	if (!tc || !cn || !size)
+		return EINVAL;
+
+	cert = SSL_get_peer_certificate(tc->ssl);
+	if (!cert)
+		return ENOENT;
+
+	n = X509_NAME_get_text_by_NID(X509_get_subject_name(cert),
+				      NID_commonName, cn, (int)size);
+
+	X509_free(cert);
+
+	if (n < 0) {
+		ERR_clear_error();
+		return ENOENT;
+	}
+
+	return 0;
+}
+
+
+/**
+ * Verify peer certificate of a TLS connection
+ *
+ * @param tc TLS Connection
+ *
+ * @return 0 if verified, otherwise errorcode
+ */
+int tls_peer_verify(const struct tls_conn *tc)
+{
+	if (!tc)
+		return EINVAL;
+
+	if (SSL_get_verify_result(tc->ssl) != X509_V_OK)
+		return EAUTH;
+
+	return 0;
+}
+
+
+/**
+ * Get SRTP suite and keying material of a TLS connection
+ *
+ * @param tc           TLS Connection
+ * @param suite        Returned SRTP suite
+ * @param cli_key      Client key
+ * @param cli_key_size Client key size
+ * @param srv_key      Server key
+ * @param srv_key_size Server key size
+ *
+ * @return 0 if success, otherwise errorcode
+ */
+int tls_srtp_keyinfo(const struct tls_conn *tc, enum srtp_suite *suite,
+		     uint8_t *cli_key, size_t cli_key_size,
+		     uint8_t *srv_key, size_t srv_key_size)
+{
+#ifdef USE_OPENSSL_SRTP
+	static const char *label = "EXTRACTOR-dtls_srtp";
+	size_t key_size, salt_size, size;
+	SRTP_PROTECTION_PROFILE *sel;
+	uint8_t keymat[256], *p;
+
+	if (!tc || !suite || !cli_key || !srv_key)
+		return EINVAL;
+
+	sel = SSL_get_selected_srtp_profile(tc->ssl);
+	if (!sel)
+		return ENOENT;
+
+	switch (sel->id) {
+
+	case SRTP_AES128_CM_SHA1_80:
+		*suite = SRTP_AES_CM_128_HMAC_SHA1_80;
+		key_size  = 16;
+		salt_size = 14;
+		break;
+
+	case SRTP_AES128_CM_SHA1_32:
+		*suite = SRTP_AES_CM_128_HMAC_SHA1_32;
+		key_size  = 16;
+		salt_size = 14;
+		break;
+
+#ifdef SRTP_AEAD_AES_128_GCM
+	case SRTP_AEAD_AES_128_GCM:
+		*suite = SRTP_AES_128_GCM;
+		key_size  = 16;
+		salt_size = 12;
+		break;
+#endif
+
+#ifdef SRTP_AEAD_AES_256_GCM
+	case SRTP_AEAD_AES_256_GCM:
+		*suite = SRTP_AES_256_GCM;
+		key_size  = 32;
+		salt_size = 12;
+		break;
+#endif
+
+	default:
+		return ENOSYS;
+	}
+
+	size = key_size + salt_size;
+
+	if (cli_key_size < size || srv_key_size < size)
+		return EOVERFLOW;
+
+	if (sizeof(keymat) < 2*size)
+		return EOVERFLOW;
+
+	if (1 != SSL_export_keying_material(tc->ssl, keymat, 2*size, label,
+					    strlen(label), NULL, 0, 0)) {
+		ERR_clear_error();
+		return ENOENT;
+	}
+
+	p = keymat;
+
+	memcpy(cli_key,            p, key_size);  p += key_size;
+	memcpy(srv_key,            p, key_size);  p += key_size;
+	memcpy(cli_key + key_size, p, salt_size); p += salt_size;
+	memcpy(srv_key + key_size, p, salt_size);
+
+	return 0;
+#else
+	(void)tc;
+	(void)suite;
+	(void)cli_key;
+	(void)cli_key_size;
+	(void)srv_key;
+	(void)srv_key_size;
+
+	return ENOSYS;
+#endif
+}
+
+
+/**
+ * Get cipher name of a TLS connection
+ *
+ * @param tc TLS Connection
+ *
+ * @return name of cipher actually used.
+ */
+const char *tls_cipher_name(const struct tls_conn *tc)
+{
+	if (!tc)
+		return NULL;
+
+	return SSL_get_cipher_name(tc->ssl);
+}
+
+
+/**
+ * Set the ciphers to use for this TLS context
+ *
+ * @param tls      TLS Context
+ * @param cipherv  Vector of cipher names, in order of priority
+ * @param count    Number of cipher names in the vector
+ *
+ * @return 0 if success, otherwise errorcode
+ */
+int tls_set_ciphers(struct tls *tls, const char *cipherv[], size_t count)
+{
+	struct mbuf *mb;
+	int r, err;
+	size_t i;
+
+	if (!tls || !cipherv || !count)
+		return EINVAL;
+
+	mb = mbuf_alloc(32 * count);
+	if (!mb)
+		return ENOMEM;
+
+	for (i=0; i<count; i++) {
+
+		err = mbuf_printf(mb, "%s%s", i>0 ? ":" : "", cipherv[i]);
+		if (err)
+			goto out;
+	}
+
+	err = mbuf_write_u8(mb, '\0');
+	if (err)
+		goto out;
+
+	r = SSL_CTX_set_cipher_list(tls->ctx, (char *)mb->buf);
+	if (r <= 0) {
+		ERR_clear_error();
+		err = EPROTO;
+		goto out;
+	}
+
+ out:
+	mem_deref(mb);
+
+	return err;
+}
+
+
+/**
+ * Set the server name on a TLS Connection, using TLS SNI extension.
