dropbear-0.45-urandom.patch

   1 --- dropbear-0.45.orig/options.h        2005-03-08 14:43:07.000000000 -0500
   2 +++ dropbear-0.45/options.h     2005-03-08 14:44:41.000000000 -0500
   3 @@ -148,6 +148,10 @@
   4  /* prngd must be manually set up to produce output */
   5  /*#define DROPBEAR_PRNGD_SOCKET "/var/run/dropbear-rng"*/
   6
   7 +/* If the normal random source would block for a while, fall back to
   8 + * the urandom source so that connections don't hang forever. */
   9 +#define DROPBEAR_URANDOM_DEV "/dev/urandom"
  10 +
  11  /* Specify the number of clients we will allow to be connected but
  12   * not yet authenticated. After this limit, connections are rejected */
  13  #ifndef MAX_UNAUTH_CLIENTS
  14 diff -ur dropbear-0.45.orig/random.c dropbear-0.45/random.c
  15 --- dropbear-0.45.orig/random.c 2005-03-08 14:43:07.000000000 -0500
  16 +++ dropbear-0.45/random.c      2005-03-08 14:57:31.000000000 -0500
  17 @@ -57,9 +57,14 @@
  18         struct sockaddr_un egdsock;
  19         char egdcmd[2];
  20  #endif
  21 +       mode_t readmode = O_RDONLY;
  22 +#ifdef DROPBEAR_URANDOM_DEV
  23 +       unsigned int readtries = 0;
  24 +       readmode |= O_NONBLOCK;
  25 +#endif
  26
  27  #ifdef DROPBEAR_RANDOM_DEV
  28 -       readfd = open(DROPBEAR_RANDOM_DEV, O_RDONLY);
  29 +       readfd = open(DROPBEAR_RANDOM_DEV, readmode);
  30         if (readfd < 0) {
  31                 dropbear_exit("couldn't open random device");
  32         }
  33 @@ -97,6 +102,24 @@
  34                         if (readlen < 0 && errno == EINTR) {
  35                                 continue;
  36                         }
  37 +#ifdef DROPBEAR_URANDOM_DEV
  38 +                       /* if the main random source blocked, lets retry a few times,
  39 +                        * but then give up and try a constant random source. */
  40 +                       if (readlen < 0 && errno == EAGAIN) {
  41 +                               ++readtries;
  42 +                               if (readtries < 5) {
  43 +                                       sleep(1);
  44 +                                       continue;
  45 +                               } else if (readtries == 5) {
  46 +                                       close (readfd);
  47 +                                       readfd = open(DROPBEAR_URANDOM_DEV, readmode);
  48 +                                       if (readfd < 0) {
  49 +                                               dropbear_exit("couldn't open secondary random device");
  50 +                                       }
  51 +                                       continue;
  52 +                               }
  53 +                       }
  54 +#endif
  55                         dropbear_exit("error reading random source");
  56                 }
  57                 readpos += readlen;