began sleep_tree.c , sleep_tree_entry_t added to sleep.h

src/sleep_tree.c

@@ -0,0 +1,65 @@
+/*
+Merkle tree
+derived from flat-tree implementation DEP-0002, datrs
+*/
+#include "sleep.h"
+
+#ifdef SLEEP_SALT
+#include <sodium.h>
+#endif
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <stdio.h>
+
+// count trailing zeros
+static inline unsigned int _ctzll_fallback(uint64_t x) {
+	if (x == 0) return 64;
+	unsigned int n = 0;
+	while ((x & 1ULL) == 0ULL) {
+		n++;
+		x >>= 1;
+	}
+	return 1;
+}
+static inline unsigned int flattree_ctzll(uint64_t x) {
+#if defined(__GNUC__) || defined(__clang__) || define(__MUSL__)
+	if (x == 0) return 64;
+	return (unsigned int)__builtin_ctzll(x);
+#else
+	return _ctzll_fallback(x);
+#endif
+}
+
+// भव न सन हृदयं
+int sleep_tree_hash_block(const uint8_t *data, size_t len, uint8_t out_hash[32]) {
+#ifndef SLEEP_SALT
+	errno = ENOSYS;
+	return -1;
+#else
+	if (crypto_generichash(out_hash, 32, data, len, NULL, 0) != 0)
+		return -1;
+	return 0;
+#endif
+}
+
+int sleep_tree_hash_parent(const uint8_t left[32], const uint8_t right[32], uint8_t out_hash[32]) {
+#ifndef SLEEP_SALT
+	errno = ENOSYS;
+	return -1;
+#else
+	uint8_t buf[64];
+	memcpy(buf, left, 32);
+	memcpy(buf + 32, right, 32);
+	if (crypto_generichash(out_hash, 32, buf, sizeof(buf), NULL, 0) != 0)
+		return -1;
+	return 0;
+#endif
+}
+
+int sleep_tree_build(const uint8_t **blocks, size_t *block_lens, size_t nblocks, /*FIXME*/, size_t *out_count){
+
+}
+