Implement native bech32 segwit address support.

src/libckpool.c

@@ -1730,9 +1730,54 @@ char *http_base64(const char *src)
 	return (str);
 }
 
+static const int8_t charset_rev[128] = {
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	15, -1, 10, 17, 21, 20, 26, 30,  7,  5, -1, -1, -1, -1, -1, -1,
+	-1, 29, -1, 24, 13, 25,  9,  8, 23, -1, 18, 22, 31, 27, 19, -1,
+	1,  0,  3, 16, 11, 28, 12, 14,  6,  4,  2, -1, -1, -1, -1, -1,
+	-1, 29, -1, 24, 13, 25,  9,  8, 23, -1, 18, 22, 31, 27, 19, -1,
+	1,  0,  3, 16, 11, 28, 12, 14,  6,  4,  2, -1, -1, -1, -1, -1
+};
+
 /* It's assumed that there is no chance of sending invalid chars to these
  * functions as they should have been checked beforehand. */
-static void address_to_pubkeytxn(char *pkh, const char *addr)
+static void bech32_decode(uint8_t *data, int *data_len, const char *input)
+{
+	int input_len = strlen(input), hrp_len, i;
+
+	*data_len = 0;
+	while (*data_len < input_len && input[(input_len - 1) - *data_len] != '1')
+		++(*data_len);
+	hrp_len = input_len - (1 + *data_len);
+	*(data_len) -= 6;
+	for (i = hrp_len + 1; i < input_len; i++) {
+		int v = (input[i] & 0x80) ? -1 : charset_rev[(int)input[i]];
+
+		if (i + 6 < input_len)
+			data[i - (1 + hrp_len)] = v;
+	}
+}
+
+static void convert_bits(char *out, int *outlen, const uint8_t *in,
+			 int inlen)
+{
+	const int outbits = 8, inbits = 5;
+	uint32_t val = 0, maxv = (((uint32_t)1) << outbits) - 1;
+	int bits = 0;
+
+	while (inlen--) {
+		val = (val << inbits) | *(in++);
+		bits += inbits;
+		while (bits >= outbits) {
+			bits -= outbits;
+			out[(*outlen)++] = (val >> bits) & maxv;
+		}
+	}
+}
+
+static int address_to_pubkeytxn(char *pkh, const char *addr)
 {
 	char b58bin[25] = {};
 
@@ -1743,9 +1788,10 @@ static void address_to_pubkeytxn(char *pkh, const char *addr)
 	memcpy(&pkh[3], &b58bin[1], 20);
 	pkh[23] = 0x88;
 	pkh[24] = 0xac;
+	return 25;
 }
 
-static void address_to_scripttxn(char *psh, const char *addr)
+static int address_to_scripttxn(char *psh, const char *addr)
 {
 	char b58bin[25] = {};
 
@@ -1754,22 +1800,33 @@ static void address_to_scripttxn(char *psh, const char *addr)
 	psh[1] = 0x14;
 	memcpy(&psh[2], &b58bin[1], 20);
 	psh[22] = 0x87;
+	return 23;
+}
+
+static int segaddress_to_txn(char *p2h, const char *addr)
+{
+	int data_len, witdata_len = 0;
+	char *witdata = &p2h[2];
+	uint8_t data[84];
+
+	bech32_decode(data, &data_len, addr);
+	p2h[0] = data[0];
+	/* Witness version is > 0 */
+	if (p2h[0])
+		p2h[0] += 0x50;
+	convert_bits(witdata, &witdata_len, data + 1, data_len - 1);
+	p2h[1] = witdata_len;
+	return witdata_len + 2;
 }
 
 /* Convert an address to a transaction and return the length of the transaction */
 int address_to_txn(char *p2h, const char *addr, const bool script, const bool segwit)
 {
-	if (unlikely(segwit)) {
-		/* It should be impossible to hit this for now */
-		LOGEMERG("Segwit bech32 address passed to address_to_txn while unsupported.");
-		return 0;
-	}
-	if (script) {
-		address_to_scripttxn(p2h, addr);
-		return 23;
-	}
-	address_to_pubkeytxn(p2h, addr);
-	return 25;
+	if (segwit)
+		return segaddress_to_txn(p2h, addr);
+	if (script)
+		return address_to_scripttxn(p2h, addr);
+	return address_to_pubkeytxn(p2h, addr);
 }
 
 /*  For encoding nHeight into coinbase, return how many bytes were used */

src/stratifier.c

@@ -389,9 +389,9 @@ static const char *ckdb_seq_names[] = {
 struct stratifier_data {
 	ckpool_t *ckp;
 
-	char txnbin[40];
+	char txnbin[48];
 	int txnlen;
-	char dontxnbin[40];
+	char dontxnbin[48];
 	int dontxnlen;
 
 	pool_stats_t stats;
@@ -579,7 +579,7 @@ static void generate_coinbase(const ckpool_t *ckp, workbase_t *wb)
 	len += wb->enonce1varlen;
 	len += wb->enonce2varlen;
 
-	wb->coinb2bin = ckzalloc(256);
+	wb->coinb2bin = ckzalloc(512);
 	memcpy(wb->coinb2bin, "\x0a\x63\x6b\x70\x6f\x6f\x6c", 7);
 	wb->coinb2len = 7;
 	if (ckp->btcsig) {
@@ -5331,8 +5331,6 @@ static user_instance_t *generate_user(ckpool_t *ckp, stratum_instance_t *client,
 	/* Is this a btc address based username? */
 	if (!ckp->proxy && (new_user || !user->btcaddress) && (len > 26 && len < 35))
 		user->btcaddress = generator_checkaddr(ckp, username, &user->script, &user->segwit);
-	if (user->segwit) /* Bech32 addresses currently unsupported */
-		user->btcaddress = false;
 	if (new_user) {
 		LOGNOTICE("Added new user %s%s", username, user->btcaddress ?
 			  " as address based registration" : "");
@@ -6839,8 +6837,6 @@ static user_instance_t *generate_remote_user(ckpool_t *ckp, const char *workerna
 	/* Is this a btc address based username? */
 	if (!ckp->proxy && (new_user || !user->btcaddress) && (len > 26 && len < 35))
 		user->btcaddress = generator_checkaddr(ckp, username, &user->script, &user->segwit);
-	if (user->segwit)
-		user->btcaddress = false;
 	if (new_user) {
 		LOGNOTICE("Added new remote user %s%s", username, user->btcaddress ?
 			  " as address based registration" : "");
@@ -8638,10 +8634,6 @@ void *stratifier(void *arg)
 			LOGEMERG("Fatal: btcaddress invalid according to bitcoind");
 			goto out;
 		}
-		if (ckp->segwit) {
-			LOGEMERG("Fatal: bech32 addresses not currently supported");
-			goto out;
-		}
 
 		/* Store this for use elsewhere */
 		hex2bin(scriptsig_header_bin, scriptsig_header, 41);