diff options
Diffstat (limited to 'libpam/pam_delay.c')
| -rw-r--r-- | libpam/pam_delay.c | 41 |
1 files changed, 30 insertions, 11 deletions
diff --git a/libpam/pam_delay.c b/libpam/pam_delay.c index 549da896..9c6716a1 100644 --- a/libpam/pam_delay.c +++ b/libpam/pam_delay.c @@ -14,12 +14,17 @@ */ #include "pam_private.h" +#include <limits.h> #include <unistd.h> #include <time.h> +#ifdef HAVE_SYS_RANDOM_H +#include <sys/random.h> +#endif + /* ********************************************************************** * initialize the time as unset, this is set on the return from the - * authenticating pair of of the libpam pam_XXX calls. + * authenticating pair of the libpam pam_XXX calls. */ void _pam_reset_timer(pam_handle_t *pamh) @@ -51,29 +56,40 @@ void _pam_start_timer(pam_handle_t *pamh) * in C'. It is *not* a cryptographically strong generator, but it is * probably "good enough" for our purposes here. * - * /dev/random might be a better place to look for some numbers... + * If getrandom is available, retrieve random number from there. */ static unsigned int _pam_rand(unsigned int seed) { +#ifdef HAVE_GETRANDOM + unsigned int value; + + if (getrandom(&value, sizeof(value), GRND_NONBLOCK) == + (ssize_t) sizeof(value)) { + return value; + } +#endif + #define N1 1664525 #define N2 1013904223 return N1*seed + N2; } -static unsigned int _pam_compute_delay(unsigned int seed, unsigned int base) +static unsigned long long _pam_compute_delay(unsigned int seed, + unsigned int base) { int i; double sum; - unsigned int ans; + unsigned long long ans; for (sum=i=0; i<3; ++i) { seed = _pam_rand(seed); sum += (double) ((seed / 10) % 1000000); } sum = (sum/3.)/1e6 - .5; /* rescale */ - ans = (unsigned int) ( base*(1.+sum) ); - D(("random number: base=%u -> ans=%u\n", base, ans)); + sum = base*(1.+sum); + ans = sum > (double) ULLONG_MAX ? ULLONG_MAX : (unsigned long long) sum; + D(("random number: base=%u -> ans=%llu\n", base, ans)); return ans; } @@ -88,7 +104,7 @@ static unsigned int _pam_compute_delay(unsigned int seed, unsigned int base) void _pam_await_timer(pam_handle_t *pamh, int status) { - unsigned int delay; + unsigned long long delay; D(("waiting?...")); delay = _pam_compute_delay(pamh->fail_delay.begin, @@ -99,6 +115,7 @@ void _pam_await_timer(pam_handle_t *pamh, int status) void (*fn)(int, unsigned, void *); } hack_fn_u; void *appdata_ptr; + unsigned int delay_uint; if (pamh->pam_conversation) { appdata_ptr = pamh->pam_conversation->appdata_ptr; @@ -106,14 +123,16 @@ void _pam_await_timer(pam_handle_t *pamh, int status) appdata_ptr = NULL; } - /* always call the applications delay function, even if + delay_uint = delay > UINT_MAX ? UINT_MAX : (unsigned int) delay; + + /* always call the application's delay function, even if the delay is zero - indicate status */ hack_fn_u.value = pamh->fail_delay.delay_fn_ptr; - hack_fn_u.fn(status, delay, appdata_ptr); + hack_fn_u.fn(status, delay_uint, appdata_ptr); } else if (status != PAM_SUCCESS && pamh->fail_delay.set) { - D(("will wait %u usec", delay)); + D(("will wait %llu usec", delay)); if (delay > 0) { struct timeval tval; @@ -138,7 +157,7 @@ int pam_fail_delay(pam_handle_t *pamh, unsigned int usec) { unsigned int largest; - IF_NO_PAMH("pam_fail_delay", pamh, PAM_SYSTEM_ERR); + IF_NO_PAMH(pamh, PAM_SYSTEM_ERR); D(("setting delay to %u",usec)); |