+ *
+ * @param tc         TLS Connection
+ * @param servername Server name
+ *
+ * @return 0 if success, otherwise errorcode
+ */
+int tls_set_servername(struct tls_conn *tc, const char *servername)
+{
+	if (!tc || !servername)
+		return EINVAL;
+
+	if (1 != SSL_set_tlsext_host_name(tc->ssl, servername)) {
+		DEBUG_WARNING("tls: SSL_set_tlsext_host_name error\n");
+		ERR_clear_error();
+		return EPROTO;
+	}
+
+	return 0;
+}
+
+
+static int print_error(const char *str, size_t len, void *unused)
+{
+	(void)unused;
+	DEBUG_WARNING("%b", str, len);
+
+	return 1;
+}
+
+
+void tls_flush_error(void)
+{
+	ERR_print_errors_cb(print_error, NULL);
+}
+
+
+/**
+ * Get the backend-specific (OpenSSL) context
+ *
+ * @param tls  Generic TLS Context
+ *
+ * @return OpenSSL context
+ */
+struct ssl_ctx_st *tls_openssl_context(const struct tls *tls)
+{
+	return tls ? tls->ctx : NULL;
+}
diff --git a/src/tls/openssl/tls.h b/src/tls/openssl/tls.h
new file mode 100644
index 0000000..2c621d5
--- /dev/null
+++ b/src/tls/openssl/tls.h
@@ -0,0 +1,35 @@
+/**
+ * @file openssl/tls.h TLS backend using OpenSSL (Internal API)
+ *
+ * Copyright (C) 2010 Creytiv.com
+ */
+
+
+/*
+ * Mapping of feature macros
+ */
+
+#if OPENSSL_VERSION_NUMBER >= 0x10100000L
+#define TLS_BIO_OPAQUE 1
+#endif
+
+#if defined (LIBRESSL_VERSION_NUMBER)
+#undef  TLS_BIO_OPAQUE
+#endif
+
+
+#if OPENSSL_VERSION_NUMBER >= 0x10100000L && \
+	!defined(LIBRESSL_VERSION_NUMBER)
+#define SSL_state SSL_get_state
+#define SSL_ST_OK TLS_ST_OK
+#endif
+
+
+struct tls {
+	SSL_CTX *ctx;
+	X509 *cert;
+	char *pass;  /* password for private key */
+};
+
+
+void tls_flush_error(void);
diff --git a/src/tls/openssl/tls_tcp.c b/src/tls/openssl/tls_tcp.c
new file mode 100644
index 0000000..ef3601e
--- /dev/null
+++ b/src/tls/openssl/tls_tcp.c
@@ -0,0 +1,437 @@
+/**
+ * @file openssl/tls_tcp.c TLS/TCP backend using OpenSSL
+ *
+ * Copyright (C) 2010 Creytiv.com
+ */
+
+#include <openssl/ssl.h>
+#include <openssl/err.h>
+#include <re_types.h>
+#include <re_fmt.h>
+#include <re_mem.h>
+#include <re_mbuf.h>
+#include <re_main.h>
+#include <re_sa.h>
+#include <re_net.h>
+#include <re_srtp.h>
+#include <re_tcp.h>
+#include <re_tls.h>
+#include "tls.h"
+
+
+#define DEBUG_MODULE "tls"
+#define DEBUG_LEVEL 5
+#include <re_dbg.h>
+
+
+/* NOTE: shadow struct defined in tls_*.c */
+struct tls_conn {
+	SSL *ssl;
+#ifdef TLS_BIO_OPAQUE
+	BIO_METHOD *biomet;
+#endif
+	BIO *sbio_out;
+	BIO *sbio_in;
+	struct tcp_helper *th;
+	struct tcp_conn *tcp;
+	bool active;
+	bool up;
+};
+
+
+static void destructor(void *arg)
+{
+	struct tls_conn *tc = arg;
+
+	if (tc->ssl) {
+		int r = SSL_shutdown(tc->ssl);
+		if (r <= 0)
+			ERR_clear_error();
+
+		SSL_free(tc->ssl);
+	}
+
+#ifdef TLS_BIO_OPAQUE
+	if (tc->biomet)
+		BIO_meth_free(tc->biomet);
+#endif
+
+	mem_deref(tc->th);
+	mem_deref(tc->tcp);
+}
+
+
+static int bio_create(BIO *b)
+{
+#ifdef TLS_BIO_OPAQUE
+	BIO_set_init(b, 1);
+	BIO_set_data(b, NULL);
+	BIO_set_flags(b, 0);
+#else
+	b->init  = 1;
+	b->num   = 0;
+	b->ptr   = NULL;
+	b->flags = 0;
+#endif
+
+	return 1;
+}
+
+
+static int bio_destroy(BIO *b)
+{
+	if (!b)
+		return 0;
+
+#ifdef TLS_BIO_OPAQUE
+	BIO_set_init(b, 0);
+	BIO_set_data(b, NULL);
+	BIO_set_flags(b, 0);
+#else
+	b->ptr   = NULL;
+	b->init  = 0;
+	b->flags = 0;
+#endif
+
+	return 1;
+}
+
+
+static int bio_write(BIO *b, const char *buf, int len)
+{
+#ifdef TLS_BIO_OPAQUE
+	struct tls_conn *tc = BIO_get_data(b);
+#else
+	struct tls_conn *tc = b->ptr;
+#endif
+	struct mbuf mb;
+	int err;
+
