Add SHA3 hashing

- added these variants: SHA3-256, SHA3-384, SHA3-512
- reordered also the hashing id's
- added some notes about them in DOC/Hashes.txt

Signed-off-by: Tino Reichardt <milky-7zip@mcmilk.de>

C/hashes/sha3.h

@@ -0,0 +1,43 @@
+
+/**
+ * Canonical implementation of Init/Update/Finalize for SHA-3 byte input.
+ * Based on code from https://github.com/brainhub/SHA3IUF/
+ *
+ * This work is released into the public domain with CC0 1.0.
+ *
+ * Copyright (c) 2015. Andrey Jivsov <crypto@brainhub.org>
+ * Copyright (c) 2023 Tino Reichardt <milky-7zip@mcmilk.de>
+ */
+
+#ifndef SHA3_H
+#define SHA3_H
+
+#include <stdint.h>
+
+#define SHA3_256_DIGEST_LENGTH 32
+#define SHA3_384_DIGEST_LENGTH 48
+#define SHA3_512_DIGEST_LENGTH 64
+
+/* 'Words' here refers to uint64_t */
+#define SHA3_KECCAK_SPONGE_WORDS (200 / sizeof(uint64_t))
+typedef struct sha3_context_ {
+	/* the portion of the input message that we didn't consume yet */
+	uint64_t saved;
+	uint64_t byteIndex;	/* 0..7--the next byte after the set one */
+	uint64_t wordIndex;	/* 0..24--the next word to integrate input */
+	uint64_t capacityWords;	/* the double size of the hash output in words */
+
+	/* Keccak's state */
+	union {
+		uint64_t s[SHA3_KECCAK_SPONGE_WORDS];
+		uint8_t sb[SHA3_KECCAK_SPONGE_WORDS * 8];
+	} u;
+
+	unsigned digest_length;
+} SHA3_CTX;
+
+void SHA3_Init(SHA3_CTX * ctx, unsigned bitSize);
+void SHA3_Update(SHA3_CTX * ctx, void const *bufIn, size_t len);
+void SHA3_Final(void *, SHA3_CTX * ctx);
+
+#endif