crypto.cpp

#include <cryptofuzz/crypto.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <climits>

namespace cryptofuzz {
namespace crypto {
namespace impl {

#if defined(__clang__)
#define rotate_right_32 __builtin_rotateright32
#define rotate_left_32 __builtin_rotateleft32
#else
static uint32_t rotate_right_32(uint32_t value, unsigned int count) {
    const unsigned int mask = (CHAR_BIT * sizeof(value)) - 1;
    count &= mask;
    return (value >> count) | (value << ((-count) & mask));
}
static uint32_t rotate_left_32(uint32_t value, unsigned int count) {
    const unsigned int mask = (CHAR_BIT * sizeof(value)) - 1;
    count &= mask;
    return (value << count) | (value >> ((-count) & mask));
}
#endif

/* LibTomCrypt, modular cryptographic library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */

#define ROR(x,n) rotate_right_32(x,n)
#define ROL(x,n) rotate_left_32(x,n)
#define ROLc(x,n) ROL(x,n)
#define RORc(x,n) ROR(x,n)

#define XMEMCPY memcpy

#define LTC_ARGCHK(...)

#define MIN(x, y) ( ((x)<(y))?(x):(y) )

#define STORE32H(x, y)                          \
do { ulong32 ttt = __builtin_bswap32 ((x));     \
      XMEMCPY ((y), &ttt, 4); } while(0)

#define LOAD32H(x, y)                           \
do { XMEMCPY (&(x), (y), 4);                    \
      (x) = __builtin_bswap32 ((x)); } while(0)

#define STORE64H(x, y)                          \
do { ulong64 ttt = __builtin_bswap64 ((x));     \
      XMEMCPY ((y), &ttt, 8); } while(0)

#define LOAD64H(x, y)                           \
do { XMEMCPY (&(x), (y), 8);                    \
      (x) = __builtin_bswap64 ((x)); } while(0)

typedef uint64_t ulong64;
typedef uint32_t ulong32;

/* error codes [will be expanded in future releases] */
enum {
   CRYPT_OK=0,             /* Result OK */
   CRYPT_ERROR,            /* Generic Error */
   CRYPT_NOP,              /* Not a failure but no operation was performed */

   CRYPT_INVALID_KEYSIZE,  /* Invalid key size given */
   CRYPT_INVALID_ROUNDS,   /* Invalid number of rounds */
   CRYPT_FAIL_TESTVECTOR,  /* Algorithm failed test vectors */

   CRYPT_BUFFER_OVERFLOW,  /* Not enough space for output */
   CRYPT_INVALID_PACKET,   /* Invalid input packet given */

   CRYPT_INVALID_PRNGSIZE, /* Invalid number of bits for a PRNG */
   CRYPT_ERROR_READPRNG,   /* Could not read enough from PRNG */

   CRYPT_INVALID_CIPHER,   /* Invalid cipher specified */
   CRYPT_INVALID_HASH,     /* Invalid hash specified */
   CRYPT_INVALID_PRNG,     /* Invalid PRNG specified */

   CRYPT_MEM,              /* Out of memory */

   CRYPT_PK_TYPE_MISMATCH, /* Not equivalent types of PK keys */
   CRYPT_PK_NOT_PRIVATE,   /* Requires a private PK key */

   CRYPT_INVALID_ARG,      /* Generic invalid argument */
   CRYPT_FILE_NOTFOUND,    /* File Not Found */

   CRYPT_PK_INVALID_TYPE,  /* Invalid type of PK key */

   CRYPT_OVERFLOW,         /* An overflow of a value was detected/prevented */

   CRYPT_PK_ASN1_ERROR,    /* An error occurred while en- or decoding ASN.1 data */

   CRYPT_INPUT_TOO_LONG,   /* The input was longer than expected. */

   CRYPT_PK_INVALID_SIZE,  /* Invalid size input for PK parameters */

   CRYPT_INVALID_PRIME_SIZE,/* Invalid size of prime requested */
   CRYPT_PK_INVALID_PADDING, /* Invalid padding on input */

   CRYPT_HASH_OVERFLOW      /* Hash applied to too many bits */
};

