1 /* $NetBSD: tls.h,v 1.3 2018/02/08 17:45:29 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 2008 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Martin Sch�tte. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 /* 39 * tls.h 40 * 41 */ 42 #ifndef _TLS_H 43 #define _TLS_H 44 #include <openssl/x509v3.h> 45 #include <openssl/err.h> 46 #include <openssl/rand.h> 47 #include <openssl/pem.h> 48 #include <openssl/dh.h> 49 50 /* initial size for TLS inbuf, minimum prefix + linelength 51 * guaranteed to be accepted */ 52 #define TLS_MIN_LINELENGTH (2048 + 5) 53 /* usually the inbuf is enlarged as needed and then kept. 54 * if bigger than TLS_PERSIST_LINELENGTH, then shrink 55 * to TLS_LARGE_LINELENGTH immediately */ 56 #define TLS_LARGE_LINELENGTH 8192 57 #define TLS_PERSIST_LINELENGTH 32768 58 59 /* timeout to call non-blocking TLS operations again */ 60 #define TLS_RETRY_EVENT_USEC 20000 61 62 /* reconnect to lost server after n sec (initial value) */ 63 #define TLS_RECONNECT_SEC 10 64 /* backoff connection attempts */ 65 #define TLS_RECONNECT_BACKOFF_FACTOR 15/10 66 #define TLS_RECONNECT_BACKOFF(x) (x) = (x) * TLS_RECONNECT_BACKOFF_FACTOR 67 /* abandon connection attempts after n sec 68 * This has to be <= 5h (with 10sec initial interval), 69 * otherwise a daily SIGHUP from newsylog will reset 70 * all timers and the giveup time will never be reached 71 * 72 * set here: 2h, reached after ca. 7h of reconnecting 73 */ 74 #define TLS_RECONNECT_GIVEUP 60*60*2 75 76 /* default algorithm for certificate fingerprints */ 77 #define DEFAULT_FINGERPRINT_ALG "sha-1" 78 79 /* default X.509 files */ 80 #define DEFAULT_X509_CERTFILE "/etc/openssl/default.crt" 81 #define DEFAULT_X509_KEYFILE "/etc/openssl/default.key" 82 83 /* options for peer certificate verification */ 84 #define X509VERIFY_ALWAYS 0 85 #define X509VERIFY_IFPRESENT 1 86 #define X509VERIFY_NONE 2 87 88 /* attributes for self-generated keys/certificates */ 89 #define TLS_GENCERT_BITS 1024 90 #define TLS_GENCERT_SERIAL 1 91 #define TLS_GENCERT_DAYS 5*365 92 93 /* TLS connection states */ 94 #define ST_NONE 0 95 #define ST_TLS_EST 1 96 #define ST_TCP_EST 2 97 #define ST_CONNECTING 3 98 #define ST_ACCEPTING 4 99 #define ST_READING 5 100 #define ST_WRITING 6 101 #define ST_EOF 7 102 #define ST_CLOSING0 8 103 #define ST_CLOSING1 9 104 #define ST_CLOSING2 10 105 106 /* backlog for listen */ 107 #define TLSBACKLOG 4 108 /* close TLS connection after multiple 'soft' errors */ 109 #define TLS_MAXERRORCOUNT 4 110 111 /* 112 * holds TLS related settings for one connection to be 113 * included in the SSL object and available in callbacks 114 * 115 * Many fields have a slightly different semantic for 116 * incoming and outgoing connections: 117 * - for outgoing connections it contains the values from syslog.conf and 118 * the server's cert is checked against these values by check_peer_cert() 119 * - for incoming connections it is not used for checking, instead 120 * dispatch_tls_accept() fills in the connected hostname/port and 121 * check_peer_cert() fills in subject and fingerprint from the peer cert 122 */ 123 struct tls_conn_settings { 124 unsigned send_queue:1, /* currently sending buffer */ 125 errorcount:4, /* counter [0;TLS_MAXERRORCOUNT] */ 126 accepted:1, /* workaround cf. check_peer_cert*/ 127 shutdown:1, /* fast connection close on exit */ 128 x509verify:2, /* kind of validation needed */ 129 incoming:1, /* set if we are server */ 130 state:4; /* outgoing connection state */ 131 struct event *event; /* event for read/write activity */ 132 struct event *retryevent; /* event for retries */ 133 SSL *sslptr; /* active SSL object */ 134 char *hostname; /* hostname or IP we connect to */ 135 char *port; /* service name or port number */ 136 char *subject; /* configured hostname in cert */ 137 char *fingerprint; /* fingerprint of peer cert */ 138 char *certfile; /* filename of peer cert */ 139 unsigned reconnect; /* seconds between reconnects */ 140 }; 141 142 /* argument struct only used for tls_send() */ 143 struct tls_send_msg { 144 struct filed *f; 145 struct buf_queue *qentry; 146 char *line; /* formatted message */ 147 size_t linelen; 148 size_t offset; /* in case of partial writes */ 149 }; 150 151 /* return values for TLS_examine_error() */ 152 #define TLS_OK 0 /* no real problem, just ignore */ 153 #define TLS_RETRY_READ 1 /* just retry, non-blocking operation not finished yet */ 154 #define TLS_RETRY_WRITE 2 /* just retry, non-blocking operation not finished yet */ 155 #define TLS_TEMP_ERROR 4 /* recoverable error condition, but try again */ 156 #define TLS_PERM_ERROR 8 /* non-recoverable error condition, closed TLS and socket */ 157 158 /* global TLS setup and utility */ 159 char *init_global_TLS_CTX(void); 160 struct socketEvent *socksetup_tls(const int, const char *, const char *); 161 int check_peer_cert(int, X509_STORE_CTX *); 162 int accept_cert(const char* , struct tls_conn_settings *, char *, char *); 163 int deny_cert(struct tls_conn_settings *, char *, char *); 164 bool read_certfile(X509 **, const char *); 165 bool write_x509files(EVP_PKEY *, X509 *, const char *, const char *); 166 bool mk_x509_cert(X509 **, EVP_PKEY **, int, int, int); 167 bool x509_cert_add_subjectAltName(X509 *, X509V3_CTX *); 168 int tls_examine_error(const char *, const SSL *, struct tls_conn_settings *, const int); 169 170 bool get_fingerprint(const X509 *, char **, const char *); 171 bool get_commonname(X509 *, char **); 172 bool match_hostnames(X509 *, const char *, const char *); 173 bool match_fingerprint(const X509 *, const char *); 174 bool match_certfile(const X509 *, const char *); 175 176 /* configuration & parsing */ 177 bool parse_tls_destination(const char *, struct filed *, size_t); 178 /* event callbacks */ 179 void dispatch_socket_accept(int, short, void *); 180 void dispatch_tls_accept(int, short, void *); 181 void dispatch_tls_read(int, short, void *); 182 void dispatch_tls_send(int, short, void *); 183 void dispatch_tls_eof(int, short, void *); 184 void dispatch_SSL_connect(int, short, void *); 185 void dispatch_SSL_shutdown(int, short, void *); 186 void dispatch_force_tls_reconnect(int, short, void *); 187 188 bool tls_connect(struct tls_conn_settings *); 189 void tls_reconnect(int, short, void *); 190 bool tls_send(struct filed *, char *, size_t, struct buf_queue*); 191 void tls_split_messages(struct TLS_Incoming_Conn *); 192 193 void free_tls_conn(struct tls_conn_settings *); 194 void free_tls_sslptr(struct tls_conn_settings *); 195 void free_tls_send_msg(struct tls_send_msg *); 196 197 #endif /* !_TLS_H */ 198