ustream-ssl.c

   1 /*
   2  * ustream-ssl - library for SSL over ustream
   3  *
   4  * Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
   5  *
   6  * Permission to use, copy, modify, and/or distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include <errno.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <libubox/ustream.h>
  23
  24 #include "ustream-ssl.h"
  25 #include "ustream-internal.h"
  26
  27 static void ustream_ssl_error_cb(struct uloop_timeout *t)
  28 {
  29         struct ustream_ssl *us = container_of(t, struct ustream_ssl, error_timer);
  30         static char buffer[128];
  31         int error = us->error;
  32
  33         if (us->notify_error)
  34                 us->notify_error(us, error, __ustream_ssl_strerror(us->error, buffer, sizeof(buffer)));
  35 }
  36
  37 static void ustream_ssl_check_conn(struct ustream_ssl *us)
  38 {
  39         if (us->connected || us->error)
  40                 return;
  41
  42         if (__ustream_ssl_connect(us) == U_SSL_OK) {
  43
  44                 /* __ustream_ssl_connect() will also return U_SSL_OK when certificate
  45                  * verification failed!
  46                  *
  47                  * Applications may register a custom .notify_verify_error callback in the
  48                  * struct ustream_ssl which is called upon verification failures, but there
  49                  * is no straight forward way for the callback to terminate the connection
  50                  * initiation right away, e.g. through a true or false return value.
  51                  *
  52                  * Instead, existing implementations appear to set .eof field of the underlying
  53                  * ustream in the hope that this inhibits further operations on the stream.
  54                  *
  55                  * Declare this informal behaviour "official" and check for the state of the
  56                  * .eof member after __ustream_ssl_connect() returned, and do not write the
  57                  * pending data if it is set to true.
  58                  */
  59
  60                 if (us->stream.eof)
  61                         return;
  62
  63                 us->connected = true;
  64                 if (us->notify_connected)
  65                         us->notify_connected(us);
  66                 ustream_write_pending(&us->stream);
  67         }
  68 }
  69
  70 static bool __ustream_ssl_poll(struct ustream *s)
  71 {
  72         struct ustream_ssl *us = container_of(s->next, struct ustream_ssl, stream);
  73         char *buf;
  74         int len, ret;
  75         bool more = false;
  76
  77         ustream_ssl_check_conn(us);
  78         if (!us->connected || us->error)
  79                 return false;
  80
  81         do {
  82                 buf = ustream_reserve(&us->stream, 1, &len);
  83                 if (!len)
  84                         break;
  85
  86                 ret = __ustream_ssl_read(us, buf, len);
  87                 switch (ret) {
  88                 case U_SSL_PENDING:
  89                         return more;
  90                 case U_SSL_ERROR:
  91                         return false;
  92                 case 0:
  93                         us->stream.eof = true;
  94                         ustream_state_change(&us->stream);
  95                         return false;
  96                 default:
  97                         ustream_fill_read(&us->stream, ret);
  98                         more = true;
  99                         continue;
 100                 }
 101         } while (1);
 102
 103         return more;
 104 }
 105
 106 static void ustream_ssl_notify_read(struct ustream *s, int bytes)
 107 {
 108         __ustream_ssl_poll(s);
 109 }
 110
 111 static void ustream_ssl_notify_write(struct ustream *s, int bytes)
 112 {
 113         struct ustream_ssl *us = container_of(s->next, struct ustream_ssl, stream);
 114
 115         ustream_ssl_check_conn(us);
 116         ustream_write_pending(s->next);
 117 }
 118
