/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
 *  Authors: Jeffrey Stedfast <fejj@ximian.com>
 *
 *  Copyright 2001 Ximian, Inc. (www.ximian.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU Lesser General Public
 * License 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 Lesser 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.
 *
 */


#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#ifdef HAVE_OPENSSL

#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>

#include <openssl/err.h>
#include <openssl/ssl.h>
#include <openssl/x509.h>

#include "camel-certdb.h"
#include "camel-operation.h"
#include "camel-service.h"
#include "camel-session.h"

#include "camel-tcp-stream-ssl.h"

#define d(x)

#define TIMEOUT_USEC  (10000)

static CamelTcpStreamClass *parent_class = NULL;

/* Returns the class for a CamelTcpStreamSSL */
#define CTSR_CLASS(so) CAMEL_TCP_STREAM_SSL_CLASS (CAMEL_OBJECT_GET_CLASS (so))

static ssize_t stream_read (CamelStream *stream, char *buffer, size_t n);
static ssize_t stream_write (CamelStream *stream, const char *buffer, size_t n);
static int stream_flush  (CamelStream *stream);
static int stream_close  (CamelStream *stream);

static int stream_connect (CamelTcpStream *stream, struct hostent *host, int port);
static int stream_getsockopt (CamelTcpStream *stream, CamelSockOptData *data);
static int stream_setsockopt (CamelTcpStream *stream, const CamelSockOptData *data);
static CamelTcpAddress *stream_get_local_address (CamelTcpStream *stream);
static CamelTcpAddress *stream_get_remote_address (CamelTcpStream *stream);

static SSL *open_ssl_connection (CamelService *service, int sockfd, CamelTcpStreamSSL *openssl);

struct _CamelTcpStreamSSLPrivate {
	int sockfd;
	SSL *ssl;

	CamelService *service;
	char *expected_host;
	gboolean ssl_mode;
	guint32 flags;
};

static void
camel_tcp_stream_ssl_class_init (CamelTcpStreamSSLClass *camel_tcp_stream_ssl_class)
{
	CamelTcpStreamClass *camel_tcp_stream_class =
		CAMEL_TCP_STREAM_CLASS (camel_tcp_stream_ssl_class);
	CamelStreamClass *camel_stream_class =
		CAMEL_STREAM_CLASS (camel_tcp_stream_ssl_class);

	parent_class = CAMEL_TCP_STREAM_CLASS (camel_type_get_global_classfuncs (camel_tcp_stream_get_type ()));

	/* virtual method overload */
	camel_stream_class->read = stream_read;
	camel_stream_class->write = stream_write;
	camel_stream_class->flush = stream_flush;
	camel_stream_class->close = stream_close;

	camel_tcp_stream_class->connect = stream_connect;
	camel_tcp_stream_class->getsockopt = stream_getsockopt;
	camel_tcp_stream_class->setsockopt = stream_setsockopt;
	camel_tcp_stream_class->get_local_address  = stream_get_local_address;
	camel_tcp_stream_class->get_remote_address = stream_get_remote_address;

	/* init OpenSSL stuff */
	SSLeay_add_ssl_algorithms ();
	SSL_load_error_strings ();
}

static void
camel_tcp_stream_ssl_init (gpointer object, gpointer klass)
{
	CamelTcpStreamSSL *stream = CAMEL_TCP_STREAM_SSL (object);

	stream->priv = g_new0 (struct _CamelTcpStreamSSLPrivate, 1);
	stream->priv->sockfd = -1;
}

static void
camel_tcp_stream_ssl_finalize (CamelObject *object)
{
	CamelTcpStreamSSL *stream = CAMEL_TCP_STREAM_SSL (object);

	if (stream->priv->ssl) {
		SSL_shutdown (stream->priv->ssl);

