diff options
Diffstat (limited to 'contrib/unbound/util/random.c')
| -rw-r--r-- | contrib/unbound/util/random.c | 74 |
1 files changed, 71 insertions, 3 deletions
diff --git a/contrib/unbound/util/random.c b/contrib/unbound/util/random.c index 71f0ba5..684464e 100644 --- a/contrib/unbound/util/random.c +++ b/contrib/unbound/util/random.c @@ -68,6 +68,8 @@ /* nss3 */ #include "secport.h" #include "pk11pub.h" +#elif defined(HAVE_NETTLE) +#include "yarrow.h" #endif /** @@ -76,7 +78,7 @@ */ #define MAX_VALUE 0x7fffffff -#ifndef HAVE_NSS +#if defined(HAVE_SSL) void ub_systemseed(unsigned int ATTR_UNUSED(seed)) { @@ -110,7 +112,7 @@ ub_random_max(struct ub_randstate* state, long int x) return (long)arc4random_uniform((uint32_t)x); } -#else +#elif defined(HAVE_NSS) /* not much to remember for NSS since we use its pk11_random, placeholder */ struct ub_randstate { @@ -144,6 +146,72 @@ long int ub_random(struct ub_randstate* ATTR_UNUSED(state)) return x & MAX_VALUE; } +#elif defined(HAVE_NETTLE) + +/** + * libnettle implements a Yarrow-256 generator (SHA256 + AES), + * and we have to ensure it is seeded before use. + */ +struct ub_randstate { + struct yarrow256_ctx ctx; + int seeded; +}; + +void ub_systemseed(unsigned int ATTR_UNUSED(seed)) +{ +/** + * We seed on init and not here, as we need the ctx to re-seed. + * This also means that re-seeding is not supported. + */ + log_err("Re-seeding not supported, generator untouched"); +} + +struct ub_randstate* ub_initstate(unsigned int seed, + struct ub_randstate* ATTR_UNUSED(from)) +{ + struct ub_randstate* s = (struct ub_randstate*)calloc(1, sizeof(*s)); + uint8_t buf[YARROW256_SEED_FILE_SIZE]; + if(!s) { + log_err("malloc failure in random init"); + return NULL; + } + /* Setup Yarrow context */ + yarrow256_init(&s->ctx, 0, NULL); + + if(getentropy(buf, sizeof(buf)) != -1) { + /* got entropy */ + yarrow256_seed(&s->ctx, YARROW256_SEED_FILE_SIZE, buf); + s->seeded = yarrow256_is_seeded(&s->ctx); + } else { + /* Stretch the uint32 input seed and feed it to Yarrow */ + uint32_t v = seed; + size_t i; + for(i=0; i < (YARROW256_SEED_FILE_SIZE/sizeof(seed)); i++) { + memmove(buf+i*sizeof(seed), &v, sizeof(seed)); + v = v*seed + (uint32_t)i; + } + yarrow256_seed(&s->ctx, YARROW256_SEED_FILE_SIZE, buf); + s->seeded = yarrow256_is_seeded(&s->ctx); + } + + return s; +} + +long int ub_random(struct ub_randstate* s) +{ + /* random 31 bit value. */ + long int x = 0; + if (!s || !s->seeded) { + log_err("Couldn't generate randomness, Yarrow-256 generator not yet seeded"); + } else { + yarrow256_random(&s->ctx, sizeof(x), (uint8_t *)&x); + } + return x & MAX_VALUE; +} +#endif /* HAVE_SSL or HAVE_NSS or HAVE_NETTLE */ + + +#if defined(HAVE_NSS) || defined(HAVE_NETTLE) long int ub_random_max(struct ub_randstate* state, long int x) { @@ -155,7 +223,7 @@ ub_random_max(struct ub_randstate* state, long int x) v = ub_random(state); return (v % x); } -#endif /* HAVE_NSS */ +#endif /* HAVE_NSS or HAVE_NETTLE */ void ub_randfree(struct ub_randstate* s) |
