Add TurboSHAKE XOF functions.

TurboSHAKE128 and TurboSHAKE256 as described in https://keccak.team/files/TurboSHAKE.pdf.

#691

Author: MarekKnapek

src/hashes/sha3.c

@@ -130,6 +130,8 @@ const struct ltc_hash_descriptor keccak_512_desc =
 
 #define SHA3_KECCAK_SPONGE_WORDS 25 /* 1600 bits > 200 bytes > 25 x ulong64 */
 #define SHA3_KECCAK_ROUNDS 24
+#define SHA3_KECCAK_TURBO_ROUNDS 12
+#define SHA3_KECCAK_TURBO_RC_OFFSET 12
 
 static const ulong64 s_keccakf_rndc[24] = {
    CONST64(0x0000000000000001), CONST64(0x0000000000008082),
@@ -192,6 +194,44 @@ static void s_keccakf(ulong64 s[25])
    }
 }
 
+static void s_keccak_turbo_f(ulong64 s[25])
+{
+   int i, j, round;
+   ulong64 t, bc[5];
+
+   for(round = 0; round < SHA3_KECCAK_TURBO_ROUNDS; round++) {
+      /* Theta */
+      for(i = 0; i < 5; i++) {
+         bc[i] = s[i] ^ s[i + 5] ^ s[i + 10] ^ s[i + 15] ^ s[i + 20];
+      }
+      for(i = 0; i < 5; i++) {
+         t = bc[(i + 4) % 5] ^ ROL64(bc[(i + 1) % 5], 1);
+         for(j = 0; j < 25; j += 5) {
+            s[j + i] ^= t;
+         }
+      }
+      /* Rho Pi */
+      t = s[1];
+      for(i = 0; i < 24; i++) {
+         j = s_keccakf_piln[i];
+         bc[0] = s[j];
+         s[j] = ROL64(t, s_keccakf_rotc[i]);
+         t = bc[0];
+      }
+      /* Chi */
+      for(j = 0; j < 25; j += 5) {
+         for(i = 0; i < 5; i++) {
+            bc[i] = s[j + i];
+         }
+         for(i = 0; i < 5; i++) {
+            s[j + i] ^= (~bc[(i + 1) % 5]) & bc[(i + 2) % 5];
+         }
+      }
+      /* Iota */
+      s[0] ^= s_keccakf_rndc[SHA3_KECCAK_TURBO_RC_OFFSET + round];
+   }
+}
+
 static LTC_INLINE int ss_done(hash_state *md, unsigned char *hash, ulong64 pad)
 {
    unsigned i;
@@ -309,6 +349,58 @@ int sha3_process(hash_state *md, const unsigned char *in, unsigned long inlen)
    return CRYPT_OK;
 }
 
+int sha3_turbo_process(hash_state *md, const unsigned char *in, unsigned long inlen)
+{
+   /* 0...7 -- how much is needed to have a word */
+   unsigned old_tail = (8 - md->sha3.byte_index) & 7;
+
+   unsigned long words;
+   unsigned tail;
+   unsigned long i;
+
+   if (inlen == 0) return CRYPT_OK; /* nothing to do */
+   LTC_ARGCHK(md != NULL);
+   LTC_ARGCHK(in != NULL);
+
+   if(inlen < old_tail) {       /* have no complete word or haven't started the word yet */
+      while (inlen--) md->sha3.saved |= (ulong64) (*(in++)) << ((md->sha3.byte_index++) * 8);
+      return CRYPT_OK;
+   }
+
+   if(old_tail) {               /* will have one word to process */
+      inlen -= old_tail;
+      while (old_tail--) md->sha3.saved |= (ulong64) (*(in++)) << ((md->sha3.byte_index++) * 8);
+      /* now ready to add saved to the sponge */
+      md->sha3.s[md->sha3.word_index] ^= md->sha3.saved;
+      md->sha3.byte_index = 0;
+      md->sha3.saved = 0;
+      if(++md->sha3.word_index == (SHA3_KECCAK_SPONGE_WORDS - md->sha3.capacity_words)) {
+         s_keccak_turbo_f(md->sha3.s);
+         md->sha3.word_index = 0;
+      }
+   }
+
+   /* now work in full words directly from input */
+   words = inlen / sizeof(ulong64);
+   tail = inlen - words * sizeof(ulong64);
+
+   for(i = 0; i < words; i++, in += sizeof(ulong64)) {
+      ulong64 t;
+      LOAD64L(t, in);
+      md->sha3.s[md->sha3.word_index] ^= t;
+      if(++md->sha3.word_index == (SHA3_KECCAK_SPONGE_WORDS - md->sha3.capacity_words)) {
+         s_keccak_turbo_f(md->sha3.s);
+         md->sha3.word_index = 0;
+      }
+   }
+
+   /* finally, save the partial word */
+   while (tail--) {
+      md->sha3.saved |= (ulong64) (*(in++)) << ((md->sha3.byte_index++) * 8);
+   }
+   return CRYPT_OK;
+}
+
 #ifdef LTC_SHA3
 int sha3_done(hash_state *md, unsigned char *out)
 {
@@ -361,6 +453,43 @@ int sha3_shake_done(hash_state *md, unsigned char *out, unsigned long outlen)
    return CRYPT_OK;
 }
 