+	mb.buf = (void *)buf;
+	mb.pos = 0;
+	mb.end = mb.size = len;
+
+	err = tcp_send_helper(tc->tcp, &mb, tc->th);
+	if (err)
+		return -1;
+
+	return len;
+}
+
+
+static long bio_ctrl(BIO *b, int cmd, long num, void *ptr)
+{
+	(void)b;
+	(void)num;
+	(void)ptr;
+
+	if (cmd == BIO_CTRL_FLUSH) {
+		/* The OpenSSL library needs this */
+		return 1;
+	}
+
+	return 0;
+}
+
+
+#ifdef TLS_BIO_OPAQUE
+
+static BIO_METHOD *bio_method_tcp(void)
+{
+	BIO_METHOD *method;
+
+	method = BIO_meth_new(BIO_TYPE_SOURCE_SINK, "tcp_send");
+	if (!method) {
+		DEBUG_WARNING("alloc: BIO_meth_new() failed\n");
+		ERR_clear_error();
+		return NULL;
+	}
+
+	BIO_meth_set_write(method, bio_write);
+	BIO_meth_set_ctrl(method, bio_ctrl);
+	BIO_meth_set_create(method, bio_create);
+	BIO_meth_set_destroy(method, bio_destroy);
+
+	return method;
+}
+
+#else
+
+static struct bio_method_st bio_tcp_send = {
+	BIO_TYPE_SOURCE_SINK,
+	"tcp_send",
+	bio_write,
+	0,
+	0,
+	0,
+	bio_ctrl,
+	bio_create,
+	bio_destroy,
+	0
+};
+
+#endif
+
+
+static int tls_connect(struct tls_conn *tc)
+{
+	int err = 0, r;
+
+	ERR_clear_error();
+
+	r = SSL_connect(tc->ssl);
+	if (r <= 0) {
+		const int ssl_err = SSL_get_error(tc->ssl, r);
+
+		ERR_clear_error();
+
+		switch (ssl_err) {
+
+		case SSL_ERROR_WANT_READ:
+			break;
+
+		default:
+			DEBUG_WARNING("connect: error (r=%d, ssl_err=%d)\n",
+				      r, ssl_err);
+			err = EPROTO;
+			break;
+		}
+	}
+
+	return err;
+}
+
+
+static int tls_accept(struct tls_conn *tc)
+{
+	int err = 0, r;
+
+	ERR_clear_error();
+
+	r = SSL_accept(tc->ssl);
+	if (r <= 0) {
+		const int ssl_err = SSL_get_error(tc->ssl, r);
+
+		ERR_clear_error();
+
+		switch (ssl_err) {
+
+		case SSL_ERROR_WANT_READ:
+			break;
+
+		default:
+			DEBUG_WARNING("accept error: (r=%d, ssl_err=%d)\n",
+				      r, ssl_err);
+			err = EPROTO;
+			break;
+		}
+	}
+
+	return err;
+}
+
+
+static bool estab_handler(int *err, bool active, void *arg)
+{
+	struct tls_conn *tc = arg;
+
+	DEBUG_INFO("tcp established (active=%u)\n", active);
+
+	if (!active)
+		return true;
+
+	tc->active = true;
+	*err = tls_connect(tc);
+
+	return true;
+}
+
+
+static bool recv_handler(int *err, struct mbuf *mb, bool *estab, void *arg)
+{
+	struct tls_conn *tc = arg;
+	int r;
+
+	/* feed SSL data to the BIO */
+	r = BIO_write(tc->sbio_in, mbuf_buf(mb), (int)mbuf_get_left(mb));
+	if (r <= 0) {
+		DEBUG_WARNING("recv: BIO_write %d\n", r);
+		ERR_clear_error();
+		*err = ENOMEM;
+		return true;
+	}
+
+	if (SSL_state(tc->ssl) != SSL_ST_OK) {
+
+		if (tc->up) {
+			*err = EPROTO;
+			return true;
+		}
+
+		if (tc->active) {
+			*err = tls_connect(tc);
+		}
+		else {
+			*err = tls_accept(tc);
+		}
+
+		DEBUG_INFO("state=0x%04x\n", SSL_state(tc->ssl));
+
+		/* TLS connection is established */
+		if (SSL_state(tc->ssl) != SSL_ST_OK)
+			return true;
+
+		*estab = true;
+		tc->up = true;
+	}
+
+	mbuf_set_pos(mb, 0);
+
+	for (;;) {
+		int n;
+
+		if (mbuf_get_space(mb) < 4096) {
+			*err = mbuf_resize(mb, mb->size + 8192);
+			if (*err)
+				return true;
+		}
+
+		ERR_clear_error();
+
+		n = SSL_read(tc->ssl, mbuf_buf(mb), (int)mbuf_get_space(mb));
+		if (n <= 0) {
+			const int ssl_err = SSL_get_error(tc->ssl, n);
+
+			ERR_clear_error();
+
+			switch (ssl_err) {
+
+			case SSL_ERROR_WANT_READ:
+				break;
+
+			case SSL_ERROR_ZERO_RETURN:
+				*err = ECONNRESET;
+				return true;
+
+			default:
+				*err = EPROTO;
+				return true;
+			}
+
+			break;
+		}
+
+		mb->pos += n;
+	}
+
+	mbuf_set_end(mb, mb->pos);
+	mbuf_set_pos(mb, 0);
+
+	return false;
+}
+
+
