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SSLproxy/pxyconn.c
Daniel Roethlisberger b82ca9b414 Print status of free'd SSL structs in debug mode
2014-01-11 17:28:41 +01:00

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/*
* SSLsplit - transparent and scalable SSL/TLS interception
* Copyright (c) 2009-2014, Daniel Roethlisberger <daniel@roe.ch>
* All rights reserved.
* http://www.roe.ch/SSLsplit
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice unmodified, this list of conditions, and the following
* disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "pxyconn.h"
#include "pxysslshut.h"
#include "cachemgr.h"
#include "ssl.h"
#include "opts.h"
#include "sys.h"
#include "util.h"
#include "base64.h"
#include "url.h"
#include "log.h"
#include "attrib.h"
#include <netinet/in.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <event2/event.h>
#include <event2/listener.h>
#include <event2/bufferevent.h>
#include <event2/bufferevent_ssl.h>
#include <event2/buffer.h>
#include <event2/thread.h>
#include <event2/dns.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
#include <openssl/rand.h>
#include <openssl/x509.h>
#include <openssl/x509v3.h>
/*
* Maximum size of data to buffer per connection direction before
* temporarily stopping to read data from the other end.
*/
#define OUTBUF_LIMIT (128*1024)
/*
* Print helper for logging code.
*/
#define STRORDASH(x) (((x)&&*(x))?(x):"-")
/*
* Context used for all server sessions.
*/
#ifdef USE_SSL_SESSION_ID_CONTEXT
static unsigned long ssl_session_context = 0x31415926;
#endif /* USE_SSL_SESSION_ID_CONTEXT */
/*
* Proxy connection context state, describes a proxy connection
* with source and destination socket bufferevents, SSL context and
* other session state. One of these exists per handled proxy
* connection.
*/
/* single dst or src socket bufferevent descriptor */
typedef struct pxy_conn_desc {
struct bufferevent *bev;
SSL *ssl;
unsigned int closed : 1;
} pxy_conn_desc_t;
/* actual proxy connection state consisting of two connection descriptors,
* connection-wide state and the specs and options */
typedef struct pxy_conn_ctx {
/* per-connection state */
struct pxy_conn_desc src;
struct pxy_conn_desc dst;
/* status flags */
unsigned int immutable_cert : 1; /* 1 if the cert cannot be changed */
unsigned int connected : 1; /* 0 until both ends are connected */
unsigned int seen_req_header : 1; /* 0 until request header complete */
unsigned int seen_resp_header : 1; /* 0 until response hdr complete */
unsigned int sent_http_conn_close : 1; /* 0 until Conn: close sent */
unsigned int passthrough : 1; /* 1 if SSL passthrough is active */
unsigned int ocsp_denied : 1; /* 1 if OCSP was denied */
unsigned int enomem : 1; /* 1 if out of memory */
unsigned int sni_peek_retries : 6; /* max 64 SNI parse retries */
/* server name indicated by client in SNI TLS extension */
char *sni;
/* log strings from socket */
char *src_str;
char *dst_str;
/* log strings from HTTP request */
char *http_method;
char *http_uri;
char *http_host;
char *http_content_type;
/* log strings from HTTP response */
char *http_status_code;
char *http_status_text;
char *http_content_length;
/* log strings from SSL context */
char *ssl_names;
char *ssl_orignames;
/* content log context */
log_content_ctx_t logctx;
/* store fd and fd event while connected is 0 */
evutil_socket_t fd;
struct event *ev;
/* original destination address, family and certificate */
struct sockaddr_storage addr;
socklen_t addrlen;
int af;
X509 *origcrt;
/* references to event base and configuration */
struct event_base *evbase;
struct evdns_base *dnsbase;
int thridx;
pxy_thrmgr_ctx_t *thrmgr;
proxyspec_t *spec;
opts_t *opts;
} pxy_conn_ctx_t;
#define WANT_CONNECT_LOG(ctx) ((ctx)->opts->connectlog||!(ctx)->opts->detach)
#define WANT_CONTENT_LOG(ctx) ((ctx)->opts->contentlog&&!(ctx)->passthrough)
static pxy_conn_ctx_t *
pxy_conn_ctx_new(proxyspec_t *spec, opts_t *opts,
pxy_thrmgr_ctx_t *thrmgr, evutil_socket_t fd)
MALLOC NONNULL(1,2,3);
static pxy_conn_ctx_t *
pxy_conn_ctx_new(proxyspec_t *spec, opts_t *opts,
pxy_thrmgr_ctx_t *thrmgr, evutil_socket_t fd)
{
pxy_conn_ctx_t *ctx = malloc(sizeof(pxy_conn_ctx_t));
if (!ctx)
return NULL;
memset(ctx, 0, sizeof(pxy_conn_ctx_t));
ctx->spec = spec;
ctx->opts = opts;
ctx->fd = fd;
ctx->thridx = pxy_thrmgr_attach(thrmgr, &ctx->evbase, &ctx->dnsbase);
ctx->thrmgr = thrmgr;
#ifdef DEBUG_PROXY
if (OPTS_DEBUG(opts)) {
log_dbg_printf("%p pxy_conn_ctx_new\n",
(void*)ctx);
}
#endif /* DEBUG_PROXY */
return ctx;
}
static void
pxy_conn_ctx_free(pxy_conn_ctx_t *ctx) NONNULL(1);
static void
pxy_conn_ctx_free(pxy_conn_ctx_t *ctx)
{
#ifdef DEBUG_PROXY
if (OPTS_DEBUG(ctx->opts)) {
log_dbg_printf("%p pxy_conn_ctx_free\n",
(void*)ctx);
}
#endif /* DEBUG_PROXY */
pxy_thrmgr_detach(ctx->thrmgr, ctx->thridx);
if (ctx->src_str) {
free(ctx->src_str);
}
if (ctx->dst_str) {
free(ctx->dst_str);
}
if (ctx->http_method) {
free(ctx->http_method);
}
if (ctx->http_uri) {
free(ctx->http_uri);
}
if (ctx->http_host) {
free(ctx->http_host);
}
if (ctx->http_content_type) {
free(ctx->http_content_type);
}
if (ctx->http_status_code) {
free(ctx->http_status_code);
}
if (ctx->http_status_text) {
free(ctx->http_status_text);
}
if (ctx->http_content_length) {
free(ctx->http_content_length);
}
if (ctx->ssl_names) {
free(ctx->ssl_names);
}
if (ctx->ssl_orignames) {
free(ctx->ssl_orignames);
}
if (ctx->origcrt) {
X509_free(ctx->origcrt);
}
if (ctx->ev) {
event_free(ctx->ev);
}
if (ctx->sni) {
free(ctx->sni);
}
if (WANT_CONTENT_LOG(ctx)) {
log_content_close(&ctx->logctx);
}
free(ctx);
}
/* forward declaration of libevent callbacks */
static void pxy_bev_readcb(struct bufferevent *, void *);
static void pxy_bev_writecb(struct bufferevent *, void *);
static void pxy_bev_eventcb(struct bufferevent *, short, void *);
static void pxy_fd_readcb(evutil_socket_t, short, void *);
/* forward declaration of OpenSSL callbacks */
#ifndef OPENSSL_NO_TLSEXT
static int pxy_ossl_servername_cb(SSL *ssl, int *al, void *arg);
#endif /* !OPENSSL_NO_TLSEXT */
static int pxy_ossl_sessnew_cb(SSL *, SSL_SESSION *);
static void pxy_ossl_sessremove_cb(SSL_CTX *, SSL_SESSION *);
static SSL_SESSION * pxy_ossl_sessget_cb(SSL *, unsigned char *, int, int *);
/*
* Dump information on a certificate to the debug log.