		if (stream->priv->ssl->ctx) {
			SSL_CTX_free (stream->priv->ssl->ctx);
		}

		SSL_free (stream->priv->ssl);
	}

	if (stream->priv->sockfd != -1)
		close (stream->priv->sockfd);

	g_free (stream->priv->expected_host);

	g_free (stream->priv);
}


CamelType
camel_tcp_stream_ssl_get_type (void)
{
	static CamelType type = CAMEL_INVALID_TYPE;

	if (type == CAMEL_INVALID_TYPE) {
		type = camel_type_register (camel_tcp_stream_get_type (),
					    "CamelTcpStreamSSL",
					    sizeof (CamelTcpStreamSSL),
					    sizeof (CamelTcpStreamSSLClass),
					    (CamelObjectClassInitFunc) camel_tcp_stream_ssl_class_init,
					    NULL,
					    (CamelObjectInitFunc) camel_tcp_stream_ssl_init,
					    (CamelObjectFinalizeFunc) camel_tcp_stream_ssl_finalize);
	}

	return type;
}


/**
 * camel_tcp_stream_ssl_new:
 * @service: camel service
 * @expected_host: host that the stream is expecting to connect with.
 * @flags: flags
 *
 * Since the SSL certificate authenticator may need to prompt the
 * user, a CamelService is needed. @expected_host is needed as a
 * protection against an MITM attack.
 *
 * Return value: a ssl stream (in ssl mode)
 **/
CamelStream *
camel_tcp_stream_ssl_new (CamelService *service, const char *expected_host, guint32 flags)
{
	CamelTcpStreamSSL *stream;

	stream = CAMEL_TCP_STREAM_SSL (camel_object_new (camel_tcp_stream_ssl_get_type ()));

	stream->priv->service = service;
	stream->priv->expected_host = g_strdup (expected_host);
	stream->priv->ssl_mode = TRUE;
	stream->priv->flags = flags;

	return CAMEL_STREAM (stream);
}


/**
 * camel_tcp_stream_ssl_new_raw:
 * @service: camel service
 * @expected_host: host that the stream is expecting to connect with.
 * @flags: flags
 *
 * Since the SSL certificate authenticator may need to prompt the
 * user, a CamelService is needed. @expected_host is needed as a
 * protection against an MITM attack.
 *
 * Return value: a ssl-capable stream (in non ssl mode)
 **/
CamelStream *
camel_tcp_stream_ssl_new_raw (CamelService *service, const char *expected_host, guint32 flags)
{
	CamelTcpStreamSSL *stream;

	stream = CAMEL_TCP_STREAM_SSL (camel_object_new (camel_tcp_stream_ssl_get_type ()));

	stream->priv->service = service;
	stream->priv->expected_host = g_strdup (expected_host);
	stream->priv->ssl_mode = FALSE;
	stream->priv->flags = flags;

	return CAMEL_STREAM (stream);
}


static int
ssl_errno (SSL *ssl, int ret)
{
	switch (SSL_get_error (ssl, ret)) {
	case SSL_ERROR_NONE:
		return 0;
	case SSL_ERROR_ZERO_RETURN:
		/* this one does not map well at all */
		d(printf ("ssl_errno: SSL_ERROR_ZERO_RETURN\n"));
		return EINVAL;
	case SSL_ERROR_WANT_READ:   /* non-fatal; retry */
	case SSL_ERROR_WANT_WRITE:  /* non-fatal; retry */
		d(printf ("ssl_errno: SSL_ERROR_WANT_[READ,WRITE]\n"));
		return EAGAIN;
	case SSL_ERROR_SYSCALL:
		d(printf ("ssl_errno: SSL_ERROR_SYSCALL\n"));
		return EINTR;
	case SSL_ERROR_SSL:
		d(printf ("ssl_errno: SSL_ERROR_SSL  <-- very useful error...riiiiight\n"));
		return EINTR;
	default:
		d(printf ("ssl_errno: default error\n"));
		return EINTR;
	}
}