+static bool send_handler(int *err, struct mbuf *mb, void *arg)
+{
+	struct tls_conn *tc = arg;
+	int r;
+
+	ERR_clear_error();
+
+	r = SSL_write(tc->ssl, mbuf_buf(mb), (int)mbuf_get_left(mb));
+	if (r <= 0) {
+		DEBUG_WARNING("SSL_write: %d\n", SSL_get_error(tc->ssl, r));
+		ERR_clear_error();
+		*err = EPROTO;
+	}
+
+	return true;
+}
+
+
+/**
+ * Start TLS on a TCP-connection
+ *
+ * @param ptc   Pointer to allocated TLS connectioon
+ * @param tls   TLS Context
+ * @param tcp   TCP Connection
+ * @param layer Protocol stack layer
+ *
+ * @return 0 if success, otherwise errorcode
+ */
+int tls_start_tcp(struct tls_conn **ptc, struct tls *tls, struct tcp_conn *tcp,
+		  int layer)
+{
+	struct tls_conn *tc;
+	int err;
+
+	if (!ptc || !tls || !tcp)
+		return EINVAL;
+
+	tc = mem_zalloc(sizeof(*tc), destructor);
+	if (!tc)
+		return ENOMEM;
+
+	err = tcp_register_helper(&tc->th, tcp, layer, estab_handler,
+				  send_handler, recv_handler, tc);
+	if (err)
+		goto out;
+
+	tc->tcp = mem_ref(tcp);
+
+#ifdef TLS_BIO_OPAQUE
+	tc->biomet = bio_method_tcp();
+	if (!tc->biomet) {
+		err = ENOMEM;
+		goto out;
+	}
+#endif
+
+	err = ENOMEM;
+
+	/* Connect the SSL socket */
+	tc->ssl = SSL_new(tls->ctx);
+	if (!tc->ssl) {
+		DEBUG_WARNING("alloc: SSL_new() failed (ctx=%p)\n", tls->ctx);
+		ERR_clear_error();
+		goto out;
+	}
+
+	tc->sbio_in = BIO_new(BIO_s_mem());
+	if (!tc->sbio_in) {
+		DEBUG_WARNING("alloc: BIO_new() failed\n");
+		ERR_clear_error();
+		goto out;
+	}
+
+
+#ifdef TLS_BIO_OPAQUE
+	tc->sbio_out = BIO_new(tc->biomet);
+#else
+	tc->sbio_out = BIO_new(&bio_tcp_send);
+#endif
+	if (!tc->sbio_out) {
+		DEBUG_WARNING("alloc: BIO_new_socket() failed\n");
+		ERR_clear_error();
+		BIO_free(tc->sbio_in);
+		goto out;
+	}
+
+#ifdef TLS_BIO_OPAQUE
+	BIO_set_data(tc->sbio_out, tc);
+#else
+	tc->sbio_out->ptr = tc;
+#endif
+
+	SSL_set_bio(tc->ssl, tc->sbio_in, tc->sbio_out);
+
+	err = 0;
+
+ out:
+	if (err)
+		mem_deref(tc);
+	else
+		*ptc = tc;
+
+	return err;
+}
diff --git a/src/tls/openssl/tls_udp.c b/src/tls/openssl/tls_udp.c
new file mode 100644
index 0000000..4ec81a3
--- /dev/null
+++ b/src/tls/openssl/tls_udp.c
@@ -0,0 +1,883 @@
+/**
+ * @file openssl/tls_udp.c DTLS backend using OpenSSL
+ *
+ * Copyright (C) 2010 Creytiv.com
+ */
+
+#include <sys/time.h>
+#include <openssl/ssl.h>
+#include <openssl/err.h>
+#include <re_types.h>
+#include <re_fmt.h>
+#include <re_mem.h>
+#include <re_mbuf.h>
+#include <re_list.h>
+#include <re_hash.h>
+#include <re_sa.h>
+#include <re_srtp.h>
+#include <re_udp.h>
+#include <re_tmr.h>
+#include <re_tls.h>
+#include "tls.h"
+
+
+#define DEBUG_MODULE "dtls"
+#define DEBUG_LEVEL 5
+#include <re_dbg.h>
+
+
+enum {
+	MTU_DEFAULT  = 1400,
+	MTU_FALLBACK = 548,
+};
+
+
+struct dtls_sock {
+	struct sa peer;
+	struct udp_helper *uh;
+	struct udp_sock *us;
+	struct hash *ht;
+	struct mbuf *mb;
+	dtls_conn_h *connh;
+	void *arg;
+	size_t mtu;
+};
+
+
+/* NOTE: shadow struct defined in tls_*.c */
+struct tls_conn {
+	SSL *ssl;             /* inheritance */
+#ifdef TLS_BIO_OPAQUE
+	BIO_METHOD *biomet;
+#endif
+	BIO *sbio_out;
+	BIO *sbio_in;
+	struct tmr tmr;
+	struct sa peer;
+	struct le he;
+	struct dtls_sock *sock;
+	dtls_estab_h *estabh;
+	dtls_recv_h *recvh;
+	dtls_close_h *closeh;
+	void *arg;
+	bool active;
+	bool up;
+};
+
+
+static int bio_create(BIO *b)
+{
+#ifdef TLS_BIO_OPAQUE
+	BIO_set_init(b, 1);
+	BIO_set_data(b, NULL);
+	BIO_set_flags(b, 0);
+#else
+	b->init  = 1;
+	b->num   = 0;
+	b->ptr   = NULL;
+	b->flags = 0;
+#endif
+
+	return 1;
+}