*/
static void
pxy_debug_crt(X509 *crt)
{
char *sj = ssl_x509_subject(crt);
if (sj) {
log_dbg_printf("Subject DN: %s\n", sj);
free(sj);
}
char *names = ssl_x509_names_to_str(crt);
if (names) {
log_dbg_printf("Common Names: %s\n", names);
free(names);
}
unsigned char fpr[SSL_X509_FPRSZ];
if (ssl_x509_fingerprint_sha1(crt, fpr) == -1) {
log_err_printf("Warning: Error generating X509 fingerprint\n");
} else {
log_dbg_printf("Fingerprint: " "%02x:%02x:%02x:%02x:"
"%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:"
"%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
fpr[0], fpr[1], fpr[2], fpr[3], fpr[4],
fpr[5], fpr[6], fpr[7], fpr[8], fpr[9],
fpr[10], fpr[11], fpr[12], fpr[13], fpr[14],
fpr[15], fpr[16], fpr[17], fpr[18], fpr[19]);
}
#ifdef DEBUG_CERTIFICATE
/* dump certificate */
log_dbg_print_free(ssl_x509_to_str(crt));
log_dbg_print_free(ssl_x509_to_pem(crt));
#endif /* DEBUG_CERTIFICATE */
}
static void
pxy_log_connect_nonhttp(pxy_conn_ctx_t *ctx)
{
char *msg;
int rv;
if (!ctx->spec->ssl || ctx->passthrough) {
rv = asprintf(&msg, "%s %s %s\n",
ctx->passthrough ? "passthrough" : "tcp",
STRORDASH(ctx->src_str),
STRORDASH(ctx->dst_str));
} else {
rv = asprintf(&msg, "ssl %s %s "
"sni:%s crt:%s origcrt:%s\n",
STRORDASH(ctx->src_str),
STRORDASH(ctx->dst_str),
STRORDASH(ctx->sni),
STRORDASH(ctx->ssl_names),
STRORDASH(ctx->ssl_orignames));
}
if ((rv == -1) || !msg) {
ctx->enomem = 1;
return;
}
if (!ctx->opts->detach) {
log_err_printf("%s", msg);
}
if (ctx->opts->connectlog) {
log_connect_print_free(msg);
} else {
free(msg);
}
}
static void
pxy_log_connect_http(pxy_conn_ctx_t *ctx)
{
char *msg;
int rv;
#ifdef DEBUG_PROXY
if (ctx->passthrough) {
log_err_printf("Warning: pxy_log_connect_http called while in "
"passthrough mode\n");
return;
}
#endif
if (!ctx->spec->ssl) {
rv = asprintf(&msg, "http %s %s %s %s %s %s %s%s\n",
STRORDASH(ctx->src_str),
STRORDASH(ctx->dst_str),
STRORDASH(ctx->http_host),
STRORDASH(ctx->http_method),
STRORDASH(ctx->http_uri),
STRORDASH(ctx->http_status_code),
STRORDASH(ctx->http_content_length),
ctx->ocsp_denied ? " ocsp:denied" : "");
} else {
rv = asprintf(&msg, "https %s %s %s %s %s %s %s "
"sni:%s crt:%s origcrt:%s%s\n",
STRORDASH(ctx->src_str),
STRORDASH(ctx->dst_str),
STRORDASH(ctx->http_host),
STRORDASH(ctx->http_method),
STRORDASH(ctx->http_uri),
STRORDASH(ctx->http_status_code),
STRORDASH(ctx->http_content_length),
STRORDASH(ctx->sni),
STRORDASH(ctx->ssl_names),
STRORDASH(ctx->ssl_orignames),
ctx->ocsp_denied ? " ocsp:denied" : "");
}
if ((rv == -1) || !msg) {
ctx->enomem = 1;
return;
}
if (!ctx->opts->detach) {
log_err_printf("%s", msg);
}
if (ctx->opts->connectlog) {
log_connect_print_free(msg);
} else {
free(msg);
}
}
/*
* Called by OpenSSL when a new src SSL session is created.
* Return 0 means remove session from internal session cache.
*/
#ifdef DISABLE_SSLV2_SESSION_CACHE
#define MAYBE_UNUSED
#else /* !DISABLE_SSLV2_SESSION_CACHE */
#define MAYBE_UNUSED UNUSED
#endif /* !DISABLE_SSLV2_SESSION_CACHE */
static int
pxy_ossl_sessnew_cb(MAYBE_UNUSED SSL *ssl, SSL_SESSION *sess)
#undef MAYBE_UNUSED
{
#ifdef DEBUG_SESSION_CACHE
log_dbg_printf("===> OpenSSL new session callback:\n");
if (sess) {
log_dbg_print_free(ssl_session_to_str(sess));
}
#endif /* DEBUG_SESSION_CACHE */
#ifdef DISABLE_SSLV2_SESSION_CACHE
/* Session resumption seems to fail for SSLv2 with protocol
* parsing errors, so we disable caching for SSLv2. */
if (SSL_version(ssl) == SSL2_VERSION) {
log_err_printf("Warning: Session resumption denied to SSLv2"
"client.\n");
return 0;
}
#endif /* DISABLE_SSLV2_SESSION_CACHE */
cachemgr_ssess_set(sess);
return 0;
}
/*
* Called by OpenSSL when a src SSL session should be removed.
*/
static void
pxy_ossl_sessremove_cb(UNUSED SSL_CTX *sslctx, SSL_SESSION *sess)
{
#ifdef DEBUG_SESSION_CACHE
log_dbg_printf("===> OpenSSL remove session callback:\n");
if (sess) {
log_dbg_print_free(ssl_session_to_str(sess));
}
#endif /* DEBUG_SESSION_CACHE */
cachemgr_ssess_del(sess);
}
/*
* Called by OpenSSL when a src SSL session is requested by the client.
*/
static SSL_SESSION *
pxy_ossl_sessget_cb(UNUSED SSL *ssl, unsigned char *id, int idlen, int *copy)
{
SSL_SESSION *sess;
#ifdef DEBUG_SESSION_CACHE
log_dbg_printf("===> OpenSSL get session callback:\n");
#endif /* DEBUG_SESSION_CACHE */
*copy = 0; /* SSL should not increment reference count of session */
sess = cachemgr_ssess_get(id, idlen);
#ifdef DEBUG_SESSION_CACHE
if (sess) {
log_dbg_print_free(ssl_session_to_str(sess));
}
#endif /* DEBUG_SESSION_CACHE */
log_dbg_printf("SSL session cache: %s\n", sess ? "HIT" : "MISS");
return sess;
}
/*
* Create and set up a new SSL_CTX instance for terminating SSL.
* Set up all the necessary callbacks, the certificate, the cert chain and key.
