sys/sys/csprng.h

   1 #ifndef _SYS_CSPRNG_H_
   2 #define _SYS_CSPRNG_H_
   3
   4 #include <crypto/sha2/sha2.h>
   5 #include <crypto/chacha/chacha.h>
   6
   7 #include <sys/callout.h>
   8 #include <sys/spinlock.h>
   9 #include <sys/time.h>
  10
  11 /* Flags for various calls */
  12 #define CSPRNG_TRYLOCK          0x0001
  13 #define CSPRNG_UNLIMITED        0x0002
  14
  15 struct csprng_pool {
  16         uint64_t        bytes;
  17         SHA256_CTX      hash_ctx;
  18
  19         struct spinlock lock;
  20 };
  21
  22 CTASSERT(SHA256_DIGEST_LENGTH == 32);
  23
  24 struct csprng_state {
  25         uint8_t         key[SHA256_DIGEST_LENGTH];
  26         uint64_t        nonce;          /* Effectively high 64-bits of ctr */
  27         uint64_t        ctr;
  28
  29         uint64_t        reseed_cnt;     /* Times we have reseeded */
  30
  31         chacha_ctx      cipher_ctx;     /* (Stream) cipher context */
  32
  33         /* Pools and the per-source round robin pool index */
  34         struct csprng_pool pool[32];
  35         uint8_t         src_pool_idx[256];
  36
  37         struct spinlock lock;
  38         struct callout  reseed_callout;
  39         uint32_t        failed_reseeds;
  40         int             callout_based_reseed;
  41         struct timeval  last_reseed;
  42 };
  43
  44 int csprng_init(struct csprng_state *state);
  45 int csprng_init_reseed(struct csprng_state *state);
  46 int csprng_get_random(struct csprng_state *state, uint8_t *out, int bytes,
  47     int flags);
  48 int csprng_add_entropy(struct csprng_state *state, int src_id,
  49     const uint8_t *entropy, size_t bytes, int flags);
  50
  51 #endif