external/ibm-public/postfix/dist/src/tls/tls_stream.c

   1 /*      $NetBSD$        */
   2
   3 /*++
   4 /* NAME
   5 /*      tls_stream
   6 /* SUMMARY
   7 /*      VSTREAM over TLS
   8 /* SYNOPSIS
   9 /*      #define TLS_INTERNAL
  10 /*      #include <tls.h>
  11 /*
  12 /*      void    tls_stream_start(stream, context)
  13 /*      VSTREAM *stream;
  14 /*      TLS_SESS_STATE *context;
  15 /*
  16 /*      void    tls_stream_stop(stream)
  17 /*      VSTREAM *stream;
  18 /* DESCRIPTION
  19 /*      This module implements the VSTREAM over TLS support user interface.
  20 /*      The hard work is done elsewhere.
  21 /*
  22 /*      tls_stream_start() enables TLS on the named stream. All read
  23 /*      and write operations are directed through the TLS library,
  24 /*      using the state information specified with the context argument.
  25 /*
  26 /*      tls_stream_stop() replaces the VSTREAM read/write routines
  27 /*      by dummies that have no side effects, and deletes the
  28 /*      VSTREAM's reference to the TLS context.
  29 /* SEE ALSO
  30 /*      dummy_read(3), placebo read routine
  31 /*      dummy_write(3), placebo write routine
  32 /* LICENSE
  33 /* .ad
  34 /* .fi
  35 /*      This software is free. You can do with it whatever you want.
  36 /*      The original author kindly requests that you acknowledge
  37 /*      the use of his software.
  38 /* AUTHOR(S)
  39 /*      Based on code that was originally written by:
  40 /*      Lutz Jaenicke
  41 /*      BTU Cottbus
  42 /*      Allgemeine Elektrotechnik
  43 /*      Universitaetsplatz 3-4
  44 /*      D-03044 Cottbus, Germany
  45 /*
  46 /*      Updated by:
  47 /*      Wietse Venema
  48 /*      IBM T.J. Watson Research
  49 /*      P.O. Box 704
  50 /*      Yorktown Heights, NY 10598, USA
  51 /*--*/
  52
  53 /* System library. */
  54
  55 #include <sys_defs.h>
  56
  57 #ifdef USE_TLS
  58
  59 /* Utility library. */
  60
  61 #include <iostuff.h>
  62 #include <vstream.h>
  63 #include <msg.h>
  64
  65 /* TLS library. */
  66
  67 #define TLS_INTERNAL
  68 #include <tls.h>
  69
  70 /* tls_timed_read - read content from stream, then TLS decapsulate */
  71
  72 static ssize_t tls_timed_read(int fd, void *buf, size_t len, int timeout,
  73                                       void *context)
  74 {
  75     const char *myname = "tls_timed_read";
  76     ssize_t ret;
  77     TLS_SESS_STATE *TLScontext;
  78
  79     TLScontext = (TLS_SESS_STATE *) context;
  80     if (!TLScontext)
  81         msg_panic("%s: no context", myname);
  82
  83     ret = tls_bio_read(fd, buf, len, timeout, TLScontext);
  84     if (ret > 0 && TLScontext->log_level >= 4)
  85         msg_info("Read %ld chars: %.*s",
  86                  (long) ret, (int) (ret > 40 ? 40 : ret), (char *) buf);
  87     return (ret);
  88 }
  89
  90 /* tls_timed_write - TLS encapsulate content, then write to stream */
  91
  92 static ssize_t tls_timed_write(int fd, void *buf, size_t len, int timeout,
  93                                        void *context)
  94 {
  95     const char *myname = "tls_timed_write";
  96     TLS_SESS_STATE *TLScontext;
  97
  98     TLScontext = (TLS_SESS_STATE *) context;
  99     if (!TLScontext)
 100         msg_panic("%s: no context", myname);
 101
 102     if (TLScontext->log_level >= 4)
 103         msg_info("Write %ld chars: %.*s",
 104                  (long) len, (int) (len > 40 ? 40 : len), (char *) buf);
 105     return (tls_bio_write(fd, buf, len, timeout, TLScontext));
 106 }
 107
 108 /* tls_stream_start - start VSTREAM over TLS */
 109
 110 void    tls_stream_start(VSTREAM *stream, TLS_SESS_STATE *context)
 111 {
 112     vstream_control(stream,
 113                     VSTREAM_CTL_READ_FN, tls_timed_read,
 114                     VSTREAM_CTL_WRITE_FN, tls_timed_write,
 115                     VSTREAM_CTL_CONTEXT, (void *) context,
 116                     VSTREAM_CTL_END);
 117 }
 118
 119 /* tls_stream_stop - stop VSTREAM over TLS */
 120
 121 void    tls_stream_stop(VSTREAM *stream)
 122 {
 123
 124     /*
 125      * Prevent data leakage after TLS is turned off. The Postfix/TLS patch
 126      * provided null function pointers; we use dummy routines that make less
 127      * noise when used.
 128      */
 129     vstream_control(stream,
 130                     VSTREAM_CTL_READ_FN, dummy_read,
 131                     VSTREAM_CTL_WRITE_FN, dummy_write,
 132                     VSTREAM_CTL_CONTEXT, (void *) 0,
 133                     VSTREAM_CTL_END);
 134 }
 135
 136 #endif