+
+
+static int bio_destroy(BIO *b)
+{
+	if (!b)
+		return 0;
+
+#ifdef TLS_BIO_OPAQUE
+	BIO_set_init(b, 0);
+	BIO_set_data(b, NULL);
+	BIO_set_flags(b, 0);
+#else
+	b->ptr   = NULL;
+	b->init  = 0;
+	b->flags = 0;
+#endif
+
+	return 1;
+}
+
+
+static int bio_write(BIO *b, const char *buf, int len)
+{
+#ifdef TLS_BIO_OPAQUE
+	struct tls_conn *tc = BIO_get_data(b);
+#else
+	struct tls_conn *tc = b->ptr;
+#endif
+	struct mbuf *mb;
+	enum {SPACE = 4};
+	int err;
+
+	mb = mbuf_alloc(SPACE + len);
+	if (!mb)
+		return -1;
+
+	mb->pos = SPACE;
+	(void)mbuf_write_mem(mb, (void *)buf, len);
+	mb->pos = SPACE;
+
+	err = udp_send_helper(tc->sock->us, &tc->peer, mb, tc->sock->uh);
+
+	mem_deref(mb);
+
+	return err ? -1 : len;
+}
+
+
+static long bio_ctrl(BIO *b, int cmd, long num, void *ptr)
+{
+#ifdef TLS_BIO_OPAQUE
+	struct tls_conn *tc = BIO_get_data(b);
+#else
+	struct tls_conn *tc = b->ptr;
+#endif
+	(void)num;
+	(void)ptr;
+
+	switch (cmd) {
+
+	case BIO_CTRL_FLUSH:
+		/* The OpenSSL library needs this */
+		return 1;
+
+#if defined (BIO_CTRL_DGRAM_QUERY_MTU)
+	case BIO_CTRL_DGRAM_QUERY_MTU:
+		return tc ? tc->sock->mtu : MTU_DEFAULT;
+#endif
+
+#if defined (BIO_CTRL_DGRAM_GET_FALLBACK_MTU)
+	case BIO_CTRL_DGRAM_GET_FALLBACK_MTU:
+		return MTU_FALLBACK;
+#endif
+	}
+
+	return 0;
+}
+
+
+#ifdef TLS_BIO_OPAQUE
+
+static BIO_METHOD *bio_method_udp(void)
+{
+	BIO_METHOD *method;
+
+	method = BIO_meth_new(BIO_TYPE_SOURCE_SINK, "udp_send");
+	if (!method) {
+		DEBUG_WARNING("alloc: BIO_meth_new() failed\n");
+		ERR_clear_error();
+		return NULL;
+	}
+
+	BIO_meth_set_write(method, bio_write);
+	BIO_meth_set_ctrl(method, bio_ctrl);
+	BIO_meth_set_create(method, bio_create);
+	BIO_meth_set_destroy(method, bio_destroy);
+
+	return method;
+}
+
+#else
+
+static struct bio_method_st bio_udp_send = {
+	BIO_TYPE_SOURCE_SINK,
+	"udp_send",
+	bio_write,
+	0,
+	0,
+	0,
+	bio_ctrl,
+	bio_create,
+	bio_destroy,
+	0
+};
+
+#endif
+
+
+static void tls_close(struct tls_conn *tc)
+{
+	int r;
+
+	if (!tc->ssl)
+		return;
+
+	r = SSL_shutdown(tc->ssl);
+	if (r <= 0)
+		ERR_clear_error();
+
+	SSL_free(tc->ssl);
+	tc->ssl = NULL;
+}
+
+
+static void conn_destructor(void *arg)
+{
+	struct tls_conn *tc = arg;
+
+	hash_unlink(&tc->he);
+	tmr_cancel(&tc->tmr);
+	tls_close(tc);
+
+#ifdef TLS_BIO_OPAQUE
+	if (tc->biomet)
+		BIO_meth_free(tc->biomet);
+#endif
+
+	mem_deref(tc->sock);
+}
+
+
+static void conn_close(struct tls_conn *tc, int err)
+{
+	tmr_cancel(&tc->tmr);
+	tls_close(tc);
+	tc->up = false;
+
+	if (tc->closeh)
+		tc->closeh(err, tc->arg);
+}
+
+
+#if defined (DTLS_CTRL_HANDLE_TIMEOUT) && defined(DTLS_CTRL_GET_TIMEOUT)
+
+static void check_timer(struct tls_conn *tc);
+
+
+static void timeout(void *arg)
+{
+	struct tls_conn *tc = arg;
+
+	DEBUG_INFO("timeout\n");
+
+	if (0 <= DTLSv1_handle_timeout(tc->ssl)) {
+
+		check_timer(tc);
+	}
+	else {
+		ERR_clear_error();
+		conn_close(tc, ETIMEDOUT);
+	}
+}
+
+
+static void check_timer(struct tls_conn *tc)
+{
+	struct timeval tv = {0, 0};
+
+	if (1 == DTLSv1_get_timeout(tc->ssl, &tv)) {
+
+		tmr_start(&tc->tmr, tv.tv_sec * 1000 + tv.tv_usec / 1000,
+			  timeout, tc);
+	}
+	else {
+		tmr_cancel(&tc->tmr);
+	}
+}
+
+#else
+
+static void check_timer(struct tls_conn *tc)
+{
+	(void)tc;
+}
+
+#endif
+
+
+static int tls_connect(struct tls_conn *tc)
+{
+	int r;
+
+	ERR_clear_error();
+
+	r = SSL_connect(tc->ssl);
+	if (r <= 0) {
+		const int ssl_err = SSL_get_error(tc->ssl, r);
+
+		tls_flush_error();
+
+		switch (ssl_err) {
+
+		case SSL_ERROR_WANT_READ:
