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| author | Nikos Mavrogiannopoulos <nmav@gnutls.org> | 2017-02-26 19:56:09 +0100 |
|---|---|---|
| committer | Nikos Mavrogiannopoulos <nmav@gnutls.org> | 2017-03-06 22:24:33 +0100 |
| commit | 4c450f23398ec50567eb9473d040ea76751a97ea (patch) | |
| tree | cb5267730710821684434c533371966e5b16d2d1 | |
| parent | cc6876289ec927350c39e562bd5b0c1f090d5149 (diff) | |
| download | gnutls-4c450f23398ec50567eb9473d040ea76751a97ea.tar.gz | |
nettle/rnd: specify different limits for rekey in PRNGs
Signed-off-by: Nikos Mavrogiannopoulos <nmav@gnutls.org>
| -rw-r--r-- | lib/nettle/rnd.c | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/lib/nettle/rnd.c b/lib/nettle/rnd.c index 0fb8cee9c3..fd0ad9e668 100644 --- a/lib/nettle/rnd.c +++ b/lib/nettle/rnd.c @@ -34,7 +34,12 @@ #define PRNG_KEY_SIZE CHACHA_KEY_SIZE /* after this number of bytes PRNG will rekey */ -#define PRNG_RESEED_BYTES (1048576) + +static const unsigned prng_reseed_limits[] = { + [GNUTLS_RND_NONCE] = 1024*1024, /* 1 MB */ + [GNUTLS_RND_RANDOM] = 16*1024, /* 16 kb */ + [GNUTLS_RND_KEY] = 1024 /* 1 kb */ +}; struct prng_ctx_st { struct chacha_ctx ctx; @@ -153,8 +158,11 @@ wrap_nettle_rnd(void *_ctx, int level, void *data, size_t datasize) prng_ctx = &ctx->normal; else if (level == GNUTLS_RND_KEY) prng_ctx = &ctx->strong; - else + else if (level == GNUTLS_RND_NONCE) prng_ctx = &ctx->nonce; + else + return gnutls_assert_val(GNUTLS_E_RANDOM_FAILED); + /* we don't really need memset here, but otherwise we * get filled with valgrind warnings */ @@ -164,7 +172,7 @@ wrap_nettle_rnd(void *_ctx, int level, void *data, size_t datasize) reseed = 1; } - if (reseed != 0 || prng_ctx->counter > PRNG_RESEED_BYTES) { + if (reseed != 0 || prng_ctx->counter > prng_reseed_limits[level]) { uint8_t new_key[PRNG_KEY_SIZE]; if (level == GNUTLS_RND_NONCE) { @@ -204,9 +212,9 @@ static void wrap_nettle_rnd_refresh(void *_ctx) char tmp; /* force reseed */ - ctx->nonce.counter = PRNG_RESEED_BYTES+1; - ctx->normal.counter = PRNG_RESEED_BYTES+1; - ctx->strong.counter = PRNG_RESEED_BYTES+1; + ctx->nonce.counter = prng_reseed_limits[GNUTLS_RND_NONCE]+1; + ctx->normal.counter = prng_reseed_limits[GNUTLS_RND_RANDOM]+1; + ctx->strong.counter = prng_reseed_limits[GNUTLS_RND_KEY]+1; wrap_nettle_rnd(_ctx, GNUTLS_RND_NONCE, &tmp, 1); wrap_nettle_rnd(_ctx, GNUTLS_RND_RANDOM, &tmp, 1); |