/**
 * camel_tcp_stream_ssl_enable_ssl:
 * @stream: ssl stream
 *
 * Toggles an ssl-capable stream into ssl mode (if it isn't already).
 *
 * Returns 0 on success or -1 on fail.
 **/
int
camel_tcp_stream_ssl_enable_ssl (CamelTcpStreamSSL *stream)
{
	SSL *ssl;

	g_return_val_if_fail (CAMEL_IS_TCP_STREAM_SSL (stream), -1);

	if (stream->priv->sockfd != -1 && !stream->priv->ssl_mode) {
		ssl = open_ssl_connection (stream->priv->service, stream->priv->sockfd, stream);
		if (ssl == NULL) {
			stream->priv->sockfd = -1;
			return -1;
		}

		stream->priv->ssl = ssl;
	}

	stream->priv->ssl_mode = TRUE;

	return 0;
}


static ssize_t
stream_read (CamelStream *stream, char *buffer, size_t n)
{
	CamelTcpStreamSSL *openssl = CAMEL_TCP_STREAM_SSL (stream);
	SSL *ssl = openssl->priv->ssl;
	ssize_t nread;
	int cancel_fd;

	if (camel_operation_cancel_check (NULL)) {
		errno = EINTR;
		return -1;
	}

	cancel_fd = camel_operation_cancel_fd (NULL);
	if (cancel_fd == -1) {
		do {
			if (ssl) {
				nread = SSL_read (ssl, buffer, n);
				if (nread < 0)
					errno = ssl_errno (ssl, nread);
			} else {
				nread = read (openssl->priv->sockfd, buffer, n);
			}
		} while (nread < 0 && (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK));
	} else {
		int error, flags, fdmax;
		struct timeval timeout;
		fd_set rdset;

		flags = fcntl (openssl->priv->sockfd, F_GETFL);
		fcntl (openssl->priv->sockfd, F_SETFL, flags | O_NONBLOCK);

		fdmax = MAX (openssl->priv->sockfd, cancel_fd) + 1;

		do {
			FD_ZERO (&rdset);
			FD_SET (openssl->priv->sockfd, &rdset);
			FD_SET (cancel_fd, &rdset);

			timeout.tv_sec = 0;
			timeout.tv_usec = TIMEOUT_USEC;

			select (fdmax, &rdset, 0, 0, &timeout);
			if (FD_ISSET (cancel_fd, &rdset)) {
				fcntl (openssl->priv->sockfd, F_SETFL, flags);
				errno = EINTR;
				return -1;
			}

			do {
				if (ssl) {
					nread = SSL_read (ssl, buffer, n);
					if (nread < 0)
						errno = ssl_errno (ssl, nread);
				} else {
					nread = read (openssl->priv->sockfd, buffer, n);
				}
			} while (nread < 0 && errno == EINTR);
		} while (nread < 0 && (errno == EAGAIN || errno == EWOULDBLOCK));

		error = errno;
		fcntl (openssl->priv->sockfd, F_SETFL, flags);
		errno = error;
	}

	return nread;
}

static ssize_t
stream_write (CamelStream *stream, const char *buffer, size_t n)
{
	CamelTcpStreamSSL *openssl = CAMEL_TCP_STREAM_SSL (stream);
	SSL *ssl = openssl->priv->ssl;
	ssize_t w, written = 0;
	int cancel_fd;

	if (camel_operation_cancel_check (NULL)) {
		errno = EINTR;
		return -1;
	}

	cancel_fd = camel_operation_cancel_fd (NULL);
	if (cancel_fd == -1) {
		do {
			do {
				if (ssl) {
					w = SSL_write (ssl, buffer + written, n - written);
					if (w < 0)
						errno = ssl_errno (ssl, w);
				} else {
					w = write (openssl->priv->sockfd, buffer + written, n - written);
				}
			} while (w < 0 && (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK));