 119 static void ustream_ssl_notify_state(struct ustream *s)
 120 {
 121         s->next->write_error = true;
 122         ustream_state_change(s->next);
 123 }
 124
 125 static int ustream_ssl_write(struct ustream *s, const char *buf, int len, bool more)
 126 {
 127         struct ustream_ssl *us = container_of(s, struct ustream_ssl, stream);
 128
 129         if (!us->connected || us->error)
 130                 return 0;
 131
 132         if (us->conn->w.data_bytes)
 133                 return 0;
 134
 135         return __ustream_ssl_write(us, buf, len);
 136 }
 137
 138 static void ustream_ssl_set_read_blocked(struct ustream *s)
 139 {
 140         struct ustream_ssl *us = container_of(s, struct ustream_ssl, stream);
 141
 142         ustream_set_read_blocked(us->conn, !!s->read_blocked);
 143 }
 144
 145 static void ustream_ssl_free(struct ustream *s)
 146 {
 147         struct ustream_ssl *us = container_of(s, struct ustream_ssl, stream);
 148
 149         if (us->conn) {
 150                 us->conn->next = NULL;
 151                 us->conn->notify_read = NULL;
 152                 us->conn->notify_write = NULL;
 153                 us->conn->notify_state = NULL;
 154         }
 155
 156         uloop_timeout_cancel(&us->error_timer);
 157         __ustream_ssl_session_free(us->ssl);
 158         free(us->peer_cn);
 159
 160         us->ctx = NULL;
 161         us->ssl = NULL;
 162         us->conn = NULL;
 163         us->peer_cn = NULL;
 164         us->connected = false;
 165         us->error = false;
 166         us->valid_cert = false;
 167         us->valid_cn = false;
 168 }
 169
 170 static bool ustream_ssl_poll(struct ustream *s)
 171 {
 172         struct ustream_ssl *us = container_of(s, struct ustream_ssl, stream);
 173         bool fd_poll;
 174
 175         fd_poll = ustream_poll(us->conn);
 176         return __ustream_ssl_poll(us->conn) || fd_poll;
 177 }
 178
 179 static void ustream_ssl_stream_init(struct ustream_ssl *us)
 180 {
 181         struct ustream *conn = us->conn;
 182         struct ustream *s = &us->stream;
 183
 184         conn->notify_read = ustream_ssl_notify_read;
 185         conn->notify_write = ustream_ssl_notify_write;
 186         conn->notify_state = ustream_ssl_notify_state;
 187
 188         s->free = ustream_ssl_free;
 189         s->write = ustream_ssl_write;
 190         s->poll = ustream_ssl_poll;
 191         s->set_read_blocked = ustream_ssl_set_read_blocked;
 192         ustream_init_defaults(s);
 193 }
 194
 195 static int _ustream_ssl_init(struct ustream_ssl *us, struct ustream *conn, struct ustream_ssl_ctx *ctx, bool server)
 196 {
 197         us->error_timer.cb = ustream_ssl_error_cb;
 198         us->server = server;
 199         us->conn = conn;
 200         us->ctx = ctx;
 201
 202 #if defined(HAVE_WOLFSSL) && defined(NO_WOLFSSL_SSLSETIO_SEND_RECV)
 203         ustream_set_io(ctx, NULL, conn);
 204 #endif
 205         us->ssl = __ustream_ssl_session_new(us->ctx);
 206         if (!us->ssl)
 207                 return -ENOMEM;
 208
 209         conn->next = &us->stream;
 210         ustream_set_io(ctx, us->ssl, conn);
 211         ustream_ssl_stream_init(us);
 212
 213         if (us->server_name)
 214                 __ustream_ssl_set_server_name(us);
 215
 216         ustream_ssl_check_conn(us);
 217
 218         return 0;
 219 }
 220
 221 static int _ustream_ssl_set_peer_cn(struct ustream_ssl *us, const char *name)
 222 {
 223         us->peer_cn = strdup(name);
 224         __ustream_ssl_update_peer_cn(us);
 225
 226         return 0;
 227 }
 228
 229 const struct ustream_ssl_ops ustream_ssl_ops = {
 230         .context_new = __ustream_ssl_context_new,
 231         .context_set_crt_file = __ustream_ssl_set_crt_file,
 232         .context_set_key_file = __ustream_ssl_set_key_file,
 233         .context_add_ca_crt_file = __ustream_ssl_add_ca_crt_file,
 234         .context_free = __ustream_ssl_context_free,
 235         .init = _ustream_ssl_init,
 236         .set_peer_cn = _ustream_ssl_set_peer_cn,
 237 };