#define HASH_PROCESS(func_name, compress_name, state_var, block_size)                       \
int func_name (hash_state * md, const unsigned char *in, unsigned long inlen)               \
{                                                                                           \
    unsigned long n;                                                                        \
    int           err;                                                                      \
    LTC_ARGCHK(md != NULL);                                                                 \
    LTC_ARGCHK(in != NULL);                                                                 \
    if (md-> state_var .curlen > sizeof(md-> state_var .buf)) {                             \
       return CRYPT_INVALID_ARG;                                                            \
    }                                                                                       \
    if ((md-> state_var .length + inlen * 8) < md-> state_var .length) {                        \
      return CRYPT_HASH_OVERFLOW;                                                           \
    }                                                                                       \
    while (inlen > 0) {                                                                     \
        if (md-> state_var .curlen == 0 && inlen >= block_size) {                           \
           if ((err = compress_name (md, in)) != CRYPT_OK) {                                \
              return err;                                                                   \
           }                                                                                \
           md-> state_var .length += block_size * 8;                                        \
           in             += block_size;                                                    \
           inlen          -= block_size;                                                    \
        } else {                                                                            \
           n = MIN(inlen, (block_size - md-> state_var .curlen));                           \
           XMEMCPY(md-> state_var .buf + md-> state_var.curlen, in, (size_t)n);             \
           md-> state_var .curlen += n;                                                     \
           in             += n;                                                             \
           inlen          -= n;                                                             \
           if (md-> state_var .curlen == block_size) {                                      \
              if ((err = compress_name (md, md-> state_var .buf)) != CRYPT_OK) {            \
                 return err;                                                                \
              }                                                                             \
              md-> state_var .length += 8*block_size;                                       \
              md-> state_var .curlen = 0;                                                   \
           }                                                                                \
       }                                                                                    \
    }                                                                                       \
    return CRYPT_OK;                                                                        \
}

struct sha1_state {
    ulong64 length;
    ulong32 state[5], curlen;
    unsigned char buf[64];
};

struct sha256_state {
    ulong64 length;
    ulong32 state[8], curlen;
    unsigned char buf[64];
};

typedef union Hash_state {
    char dummy[1];
    struct sha1_state   sha1;
    struct sha256_state sha256;
    void *data;
} hash_state;

/**
  @file sha1.c
  LTC_SHA1 code by Tom St Denis
*/


#define F0(x,y,z)  (z ^ (x & (y ^ z)))
#define F1(x,y,z)  (x ^ y ^ z)
#define F2(x,y,z)  ((x & y) | (z & (x | y)))
#define F3(x,y,z)  (x ^ y ^ z)

#ifdef LTC_CLEAN_STACK
static int ss_sha1_compress(hash_state *md, const unsigned char *buf)
#else
static int  s_sha1_compress(hash_state *md, const unsigned char *buf)
#endif
{
    ulong32 a,b,c,d,e,W[80],i;
#ifdef LTC_SMALL_CODE
    ulong32 t;
#endif

    /* copy the state into 512-bits into W[0..15] */
    for (i = 0; i < 16; i++) {
        LOAD32H(W[i], buf + (4*i));
    }

    /* copy state */
    a = md->sha1.state[0];
    b = md->sha1.state[1];
    c = md->sha1.state[2];
    d = md->sha1.state[3];
    e = md->sha1.state[4];

    /* expand it */
    for (i = 16; i < 80; i++) {
        W[i] = ROL(W[i-3] ^ W[i-8] ^ W[i-14] ^ W[i-16], 1);
    }

    /* compress */
    /* round one */
    #define FF0(a,b,c,d,e,i) e = (ROLc(a, 5) + F0(b,c,d) + e + W[i] + 0x5a827999UL); b = ROLc(b, 30);
    #define FF1(a,b,c,d,e,i) e = (ROLc(a, 5) + F1(b,c,d) + e + W[i] + 0x6ed9eba1UL); b = ROLc(b, 30);
    #define FF2(a,b,c,d,e,i) e = (ROLc(a, 5) + F2(b,c,d) + e + W[i] + 0x8f1bbcdcUL); b = ROLc(b, 30);
    #define FF3(a,b,c,d,e,i) e = (ROLc(a, 5) + F3(b,c,d) + e + W[i] + 0xca62c1d6UL); b = ROLc(b, 30);