			if (w > 0)
				written += w;
		} while (w != -1 && written < n);
	} else {
		int error, flags, fdmax;
		struct timeval timeout;
		fd_set rdset, wrset;

		flags = fcntl (openssl->priv->sockfd, F_GETFL);
		fcntl (openssl->priv->sockfd, F_SETFL, flags | O_NONBLOCK);

		fdmax = MAX (openssl->priv->sockfd, cancel_fd) + 1;

		do {
			FD_ZERO (&rdset);
			FD_ZERO (&wrset);
			FD_SET (openssl->priv->sockfd, &wrset);
			FD_SET (cancel_fd, &rdset);

			timeout.tv_sec = 0;
			timeout.tv_usec = TIMEOUT_USEC;
			select (fdmax, &rdset, &wrset, 0, &timeout);
			if (FD_ISSET (cancel_fd, &rdset)) {
				fcntl (openssl->priv->sockfd, F_SETFL, flags);
				errno = EINTR;
				return -1;
			}

			do {
				if (ssl) {
					w = SSL_write (ssl, buffer + written, n - written);
					if (w < 0)
						errno = ssl_errno (ssl, w);
				} else {
					w = write (openssl->priv->sockfd, buffer + written, n - written);
				}
			} while (w < 0 && errno == EINTR);

			if (w < 0) {
				if (errno == EAGAIN || errno == EWOULDBLOCK) {
					w = 0;
				} else {
					error = errno;
					fcntl (openssl->priv->sockfd, F_SETFL, flags);
					errno = error;
					return -1;
				}
			} else
				written += w;
		} while (w >= 0 && written < n);

		fcntl (openssl->priv->sockfd, F_SETFL, flags);
	}

	return written;
}

static int
stream_flush (CamelStream *stream)
{
	return 0;
}


static void
close_ssl_connection (SSL *ssl)
{
	if (ssl) {
		SSL_shutdown (ssl);

		if (ssl->ctx)
			SSL_CTX_free (ssl->ctx);

		SSL_free (ssl);
	}
}

static int
stream_close (CamelStream *stream)
{
	close_ssl_connection (((CamelTcpStreamSSL *)stream)->priv->ssl);
	((CamelTcpStreamSSL *)stream)->priv->ssl = NULL;

	if (close (((CamelTcpStreamSSL *)stream)->priv->sockfd) == -1)
		return -1;

	((CamelTcpStreamSSL *)stream)->priv->sockfd = -1;
	return 0;
}

/* this is a 'cancellable' connect, cancellable from camel_operation_cancel etc */
/* returns -1 & errno == EINTR if the connection was cancelled */
static int
socket_connect (struct hostent *h, int port)
{
#ifdef ENABLE_IPv6
	struct sockaddr_in6 sin6;
#endif
	struct sockaddr_in sin;
	struct sockaddr *saddr;
	struct timeval tv;
	socklen_t len;
	int cancel_fd;
	int ret, fd;

	/* see if we're cancelled yet */
	if (camel_operation_cancel_check (NULL)) {
		errno = EINTR;
		return -1;
	}

	/* setup connect, we do it using a nonblocking socket so we can poll it */
#ifdef ENABLE_IPv6
	if (h->h_addrtype == AF_INET6) {
		sin6.sin6_port = htons (port);
		sin6.sin6_family = h->h_addrtype;
		memcpy (&sin6.sin6_addr, h->h_addr, sizeof (sin6.sin6_addr));
		saddr = (struct sockaddr *) &sin6;
		len = sizeof (sin6);
	} else {
#endif
		sin.sin_port = htons (port);
		sin.sin_family = h->h_addrtype;
		memcpy (&sin.sin_addr, h->h_addr, sizeof (sin.sin_addr));
		saddr = (struct sockaddr *) &sin;
		len = sizeof (sin);
#ifdef ENABLE_IPv6
	}
#endif

	fd = socket (h->h_addrtype, SOCK_STREAM, 0);