*/
static SSL_CTX *
pxy_srcsslctx_create(pxy_conn_ctx_t *ctx, X509 *crt, STACK_OF(X509) *chain,
EVP_PKEY *key)
{
SSL_CTX *sslctx = SSL_CTX_new(SSLv23_method());
if (!sslctx)
return NULL;
SSL_CTX_set_options(sslctx, SSL_OP_ALL);
#ifdef SSL_OP_TLS_ROLLBACK_BUG
SSL_CTX_set_options(sslctx, SSL_OP_TLS_ROLLBACK_BUG);
#endif /* SSL_OP_TLS_ROLLBACK_BUG */
#ifdef SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
SSL_CTX_set_options(sslctx, SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION);
#endif /* SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION */
#ifdef SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS
SSL_CTX_set_options(sslctx, SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS);
#endif /* SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS */
#ifdef SSL_OP_NO_TICKET
SSL_CTX_set_options(sslctx, SSL_OP_NO_TICKET);
#endif /* SSL_OP_NO_TICKET */
#ifdef SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
SSL_CTX_set_options(sslctx,
SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION);
#endif /* SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION */
#ifdef SSL_OP_NO_COMPRESSION
if (!ctx->opts->sslcomp) {
SSL_CTX_set_options(sslctx, SSL_OP_NO_COMPRESSION);
}
#endif /* SSL_OP_NO_COMPRESSION */
#if DISABLE_SSLV2_SERVER
SSL_CTX_set_options(sslctx, SSL_OP_NO_SSLv2);
#endif /* DISABLE_SSLV2_SERVER */
SSL_CTX_set_cipher_list(sslctx, ctx->opts->ciphers);
SSL_CTX_sess_set_new_cb(sslctx, pxy_ossl_sessnew_cb);
SSL_CTX_sess_set_remove_cb(sslctx, pxy_ossl_sessremove_cb);
SSL_CTX_sess_set_get_cb(sslctx, pxy_ossl_sessget_cb);
SSL_CTX_set_session_cache_mode(sslctx, SSL_SESS_CACHE_SERVER |
SSL_SESS_CACHE_NO_INTERNAL);
#ifdef USE_SSL_SESSION_ID_CONTEXT
SSL_CTX_set_session_id_context(sslctx, (void *)(&ssl_session_context),
sizeof(ssl_session_context));
#endif /* USE_SSL_SESSION_ID_CONTEXT */
#ifndef OPENSSL_NO_TLSEXT
SSL_CTX_set_tlsext_servername_callback(sslctx, pxy_ossl_servername_cb);
SSL_CTX_set_tlsext_servername_arg(sslctx, ctx);
#endif /* !OPENSSL_NO_TLSEXT */
#ifndef OPENSSL_NO_DH
if (ctx->opts->dh) {
SSL_CTX_set_tmp_dh(sslctx, ctx->opts->dh);
} else if (EVP_PKEY_type(ctx->opts->key->type) != EVP_PKEY_RSA) {
SSL_CTX_set_tmp_dh_callback(sslctx, ssl_tmp_dh_callback);
}
#endif /* !OPENSSL_NO_DH */
#ifndef OPENSSL_NO_ECDH
if (ctx->opts->ecdhcurve) {
EC_KEY *ecdh = ssl_ec_by_name(ctx->opts->ecdhcurve);
SSL_CTX_set_tmp_ecdh(sslctx, ecdh);
EC_KEY_free(ecdh);
} else if (EVP_PKEY_type(ctx->opts->key->type) != EVP_PKEY_RSA) {
EC_KEY *ecdh = ssl_ec_by_name(NULL);
SSL_CTX_set_tmp_ecdh(sslctx, ecdh);
EC_KEY_free(ecdh);
}
#endif /* !OPENSSL_NO_ECDH */
SSL_CTX_use_certificate(sslctx, crt);
SSL_CTX_use_PrivateKey(sslctx, key);
for (int i = 0; i < sk_X509_num(chain); i++) {
X509 *c = sk_X509_value(chain, i);
ssl_x509_refcount_inc(c); /* next call consumes a reference */
SSL_CTX_add_extra_chain_cert(sslctx, c);
}
#ifdef DEBUG_SESSION_CACHE
if (OPTS_DEBUG(ctx->opts)) {
int mode = SSL_CTX_get_session_cache_mode(sslctx);
log_dbg_printf("SSL session cache mode: %08x\n", mode);
if (mode == SSL_SESS_CACHE_OFF)
log_dbg_printf("SSL_SESS_CACHE_OFF\n");
if (mode & SSL_SESS_CACHE_CLIENT)
log_dbg_printf("SSL_SESS_CACHE_CLIENT\n");
if (mode & SSL_SESS_CACHE_SERVER)
log_dbg_printf("SSL_SESS_CACHE_SERVER\n");
if (mode & SSL_SESS_CACHE_NO_AUTO_CLEAR)
log_dbg_printf("SSL_SESS_CACHE_NO_AUTO_CLEAR\n");
if (mode & SSL_SESS_CACHE_NO_INTERNAL_LOOKUP)
log_dbg_printf("SSL_SESS_CACHE_NO_INTERNAL_LOOKUP\n");
if (mode & SSL_SESS_CACHE_NO_INTERNAL_STORE)
log_dbg_printf("SSL_SESS_CACHE_NO_INTERNAL_STORE\n");
}
#endif /* DEBUG_SESSION_CACHE */
return sslctx;
}
static cert_t *
pxy_srccert_create(pxy_conn_ctx_t *ctx)
{
cert_t *cert = NULL;
char *wildcarded;
if (ctx->opts->tgcrtdir) {
if (ctx->sni) {
cert = cachemgr_tgcrt_get(ctx->sni);
if (!cert) {
wildcarded = ssl_wildcardify(ctx->sni);
if (!wildcarded) {
ctx->enomem = 1;
return NULL;
}
cert = cachemgr_tgcrt_get(wildcarded);
free(wildcarded);
}
if (cert && OPTS_DEBUG(ctx->opts)) {
log_dbg_printf("Target cert by SNI\n");
}
} else if (ctx->origcrt) {
char **names = ssl_x509_names(ctx->origcrt);
for (char **p = names; *p; p++) {
if (!cert) {
cert = cachemgr_tgcrt_get(*p);
}
if (!cert) {
wildcarded = ssl_wildcardify(*p);
if (!wildcarded) {
ctx->enomem = 1;
} else {
cert = cachemgr_tgcrt_get(
wildcarded);
free(wildcarded);
}
}
free(*p);
}
free(names);
if (ctx->enomem) {
return NULL;
}
if (cert && OPTS_DEBUG(ctx->opts)) {
log_dbg_printf("Target cert by origcrt\n");
}
}
if (cert) {
ctx->immutable_cert = 1;
}
}
if (!cert && ctx->origcrt && ctx->opts->key) {
cert = cert_new();
cert->crt = cachemgr_fkcrt_get(ctx->origcrt);
if (cert->crt) {
if (OPTS_DEBUG(ctx->opts))
log_dbg_printf("Certificate cache: HIT\n");
} else {
if (OPTS_DEBUG(ctx->opts))
log_dbg_printf("Certificate cache: MISS\n");
cert->crt = ssl_x509_forge(ctx->opts->cacrt,
ctx->opts->cakey,
ctx->origcrt, NULL,
ctx->opts->key);
cachemgr_fkcrt_set(ctx->origcrt, cert->crt);
}
cert_set_key(cert, ctx->opts->key);
cert_set_chain(cert, ctx->opts->chain);
}
return cert;
}
/*
* Create new SSL context for the incoming connection, based on the original
* destination SSL certificate.
* Returns NULL if no suitable certificate could be found.
*/
static SSL *
pxy_srcssl_create(pxy_conn_ctx_t *ctx, SSL *origssl)
{
cert_t *cert;
cachemgr_dsess_set((struct sockaddr*)&ctx->addr,
ctx->addrlen, ctx->sni,
SSL_get0_session(origssl));
ctx->origcrt = SSL_get_peer_certificate(origssl);
if (OPTS_DEBUG(ctx->opts)) {
if (ctx->origcrt) {
log_dbg_printf("===> Original server certificate:\n");
pxy_debug_crt(ctx->origcrt);
} else {
log_dbg_printf("===> Original server has no cert!\n");
}
}
cert = pxy_srccert_create(ctx);
if (!cert)
return NULL;
if (OPTS_DEBUG(ctx->opts)) {
log_dbg_printf("===> Forged server certificate:\n");
pxy_debug_crt(cert->crt);
}
if (WANT_CONNECT_LOG(ctx)) {
ctx->ssl_names = ssl_x509_names_to_str(cert->crt);
if (!ctx->ssl_names)
ctx->enomem = 1;
if (ctx->origcrt) {
ctx->ssl_orignames = ssl_x509_names_to_str(
ctx->origcrt);
if (!ctx->ssl_orignames)
ctx->enomem = 1;
}
}
SSL_CTX *sslctx = pxy_srcsslctx_create(ctx, cert->crt, cert->chain,
cert->key);
cert_free(cert);
if (!sslctx) {
ctx->enomem = 1;
return NULL;
}
SSL *ssl = SSL_new(sslctx);
SSL_CTX_free(sslctx); /* SSL_new() increments refcount */
if (!ssl) {
ctx->enomem = 1;
return NULL;
}
#ifdef USE_FOOTPRINT_HACKS
/* lower memory footprint for idle connections */
SSL_set_mode(ssl, SSL_get_mode(ssl) | SSL_MODE_RELEASE_BUFFERS);
#endif /* USE_FOOTPRINT_HACKS */
return ssl;
}
#ifndef OPENSSL_NO_TLSEXT
/*
* OpenSSL servername callback, called when OpenSSL receives a servername
* TLS extension in the clientHello. Must switch to a new SSL_CTX with
* a different certificate if we want to replace the server cert here.
