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                 if (ret == U_SSL_PENDING) {
  88                         ustream_poll(us->conn);
  89                         ret = __ustream_ssl_read(us, buf, len);
  90                 }
  91
  92                 switch (ret) {
  93                 case U_SSL_PENDING:
  94                         return more;
  95                 case U_SSL_ERROR:
  96                         return false;
  97                 case 0:
  98                         us->stream.eof = true;
  99                         ustream_state_change(&us->stream);
 100                         return false;
 101                 default:
 102                         ustream_fill_read(&us->stream, ret);
 103                         more = true;
 104                         continue;
 105                 }
 106         } while (1);
 107
 108         return more;
 109 }
 110
 111 static void ustream_ssl_notify_read(struct ustream *s, int bytes)
 112 {
 113         __ustream_ssl_poll(s);
 114 }
 115
 116 static void ustream_ssl_notify_write(struct ustream *s, int bytes)
 117 {
 118         struct ustream_ssl *us = container_of(s->next, struct ustream_ssl, stream);
 119
 120         ustream_ssl_check_conn(us);
 121         ustream_write_pending(s->next);
 122 }
 123
 124 static void ustream_ssl_notify_state(struct ustream *s)
 125 {
 126         s->next->write_error = true;
 127         ustream_state_change(s->next);
 128 }
 129
 130 static int ustream_ssl_write(struct ustream *s, const char *buf, int len, bool more)
 131 {
 132         struct ustream_ssl *us = container_of(s, struct ustream_ssl, stream);
 133
 134         if (!us->connected || us->error)
 135                 return 0;
 136
 137         if (us->conn->w.data_bytes)
 138                 return 0;
 139
 140         return __ustream_ssl_write(us, buf, len);
 141 }
 142
 143 static void ustream_ssl_set_read_blocked(struct ustream *s)
 144 {
 145         struct ustream_ssl *us = container_of(s, struct ustream_ssl, stream);
 146
 147         ustream_set_read_blocked(us->conn, !!s->read_blocked);
 148 }
 149
 150 static void ustream_ssl_free(struct ustream *s)
 151 {
 152         struct ustream_ssl *us = container_of(s, struct ustream_ssl, stream);
 153
 154         if (us->conn) {
 155                 us->conn->next = NULL;
 156                 us->conn->notify_read = NULL;
 157                 us->conn->notify_write = NULL;
 158                 us->conn->notify_state = NULL;
 159         }
 160
 161         uloop_timeout_cancel(&us->error_timer);
 162         __ustream_ssl_session_free(us->ssl);
 163         free(us->peer_cn);
 164
 165         us->ctx = NULL;
 166         us->ssl = NULL;
 167         us->conn = NULL;
 168         us->peer_cn = NULL;
 169         us->connected = false;
 170         us->error = false;
 171         us->valid_cert = false;
 172         us->valid_cn = false;
 173 }
 174
 175 static bool ustream_ssl_poll(struct ustream *s)
 176 {
 177         struct ustream_ssl *us = container_of(s, struct ustream_ssl, stream);
 178         bool fd_poll;
 179
 180         fd_poll = ustream_poll(us->conn);
 181         return __ustream_ssl_poll(us->conn) || fd_poll;
 182 }
 183
 184 static void ustream_ssl_stream_init(struct ustream_ssl *us)
 185 {
 186         struct ustream *conn = us->conn;
 187         struct ustream *s = &us->stream;
 188
 189         conn->notify_read = ustream_ssl_notify_read;
 190         conn->notify_write = ustream_ssl_notify_write;
 191         conn->notify_state = ustream_ssl_notify_state;
 192
 193         s->free = ustream_ssl_free;
 194         s->write = ustream_ssl_write;
 195         s->poll = ustream_ssl_poll;
 196         s->set_read_blocked = ustream_ssl_set_read_blocked;
 197         ustream_init_defaults(s);
 198 }
 199
 200 static int _ustream_ssl_init(struct ustream_ssl *us, struct ustream *conn, struct ustream_ssl_ctx *ctx, bool server)
 201 {
 202         us->error_timer.cb = ustream_ssl_error_cb;
 203         us->server = server;
 204         us->conn = conn;
 205         us->ctx = ctx;
 206
 207         us->ssl = __ustream_ssl_session_new(us->ctx);
 208         if (!us->ssl)
 209                 return -ENOMEM;
 210
 211         conn->r.max_buffers = 4;
 212         conn->next = &us->stream;
 213         ustream_set_io(ctx, us->ssl, conn);
 214         ustream_ssl_stream_init(us);
 215
 216         if (us->server_name)
 217                 __ustream_ssl_set_server_name(us);
 218
 219         ustream_ssl_check_conn(us);
 220
 221         return 0;
 222 }
 223
 224 static int _ustream_ssl_set_peer_cn(struct ustream_ssl *us, const char *name)
 225 {
 226         us->peer_cn = strdup(name);
 227         __ustream_ssl_update_peer_cn(us);
 228
 229         return 0;
 230 }
 231
 232 const struct ustream_ssl_ops ustream_ssl_ops = {
 233         .context_new = __ustream_ssl_context_new,
 234         .context_set_crt_file = __ustream_ssl_set_crt_file,
 235         .context_set_key_file = __ustream_ssl_set_key_file,
 236         .context_add_ca_crt_file = __ustream_ssl_add_ca_crt_file,
 237         .context_set_ciphers = __ustream_ssl_set_ciphers,
 238         .context_set_require_validation = __ustream_ssl_set_require_validation,
 239         .context_set_debug = __ustream_ssl_set_debug,
 240         .context_free = __ustream_ssl_context_free,
 241         .init = _ustream_ssl_init,
 242         .set_peer_cn = _ustream_ssl_set_peer_cn,
 243 };