	cancel_fd = camel_operation_cancel_fd (NULL);
	if (cancel_fd == -1) {
		ret = connect (fd, saddr, len);
		if (ret == -1) {
			close (fd);
			return -1;
		}

		return fd;
	} else {
		fd_set rdset, wrset;
		int flags, fdmax;

		flags = fcntl (fd, F_GETFL);
		fcntl (fd, F_SETFL, flags | O_NONBLOCK);

		ret = connect (fd, saddr, len);
		if (ret == 0) {
			fcntl (fd, F_SETFL, flags);
			return fd;
		}

		if (errno != EINPROGRESS) {
			close (fd);
			return -1;
		}

		FD_ZERO (&rdset);
		FD_ZERO (&wrset);
		FD_SET (fd, &wrset);
		FD_SET (cancel_fd, &rdset);
		fdmax = MAX (fd, cancel_fd) + 1;
		tv.tv_usec = 0;
		tv.tv_sec = 60 * 4;

		if (select (fdmax, &rdset, &wrset, 0, &tv) == 0) {
			close (fd);
			errno = ETIMEDOUT;
			return -1;
		}

		if (cancel_fd != -1 && FD_ISSET (cancel_fd, &rdset)) {
			close (fd);
			errno = EINTR;
			return -1;
		} else {
			len = sizeof (int);

			if (getsockopt (fd, SOL_SOCKET, SO_ERROR, &ret, &len) == -1) {
				close (fd);
				return -1;
			}

			if (ret != 0) {
				close (fd);
				errno = ret;
				return -1;
			}
		}

		fcntl (fd, F_SETFL, flags);
	}

	return fd;
}

static const char *
x509_strerror (int err)
{
	switch (err) {
	case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
		return _("Unable to get issuer's certificate");
	case X509_V_ERR_UNABLE_TO_GET_CRL:
		return _("Unable to get Certificate Revocation List");
	case X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE:
		return _("Unable to decrypt certificate signature");
	case X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE:
		return _("Unable to decrypt Certificate Revocation List signature");
	case X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY:
		return _("Unable to decode issuer's public key");
	case X509_V_ERR_CERT_SIGNATURE_FAILURE:
		return _("Certificate signature failure");
	case X509_V_ERR_CRL_SIGNATURE_FAILURE:
		return _("Certificate Revocation List signature failure");
	case X509_V_ERR_CERT_NOT_YET_VALID:
		return _("Certificate not yet valid");
	case X509_V_ERR_CERT_HAS_EXPIRED:
		return _("Certificate has expired");
	case X509_V_ERR_CRL_NOT_YET_VALID:
		return _("CRL not yet valid");
	case X509_V_ERR_CRL_HAS_EXPIRED:
		return _("CRL has expired");
	case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD:
	case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD:
	case X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD:
	case X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD:
		return _("Error in CRL");
	case X509_V_ERR_OUT_OF_MEM:
		return _("Out of memory");
	case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT:
		return _("Zero-depth self-signed certificate");
	case X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN:
		return _("Self-signed certificate in chain");
	case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY:
		return _("Unable to get issuer's certificate locally");
	case X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE:
		return _("Unable to verify leaf signature");
	case X509_V_ERR_CERT_CHAIN_TOO_LONG:
		return _("Certificate chain too long");
	case X509_V_ERR_CERT_REVOKED:
		return _("Certificate Revoked");
	case X509_V_ERR_INVALID_CA:
		return _("Invalid Certificate Authority (CA)");
	case X509_V_ERR_PATH_LENGTH_EXCEEDED:
		return _("Path length exceeded");
	case X509_V_ERR_INVALID_PURPOSE:
		return _("Invalid purpose");
	case X509_V_ERR_CERT_UNTRUSTED:
		return _("Certificate untrusted");
	case X509_V_ERR_CERT_REJECTED:
		return _("Certificate rejected");
		/* These are 'informational' when looking for issuer cert */
	case X509_V_ERR_SUBJECT_ISSUER_MISMATCH:
		return _("Subject/Issuer mismatch");
	case X509_V_ERR_AKID_SKID_MISMATCH:
		return _("AKID/SKID mismatch");
	case X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH:
		return _("AKID/Issuer serial mismatch");
	case X509_V_ERR_KEYUSAGE_NO_CERTSIGN:
		return _("Key usage does not support certificate signing");
		/* The application is not happy */
	case X509_V_ERR_APPLICATION_VERIFICATION:
		return _("Error in application verification");
	default:
		return _("Unknown");
	}
}