#ifdef LTC_SMALL_CODE

    for (i = 0; i < 20; ) {
       FF0(a,b,c,d,e,i++); t = e; e = d; d = c; c = b; b = a; a = t;
    }

    for (; i < 40; ) {
       FF1(a,b,c,d,e,i++); t = e; e = d; d = c; c = b; b = a; a = t;
    }

    for (; i < 60; ) {
       FF2(a,b,c,d,e,i++); t = e; e = d; d = c; c = b; b = a; a = t;
    }

    for (; i < 80; ) {
       FF3(a,b,c,d,e,i++); t = e; e = d; d = c; c = b; b = a; a = t;
    }

#else

    for (i = 0; i < 20; ) {
       FF0(a,b,c,d,e,i++);
       FF0(e,a,b,c,d,i++);
       FF0(d,e,a,b,c,i++);
       FF0(c,d,e,a,b,i++);
       FF0(b,c,d,e,a,i++);
    }

    /* round two */
    for (; i < 40; )  {
       FF1(a,b,c,d,e,i++);
       FF1(e,a,b,c,d,i++);
       FF1(d,e,a,b,c,i++);
       FF1(c,d,e,a,b,i++);
       FF1(b,c,d,e,a,i++);
    }

    /* round three */
    for (; i < 60; )  {
       FF2(a,b,c,d,e,i++);
       FF2(e,a,b,c,d,i++);
       FF2(d,e,a,b,c,i++);
       FF2(c,d,e,a,b,i++);
       FF2(b,c,d,e,a,i++);
    }

    /* round four */
    for (; i < 80; )  {
       FF3(a,b,c,d,e,i++);
       FF3(e,a,b,c,d,i++);
       FF3(d,e,a,b,c,i++);
       FF3(c,d,e,a,b,i++);
       FF3(b,c,d,e,a,i++);
    }
#endif

    #undef FF0
    #undef FF1
    #undef FF2
    #undef FF3

    /* store */
    md->sha1.state[0] = md->sha1.state[0] + a;
    md->sha1.state[1] = md->sha1.state[1] + b;
    md->sha1.state[2] = md->sha1.state[2] + c;
    md->sha1.state[3] = md->sha1.state[3] + d;
    md->sha1.state[4] = md->sha1.state[4] + e;

    return CRYPT_OK;
}

#ifdef LTC_CLEAN_STACK
static int s_sha1_compress(hash_state *md, const unsigned char *buf)
{
   int err;
   err = ss_sha1_compress(md, buf);
   burn_stack(sizeof(ulong32) * 87);
   return err;
}
#endif

/**
   Initialize the hash state
   @param md   The hash state you wish to initialize
   @return CRYPT_OK if successful
*/
int sha1_init(hash_state * md)
{
   LTC_ARGCHK(md != NULL);
   md->sha1.state[0] = 0x67452301UL;
   md->sha1.state[1] = 0xefcdab89UL;
   md->sha1.state[2] = 0x98badcfeUL;
   md->sha1.state[3] = 0x10325476UL;
   md->sha1.state[4] = 0xc3d2e1f0UL;
   md->sha1.curlen = 0;
   md->sha1.length = 0;
   return CRYPT_OK;
}

/**
   Process a block of memory though the hash
   @param md     The hash state
   @param in     The data to hash
   @param inlen  The length of the data (octets)
   @return CRYPT_OK if successful
*/
HASH_PROCESS(sha1_process, s_sha1_compress, sha1, 64)

/**
   Terminate the hash to get the digest
   @param md  The hash state
   @param out [out] The destination of the hash (20 bytes)
   @return CRYPT_OK if successful
*/
int sha1_done(hash_state * md, unsigned char *out)
{
    int i;

    LTC_ARGCHK(md  != NULL);
    LTC_ARGCHK(out != NULL);

    if (md->sha1.curlen >= sizeof(md->sha1.buf)) {
       return CRYPT_INVALID_ARG;
    }

    /* increase the length of the message */
    md->sha1.length += md->sha1.curlen * 8;

    /* append the '1' bit */
    md->sha1.buf[md->sha1.curlen++] = (unsigned char)0x80;

    /* if the length is currently above 56 bytes we append zeros
     * then compress.  Then we can fall back to padding zeros and length
     * encoding like normal.
     */
    if (md->sha1.curlen > 56) {
        while (md->sha1.curlen < 64) {
            md->sha1.buf[md->sha1.curlen++] = (unsigned char)0;
        }
        s_sha1_compress(md, md->sha1.buf);
        md->sha1.curlen = 0;
    }

    /* pad upto 56 bytes of zeroes */
    while (md->sha1.curlen < 56) {
        md->sha1.buf[md->sha1.curlen++] = (unsigned char)0;
    }