+			break;
+
+		default:
+			DEBUG_WARNING("connect error: %i\n", ssl_err);
+			return EPROTO;
+		}
+	}
+
+	check_timer(tc);
+
+	return 0;
+}
+
+
+static int tls_accept(struct tls_conn *tc)
+{
+	int r;
+
+	ERR_clear_error();
+
+	r = SSL_accept(tc->ssl);
+	if (r <= 0) {
+		const int ssl_err = SSL_get_error(tc->ssl, r);
+
+		tls_flush_error();
+
+		switch (ssl_err) {
+
+		case SSL_ERROR_WANT_READ:
+			break;
+
+		default:
+			DEBUG_WARNING("accept error: %i\n", ssl_err);
+			return EPROTO;
+		}
+	}
+
+	check_timer(tc);
+
+	return 0;
+}
+
+
+static void conn_recv(struct tls_conn *tc, struct mbuf *mb)
+{
+	int err, r;
+
+	if (!tc->ssl)
+		return;
+
+	/* feed SSL data to the BIO */
+	r = BIO_write(tc->sbio_in, mbuf_buf(mb), (int)mbuf_get_left(mb));
+	if (r <= 0) {
+		DEBUG_WARNING("receive bio write error: %i\n", r);
+		ERR_clear_error();
+		conn_close(tc, ENOMEM);
+		return;
+	}
+
+	if (SSL_state(tc->ssl) != SSL_ST_OK) {
+
+		if (tc->up) {
+			conn_close(tc, EPROTO);
+			return;
+		}
+
+		if (tc->active) {
+			err = tls_connect(tc);
+		}
+		else {
+			err = tls_accept(tc);
+		}
+
+		if (err) {
+			conn_close(tc, err);
+			return;
+		}
+
+		DEBUG_INFO("%s: state=0x%04x\n",
+			   tc->active ? "client" : "server",
+			   SSL_state(tc->ssl));
+
+		/* TLS connection is established */
+		if (SSL_state(tc->ssl) != SSL_ST_OK)
+			return;
+
+		tc->up = true;
+
+		if (tc->estabh) {
+			uint32_t nrefs;
+
+			mem_ref(tc);
+
+			tc->estabh(tc->arg);
+
+                        nrefs = mem_nrefs(tc);
+                        mem_deref(tc);
+
+                        /* check if connection was deref'd from handler */
+                        if (nrefs == 1)
+                                return;
+		}
+	}
+
+	mbuf_set_pos(mb, 0);
+
+	for (;;) {
+		int n;
+
+		if (mbuf_get_space(mb) < 4096) {
+			err = mbuf_resize(mb, mb->size + 8192);
+			if (err) {
+				conn_close(tc, err);
+				return;
+			}
+		}
+
+		ERR_clear_error();
+
+		n = SSL_read(tc->ssl, mbuf_buf(mb), (int)mbuf_get_space(mb));
+		if (n <= 0) {
+			const int ssl_err = SSL_get_error(tc->ssl, n);
+
+			ERR_clear_error();
+
+			switch (ssl_err) {
+
+			case SSL_ERROR_WANT_READ:
+				break;
+
+			case SSL_ERROR_ZERO_RETURN:
+				conn_close(tc, ECONNRESET);
+				return;
+
+			default:
+				DEBUG_WARNING("read error: %i\n", ssl_err);
+				conn_close(tc, EPROTO);
+				return;
+			}
+
+			break;
+		}
+
+		mb->pos += n;
+	}
+
+	mbuf_set_end(mb, mb->pos);
+	mbuf_set_pos(mb, 0);
+
+	if (tc->recvh && mbuf_get_left(mb) > 0)
+		tc->recvh(mb, tc->arg);
+
+	return;
+}
+
+
+static int conn_alloc(struct tls_conn **ptc, struct tls *tls,
+		      struct dtls_sock *sock, const struct sa *peer,
+		      dtls_estab_h *estabh, dtls_recv_h *recvh,
+		      dtls_close_h *closeh, void *arg)
+{
+	struct tls_conn *tc;
+	int err = 0;
+
+	tc = mem_zalloc(sizeof(*tc), conn_destructor);
+	if (!tc)
+		return ENOMEM;
+
+	hash_append(sock->ht, sa_hash(peer, SA_ALL), &tc->he, tc);
+
+	tc->sock   = mem_ref(sock);
+	tc->peer   = *peer;
+	tc->estabh = estabh;
+	tc->recvh  = recvh;
+	tc->closeh = closeh;
+	tc->arg    = arg;
+
+#ifdef TLS_BIO_OPAQUE
+	tc->biomet = bio_method_udp();
+	if (!tc->biomet) {
+		err = ENOMEM;
+		goto out;
+	}
+#endif
+
+	/* Connect the SSL socket */
+	tc->ssl = SSL_new(tls->ctx);
+	if (!tc->ssl) {
+		DEBUG_WARNING("ssl new failed: %i\n",
+			      ERR_GET_REASON(ERR_get_error()));
+		ERR_clear_error();
+		err = ENOMEM;
+		goto out;
+	}
+
+	tc->sbio_in = BIO_new(BIO_s_mem());
+	if (!tc->sbio_in) {
+		ERR_clear_error();
+		err = ENOMEM;
+		goto out;
