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| author | Ken Raeburn <raeburn@mit.edu> | 2001-03-03 22:02:00 +0000 |
|---|---|---|
| committer | Ken Raeburn <raeburn@mit.edu> | 2001-03-03 22:02:00 +0000 |
| commit | 4531ba725b82df5c1232d763eed82930b09ec234 (patch) | |
| tree | b1d67f651d5b3a35e1c0f012cf75ea6fd7cf563b /src | |
| parent | 1d04f82647095502e00afca300c5db8c8e0a788d (diff) | |
| download | krb5-4531ba725b82df5c1232d763eed82930b09ec234.tar.gz krb5-4531ba725b82df5c1232d763eed82930b09ec234.tar.xz krb5-4531ba725b82df5c1232d763eed82930b09ec234.zip | |
init_os_ctx.c: On UNIX, seed PRNG with data from /dev/[u]random if available
git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@13050 dc483132-0cff-0310-8789-dd5450dbe970
Diffstat (limited to 'src')
| -rw-r--r-- | src/lib/krb5/os/ChangeLog | 7 | ||||
| -rw-r--r-- | src/lib/krb5/os/init_os_ctx.c | 41 |
2 files changed, 48 insertions, 0 deletions
diff --git a/src/lib/krb5/os/ChangeLog b/src/lib/krb5/os/ChangeLog index 92b42a6b2e..9fcc89b739 100644 --- a/src/lib/krb5/os/ChangeLog +++ b/src/lib/krb5/os/ChangeLog @@ -1,3 +1,10 @@ +2001-03-03 Ken Raeburn <raeburn@mit.edu> + + * init_os_ctx.c: If not Mac or Windows, define USE_RANDOM_DEVICE + and include sys/ioctl.h. + (krb5_os_init_context) [USE_RANDOM_DEVICE]: Read some bytes from + /dev/urandom or /dev/random and use them to re-seed the PRNG. + 2001-02-05 Tom Yu <tlyu@mit.edu> * prompter.c (krb5_prompter_posix): Fix up terminal modes if we're diff --git a/src/lib/krb5/os/init_os_ctx.c b/src/lib/krb5/os/init_os_ctx.c index 4168dfe463..f72d643f10 100644 --- a/src/lib/krb5/os/init_os_ctx.c +++ b/src/lib/krb5/os/init_os_ctx.c @@ -33,6 +33,11 @@ #include <PreferencesLib.h> #endif /* macintosh */ +#if !defined(macintosh) && !defined(_MSDOS) && !defined(_WIN32) +#define USE_RANDOM_DEVICE +#include <sys/ioctl.h> /* for FIONBIO */ +#endif + #if defined(_MSDOS) || defined(_WIN32) static krb5_error_code @@ -443,6 +448,42 @@ krb5_os_init_context(ctx) os_ctx->default_ccname = 0; os_ctx->default_ccprincipal = 0; +#ifdef USE_RANDOM_DEVICE + /* If the OS provides us with random or even pseudorandom + data, use it. It'll be far better than what we've got + above, but not all systems provide it (yet). + + Typical setup seems to be /dev/urandom is pseudo-random, as + good as the system can provide, but never blocking; + /dev/random is supposedly truly random (the metrics are + sometimes suspect), and may block. */ + { + char rndbytes[128]; + krb5_data seed; + int tmp; + + tmp = open ("/dev/urandom", O_RDONLY); + if (tmp == -1) { + int dontblock = 1; + tmp = open ("/dev/random", O_RDONLY); + (void) ioctl (tmp, FIONBIO, (char *) &dontblock); + } + if (tmp != -1) { + /* If this doesn't work, should we continue or + report an error that'll cause all Kerberos + programs to fail? */ + (void) read (tmp, &rndbytes, sizeof (rndbytes)); + close (tmp); + } + /* Okay. Take whatever we've got, and seed the + PRNG. */ + seed.length = sizeof(rndbytes); + seed.data = (char *) &rndbytes; + if ((retval = krb5_c_random_seed(ctx, &seed))) + return retval; + } +#endif + krb5_cc_set_default_name(ctx, NULL); retval = os_init_paths(ctx); |