/* * SSLsplit - transparent and scalable SSL/TLS interception * Copyright (c) 2009-2014, Daniel Roethlisberger * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * 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 */ /* local process ids, or -1 */ pid_t pid; uid_t uid; gid_t gid; /* 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; /* log strings from process info */ char *exec_path; char *user; char *group; /* 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->pid = -1; 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->exec_path) { free(ctx->exec_path); } if (ctx->user) { free(ctx->user); } if (ctx->group) { free(ctx->group); } 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. * OpenSSL increments the refcount before calling the callback and will * decrement it again if we return 0. Returning 1 will make OpenSSL skip * the refcount decrementing. In other words, return 0 if we did not * keep a pointer to the object (which we never do here). */ #ifdef WITH_SSLV2 #define MAYBE_UNUSED #else /* !WITH_SSLV2 */ #define MAYBE_UNUSED UNUSED #endif /* !WITH_SSLV2 */ 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)); } else { log_dbg_print("(null)\n"); } #endif /* DEBUG_SESSION_CACHE */ #ifdef WITH_SSLV2 /* 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 /* WITH_SSLV2 */ if (sess) { cachemgr_ssess_set(sess); } return 0; } /* * Called by OpenSSL when a src SSL session should be removed. * OpenSSL calls SSL_SESSION_free() after calling the callback; * we do not need to free the reference here. */ 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)); } else { log_dbg_print("(null)\n"); } #endif /* DEBUG_SESSION_CACHE */ if (sess) { 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(ctx->opts->sslmethod()); 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 */ #ifdef SSL_OP_NO_SSLv2 #ifdef WITH_SSLV2 if (ctx->opts->no_ssl2) { #endif /* WITH_SSLV2 */ SSL_CTX_set_options(sslctx, SSL_OP_NO_SSLv2); #ifdef WITH_SSLV2 } #endif /* WITH_SSLV2 */ #endif /* !SSL_OP_NO_SSLv2 */ #ifdef SSL_OP_NO_SSLv3 if (ctx->opts->no_ssl3) { SSL_CTX_set_options(sslctx, SSL_OP_NO_SSLv3); } #endif /* SSL_OP_NO_SSLv3 */ #ifdef SSL_OP_NO_TLSv1 if (ctx->opts->no_tls10) { SSL_CTX_set_options(sslctx, SSL_OP_NO_TLSv1); } #endif /* SSL_OP_NO_TLSv1 */ #ifdef SSL_OP_NO_TLSv1_1 if (ctx->opts->no_tls11) { SSL_CTX_set_options(sslctx, SSL_OP_NO_TLSv1_1); } #endif /* SSL_OP_NO_TLSv1_1 */ #ifdef SSL_OP_NO_TLSv1_2 if (ctx->opts->no_tls12) { SSL_CTX_set_options(sslctx, SSL_OP_NO_TLSv1_2); } #endif /* SSL_OP_NO_TLSv1_2 */ 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(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(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; if (ctx->opts->tgcrtdir) { if (ctx->sni) { cert = cachemgr_tgcrt_get(ctx->sni); if (!cert) { char *wildcarded; 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) { char *wildcarded; 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 SSL_MODE_RELEASE_BUFFERS /* lower memory footprint for idle connections */ SSL_set_mode(ssl, SSL_get_mode(ssl) | SSL_MODE_RELEASE_BUFFERS); #endif /* SSL_MODE_RELEASE_BUFFERS */ 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; 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)) { X509 *newcrt; SSL_CTX *newsslctx; 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; } } 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; } SSL_set_SSL_CTX(ssl, newsslctx); /* decr's old incr new refc */ SSL_CTX_free(newsslctx); 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(ctx->opts->sslmethod()); 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 */ #ifdef SSL_OP_NO_SSLv2 #ifdef WITH_SSLV2 if (ctx->opts->no_ssl2) { #endif /* WITH_SSLV2 */ SSL_CTX_set_options(sslctx, SSL_OP_NO_SSLv2); #ifdef WITH_SSLV2 } #endif /* WITH_SSLV2 */ #endif /* !SSL_OP_NO_SSLv2 */ #ifdef SSL_OP_NO_SSLv3 if (ctx->opts->no_ssl3) { SSL_CTX_set_options(sslctx, SSL_OP_NO_SSLv3); } #endif /* SSL_OP_NO_SSLv3 */ #ifdef SSL_OP_NO_TLSv1 if (ctx->opts->no_tls10) { SSL_CTX_set_options(sslctx, SSL_OP_NO_TLSv1); } #endif /* SSL_OP_NO_TLSv1 */ #ifdef SSL_OP_NO_TLSv1_1 if (ctx->opts->no_tls11) { SSL_CTX_set_options(sslctx, SSL_OP_NO_TLSv1_1); } #endif /* SSL_OP_NO_TLSv1_1 */ #ifdef SSL_OP_NO_TLSv1_2 if (ctx->opts->no_tls12) { SSL_CTX_set_options(sslctx, SSL_OP_NO_TLSv1_2); } #endif /* SSL_OP_NO_TLSv1_2 */ 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 */ #ifdef SSL_MODE_RELEASE_BUFFERS /* lower memory footprint for idle connections */ SSL_set_mode(ssl, SSL_get_mode(ssl) | SSL_MODE_RELEASE_BUFFERS); #endif /* SSL_MODE_RELEASE_BUFFERS */ /* session resuming based on remote endpoint address and port */ sess = cachemgr_dsess_get((struct sockaddr *)&ctx->addr, ctx->addrlen, ctx->sni); /* new sess inst */ if (sess) { if (OPTS_DEBUG(ctx->opts)) { log_dbg_printf("Attempt reuse dst SSL session\n"); } SSL_set_session(ssl, sess); /* increments sess refcount */ 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); /* does not inc refc */ } #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); /* does not free SSL unless the option BEV_OPT_CLOSE_ON_FREE was set */ 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) { /* parse information for connect log */ if (!ctx->http_method) { /* first line */ char *space1, *space2; 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 */ char *newhdr; if (!ctx->http_host && !strncasecmp(line, "Host:", 5)) { ctx->http_host = strdup(util_skipws(line + 5)); if (!ctx->http_host) { ctx->enomem = 1; return NULL; } } else if (!strncasecmp(line, "Content-Type:", 13)) { ctx->http_content_type = strdup(util_skipws(line + 13)); if (!ctx->http_content_type) { ctx->enomem = 1; return NULL; } } else if (!strncasecmp(line, "Connection:", 11)) { ctx->sent_http_conn_close = 1; if (!(newhdr = strdup("Connection: close"))) { ctx->enomem = 1; return NULL; } return newhdr; } else if (!strncasecmp(line, "Accept-Encoding:", 16) || !strncasecmp(line, "Keep-Alive:", 11)) { 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) { /* parse information for connect log */ if (!ctx->http_status_code) { /* first line */ char *space1, *space2; 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 { size_t len_code, len_text; 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:", 15)) { ctx->http_content_length = strdup(util_skipws(line + 15)); if (!ctx->http_content_length) { ctx->enomem = 1; return NULL; } } else if ( /* HPKP: Public Key Pinning Extension for HTTP * (draft-ietf-websec-key-pinning) * remove to prevent public key pinning */ !strncasecmp(line, "Public-Key-Pins:", 16) || !strncasecmp(line, "Public-Key-Pins-Report-Only:", 28) || /* HSTS: HTTP Strict Transport Security (RFC 6797) * remove to allow users to accept bad certs */ !strncasecmp(line, "Strict-Transport-Security:", 26) || /* Alternate Protocol * remove to prevent switching to QUIC, SPDY et al */ !strncasecmp(line, "Alternate-Protocol:", 19)) { 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; while ((line = evbuffer_readln(inbuf, NULL, EVBUFFER_EOL_CRLF))) { char *replace; 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; while ((line = evbuffer_readln(inbuf, NULL, EVBUFFER_EOL_CRLF))) { char *replace; 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.bev = NULL; 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); ctx->src.ssl = NULL; } 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 we don't analyze any headers */ 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 */ bufferevent_free_and_close_fd(bev, ctx); ctx->dst.bev = NULL; 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); ctx->dst.ssl = NULL; } 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, &ctx->pid, 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; if (ctx->pid != -1) { if (sys_proc_info(ctx->pid, &ctx->exec_path, &ctx->uid, &ctx->gid) == 0) { ctx->user = sys_user_str(ctx->uid); ctx->group = sys_group_str(ctx->gid); if (!ctx->user || !ctx->group) { 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: */