+	}
+
+#ifdef TLS_BIO_OPAQUE
+	tc->sbio_out = BIO_new(tc->biomet);
+#else
+	tc->sbio_out = BIO_new(&bio_udp_send);
+#endif
+	if (!tc->sbio_out) {
+		ERR_clear_error();
+		BIO_free(tc->sbio_in);
+		err = ENOMEM;
+		goto out;
+	}
+
+#ifdef TLS_BIO_OPAQUE
+	BIO_set_data(tc->sbio_out, tc);
+#else
+	tc->sbio_out->ptr = tc;
+#endif
+
+	SSL_set_bio(tc->ssl, tc->sbio_in, tc->sbio_out);
+
+	SSL_set_read_ahead(tc->ssl, 1);
+
+ out:
+	if (err)
+		mem_deref(tc);
+	else
+		*ptc = tc;
+
+	return err;
+}
+
+
+/**
+ * DTLS Connect
+ *
+ * @param ptc    Pointer to allocated DTLS connection
+ * @param tls    TLS Context
+ * @param sock   DTLS Socket
+ * @param peer   Peer address
+ * @param estabh Establish handler
+ * @param recvh  Receive handler
+ * @param closeh Close handler
+ * @param arg    Handler argument
+ *
+ * @return 0 if success, otherwise errorcode
+ */
+int dtls_connect(struct tls_conn **ptc, struct tls *tls,
+		 struct dtls_sock *sock, const struct sa *peer,
+		 dtls_estab_h *estabh, dtls_recv_h *recvh,
+		 dtls_close_h *closeh, void *arg)
+{
+	struct tls_conn *tc;
+	int err;
+
+	if (!ptc || !tls || !sock || !peer)
+		return EINVAL;
+
+	err = conn_alloc(&tc, tls, sock, peer, estabh, recvh, closeh, arg);
+	if (err)
+		return err;
+
+	tc->active = true;
+
+	err = tls_connect(tc);
+	if (err)
+		goto out;
+
+ out:
+	if (err)
+		mem_deref(tc);
+	else
+		*ptc = tc;
+
+	return err;
+}
+
+
+/**
+ * DTLS Accept
+ *
+ * @param ptc    Pointer to allocated DTLS connection
+ * @param tls    TLS Context
+ * @param sock   DTLS Socket
+ * @param estabh Establish handler
+ * @param recvh  Receive handler
+ * @param closeh Close handler
+ * @param arg    Handler argument
+ *
+ * @return 0 if success, otherwise errorcode
+ */
+int dtls_accept(struct tls_conn **ptc, struct tls *tls,
+		struct dtls_sock *sock,
+		dtls_estab_h *estabh, dtls_recv_h *recvh,
+		dtls_close_h *closeh, void *arg)
+{
+	struct tls_conn *tc;
+	int err, r;
+
+	if (!ptc || !tls || !sock || !sock->mb)
+		return EINVAL;
+
+	err = conn_alloc(&tc, tls, sock, &sock->peer, estabh, recvh, closeh,
+			 arg);
+	if (err)
+		return err;
+
+	tc->active = false;
+
+	r = BIO_write(tc->sbio_in, mbuf_buf(sock->mb),
+		      (int)mbuf_get_left(sock->mb));
+	if (r <= 0) {
+		DEBUG_WARNING("accept bio write error: %i\n", r);
+		ERR_clear_error();
+		err = ENOMEM;
+		goto out;
+	}
+
+	err = tls_accept(tc);
+	if (err)
+		goto out;
+
+	sock->mb = mem_deref(sock->mb);
+
+ out:
+	if (err)
+		mem_deref(tc);
+	else
+		*ptc = tc;
+
+	return err;
+}
+
+
+/**
+ * Send data on a DTLS connection
+ *
+ * @param tc DTLS connection
+ * @param mb Buffer to send
+ *
+ * @return 0 if success, otherwise errorcode
+ */
+int dtls_send(struct tls_conn *tc, struct mbuf *mb)
+{
+	int r;
+
+	if (!tc || !mb)
+		return EINVAL;
+
+	if (!tc->up || !tc->ssl)
+		return ENOTCONN;
+
+	ERR_clear_error();
+
+	r = SSL_write(tc->ssl, mbuf_buf(mb), (int)mbuf_get_left(mb));
+	if (r <= 0) {
+		DEBUG_WARNING("write error: %i\n", SSL_get_error(tc->ssl, r));
+		ERR_clear_error();
+		return EPROTO;
+	}
+
+	return 0;
+}
+
+
+/**
+ * Set handlers on a DTLS Connection
+ *
+ * @param tc     DTLS Connection
+ * @param estabh DTLS Connection Established handler
+ * @param recvh  DTLS Connection Receive data handler
+ * @param closeh DTLS Connection Close handler
+ * @param arg    Handler argument
+ */
+void dtls_set_handlers(struct tls_conn *tc, dtls_estab_h *estabh,
+		       dtls_recv_h *recvh, dtls_close_h *closeh, void *arg)
+{
+	if (!tc)
+		return;
+
+	tc->estabh = estabh;