static int
ssl_verify (int ok, X509_STORE_CTX *ctx)
{
	unsigned char md5sum[16], fingerprint[40], *f;
	CamelTcpStreamSSL *stream;
	CamelService *service;
	CamelCertDB *certdb = NULL;
	CamelCert *ccert = NULL;
	char *prompt, *cert_str;
	int err, md5len, i;
	char buf[257];
	X509 *cert;
	SSL *ssl;

	if (ok)
		return TRUE;

	ssl = X509_STORE_CTX_get_ex_data (ctx, SSL_get_ex_data_X509_STORE_CTX_idx ());

	stream = SSL_CTX_get_app_data (ssl->ctx);
	if (!stream)
		return FALSE;

	service = stream->priv->service;

	cert = X509_STORE_CTX_get_current_cert (ctx);
	err = X509_STORE_CTX_get_error (ctx);

	/* calculate the MD5 hash of the raw certificate */
	md5len = sizeof (md5sum);
	X509_digest (cert, EVP_md5 (), md5sum, &md5len);
	for (i = 0, f = fingerprint; i < 16; i++, f += 3)
		sprintf ((char *) f, "%.2x%c", md5sum[i], i != 15 ? ':' : '\0');

#define GET_STRING(name) X509_NAME_oneline (name, buf, 256)

	certdb = camel_certdb_get_default ();
	if (certdb) {
		ccert = camel_certdb_get_cert (certdb, (const char *) fingerprint);
		if (ccert) {
			if (ccert->trust != CAMEL_CERT_TRUST_UNKNOWN) {
				ok = ccert->trust != CAMEL_CERT_TRUST_NEVER;
				camel_certdb_cert_unref (certdb, ccert);
				camel_object_unref (certdb);

				return ok;
			}
		} else {
			/* create a new camel-cert */
			ccert = camel_certdb_cert_new (certdb);
			camel_cert_set_issuer (certdb, ccert, GET_STRING (X509_get_issuer_name (cert)));
			camel_cert_set_subject (certdb, ccert, GET_STRING (X509_get_subject_name (cert)));
			camel_cert_set_hostname (certdb, ccert, (const char *) stream->priv->expected_host);
			camel_cert_set_fingerprint (certdb, ccert, (const char *) fingerprint);
			camel_cert_set_trust (certdb, ccert, CAMEL_CERT_TRUST_UNKNOWN);

			/* Add the certificate to our db */
			camel_certdb_add (certdb, ccert);
		}
	}

	cert_str = g_strdup_printf (_("Issuer:            %s\n"
				      "Subject:           %s\n"
				      "Fingerprint:       %s\n"
				      "Signature:         %s"),
				    GET_STRING (X509_get_issuer_name (cert)),
				    GET_STRING (X509_get_subject_name (cert)),
				    fingerprint, cert->valid ? _("GOOD") : _("BAD"));

	prompt = g_strdup_printf (_("Bad certificate from %s:\n\n%s\n\n%s\n\n"
				    "Do you wish to accept anyway?"),
				  service->url->host, cert_str, x509_strerror (err));

	ok = camel_session_alert_user (service->session, CAMEL_SESSION_ALERT_WARNING, prompt, TRUE);
	g_free (prompt);

	if (ok && ccert) {
		camel_cert_set_trust (certdb, ccert, CAMEL_CERT_TRUST_FULLY);
		camel_certdb_touch (certdb);
	}

	if (certdb) {
		camel_certdb_cert_unref (certdb, ccert);
		camel_object_unref (certdb);
	}

	return ok;
}

static SSL *
open_ssl_connection (CamelService *service, int sockfd, CamelTcpStreamSSL *openssl)
{
	SSL_CTX *ssl_ctx = NULL;
	SSL *ssl = NULL;
	int n;