* We generate a new certificate if the current one does not match the
* supplied servername. This should only happen if the original destination
* server supplies a certificate which does not match the server name we
* indicate to it.
*/
static int
pxy_ossl_servername_cb(SSL *ssl, UNUSED int *al, void *arg)
{
pxy_conn_ctx_t *ctx = arg;
const char *sn;
X509 *sslcrt, *newcrt;
if (!(sn = SSL_get_servername(ssl, TLSEXT_NAMETYPE_host_name)))
return SSL_TLSEXT_ERR_NOACK;
if (OPTS_DEBUG(ctx->opts)) {
if (!!strcmp(sn, ctx->sni)) {
/*
* This may happen if the client resumes a session, but
* uses a different SNI hostname when resuming than it
* used when the session was created. OpenSSL
* correctly ignores the SNI in the ClientHello in this
* case, but since we have already sent the SNI onwards
* to the original destination, there is no way back.
* We log an error and hope this never happens.
*/
log_err_printf("Warning: SNI parser yielded different "
"hostname than OpenSSL callback for "
"the same ClientHello message: "
"[%s] != [%s]\n", ctx->sni, sn);
}
}
/* generate a new certificate with sn as additional altSubjectName
* and replace it both in the current SSL ctx and in the cert cache */
if (!ctx->immutable_cert &&
!ssl_x509_names_match((sslcrt = SSL_get_certificate(ssl)), sn)) {
if (OPTS_DEBUG(ctx->opts)) {
log_dbg_printf("Certificate cache: UPDATE "
"(SNI mismatch)\n");
}
newcrt = ssl_x509_forge(ctx->opts->cacrt, ctx->opts->cakey,
sslcrt, sn, ctx->opts->key);
if (!newcrt) {
ctx->enomem = 1;
return SSL_TLSEXT_ERR_NOACK;
}
cachemgr_fkcrt_set(ctx->origcrt, newcrt);
if (OPTS_DEBUG(ctx->opts)) {
log_dbg_printf("===> Updated forged server "
"certificate:\n");
pxy_debug_crt(newcrt);
}
if (WANT_CONNECT_LOG(ctx)) {
if (ctx->ssl_names) {
free(ctx->ssl_names);
}
ctx->ssl_names = ssl_x509_names_to_str(newcrt);
if (!ctx->ssl_names) {
ctx->enomem = 1;
}
}
SSL_CTX *sslctx, *newsslctx;
newsslctx = pxy_srcsslctx_create(ctx, newcrt, ctx->opts->chain,
ctx->opts->key);
if (!newsslctx) {
X509_free(newcrt);
ctx->enomem = 1;
return SSL_TLSEXT_ERR_NOACK;
}
sslctx = SSL_get_SSL_CTX(ssl);
SSL_set_SSL_CTX(ssl, newsslctx);
SSL_CTX_free(sslctx);
X509_free(newcrt);
} else if (OPTS_DEBUG(ctx->opts)) {
log_dbg_printf("Certificate cache: KEEP (SNI match or "
"target mode)\n");
}
return SSL_TLSEXT_ERR_OK;
}
#endif /* !OPENSSL_NO_TLSEXT */
/*
* Create new SSL context for outgoing connections to the original destination.
* If hostname sni is provided, use it for Server Name Indication.
*/
static SSL *
pxy_dstssl_create(pxy_conn_ctx_t *ctx)
{
SSL_CTX *sslctx;
SSL *ssl;
SSL_SESSION *sess;
sslctx = SSL_CTX_new(SSLv23_method());
if (!sslctx) {
ctx->enomem = 1;
return NULL;
}
SSL_CTX_set_options(sslctx, SSL_OP_ALL);
#ifdef SSL_OP_TLS_ROLLBACK_BUG
SSL_CTX_set_options(sslctx, SSL_OP_TLS_ROLLBACK_BUG);
#endif /* SSL_OP_TLS_ROLLBACK_BUG */
#ifdef SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
SSL_CTX_set_options(sslctx, SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION);
#endif /* SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION */
#ifdef SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS
SSL_CTX_set_options(sslctx, SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS);
#endif /* SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS */
#ifdef SSL_OP_NO_TICKET
SSL_CTX_set_options(sslctx, SSL_OP_NO_TICKET);
#endif /* SSL_OP_NO_TICKET */
#ifdef SSL_OP_NO_COMPRESSION
if (!ctx->opts->sslcomp) {
SSL_CTX_set_options(sslctx, SSL_OP_NO_COMPRESSION);
}
#endif /* SSL_OP_NO_COMPRESSION */
SSL_CTX_set_cipher_list(sslctx, ctx->opts->ciphers);
SSL_CTX_set_verify(sslctx, SSL_VERIFY_NONE, NULL);
ssl = SSL_new(sslctx);
SSL_CTX_free(sslctx); /* SSL_new() increments refcount */
if (!ssl) {
ctx->enomem = 1;
return NULL;
}
#ifndef OPENSSL_NO_TLSEXT
if (ctx->sni) {
SSL_set_tlsext_host_name(ssl, ctx->sni);
}
#endif /* !OPENSSL_NO_TLSEXT */
#if USE_FOOTPRINT_HACKS
/* lower memory footprint for idle connections */
SSL_set_mode(ssl, SSL_get_mode(ssl) | SSL_MODE_RELEASE_BUFFERS);
#endif /* USE_FOOTPRINT_HACKS */
/* session resuming based on remote endpoint address and port */
sess = cachemgr_dsess_get((struct sockaddr *)&ctx->addr,
ctx->addrlen, ctx->sni);
if (sess) {
if (OPTS_DEBUG(ctx->opts)) {
log_dbg_printf("Attempt reuse dst SSL session\n");
}
SSL_set_session(ssl, sess);
SSL_SESSION_free(sess);
}
return ssl;
}
/*
* Free bufferenvent and close underlying socket properly.
* For OpenSSL bufferevents, this will shutdown the SSL connection.
*/
static void
bufferevent_free_and_close_fd(struct bufferevent *bev, pxy_conn_ctx_t *ctx)
{
evutil_socket_t fd = bufferevent_getfd(bev);
SSL *ssl = NULL;
if (ctx->spec->ssl && !ctx->passthrough) {
ssl = bufferevent_openssl_get_ssl(bev);
}
#ifdef DEBUG_PROXY
if (OPTS_DEBUG(ctx->opts)) {
log_dbg_printf(" %p free_and_close_fd\n",
(void*)bev);
}
#endif /* DEBUG_PROXY */
bufferevent_free(bev);
if (ssl) {
pxy_ssl_shutdown(ctx->opts, ctx->evbase, ssl, fd);
} else {
evutil_closesocket(fd);
}
}
/*
* Set up a bufferevent structure for either a dst or src connection,
* optionally with or without SSL. Sets all callbacks, enables read
* and write events, but does not call bufferevent_socket_connect().
*
* For dst connections, pass -1 as fd. Pass a pointer to an initialized
* SSL struct as ssl if the connection should use SSL.
*
* Returns pointer to initialized bufferevent structure, as returned
* by bufferevent_socket_new() or bufferevent_openssl_socket_new().
*/
static struct bufferevent *
pxy_bufferevent_setup(pxy_conn_ctx_t *ctx, evutil_socket_t fd, SSL *ssl)
{
struct bufferevent *bev;
if (ssl) {
bev = bufferevent_openssl_socket_new(ctx->evbase, fd, ssl,
((fd == -1) ? BUFFEREVENT_SSL_CONNECTING
: BUFFEREVENT_SSL_ACCEPTING),
BEV_OPT_DEFER_CALLBACKS);
} else {
bev = bufferevent_socket_new(ctx->evbase, fd,
BEV_OPT_DEFER_CALLBACKS);
}
if (!bev) {
log_err_printf("Error creating bufferevent socket\n");
return NULL;
}
#if LIBEVENT_VERSION_NUMBER >= 0x02010000
if (ssl) {
/* Prevent unclean (dirty) shutdowns to cause error
* events on the SSL socket bufferevent. */
bufferevent_openssl_set_allow_dirty_shutdown(bev, 1);
}
#endif /* LIBEVENT_VERSION_NUMBER >= 0x02010000 */
bufferevent_setcb(bev, pxy_bev_readcb, pxy_bev_writecb,
pxy_bev_eventcb, ctx);
bufferevent_enable(bev, EV_READ|EV_WRITE);
#ifdef DEBUG_PROXY
if (OPTS_DEBUG(ctx->opts)) {
log_dbg_printf(" %p pxy_bufferevent_setup\n",
(void*)bev);
}
#endif /* DEBUG_PROXY */
return bev;
}
/*
* Filter a single line of HTTP request headers.
