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      1 /* Copyright (c) 2015, Google Inc.
      2  *
      3  * Permission to use, copy, modify, and/or distribute this software for any
      4  * purpose with or without fee is hereby granted, provided that the above
      5  * copyright notice and this permission notice appear in all copies.
      6  *
      7  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
      8  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
      9  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
     10  * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
     11  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
     12  * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
     13  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
     14 
     15 #ifndef OPENSSL_HEADER_CRYPTO_RAND_INTERNAL_H
     16 #define OPENSSL_HEADER_CRYPTO_RAND_INTERNAL_H
     17 
     18 #include <openssl/aes.h>
     19 #include <openssl/cpu.h>
     20 
     21 #include "../../internal.h"
     22 #include "../modes/internal.h"
     23 
     24 #if defined(__cplusplus)
     25 extern "C" {
     26 #endif
     27 
     28 
     29 // RAND_bytes_with_additional_data samples from the RNG after mixing 32 bytes
     30 // from |user_additional_data| in.
     31 void RAND_bytes_with_additional_data(uint8_t *out, size_t out_len,
     32                                      const uint8_t user_additional_data[32]);
     33 
     34 // CRYPTO_sysrand fills |len| bytes at |buf| with entropy from the operating
     35 // system.
     36 void CRYPTO_sysrand(uint8_t *buf, size_t len);
     37 
     38 // rand_fork_unsafe_buffering_enabled returns whether fork-unsafe buffering has
     39 // been enabled via |RAND_enable_fork_unsafe_buffering|.
     40 int rand_fork_unsafe_buffering_enabled(void);
     41 
     42 // CTR_DRBG_STATE contains the state of a CTR_DRBG based on AES-256. See SP
     43 // 800-90Ar1.
     44 typedef struct {
     45   AES_KEY ks;
     46   block128_f block;
     47   ctr128_f ctr;
     48   union {
     49     uint8_t bytes[16];
     50     uint32_t words[4];
     51   } counter;
     52   uint64_t reseed_counter;
     53 } CTR_DRBG_STATE;
     54 
     55 // See SP 800-90Ar1, table 3.
     56 #define CTR_DRBG_ENTROPY_LEN 48
     57 #define CTR_DRBG_MAX_GENERATE_LENGTH 65536
     58 
     59 // CTR_DRBG_init initialises |*drbg| given |CTR_DRBG_ENTROPY_LEN| bytes of
     60 // entropy in |entropy| and, optionally, a personalization string up to
     61 // |CTR_DRBG_ENTROPY_LEN| bytes in length. It returns one on success and zero
     62 // on error.
     63 OPENSSL_EXPORT int CTR_DRBG_init(CTR_DRBG_STATE *drbg,
     64                                  const uint8_t entropy[CTR_DRBG_ENTROPY_LEN],
     65                                  const uint8_t *personalization,
     66                                  size_t personalization_len);
     67 
     68 // CTR_DRBG_reseed reseeds |drbg| given |CTR_DRBG_ENTROPY_LEN| bytes of entropy
     69 // in |entropy| and, optionally, up to |CTR_DRBG_ENTROPY_LEN| bytes of
     70 // additional data. It returns one on success or zero on error.
     71 OPENSSL_EXPORT int CTR_DRBG_reseed(CTR_DRBG_STATE *drbg,
     72                                    const uint8_t entropy[CTR_DRBG_ENTROPY_LEN],
     73                                    const uint8_t *additional_data,
     74                                    size_t additional_data_len);
     75 
     76 // CTR_DRBG_generate processes to up |CTR_DRBG_ENTROPY_LEN| bytes of additional
     77 // data (if any) and then writes |out_len| random bytes to |out|, where
     78 // |out_len| <= |CTR_DRBG_MAX_GENERATE_LENGTH|. It returns one on success or
     79 // zero on error.
     80 OPENSSL_EXPORT int CTR_DRBG_generate(CTR_DRBG_STATE *drbg, uint8_t *out,
     81                                      size_t out_len,
     82                                      const uint8_t *additional_data,
     83                                      size_t additional_data_len);
     84 
     85 // CTR_DRBG_clear zeroises the state of |drbg|.
     86 OPENSSL_EXPORT void CTR_DRBG_clear(CTR_DRBG_STATE *drbg);
     87 
     88 
     89 #if defined(OPENSSL_X86_64) && !defined(OPENSSL_NO_ASM)
     90 OPENSSL_INLINE int have_rdrand(void) {
     91   return (OPENSSL_ia32cap_get()[1] & (1u << 30)) != 0;
     92 }
     93 
     94 // CRYPTO_rdrand writes eight bytes of random data from the hardware RNG to
     95 // |out|. It returns one on success or zero on hardware failure.
     96 int CRYPTO_rdrand(uint8_t out[8]);
     97 
     98 // CRYPTO_rdrand_multiple8_buf fills |len| bytes at |buf| with random data from
     99 // the hardware RNG. The |len| argument must be a multiple of eight. It returns
    100 // one on success and zero on hardware failure.
    101 int CRYPTO_rdrand_multiple8_buf(uint8_t *buf, size_t len);
    102 #endif  // OPENSSL_X86_64 && !OPENSSL_NO_ASM
    103 
    104 
    105 #if defined(__cplusplus)
    106 }  // extern C
    107 #endif
    108 
    109 #endif  // OPENSSL_HEADER_CRYPTO_RAND_INTERNAL_H
    110