	/* SSLv23_client_method will negotiate with SSL v2, v3, or TLS v1 */
	ssl_ctx = SSL_CTX_new (SSLv23_client_method ());
	g_return_val_if_fail (ssl_ctx != NULL, NULL);

	SSL_CTX_set_default_verify_paths (ssl_ctx);
	SSL_CTX_set_verify (ssl_ctx, SSL_VERIFY_PEER, &ssl_verify);
	ssl = SSL_new (ssl_ctx);
	SSL_set_fd (ssl, sockfd);

	SSL_CTX_set_app_data (ssl_ctx, openssl);

	n = SSL_connect (ssl);
	if (n != 1) {
		int errnosave = ssl_errno (ssl, n);

		SSL_shutdown (ssl);

		if (ssl->ctx)
			SSL_CTX_free (ssl->ctx);

		SSL_free (ssl);
		ssl = NULL;

		close (sockfd);

		errno = errnosave;
	}

	return ssl;
}

static int
stream_connect (CamelTcpStream *stream, struct hostent *host, int port)
{
	CamelTcpStreamSSL *openssl = CAMEL_TCP_STREAM_SSL (stream);
	SSL *ssl = NULL;
	int fd;

	g_return_val_if_fail (host != NULL, -1);

	fd = socket_connect (host, port);
	if (fd == -1)
		return -1;

	if (openssl->priv->ssl_mode) {
		ssl = open_ssl_connection (openssl->priv->service, fd, openssl);
		if (!ssl)
			return -1;
	}

	openssl->priv->sockfd = fd;
	openssl->priv->ssl = ssl;

	return 0;
}


static int
get_sockopt_level (const CamelSockOptData *data)
{
	switch (data->option) {
	case CAMEL_SOCKOPT_MAXSEGMENT:
	case CAMEL_SOCKOPT_NODELAY:
		return IPPROTO_TCP;
	default:
		return SOL_SOCKET;
	}
}

static int
get_sockopt_optname (const CamelSockOptData *data)
{
	switch (data->option) {
	case CAMEL_SOCKOPT_MAXSEGMENT:
		return TCP_MAXSEG;
	case CAMEL_SOCKOPT_NODELAY:
		return TCP_NODELAY;
	case CAMEL_SOCKOPT_BROADCAST:
		return SO_BROADCAST;
	case CAMEL_SOCKOPT_KEEPALIVE:
		return SO_KEEPALIVE;
	case CAMEL_SOCKOPT_LINGER:
		return SO_LINGER;
	case CAMEL_SOCKOPT_RECVBUFFERSIZE:
		return SO_RCVBUF;
	case CAMEL_SOCKOPT_SENDBUFFERSIZE:
		return SO_SNDBUF;
	case CAMEL_SOCKOPT_REUSEADDR:
		return SO_REUSEADDR;
	case CAMEL_SOCKOPT_IPTYPEOFSERVICE:
		return SO_TYPE;
	default:
		return -1;
	}
}

static int
stream_getsockopt (CamelTcpStream *stream, CamelSockOptData *data)
{
	int optname, optlen;

	if ((optname = get_sockopt_optname (data)) == -1)
		return -1;

	if (data->option == CAMEL_SOCKOPT_NONBLOCKING) {
		int flags;