+	tc->recvh  = recvh;
+	tc->closeh = closeh;
+	tc->arg    = arg;
+}
+
+
+/**
+ * Get the remote peer of a DTLS Connection
+ *
+ * @param tc DTLS Connection
+ *
+ * @return Remote peer
+ */
+const struct sa *dtls_peer(const struct tls_conn *tc)
+{
+	return tc ? &tc->peer : NULL;
+}
+
+
+/**
+ * Set the remote peer of a DTLS Connection
+ *
+ * @param tc     DTLS Connection
+ * @param peer   Peer address
+ */
+void dtls_set_peer(struct tls_conn *tc, const struct sa *peer)
+{
+	if (!tc || !peer)
+		return;
+
+	hash_unlink(&tc->he);
+	hash_append(tc->sock->ht, sa_hash(peer, SA_ALL), &tc->he, tc);
+
+	tc->peer = *peer;
+}
+
+
+static void sock_destructor(void *arg)
+{
+	struct dtls_sock *sock = arg;
+
+	hash_clear(sock->ht);
+	mem_deref(sock->uh);
+	mem_deref(sock->us);
+	mem_deref(sock->ht);
+	mem_deref(sock->mb);
+}
+
+
+static bool cmp_handler(struct le *le, void *arg)
+{
+	struct tls_conn *tc = le->data;
+
+	return sa_cmp(&tc->peer, arg, SA_ALL);
+}
+
+
+static struct tls_conn *conn_lookup(struct dtls_sock *sock,
+				    const struct sa *peer)
+{
+	return list_ledata(hash_lookup(sock->ht, sa_hash(peer, SA_ALL),
+                                       cmp_handler, (void *)peer));
+}
+
+
+static bool recv_handler(struct sa *src, struct mbuf *mb, void *arg)
+{
+	struct dtls_sock *sock = arg;
+	struct tls_conn *tc;
+	uint8_t b;
+
+	if (mbuf_get_left(mb) < 1)
+		return false;
+
+	b = mb->buf[mb->pos];
+	if (b < 20 || b > 63)
+		return false;
+
+	tc = conn_lookup(sock, src);
+	if (tc) {
+		conn_recv(tc, mb);
+		return true;
+	}
+
+	if (sock->connh) {
+
+		mem_deref(sock->mb);
+		sock->mb   = mem_ref(mb);
+		sock->peer = *src;
+
+		sock->connh(src, sock->arg);
+	}
+
+	return true;
+}
+
+
+/**
+ * Create DTLS Socket
+ *
+ * @param sockp  Pointer to returned DTLS Socket
+ * @param laddr  Local listen address (optional)
+ * @param us     External UDP socket (optional)
+ * @param htsize Connection hash table size
+ * @param layer  UDP protocol layer
+ * @param connh  Connect handler
+ * @param arg    Handler argument
+ *
+ * @return 0 if success, otherwise errorcode
+ */
+int dtls_listen(struct dtls_sock **sockp, const struct sa *laddr,
+		struct udp_sock *us, uint32_t htsize, int layer,
+		dtls_conn_h *connh, void *arg)
+{
+	struct dtls_sock *sock;
+	int err;
+
+	if (!sockp)
+		return EINVAL;
+
+	sock = mem_zalloc(sizeof(*sock), sock_destructor);
+	if (!sock)
+		return ENOMEM;
+
+	if (us) {
+		sock->us = mem_ref(us);
+	}
+	else {
+		err = udp_listen(&sock->us, laddr, NULL, NULL);
+		if (err)
+			goto out;
+	}
+
+	err = udp_register_helper(&sock->uh, sock->us, layer,
+				  NULL, recv_handler, sock);
+	if (err)
+		goto out;
+
+	err = hash_alloc(&sock->ht, hash_valid_size(htsize));
+	if (err)
+		goto out;
+
+	sock->mtu   = MTU_DEFAULT;
+	sock->connh = connh;
+	sock->arg   = arg;
+
+ out:
+	if (err)
+		mem_deref(sock);
+	else
+		*sockp = sock;
+
+	return err;
+}
+
+
+/**
+ * Get the underlying UDP socket of a DTLS Socket
+ *
+ * @param sock DTLS Socket
+ *
+ * @return UDP Socket
+ */
+struct udp_sock *dtls_udp_sock(struct dtls_sock *sock)
+{
+	return sock ? sock->us : NULL;
+}
+
+
+/**
+ * Set MTU on a DTLS Socket
+ *
+ * @param sock DTLS Socket
+ * @param mtu  MTU value
+ */
+void dtls_set_mtu(struct dtls_sock *sock, size_t mtu)
+{
+	if (!sock)
+		return;
+
+	sock->mtu = mtu;
+}
+
+
+void dtls_recv_packet(struct dtls_sock *sock, const struct sa *src,
+		      struct mbuf *mb)
+{
+	struct sa addr;
+
+	if (!sock || !src || !mb)
+		return;
+
+	addr = *src;
+
+	recv_handler(&addr, mb, sock);
+}