    /* store length */
    STORE64H(md->sha1.length, md->sha1.buf+56);
    s_sha1_compress(md, md->sha1.buf);

    /* copy output */
    for (i = 0; i < 5; i++) {
        STORE32H(md->sha1.state[i], out+(4*i));
    }
#ifdef LTC_CLEAN_STACK
    zeromem(md, sizeof(hash_state));
#endif
    return CRYPT_OK;
}

#ifdef LTC_SMALL_CODE
/* the K array */
static const ulong32 K[64] = {
    0x428a2f98UL, 0x71374491UL, 0xb5c0fbcfUL, 0xe9b5dba5UL, 0x3956c25bUL,
    0x59f111f1UL, 0x923f82a4UL, 0xab1c5ed5UL, 0xd807aa98UL, 0x12835b01UL,
    0x243185beUL, 0x550c7dc3UL, 0x72be5d74UL, 0x80deb1feUL, 0x9bdc06a7UL,
    0xc19bf174UL, 0xe49b69c1UL, 0xefbe4786UL, 0x0fc19dc6UL, 0x240ca1ccUL,
    0x2de92c6fUL, 0x4a7484aaUL, 0x5cb0a9dcUL, 0x76f988daUL, 0x983e5152UL,
    0xa831c66dUL, 0xb00327c8UL, 0xbf597fc7UL, 0xc6e00bf3UL, 0xd5a79147UL,
    0x06ca6351UL, 0x14292967UL, 0x27b70a85UL, 0x2e1b2138UL, 0x4d2c6dfcUL,
    0x53380d13UL, 0x650a7354UL, 0x766a0abbUL, 0x81c2c92eUL, 0x92722c85UL,
    0xa2bfe8a1UL, 0xa81a664bUL, 0xc24b8b70UL, 0xc76c51a3UL, 0xd192e819UL,
    0xd6990624UL, 0xf40e3585UL, 0x106aa070UL, 0x19a4c116UL, 0x1e376c08UL,
    0x2748774cUL, 0x34b0bcb5UL, 0x391c0cb3UL, 0x4ed8aa4aUL, 0x5b9cca4fUL,
    0x682e6ff3UL, 0x748f82eeUL, 0x78a5636fUL, 0x84c87814UL, 0x8cc70208UL,
    0x90befffaUL, 0xa4506cebUL, 0xbef9a3f7UL, 0xc67178f2UL
};
#endif

/* Various logical functions */
#define Ch(x,y,z)       (z ^ (x & (y ^ z)))
#define Maj(x,y,z)      (((x | y) & z) | (x & y))
#define S(x, n)         RORc((x),(n))
#define R(x, n)         (((x)&0xFFFFFFFFUL)>>(n))
#define Sigma0(x)       (S(x, 2) ^ S(x, 13) ^ S(x, 22))
#define Sigma1(x)       (S(x, 6) ^ S(x, 11) ^ S(x, 25))
#define Gamma0(x)       (S(x, 7) ^ S(x, 18) ^ R(x, 3))
#define Gamma1(x)       (S(x, 17) ^ S(x, 19) ^ R(x, 10))

/* compress 512-bits */
#ifdef LTC_CLEAN_STACK
static int ss_sha256_compress(hash_state * md, const unsigned char *buf)
#else
static int s_sha256_compress(hash_state * md, const unsigned char *buf)
#endif
{
    ulong32 S[8], W[64], t0, t1;
#ifdef LTC_SMALL_CODE
    ulong32 t;
#endif
    int i;

    /* copy state into S */
    for (i = 0; i < 8; i++) {
        S[i] = md->sha256.state[i];
    }

    /* copy the state into 512-bits into W[0..15] */
    for (i = 0; i < 16; i++) {
        LOAD32H(W[i], buf + (4*i));
    }

    /* fill W[16..63] */
    for (i = 16; i < 64; i++) {
        W[i] = Gamma1(W[i - 2]) + W[i - 7] + Gamma0(W[i - 15]) + W[i - 16];
    }

