contribute decently fast yggdrasil address generator in C

contrib/yggdrasil-brute-simple/util.c

@@ -0,0 +1,62 @@
+#include "yggdrasil-brute.h"
+
+int find_where(unsigned char hash[64], unsigned char besthashlist[NUMKEYS][64]) {
+	/* Where to insert hash into sorted hashlist */
+	int j;
+	int where = -1;
+	for (j = 0; j < NUMKEYS; ++j) {
+		if (memcmp(hash, besthashlist[j], 64) > 0) ++where;
+		else break;
+	}
+	return where;
+}
+
+void insert_64(unsigned char itemlist[NUMKEYS][64], unsigned char item[64], int where) {
+	int j;
+	for (j = 0; j < where; ++j) {
+		memcpy(itemlist[j], itemlist[j+1], 64);
+	}
+	memcpy(itemlist[where], item, 64);
+}
+
+void insert_32(unsigned char itemlist[NUMKEYS][32], unsigned char item[32], int where) {
+	int j;
+	for (j = 0; j < where; ++j) {
+		memcpy(itemlist[j], itemlist[j+1], 32);
+	}
+	memcpy(itemlist[where], item, 32);
+}
+
+void make_addr(unsigned char addr[32], unsigned char hash[64]) {
+	/* Public key hash to yggdrasil ipv6 address */
+	int i;
+	int offset;
+	unsigned char mask;
+	unsigned char c;
+	int ones = 0;
+	unsigned char br = 0; /* false */
+	for (i = 0; i < 64 && !br; ++i) {
+		mask = 128;
+		c = hash[i];
+		while (mask) {
+			if (c & mask) {
+				++ones;
+			} else {
+				br = 1; /* true */
+				break;
+			}
+			mask >>= 1;
+		}
+	}
+
+	addr[0] = 2;
+	addr[1] = ones;
+
+	offset = ones + 1;
+	for (i = 0; i < 14; ++i) {
+		c = hash[offset/8] << (offset%8);
+		c |= hash[offset/8 + 1] >> (8 - offset%8);
+		addr[i + 2] = c;
+		offset += 8;
+	}
+}