* Also fills in some context fields for logging.
*
* Returns NULL if the current line should be deleted from the request.
* Returns a newly allocated string if the current line should be replaced.
* Returns `line' if the line should be kept.
*/
static char *
pxy_http_reqhdr_filter_line(const char *line, pxy_conn_ctx_t *ctx)
{
char *space1, *space2, *newhdr;
/* parse information for connect log */
if (!ctx->http_method) {
/* first line */
space1 = strchr(line, ' ');
space2 = space1 ? strchr(space1 + 1, ' ') : NULL;
if (!space1) {
/* not HTTP */
ctx->seen_req_header = 1;
} else {
ctx->http_method = malloc(space1 - line + 1);
if (ctx->http_method) {
memcpy(ctx->http_method, line, space1 - line);
ctx->http_method[space1 - line] = '\0';
} else {
ctx->enomem = 1;
return NULL;
}
space1++;
if (!space2) {
/* HTTP/0.9 */
ctx->seen_req_header = 1;
space2 = space1 + strlen(space1);
}
ctx->http_uri = malloc(space2 - space1 + 1);
if (ctx->http_uri) {
memcpy(ctx->http_uri, space1, space2 - space1);
ctx->http_uri[space2 - space1] = '\0';
} else {
ctx->enomem = 1;
return NULL;
}
}
} else {
/* not first line */
if (!ctx->http_host && !strncasecmp(line, "Host: ", 6)) {
ctx->http_host = strdup(util_skipws(line + 6));
if (!ctx->http_host) {
ctx->enomem = 1;
return NULL;
}
} else if (!strncasecmp(line, "Content-Type: ", 14)) {
ctx->http_content_type = strdup(util_skipws(line + 14));
if (!ctx->http_content_type) {
ctx->enomem = 1;
return NULL;
}
} else if (!strncasecmp(line, "Connection: ", 12)) {
ctx->sent_http_conn_close = 1;
if (!(newhdr = strdup("Connection: close"))) {
ctx->enomem = 1;
return NULL;
}
return newhdr;
} else if (!strncasecmp(line, "Accept-Encoding: ", 17) ||
!strncasecmp(line, "Keep-Alive: ", 12)) {
return NULL;
} else if (line[0] == '\0') {
ctx->seen_req_header = 1;
if (!ctx->sent_http_conn_close) {
newhdr = strdup("Connection: close\r\n");
if (!newhdr) {
ctx->enomem = 1;
return NULL;
}
return newhdr;
}
}
}
return (char*)line;
}
/*
* Filter a single line of HTTP response headers.
*
* Returns NULL if the current line should be deleted from the response.
* Returns a newly allocated string if the current line should be replaced.
* Returns `line' if the line should be kept.
*/
static char *
pxy_http_resphdr_filter_line(const char *line, pxy_conn_ctx_t *ctx)
{
char *space1, *space2;
size_t len_code, len_text;
/* parse information for connect log */
if (!ctx->http_status_code) {
/* first line */
space1 = strchr(line, ' ');
space2 = space1 ? strchr(space1 + 1, ' ') : NULL;
if (!space1 || !!strncmp(line, "HTTP", 4)) {
/* not HTTP or HTTP/0.9 */
ctx->seen_resp_header = 1;
} else {
if (space2) {
len_code = space2 - space1 - 1;
len_text = strlen(space2 + 1);
} else {
len_code = strlen(space1 + 1);
len_text = 0;
}
ctx->http_status_code = malloc(len_code + 1);
ctx->http_status_text = malloc(len_text + 1);
if (!ctx->http_status_code || !ctx->http_status_text) {
ctx->enomem = 1;
return NULL;
}
memcpy(ctx->http_status_code, space1 + 1, len_code);
ctx->http_status_code[len_code] = '\0';
if (space2) {
memcpy(ctx->http_status_text,
space2 + 1, len_text);
}
ctx->http_status_text[len_text] = '\0';
}
} else {
/* not first line */
if (!ctx->http_content_length &&
!strncasecmp(line, "Content-Length: ", 16)) {
ctx->http_content_length =
strdup(util_skipws(line + 16));
if (!ctx->http_content_length) {
ctx->enomem = 1;
return NULL;
}
} else if (!strncasecmp(line, "Public-Key-Pins: ", 17) ||
!strncasecmp(line, "Public-Key-Pins-Report-Only: ", 29)) {
return NULL;
} else if (line[0] == '\0') {
ctx->seen_resp_header = 1;
}
}
return (char*)line;
}
/*
* Return 1 if uri is an OCSP GET URI, 0 if not.
*/
static int
pxy_ocsp_is_valid_uri(const char *uri, pxy_conn_ctx_t *ctx)
{
char *buf_url;
size_t sz_url;
char *buf_b64;
size_t sz_b64;
unsigned char *buf_asn1;
size_t sz_asn1;
int ret;
buf_url = strrchr(uri, '/');
if (!buf_url)
return 0;
buf_url++;
/*
* Do some quick checks to avoid unnecessary buffer allocations and
* decoding URL, Base64 and ASN.1:
* - OCSP requests begin with a SEQUENCE (0x30), so the first Base64
* byte is 'M' or, unlikely but legal, the URL encoding thereof.
* - There should be no query string in OCSP GET requests.
* - Encoded OCSP request ASN.1 blobs are longer than 32 bytes.
*/
if (buf_url[0] != 'M' && buf_url[0] != '%')
return 0;
if (strchr(uri, '?'))
return 0;
sz_url = strlen(buf_url);
if (sz_url < 32)
return 0;
buf_b64 = url_dec(buf_url, sz_url, &sz_b64);
if (!buf_b64) {
ctx->enomem = 1;
return 0;
}
buf_asn1 = base64_dec(buf_b64, sz_b64, &sz_asn1);
if (!buf_asn1) {
ctx->enomem = 1;
free(buf_b64);
return 0;
}
ret = ssl_is_ocspreq(buf_asn1, sz_asn1);
free(buf_asn1);
free(buf_b64);
return ret;
}
/*
* Called after a request header was completely read.
* If the request is an OCSP request, deny the request by sending an
* OCSP response of type tryLater and close the connection to the server.