    /* Compress */
#ifdef LTC_SMALL_CODE
#define RND(a,b,c,d,e,f,g,h,i)                         \
     t0 = h + Sigma1(e) + Ch(e, f, g) + K[i] + W[i];   \
     t1 = Sigma0(a) + Maj(a, b, c);                    \
     d += t0;                                          \
     h  = t0 + t1;

     for (i = 0; i < 64; ++i) {
         RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],i);
         t = S[7]; S[7] = S[6]; S[6] = S[5]; S[5] = S[4];
         S[4] = S[3]; S[3] = S[2]; S[2] = S[1]; S[1] = S[0]; S[0] = t;
     }
#else
#define RND(a,b,c,d,e,f,g,h,i,ki)                    \
     t0 = h + Sigma1(e) + Ch(e, f, g) + ki + W[i];   \
     t1 = Sigma0(a) + Maj(a, b, c);                  \
     d += t0;                                        \
     h  = t0 + t1;

    RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],0,0x428a2f98);
    RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],1,0x71374491);
    RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],2,0xb5c0fbcf);
    RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],3,0xe9b5dba5);
    RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],4,0x3956c25b);
    RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],5,0x59f111f1);
    RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],6,0x923f82a4);
    RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],7,0xab1c5ed5);
    RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],8,0xd807aa98);
    RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],9,0x12835b01);
    RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],10,0x243185be);
    RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],11,0x550c7dc3);
    RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],12,0x72be5d74);
    RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],13,0x80deb1fe);
    RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],14,0x9bdc06a7);
    RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],15,0xc19bf174);
    RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],16,0xe49b69c1);
    RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],17,0xefbe4786);
    RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],18,0x0fc19dc6);
    RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],19,0x240ca1cc);
    RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],20,0x2de92c6f);
    RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],21,0x4a7484aa);
    RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],22,0x5cb0a9dc);
    RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],23,0x76f988da);
    RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],24,0x983e5152);
    RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],25,0xa831c66d);
    RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],26,0xb00327c8);
    RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],27,0xbf597fc7);
    RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],28,0xc6e00bf3);
    RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],29,0xd5a79147);
    RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],30,0x06ca6351);
    RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],31,0x14292967);
    RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],32,0x27b70a85);
    RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],33,0x2e1b2138);
    RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],34,0x4d2c6dfc);
    RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],35,0x53380d13);
    RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],36,0x650a7354);
    RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],37,0x766a0abb);
    RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],38,0x81c2c92e);
    RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],39,0x92722c85);
    RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],40,0xa2bfe8a1);
    RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],41,0xa81a664b);
    RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],42,0xc24b8b70);
    RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],43,0xc76c51a3);
    RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],44,0xd192e819);
    RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],45,0xd6990624);
    RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],46,0xf40e3585);
    RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],47,0x106aa070);
    RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],48,0x19a4c116);
    RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],49,0x1e376c08);
    RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],50,0x2748774c);
    RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],51,0x34b0bcb5);
    RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],52,0x391c0cb3);
    RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],53,0x4ed8aa4a);
    RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],54,0x5b9cca4f);
    RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],55,0x682e6ff3);
    RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],56,0x748f82ee);
    RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],57,0x78a5636f);
    RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],58,0x84c87814);
    RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],59,0x8cc70208);
    RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],60,0x90befffa);
    RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],61,0xa4506ceb);
    RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],62,0xbef9a3f7);
    RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],63,0xc67178f2);
#endif
#undef RND

    /* feedback */
    for (i = 0; i < 8; i++) {
        md->sha256.state[i] = md->sha256.state[i] + S[i];
    }
    return CRYPT_OK;
}

#ifdef LTC_CLEAN_STACK
static int s_sha256_compress(hash_state * md, const unsigned char *buf)
{
    int err;
    err = ss_sha256_compress(md, buf);
    burn_stack(sizeof(ulong32) * 74);
    return err;
}
#endif

/**
   Initialize the hash state
   @param md   The hash state you wish to initialize
   @return CRYPT_OK if successful
*/
int sha256_init(hash_state * md)
{
    LTC_ARGCHK(md != NULL);

    md->sha256.curlen = 0;
    md->sha256.length = 0;
    md->sha256.state[0] = 0x6A09E667UL;
    md->sha256.state[1] = 0xBB67AE85UL;
    md->sha256.state[2] = 0x3C6EF372UL;
    md->sha256.state[3] = 0xA54FF53AUL;
    md->sha256.state[4] = 0x510E527FUL;
    md->sha256.state[5] = 0x9B05688CUL;
    md->sha256.state[6] = 0x1F83D9ABUL;
    md->sha256.state[7] = 0x5BE0CD19UL;
    return CRYPT_OK;
}

