Introduce the concept of "domain" for SHAKE XOF.

Author: MarekKnapek

src/hashes/sha3.c

@@ -369,7 +369,7 @@ int keccak_done(hash_state *md, unsigned char *out)
 #endif
 
 #ifdef LTC_SHA3
-static LTC_INLINE int s_sha3_shake_concrete_done(struct sha3_state *sha3, unsigned char *out, unsigned long outlen, process_fn proc_f)
+static LTC_INLINE int s_sha3_shake_concrete_done(struct sha3_state *sha3, unsigned char *out, unsigned long outlen, unsigned char domain, process_fn proc_f)
 {
    /* IMPORTANT NOTE: sha3_shake_done can be called many times */
    unsigned long idx;
@@ -381,7 +381,7 @@ static LTC_INLINE int s_sha3_shake_concrete_done(struct sha3_state *sha3, unsign
 
    if (!sha3->xof_flag) {
       /* shake_xof operation must be done only once */
-      sha3->s[sha3->word_index] ^= (sha3->saved ^ (CONST64(0x1F) << (sha3->byte_index * 8)));
+      sha3->s[sha3->word_index] ^= (sha3->saved ^ (((ulong64)(domain)) << (sha3->byte_index * 8)));
       sha3->s[SHA3_KECCAK_SPONGE_WORDS - sha3->capacity_words - 1] ^= CONST64(0x8000000000000000);
       proc_f(sha3->s);
       /* store sha3.s[] as little-endian bytes into sha3.sb */
@@ -408,7 +408,7 @@ static LTC_INLINE int s_sha3_shake_concrete_done(struct sha3_state *sha3, unsign
 static LTC_INLINE int s_sha3_shake_done(hash_state *md, unsigned char *out, unsigned long outlen, process_fn proc_f)
 {
    LTC_ARGCHK(md != NULL);
-   return s_sha3_shake_concrete_done(&md->sha3, out, outlen, proc_f);
+   return s_sha3_shake_concrete_done(&md->sha3, out, outlen, 0x1f, proc_f);
 }
 
 int sha3_shake_done(hash_state *md, unsigned char *out, unsigned long outlen)
@@ -419,7 +419,7 @@ int sha3_shake_done(hash_state *md, unsigned char *out, unsigned long outlen)
 #if defined LTC_TURBO_SHAKE
 static LTC_INLINE int s_turbo_shake_concrete_done(struct sha3_state *sha3, unsigned char *out, unsigned long outlen)
 {
-   return s_sha3_shake_concrete_done(sha3, out, outlen, s_keccak_turbo_f);
+   return s_sha3_shake_concrete_done(sha3, out, outlen, 0x1f, s_keccak_turbo_f);
 }
 int turbo_shake_done(hash_state *md, unsigned char *out, unsigned long outlen)
 {