*
* Reference:
* RFC 2560: X.509 Internet PKI Online Certificate Status Protocol (OCSP)
*/
static void
pxy_ocsp_deny(pxy_conn_ctx_t *ctx)
{
struct evbuffer *inbuf, *outbuf;
static const char ocspresp[] =
"HTTP/1.0 200 OK\r\n"
"Content-Type: application/ocsp-response\r\n"
"Content-Length: 5\r\n"
"Connection: close\r\n"
"\r\n"
"\x30\x03" /* OCSPResponse: SEQUENCE */
"\x0a\x01" /* OCSPResponseStatus: ENUMERATED */
"\x03"; /* tryLater (3) */
if (!ctx->http_method)
return;
if (!strncasecmp(ctx->http_method, "GET", 3) &&
pxy_ocsp_is_valid_uri(ctx->http_uri, ctx))
goto deny;
if (!strncasecmp(ctx->http_method, "POST", 4) &&
ctx->http_content_type &&
!strncasecmp(ctx->http_content_type,
"application/ocsp-request", 24))
goto deny;
return;
deny:
inbuf = bufferevent_get_input(ctx->src.bev);
outbuf = bufferevent_get_output(ctx->src.bev);
if (evbuffer_get_length(inbuf) > 0) {
if (WANT_CONTENT_LOG(ctx)) {
logbuf_t *lb;
lb = logbuf_new_alloc(evbuffer_get_length(inbuf),
-1, NULL);
if (lb &&
(evbuffer_copyout(inbuf, lb->buf, lb->sz) != -1)) {
log_content_submit(&ctx->logctx, lb, 0);
}
}
evbuffer_drain(inbuf, evbuffer_get_length(inbuf));
}
bufferevent_free_and_close_fd(ctx->dst.bev, ctx);
ctx->dst.closed = 1;
evbuffer_add_printf(outbuf, ocspresp);
ctx->ocsp_denied = 1;
if (WANT_CONTENT_LOG(ctx)) {
logbuf_t *lb;
lb = logbuf_new_copy(ocspresp, sizeof(ocspresp) - 1, -1, NULL);
if (lb) {
log_content_submit(&ctx->logctx, lb, 1);
}
}
}
void
pxy_conn_terminate_free(pxy_conn_ctx_t *ctx)
{
log_err_printf("Terminating connection%s!\n",
ctx->enomem ? " (out of memory)" : "");
if (ctx->dst.bev && !ctx->dst.closed) {
bufferevent_free_and_close_fd(ctx->dst.bev, ctx);
}
if (ctx->src.bev && !ctx->src.closed) {
bufferevent_free_and_close_fd(ctx->src.bev, ctx);
}
pxy_conn_ctx_free(ctx);
}
/*
* Callback for read events on the up- and downstram connection bufferevents.
* Called when there is data ready in the input evbuffer.
*/
static void
pxy_bev_readcb(struct bufferevent *bev, void *arg)
{
pxy_conn_ctx_t *ctx = arg;
pxy_conn_desc_t *other = (bev==ctx->src.bev) ? &ctx->dst : &ctx->src;
#ifdef DEBUG_PROXY
if (OPTS_DEBUG(ctx->opts)) {
log_dbg_printf("%p %p %s readcb\n", arg, (void*)bev,
(bev == ctx->src.bev) ? "src" : "dst");
}
#endif /* DEBUG_PROXY */
if (!ctx->connected) {
log_err_printf("readcb called when other end not connected - "
"aborting.\n");
/* XXX should signal main loop instead of calling exit() */
log_fini();
exit(EXIT_FAILURE);
}
struct evbuffer *inbuf = bufferevent_get_input(bev);
if (other->closed) {
evbuffer_drain(inbuf, evbuffer_get_length(inbuf));
return;
}
struct evbuffer *outbuf = bufferevent_get_output(other->bev);
/* request header munging */
if (ctx->spec->http && !ctx->seen_req_header && (bev == ctx->src.bev)
&& !ctx->passthrough) {
logbuf_t *lb = NULL, *tail = NULL;
char *line, *replace;
while ((line = evbuffer_readln(inbuf, NULL,
EVBUFFER_EOL_CRLF))) {
if (WANT_CONTENT_LOG(ctx)) {
logbuf_t *tmp;
tmp = logbuf_new_printf(-1, NULL,
"%s\r\n", line);
if (tail) {
if (tmp) {
tail->next = tmp;
tail = tail->next;
}
} else {
lb = tail = tmp;
}
}
replace = pxy_http_reqhdr_filter_line(line, ctx);
if (replace == line) {
evbuffer_add_printf(outbuf, "%s\r\n", line);
} else if (replace) {
evbuffer_add_printf(outbuf, "%s\r\n", replace);
free(replace);
}
free(line);
if (ctx->seen_req_header) {
/* request header complete */
if (ctx->opts->deny_ocsp) {
pxy_ocsp_deny(ctx);
}
break;
}
}
if (lb && WANT_CONTENT_LOG(ctx)) {
log_content_submit(&ctx->logctx, lb, 0);
}
if (!ctx->seen_req_header)
return;
} else
/* response header munging */
if (ctx->spec->http && !ctx->seen_resp_header && (bev == ctx->dst.bev)
&& !ctx->passthrough) {
logbuf_t *lb = NULL, *tail = NULL;
char *line, *replace;
while ((line = evbuffer_readln(inbuf, NULL,
EVBUFFER_EOL_CRLF))) {
if (WANT_CONTENT_LOG(ctx)) {
logbuf_t *tmp;
tmp = logbuf_new_printf(-1, NULL,
"%s\r\n", line);
if (tail) {
if (tmp) {
tail->next = tmp;
tail = tail->next;
}
} else {
lb = tail = tmp;
}
}
replace = pxy_http_resphdr_filter_line(line, ctx);
if (replace == line) {
evbuffer_add_printf(outbuf, "%s\r\n", line);
} else if (replace) {
evbuffer_add_printf(outbuf, "%s\r\n", replace);
free(replace);
}
free(line);
if (ctx->seen_resp_header) {
/* response header complete: log connection */
if (WANT_CONNECT_LOG(ctx)) {
pxy_log_connect_http(ctx);
}
break;
}
}
if (lb && WANT_CONTENT_LOG(ctx)) {
log_content_submit(&ctx->logctx, lb, 0);
}
if (!ctx->seen_resp_header)
return;
}
/* out of memory condition? */
if (ctx->enomem) {
pxy_conn_terminate_free(ctx);
return;
}
/* no data left after parsing headers? */
if (evbuffer_get_length(inbuf) == 0)
return;
if (WANT_CONTENT_LOG(ctx)) {
logbuf_t *lb;
lb = logbuf_new_alloc(evbuffer_get_length(inbuf), -1, NULL);
if (lb && (evbuffer_copyout(inbuf, lb->buf, lb->sz) != -1)) {
log_content_submit(&ctx->logctx, lb,
(bev != ctx->src.bev));
}
}
evbuffer_add_buffer(outbuf, inbuf);
if (evbuffer_get_length(outbuf) >= OUTBUF_LIMIT) {
/* temporarily disable data source;
* set an appropriate watermark. */
bufferevent_setwatermark(other->bev, EV_WRITE,
OUTBUF_LIMIT/2, OUTBUF_LIMIT);
bufferevent_disable(bev, EV_READ);
}
}
/*
* Callback for write events on the up- and downstream connection bufferevents.
* Called when either all data from the output evbuffer has been written,
* or if the outbuf is only half full again after having been full.
*/
static void
pxy_bev_writecb(struct bufferevent *bev, void *arg)
{
pxy_conn_ctx_t *ctx = arg;
pxy_conn_desc_t *other = (bev==ctx->src.bev) ? &ctx->dst : &ctx->src;
#ifdef DEBUG_PROXY
if (OPTS_DEBUG(ctx->opts)) {
log_dbg_printf("%p %p %s writecb\n", arg, (void*)bev,
(bev == ctx->src.bev) ? "src" : "dst");
}
#endif /* DEBUG_PROXY */
struct evbuffer *outbuf = bufferevent_get_output(bev);
if (evbuffer_get_length(outbuf) > 0) {
/* data source temporarily disabled;
* re-enable and reset watermark to 0. */
bufferevent_setwatermark(bev, EV_WRITE, 0, 0);
if (!other->closed) {
bufferevent_enable(other->bev, EV_READ);
}
} else if (other->closed) {
/* finished writing and other end is closed;
* close this end too and clean up memory */
bufferevent_free_and_close_fd(bev, ctx);
pxy_conn_ctx_free(ctx);
}
}
/*
* Callback for meta events on the up- and downstream connection bufferevents.
* Called when EOF has been reached, a connection has been made, and on errors.
