diff options
Diffstat (limited to 'random.c')
| -rw-r--r-- | random.c | 31 |
1 files changed, 28 insertions, 3 deletions
@@ -30,8 +30,9 @@ static int donerandinit = 0; /* this is used to generate unique output from the same hashpool */ -static unsigned int counter = 0; -#define MAX_COUNTER 1000000/* the max value for the counter, so it won't loop */ +static uint32_t counter = 0; +/* the max value for the counter, so it won't integer overflow */ +#define MAX_COUNTER 1<<30 static unsigned char hashpool[SHA1_HASH_SIZE]; @@ -132,7 +133,8 @@ void seedrandom() { hash_state hs; - /* initialise so compilers will be happy about hashing it */ + /* initialise so that things won't warn about + * hashing an undefined buffer */ if (!donerandinit) { m_burn(hashpool, sizeof(hashpool)); } @@ -150,6 +152,29 @@ void seedrandom() { donerandinit = 1; } +/* hash the current random pool with some unique identifiers + * for this process and point-in-time. this is used to separate + * the random pools for fork()ed processes. */ +void reseedrandom() { + + pid_t pid; + hash_state hs; + struct timeval tv; + + if (!donerandinit) { + dropbear_exit("seedrandom not done"); + } + + pid = getpid(); + gettimeofday(&tv, NULL); + + sha1_init(&hs); + sha1_process(&hs, (void*)hashpool, sizeof(hashpool)); + sha1_process(&hs, (void*)&pid, sizeof(pid)); + sha1_process(&hs, (void*)&tv, sizeof(tv)); + sha1_done(&hs, hashpool); +} + /* return len bytes of pseudo-random data */ void genrandom(unsigned char* buf, unsigned int len) { |