lib/libtls/tls_bio_cb.c

   1 /* $OpenBSD: tls_bio_cb.c,v 1.19 2017/01/12 16:18:39 jsing Exp $ */
   2 /*
   3  * Copyright (c) 2016 Tobias Pape <tobias@netshed.de>
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 #include <fcntl.h>
  19 #include <stdlib.h>
  20 #include <unistd.h>
  21
  22 #include <openssl/bio.h>
  23
  24 #include <tls.h>
  25 #include "tls_internal.h"
  26
  27 static int bio_cb_write(BIO *bio, const char *buf, int num);
  28 static int bio_cb_read(BIO *bio, char *buf, int size);
  29 static int bio_cb_puts(BIO *bio, const char *str);
  30 static long bio_cb_ctrl(BIO *bio, int cmd, long num, void *ptr);
  31
  32 static BIO_METHOD bio_cb_method = {
  33         .type = BIO_TYPE_MEM,
  34         .name = "libtls_callbacks",
  35         .bwrite = bio_cb_write,
  36         .bread = bio_cb_read,
  37         .bputs = bio_cb_puts,
  38         .ctrl = bio_cb_ctrl,
  39 };
  40
  41 static BIO_METHOD *
  42 bio_s_cb(void)
  43 {
  44         return (&bio_cb_method);
  45 }
  46
  47 static int
  48 bio_cb_puts(BIO *bio, const char *str)
  49 {
  50         return (bio_cb_write(bio, str, strlen(str)));
  51 }
  52
  53 static long
  54 bio_cb_ctrl(BIO *bio, int cmd, long num, void *ptr)
  55 {
  56         long ret = 1;
  57
  58         switch (cmd) {
  59         case BIO_CTRL_GET_CLOSE:
  60                 ret = (long)bio->shutdown;
  61                 break;
  62         case BIO_CTRL_SET_CLOSE:
  63                 bio->shutdown = (int)num;
  64                 break;
  65         case BIO_CTRL_DUP:
  66         case BIO_CTRL_FLUSH:
  67                 break;
  68         case BIO_CTRL_INFO:
  69         case BIO_CTRL_GET:
  70         case BIO_CTRL_SET:
  71         default:
  72                 ret = BIO_ctrl(bio->next_bio, cmd, num, ptr);
  73         }
  74
  75         return (ret);
  76 }
  77
  78 static int
  79 bio_cb_write(BIO *bio, const char *buf, int num)
  80 {
  81         struct tls *ctx = bio->ptr;
  82         int rv;
  83
  84         BIO_clear_retry_flags(bio);
  85         rv = (ctx->write_cb)(ctx, buf, num, ctx->cb_arg);
  86         if (rv == TLS_WANT_POLLIN) {
  87                 BIO_set_retry_read(bio);
  88                 rv = -1;
  89         } else if (rv == TLS_WANT_POLLOUT) {
  90                 BIO_set_retry_write(bio);
  91                 rv = -1;
  92         }
  93         return (rv);
  94 }
  95
  96 static int
  97 bio_cb_read(BIO *bio, char *buf, int size)
  98 {
  99         struct tls *ctx = bio->ptr;
 100         int rv;
 101
 102         BIO_clear_retry_flags(bio);
 103         rv = (ctx->read_cb)(ctx, buf, size, ctx->cb_arg);
 104         if (rv == TLS_WANT_POLLIN) {
 105                 BIO_set_retry_read(bio);
 106                 rv = -1;
 107         } else if (rv == TLS_WANT_POLLOUT) {
 108                 BIO_set_retry_write(bio);
 109                 rv = -1;
 110         }
 111         return (rv);
 112 }
 113
 114 int
 115 tls_set_cbs(struct tls *ctx, tls_read_cb read_cb, tls_write_cb write_cb,
 116     void *cb_arg)
 117 {
 118         int rv = -1;
 119         BIO *bio;
 120
 121         if (read_cb == NULL || write_cb == NULL) {
 122                 tls_set_errorx(ctx, "no callbacks provided");
 123                 goto err;
 124         }
 125
 126         ctx->read_cb = read_cb;
 127         ctx->write_cb = write_cb;
 128         ctx->cb_arg = cb_arg;
 129
 130         if ((bio = BIO_new(bio_s_cb())) == NULL) {
 131                 tls_set_errorx(ctx, "failed to create callback i/o");
 132                 goto err;
 133         }
 134         bio->ptr = ctx;
 135         bio->init = 1;
 136
 137         SSL_set_bio(ctx->ssl_conn, bio, bio);
 138
 139         rv = 0;
 140
 141  err:
 142         return (rv);
 143 }