/**
   Process a block of memory though the hash
   @param md     The hash state
   @param in     The data to hash
   @param inlen  The length of the data (octets)
   @return CRYPT_OK if successful
*/
HASH_PROCESS(sha256_process,s_sha256_compress, sha256, 64)

/**
   Terminate the hash to get the digest
   @param md  The hash state
   @param out [out] The destination of the hash (32 bytes)
   @return CRYPT_OK if successful
*/
int sha256_done(hash_state * md, unsigned char *out)
{
    int i;

    LTC_ARGCHK(md  != NULL);
    LTC_ARGCHK(out != NULL);

    if (md->sha256.curlen >= sizeof(md->sha256.buf)) {
       return CRYPT_INVALID_ARG;
    }


    /* increase the length of the message */
    md->sha256.length += md->sha256.curlen * 8;

    /* append the '1' bit */
    md->sha256.buf[md->sha256.curlen++] = (unsigned char)0x80;

    /* if the length is currently above 56 bytes we append zeros
     * then compress.  Then we can fall back to padding zeros and length
     * encoding like normal.
     */
    if (md->sha256.curlen > 56) {
        while (md->sha256.curlen < 64) {
            md->sha256.buf[md->sha256.curlen++] = (unsigned char)0;
        }
        s_sha256_compress(md, md->sha256.buf);
        md->sha256.curlen = 0;
    }

    /* pad upto 56 bytes of zeroes */
    while (md->sha256.curlen < 56) {
        md->sha256.buf[md->sha256.curlen++] = (unsigned char)0;
    }

    /* store length */
    STORE64H(md->sha256.length, md->sha256.buf+56);
    s_sha256_compress(md, md->sha256.buf);

    /* copy output */
    for (i = 0; i < 8; i++) {
        STORE32H(md->sha256.state[i], out+(4*i));
    }
#ifdef LTC_CLEAN_STACK
    zeromem(md, sizeof(hash_state));
#endif
    return CRYPT_OK;
}

} /* namespace impl */

std::vector<uint8_t> sha1(const uint8_t* data, const size_t size) {
    uint8_t out[20];

    impl::hash_state md;
    impl::sha1_init(&md);
    impl::sha1_process(&md, data, size);
    impl::sha1_done(&md, out);

    return std::vector<uint8_t>(out, out + sizeof(out));
}

std::vector<uint8_t> sha1(const std::vector<uint8_t> data) {
    return sha1(data.data(), data.size());
}

std::vector<uint8_t> sha256(const uint8_t* data, const size_t size) {
    uint8_t out[32];

    impl::hash_state md;
    impl::sha256_init(&md);
    impl::sha256_process(&md, data, size);
    impl::sha256_done(&md, out);

    return std::vector<uint8_t>(out, out + sizeof(out));
}

std::vector<uint8_t> sha256(const std::vector<uint8_t> data) {
    return sha256(data.data(), data.size());
}

std::vector<uint8_t> hmac_sha256(const uint8_t* data, const size_t size, const uint8_t* key, const size_t key_size) {
    uint8_t _key[64];
    uint8_t out[32];
    impl::hash_state inner, outer;

    impl::sha256_init(&inner);
    impl::sha256_init(&outer);

    if ( key_size <= 64 ) {
        if ( key_size ) {
            memcpy(_key, key, key_size);
        }
        memset(_key + key_size, 0, 64 - key_size);
    } else {
        const auto key_hash = sha256(key, key_size);
        memcpy(_key, key_hash.data(), key_hash.size());
        memset(_key + 32, 0, 32);
    }

    for (size_t i = 0; i < 64; i++) {
        _key[i] ^= 0x5C;
    }
    impl::sha256_process(&outer, _key, 64);

    for (int i = 0; i < 64; i++) {
        _key[i] ^= 0x5C ^ 0x36;
    }
    impl::sha256_process(&inner, _key, 64);

    impl::sha256_process(&inner, data, size);

    impl::sha256_done(&inner, out);
    impl::sha256_process(&outer, out, 32);
    impl::sha256_done(&outer, out);

    return {out, out + 32};
}

std::vector<uint8_t> hmac_sha256(const std::vector<uint8_t> data, const std::vector<uint8_t> key) {
    return hmac_sha256(data.data(), data.size(), key.data(), key.size());
}


} /* namespace crypto */
} /* namespace cryptofuzz */