*/
static void
pxy_bev_eventcb(struct bufferevent *bev, short events, void *arg)
{
pxy_conn_ctx_t *ctx = arg;
pxy_conn_desc_t *this = (bev==ctx->src.bev) ? &ctx->src : &ctx->dst;
pxy_conn_desc_t *other = (bev==ctx->src.bev) ? &ctx->dst : &ctx->src;
#ifdef DEBUG_PROXY
if (OPTS_DEBUG(ctx->opts)) {
log_dbg_printf("%p %p eventcb %s %s%s%s%s\n", arg, (void*)bev,
(bev == ctx->src.bev) ? "src" : "dst",
events & BEV_EVENT_CONNECTED ? "connected" : "",
events & BEV_EVENT_ERROR ? "error" : "",
events & BEV_EVENT_TIMEOUT ? "timeout" : "",
events & BEV_EVENT_EOF ? "eof" : "");
}
#endif /* DEBUG_PROXY */
if (events & BEV_EVENT_CONNECTED) {
if (bev != ctx->dst.bev) {
#ifdef DEBUG_PROXY
if (OPTS_DEBUG(ctx->opts)) {
log_dbg_printf("src buffer event connected: "
"ignoring event\n");
}
#endif /* DEBUG_PROXY */
return;
}
/* dst has connected */
ctx->connected = 1;
/* wrap client-side socket in an eventbuffer */
if (ctx->spec->ssl && !ctx->passthrough) {
ctx->src.ssl = pxy_srcssl_create(ctx, this->ssl);
if (!ctx->src.ssl) {
bufferevent_free_and_close_fd(bev, ctx);
ctx->dst.ssl = NULL;
if (ctx->opts->passthrough && !ctx->enomem) {
ctx->passthrough = 1;
ctx->connected = 0;
log_dbg_printf("No cert found; "
"falling back "
"to passthrough\n");
pxy_fd_readcb(ctx->fd, 0, ctx);
return;
}
evutil_closesocket(ctx->fd);
pxy_conn_ctx_free(ctx);
return;
}
}
ctx->src.bev = pxy_bufferevent_setup(ctx, ctx->fd,
ctx->src.ssl);
if (!ctx->src.bev) {
if (ctx->src.ssl) {
SSL_free(ctx->src.ssl);
}
bufferevent_free_and_close_fd(bev, ctx);
evutil_closesocket(ctx->fd);
pxy_conn_ctx_free(ctx);
return;
}
/* prepare logging, part 2 */
if (WANT_CONNECT_LOG(ctx) || WANT_CONTENT_LOG(ctx)) {
ctx->dst_str = sys_sockaddr_str((struct sockaddr *)
&ctx->addr,
ctx->addrlen);
if (!ctx->dst_str) {
ctx->enomem = 1;
pxy_conn_terminate_free(ctx);
return;
}
}
if (WANT_CONTENT_LOG(ctx)) {
log_content_open(&ctx->logctx, ctx->src_str,
ctx->dst_str);
}
/* log connection */
if (!ctx->spec->http || ctx->passthrough) {
if (WANT_CONNECT_LOG(ctx)) {
pxy_log_connect_nonhttp(ctx);
}
}
return;
}
if (events & BEV_EVENT_ERROR) {
unsigned long sslerr;
int have_sslerr = 0;
/* Can happen for socket errs, ssl errs;
* may happen for unclean ssl socket shutdowns. */
sslerr = bufferevent_get_openssl_error(bev);
if (sslerr)
have_sslerr = 1;
if (!errno && !sslerr) {
#if LIBEVENT_VERSION_NUMBER >= 0x02010000
/* We have disabled notification for unclean shutdowns
* so this should not happen; log a warning. */
log_err_printf("Warning: Spurious error from "
"bufferevent (errno=0,sslerr=0)\n");
#else /* LIBEVENT_VERSION_NUMBER < 0x02010000 */
/* Older versions of libevent will report these. */
if (OPTS_DEBUG(ctx->opts)) {
log_dbg_printf("Unclean SSL shutdown.\n");
}
#endif /* LIBEVENT_VERSION_NUMBER < 0x02010000 */
} else if (ERR_GET_REASON(sslerr) ==
SSL_R_SSLV3_ALERT_HANDSHAKE_FAILURE) {
/* these can happen due to client cert auth,
* only log error if debugging is activated */
log_dbg_printf("Error from bufferevent: "
"%i:%s %lu:%i:%s:%i:%s:%i:%s\n",
errno,
errno ? strerror(errno) : "-",
sslerr,
ERR_GET_REASON(sslerr),
sslerr ?
ERR_reason_error_string(sslerr) : "-",
ERR_GET_LIB(sslerr),
sslerr ?
ERR_lib_error_string(sslerr) : "-",
ERR_GET_FUNC(sslerr),
sslerr ?
ERR_func_error_string(sslerr) : "-");
while ((sslerr = bufferevent_get_openssl_error(bev))) {
log_dbg_printf("Additional SSL error: "
"%lu:%i:%s:%i:%s:%i:%s\n",
sslerr,
ERR_GET_REASON(sslerr),
ERR_reason_error_string(sslerr),
ERR_GET_LIB(sslerr),
ERR_lib_error_string(sslerr),
ERR_GET_FUNC(sslerr),
ERR_func_error_string(sslerr));
}
} else {
/* real errors */
log_err_printf("Error from bufferevent: "
"%i:%s %lu:%i:%s:%i:%s:%i:%s\n",
errno,
errno ? strerror(errno) : "-",
sslerr,
ERR_GET_REASON(sslerr),
sslerr ?
ERR_reason_error_string(sslerr) : "-",
ERR_GET_LIB(sslerr),
sslerr ?
ERR_lib_error_string(sslerr) : "-",
ERR_GET_FUNC(sslerr),
sslerr ?
ERR_func_error_string(sslerr) : "-");
while ((sslerr = bufferevent_get_openssl_error(bev))) {
log_err_printf("Additional SSL error: "
"%lu:%i:%s:%i:%s:%i:%s\n",
sslerr,
ERR_GET_REASON(sslerr),
ERR_reason_error_string(sslerr),
ERR_GET_LIB(sslerr),
ERR_lib_error_string(sslerr),
ERR_GET_FUNC(sslerr),
ERR_func_error_string(sslerr));
}
}
if (!ctx->connected) {
/* the callout to the original destination failed,
* e.g. because it asked for client cert auth, so
* close the accepted socket and clean up */
if (bev == ctx->dst.bev && ctx->dst.ssl &&
ctx->opts->passthrough && have_sslerr) {
/* ssl callout failed, fall back to plain
* TCP passthrough of SSL connection */
SSL_free(ctx->dst.ssl);
ctx->dst.ssl = NULL;
ctx->passthrough = 1;
log_dbg_printf("SSL dst connection failed; fal"
"ling back to passthrough\n");
pxy_fd_readcb(ctx->fd, 0, ctx);
return;
}
evutil_closesocket(ctx->fd);
other->closed = 1;
} else if (!other->closed) {
/* if the other end is still open and doesn't have data
* to send, close it, otherwise its writecb will close
* it after writing what's left in the output buffer */
struct evbuffer *outbuf;
outbuf = bufferevent_get_output(other->bev);
if (evbuffer_get_length(outbuf) == 0) {
bufferevent_free_and_close_fd(other->bev, ctx);
other->closed = 1;
}
}
goto leave;
}
if (events & BEV_EVENT_EOF) {
if (!other->closed) {
struct evbuffer *inbuf, *outbuf;
inbuf = bufferevent_get_input(bev);
outbuf = bufferevent_get_output(other->bev);
if (evbuffer_get_length(inbuf) > 0) {
evbuffer_add_buffer(outbuf, inbuf);
} else {
/* if the other end is still open and doesn't
* have data to send, close it, otherwise its
* writecb will close it after writing what's
* left in the output buffer. */
if (evbuffer_get_length(outbuf) == 0) {
bufferevent_free_and_close_fd(
other->bev, ctx);
other->closed = 1;
}
}
}
goto leave;
}
log_err_printf("Unknown bufferevent 0x%02X\n", (int)events);
return;
leave:
this->closed = 1;
bufferevent_free_and_close_fd(bev, ctx);
if (other->closed) {
pxy_conn_ctx_free(ctx);
}
}
/*
* Complete the connection. This gets called after finding out where to
* connect to.
