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      1 
      2 #include <stdlib.h>
      3 
      4 #include "crypto_core_hchacha20.h"
      5 #include "crypto_stream_chacha20.h"
      6 #include "crypto_stream_xchacha20.h"
      7 #include "private/common.h"
      8 #include "randombytes.h"
      9 
     10 size_t
     11 crypto_stream_xchacha20_keybytes(void)
     12 {
     13     return crypto_stream_xchacha20_KEYBYTES;
     14 }
     15 
     16 size_t
     17 crypto_stream_xchacha20_noncebytes(void)
     18 {
     19     return crypto_stream_xchacha20_NONCEBYTES;
     20 }
     21 
     22 size_t
     23 crypto_stream_xchacha20_messagebytes_max(void)
     24 {
     25     return crypto_stream_xchacha20_MESSAGEBYTES_MAX;
     26 }
     27 
     28 int
     29 crypto_stream_xchacha20(unsigned char *c, unsigned long long clen,
     30                         const unsigned char *n, const unsigned char *k)
     31 {
     32     unsigned char k2[crypto_core_hchacha20_OUTPUTBYTES];
     33 
     34     crypto_core_hchacha20(k2, n, k, NULL);
     35     COMPILER_ASSERT(crypto_stream_chacha20_KEYBYTES <= sizeof k2);
     36     COMPILER_ASSERT(crypto_stream_chacha20_NONCEBYTES ==
     37                     crypto_stream_xchacha20_NONCEBYTES -
     38                         crypto_core_hchacha20_INPUTBYTES);
     39 
     40     return crypto_stream_chacha20(c, clen, n + crypto_core_hchacha20_INPUTBYTES,
     41                                   k2);
     42 }
     43 
     44 int
     45 crypto_stream_xchacha20_xor_ic(unsigned char *c, const unsigned char *m,
     46                                unsigned long long mlen, const unsigned char *n,
     47                                uint64_t ic, const unsigned char *k)
     48 {
     49     unsigned char k2[crypto_core_hchacha20_OUTPUTBYTES];
     50 
     51     crypto_core_hchacha20(k2, n, k, NULL);
     52     return crypto_stream_chacha20_xor_ic(
     53         c, m, mlen, n + crypto_core_hchacha20_INPUTBYTES, ic, k2);
     54 }
     55 
     56 int
     57 crypto_stream_xchacha20_xor(unsigned char *c, const unsigned char *m,
     58                             unsigned long long mlen, const unsigned char *n,
     59                             const unsigned char *k)
     60 {
     61     return crypto_stream_xchacha20_xor_ic(c, m, mlen, n, 0U, k);
     62 }
     63 
     64 void
     65 crypto_stream_xchacha20_keygen(
     66     unsigned char k[crypto_stream_xchacha20_KEYBYTES])
     67 {
     68     randombytes_buf(k, crypto_stream_xchacha20_KEYBYTES);
     69 }
     70