+int sha3_shake_turbo_done(hash_state *md, unsigned char *out, unsigned long outlen)
+{
+   /* IMPORTANT NOTE: sha3_shake_turbo_done can be called many times */
+   unsigned long idx;
+   unsigned i;
+
+   if (outlen == 0) return CRYPT_OK; /* nothing to do */
+   LTC_ARGCHK(md  != NULL);
+   LTC_ARGCHK(out != NULL);
+
+   if (!md->sha3.xof_flag) {
+      /* shake_xof operation must be done only once */
+      md->sha3.s[md->sha3.word_index] ^= (md->sha3.saved ^ (CONST64(0x1F) << (md->sha3.byte_index * 8)));
+      md->sha3.s[SHA3_KECCAK_SPONGE_WORDS - md->sha3.capacity_words - 1] ^= CONST64(0x8000000000000000);
+      s_keccak_turbo_f(md->sha3.s);
+      /* store sha3.s[] as little-endian bytes into sha3.sb */
+      for(i = 0; i < SHA3_KECCAK_SPONGE_WORDS; i++) {
+         STORE64L(md->sha3.s[i], md->sha3.sb + i * 8);
+      }
+      md->sha3.byte_index = 0;
+      md->sha3.xof_flag = 1;
+   }
+
+   for (idx = 0; idx < outlen; idx++) {
+      if(md->sha3.byte_index >= (SHA3_KECCAK_SPONGE_WORDS - md->sha3.capacity_words) * 8) {
+         s_keccak_turbo_f(md->sha3.s);
+         /* store sha3.s[] as little-endian bytes into sha3.sb */
+         for(i = 0; i < SHA3_KECCAK_SPONGE_WORDS; i++) {
+            STORE64L(md->sha3.s[i], md->sha3.sb + i * 8);
+         }
+         md->sha3.byte_index = 0;
+      }
+      out[idx] = md->sha3.sb[md->sha3.byte_index++];
+   }
+   return CRYPT_OK;
+}
+
 int sha3_shake_memory(int num, const unsigned char *in, unsigned long inlen, unsigned char *out, const unsigned long *outlen)
 {
    hash_state md;

src/headers/tomcrypt_hash.h

@@ -265,6 +265,7 @@ int sha3_256_init(hash_state * md);
 int sha3_224_init(hash_state * md);
 /* sha3_process is the same for all variants of SHA3 + KECCAK */
 int sha3_process(hash_state * md, const unsigned char *in, unsigned long inlen);
+int sha3_turbo_process(hash_state * md, const unsigned char *in, unsigned long inlen);
 #endif
 
 #ifdef LTC_SHA3
@@ -280,7 +281,9 @@ int sha3_done(hash_state *md, unsigned char *out);
 /* SHAKE128 + SHAKE256 */
 int sha3_shake_init(hash_state *md, int num);
 #define sha3_shake_process(a,b,c) sha3_process(a,b,c)
+#define sha3_shake_turbo_process(a,b,c) sha3_turbo_process(a,b,c)
 int sha3_shake_done(hash_state *md, unsigned char *out, unsigned long outlen);
+int sha3_shake_turbo_done(hash_state *md, unsigned char *out, unsigned long outlen);
 int sha3_shake_test(void);
 int sha3_shake_memory(int num, const unsigned char *in, unsigned long inlen, unsigned char *out, const unsigned long *outlen);
 #endif