		flags = fcntl (((CamelTcpStreamSSL *) stream)->priv->sockfd, F_GETFL);
		if (flags == -1)
			return -1;

		data->value.non_blocking = flags & O_NONBLOCK ? TRUE : FALSE;

		return 0;
	}

	return getsockopt (((CamelTcpStreamSSL *) stream)->priv->sockfd,
			   get_sockopt_level (data),
			   optname,
			   (void *) &data->value,
			   (socklen_t *) &optlen);
}

static int
stream_setsockopt (CamelTcpStream *stream, const CamelSockOptData *data)
{
	int optname;

	if ((optname = get_sockopt_optname (data)) == -1)
		return -1;

	if (data->option == CAMEL_SOCKOPT_NONBLOCKING) {
		int flags, set;

		flags = fcntl (((CamelTcpStreamSSL *) stream)->priv->sockfd, F_GETFL);
		if (flags == -1)
			return -1;

		set = data->value.non_blocking ? O_NONBLOCK : 0;
		flags = (flags & ~O_NONBLOCK) | set;

		if (fcntl (((CamelTcpStreamSSL *) stream)->priv->sockfd, F_SETFL, flags) == -1)
			return -1;

		return 0;
	}

	return setsockopt (((CamelTcpStreamSSL *) stream)->priv->sockfd,
			   get_sockopt_level (data),
			   optname,
			   (void *) &data->value,
			   sizeof (data->value));
}

#ifdef ENABLE_IPv6
#define MIN_SOCKADDR_BUFLEN  (sizeof (struct sockaddr_in6))
#else
#define MIN_SOCKADDR_BUFLEN  (sizeof (struct sockaddr_in))
#endif

static CamelTcpAddress *
stream_get_local_address (CamelTcpStream *stream)
{
	unsigned char buf[MIN_SOCKADDR_BUFLEN];
#ifdef ENABLE_IPv6
	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) buf;
#endif
	struct sockaddr_in *sin = (struct sockaddr_in *) buf;
	struct sockaddr *saddr = (struct sockaddr *) buf;
	gpointer address;
	socklen_t len;
	int family;

	len = MIN_SOCKADDR_BUFLEN;

	if (getsockname (CAMEL_TCP_STREAM_SSL (stream)->priv->sockfd, saddr, &len) == -1)
		return NULL;

	if (saddr->sa_family == AF_INET) {
		family = CAMEL_TCP_ADDRESS_IPv4;
		address = &sin->sin_addr;
#ifdef ENABLE_IPv6
	} else if (saddr->sa_family == AF_INET6) {
		family = CAMEL_TCP_ADDRESS_IPv6;
		address = &sin6->sin6_addr;
#endif
	} else
		return NULL;

	return camel_tcp_address_new (family, sin->sin_port, len, address);
}

static CamelTcpAddress *
stream_get_remote_address (CamelTcpStream *stream)
{
	unsigned char buf[MIN_SOCKADDR_BUFLEN];
#ifdef ENABLE_IPv6
	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) buf;
#endif
	struct sockaddr_in *sin = (struct sockaddr_in *) buf;
	struct sockaddr *saddr = (struct sockaddr *) buf;
	gpointer address;
	socklen_t len;
	int family;

	len = MIN_SOCKADDR_BUFLEN;

	if (getpeername (CAMEL_TCP_STREAM_SSL (stream)->priv->sockfd, saddr, &len) == -1)
		return NULL;

	if (saddr->sa_family == AF_INET) {
		family = CAMEL_TCP_ADDRESS_IPv4;
		address = &sin->sin_addr;
#ifdef ENABLE_IPv6
	} else if (saddr->sa_family == AF_INET6) {
		family = CAMEL_TCP_ADDRESS_IPv6;
		address = &sin6->sin6_addr;
#endif
	} else
		return NULL;

	return camel_tcp_address_new (family, sin->sin_port, len, address);
}

#endif /* HAVE_OPENSSL */