*/
static void
pxy_conn_connect(pxy_conn_ctx_t *ctx)
{
if (!ctx->addrlen) {
log_err_printf("No target address; aborting connection\n");
evutil_closesocket(ctx->fd);
pxy_conn_ctx_free(ctx);
return;
}
/* create server-side socket and eventbuffer */
if (ctx->spec->ssl && !ctx->passthrough) {
ctx->dst.ssl = pxy_dstssl_create(ctx);
if (!ctx->dst.ssl) {
log_err_printf("Error creating SSL\n");
evutil_closesocket(ctx->fd);
pxy_conn_ctx_free(ctx);
return;
}
}
ctx->dst.bev = pxy_bufferevent_setup(ctx, -1, ctx->dst.ssl);
if (!ctx->dst.bev) {
if (ctx->dst.ssl) {
SSL_free(ctx->dst.ssl);
}
evutil_closesocket(ctx->fd);
pxy_conn_ctx_free(ctx);
return;
}
if (OPTS_DEBUG(ctx->opts)) {
char *ip = sys_sockaddr_str((struct sockaddr *)&ctx->addr,
ctx->addrlen);
log_dbg_printf("Connecting to %s\n", ip);
if (ip)
free(ip);
}
/* initiate connection */
bufferevent_socket_connect(ctx->dst.bev,
(struct sockaddr *)&ctx->addr,
ctx->addrlen);
}
#ifndef OPENSSL_NO_TLSEXT
/*
* The SNI hostname has been resolved. Fill the first resolved address into
* the context and continue connecting.
*/
static void
pxy_sni_resolve_cb(int errcode, struct evutil_addrinfo *ai, void *arg)
{
pxy_conn_ctx_t *ctx = arg;
if (errcode) {
log_err_printf("Cannot resolve SNI hostname '%s': %s\n",
ctx->sni, evutil_gai_strerror(errcode));
evutil_closesocket(ctx->fd);
pxy_conn_ctx_free(ctx);
return;
}
memcpy(&ctx->addr, ai->ai_addr, ai->ai_addrlen);
ctx->addrlen = ai->ai_addrlen;
evutil_freeaddrinfo(ai);
pxy_conn_connect(ctx);
}
#endif /* !OPENSSL_NO_TLSEXT */
/*
* The src fd is readable. This is used to sneak-preview the SNI on SSL
* connections. If ctx->ev is NULL, it was called manually for a non-SSL
* connection. If ctx->passthrough is set, it was called a second time
* after the first ssl callout failed because of client cert auth.
*/
#ifndef OPENSSL_NO_TLSEXT
#define MAYBE_UNUSED
#else /* OPENSSL_NO_TLSEXT */
#define MAYBE_UNUSED UNUSED
#endif /* OPENSSL_NO_TLSEXT */
static void
pxy_fd_readcb(MAYBE_UNUSED evutil_socket_t fd, UNUSED short what, void *arg)
#undef MAYBE_UNUSED
{
pxy_conn_ctx_t *ctx = arg;
#ifndef OPENSSL_NO_TLSEXT
/* for SSL, peek clientHello and parse SNI from it */
if (ctx->spec->ssl && !ctx->passthrough /*&& ctx->ev*/) {
unsigned char buf[1024];
ssize_t n;
n = recv(fd, buf, sizeof(buf), MSG_PEEK);
if (n == -1) {
log_err_printf("Error peeking on fd, aborting "
"connection\n");
evutil_closesocket(fd);
pxy_conn_ctx_free(ctx);
return;
}
if (n == 0) {
/* socket got closed while we were waiting */
evutil_closesocket(fd);
pxy_conn_ctx_free(ctx);
return;
}
ctx->sni = ssl_tls_clienthello_parse_sni(buf, &n);
if (OPTS_DEBUG(ctx->opts)) {
log_dbg_printf("SNI peek: [%s] [%s]\n",
ctx->sni ? ctx->sni : "n/a",
(!ctx->sni && (n == -1)) ?
"incomplete" : "complete");
}
if (!ctx->sni && (n == -1) && (ctx->sni_peek_retries++ < 50)) {
/* ssl_tls_clienthello_parse_sni indicates that we
* should retry later when we have more data, and we
* haven't reached the maximum retry count yet.
* Reschedule this event as timeout-only event in
* order to prevent busy looping over the read event.
* Because we only peeked at the pending bytes and
* never actually read them, fd is still ready for
* reading now. We use 25 * 0.2 s = 5 s timeout. */
struct timeval retry_delay = {0, 100};
event_free(ctx->ev);
ctx->ev = event_new(ctx->evbase, fd, 0,
pxy_fd_readcb, ctx);
if (!ctx->ev) {
log_err_printf("Error creating retry "
"event, aborting "
"connection\n");
evutil_closesocket(fd);
pxy_conn_ctx_free(ctx);
return;
}
event_add(ctx->ev, &retry_delay);
return;
}
event_free(ctx->ev);
ctx->ev = NULL;
}
if (ctx->sni && !ctx->addrlen && ctx->spec->sni_port) {
char sniport[6];
struct evutil_addrinfo hints;
memset(&hints, 0, sizeof(hints));
hints.ai_family = ctx->af;
hints.ai_flags = EVUTIL_AI_ADDRCONFIG;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = IPPROTO_TCP;
snprintf(sniport, sizeof(sniport), "%i", ctx->spec->sni_port);
evdns_getaddrinfo(ctx->dnsbase, ctx->sni, sniport, &hints,
pxy_sni_resolve_cb, ctx);
return;
}
#endif /* !OPENSSL_NO_TLSEXT */
pxy_conn_connect(ctx);
}
/*
* Callback for accept events on the socket listener bufferevent.
* Called when a new incoming connection has been accepted.
* Initiates the connection to the server. The incoming connection
* from the client is not being activated until we have a successful
* connection to the server, because we need the server's certificate
* in order to set up the SSL session to the client.
* For consistency, plain TCP works the same way, even if we could
* start reading from the client while waiting on the connection to
* the server to connect.
*/
void
pxy_conn_setup(evutil_socket_t fd,
struct sockaddr *peeraddr, int peeraddrlen,
pxy_thrmgr_ctx_t *thrmgr,
proxyspec_t *spec, opts_t *opts)
{
pxy_conn_ctx_t *ctx;
/* create per connection pair state and attach to thread */
ctx = pxy_conn_ctx_new(spec, opts, thrmgr, fd);
if (!ctx) {
log_err_printf("Error allocating memory\n");
evutil_closesocket(fd);
return;
}
ctx->af = peeraddr->sa_family;
/* determine original destination of connection */
if (spec->natlookup) {
/* NAT engine lookup */
ctx->addrlen = sizeof(struct sockaddr_storage);
if (spec->natlookup((struct sockaddr *)&ctx->addr,
&ctx->addrlen, fd,
peeraddr, peeraddrlen) == -1) {
log_err_printf("Connection not found in NAT "
"state table, aborting connection\n");
evutil_closesocket(fd);
pxy_conn_ctx_free(ctx);
return;
}
} else if (spec->connect_addrlen > 0) {
/* static forwarding */
ctx->addrlen = spec->connect_addrlen;
memcpy(&ctx->addr, &spec->connect_addr, ctx->addrlen);
} else {
/* SNI mode */
if (!ctx->spec->ssl) {
/* if this happens, the proxyspec parser is broken */
log_err_printf("SNI mode used for non-SSL connection; "
"aborting connection\n");
evutil_closesocket(fd);
pxy_conn_ctx_free(ctx);
return;
}
}
/* prepare logging, part 1 */
if (WANT_CONNECT_LOG(ctx) || WANT_CONTENT_LOG(ctx)) {
ctx->src_str = sys_sockaddr_str(peeraddr, peeraddrlen);
if (!ctx->src_str)
goto memout;
}
/* for SSL, defer dst connection setup to initial_readcb */
if (ctx->spec->ssl) {
ctx->ev = event_new(ctx->evbase, fd, EV_READ, pxy_fd_readcb,
ctx);
if (!ctx->ev)
goto memout;
event_add(ctx->ev, NULL);
} else {
pxy_fd_readcb(fd, 0, ctx);
}
return;
memout:
log_err_printf("Aborting connection setup (out of memory)!\n");
evutil_closesocket(fd);
pxy_conn_ctx_free(ctx);
return;
}
/* vim: set noet ft=c: */
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