implement GetAddress.multisig field

firmware/crypto.c

@@ -251,3 +251,14 @@ int cryptoMessageDecrypt(curve_point *nonce, uint8_t *payload, pb_size_t payload
 	*msg_len = o;
 	return 0;
 }
+
+int cryptoMultisigPubkeyIndex(const MultisigRedeemScriptType *multisig, const uint8_t *pubkey, uint32_t pubkey_len)
+{
+	int i;
+	for (i = 0; i < multisig->pubkeys_count; i++) {
+		if (multisig->pubkeys[i].size == pubkey_len && memcmp(multisig->pubkeys[i].bytes, pubkey, pubkey_len) == 0) {
+			return i;
+		}
+	}
+	return -1;
+}

firmware/crypto.h

@@ -25,6 +25,7 @@
 #include <stdlib.h>
 #include <secp256k1.h>
 #include <pb.h>
+#include "types.pb.h"
 
 uint32_t ser_length(uint32_t len, uint8_t *out);
 
@@ -38,4 +39,6 @@ int cryptoMessageEncrypt(curve_point *pubkey, const uint8_t *msg, pb_size_t msg_
 
 int cryptoMessageDecrypt(curve_point *nonce, uint8_t *payload, pb_size_t payload_len, const uint8_t *hmac, pb_size_t hmac_len, const uint8_t *privkey, uint8_t *msg, pb_size_t *msg_len, bool *display_only, bool *signing, uint8_t *address_raw);
 
+int cryptoMultisigPubkeyIndex(const MultisigRedeemScriptType *multisig, const uint8_t *pubkey, uint32_t pubkey_len);
+
 #endif

firmware/fsm.c

@@ -43,6 +43,7 @@
 #include "crypto.h"
 #include "base58.h"
 #include "bip39.h"
+#include "ripemd160.h"
 
 // message methods
 
@@ -487,7 +488,24 @@ void fsm_msgGetAddress(GetAddress *msg)
 
 	fsm_deriveKey(node, msg->address_n, msg->address_n_count);
 
-	ecdsa_get_address(node->public_key, coin->address_type, resp->address);
+	if (msg->has_multisig) {
+		if (cryptoMultisigPubkeyIndex(&(msg->multisig), node->public_key, 33) < 0) {
+			fsm_sendFailure(FailureType_Failure_Other, "Pubkey not found in multisig script");
+			layoutHome();
+			return;
+		}
+		uint8_t buf[32];
+		if (compile_script_multisig_hash(&(msg->multisig), buf) == 0) {
+			fsm_sendFailure(FailureType_Failure_Other, "Invalid multisig script");
+			layoutHome();
+			return;
+		}
+		ripemd160(buf, 32, buf + 1);
+		buf[0] = 0x05; // multisig cointype
+		base58_encode_check(buf, 21, resp->address);
+	} else {
+		ecdsa_get_address(node->public_key, coin->address_type, resp->address);
+	}
 
 	if (msg->has_show_display && msg->show_display) {
 		layoutAddress(resp->address);

firmware/signing.c

@@ -24,6 +24,7 @@
 #include "transaction.h"
 #include "ecdsa.h"
 #include "protect.h"
+#include "crypto.h"
 
 static uint32_t inputs_count;
 static uint32_t outputs_count;
@@ -378,14 +379,8 @@ void signing_txack(TransactionType *tx)
 						return;
 					}
 					// fill in the signature
-					int i, pubkey_idx = -1;
-					for (i = 0; i < input.multisig.pubkeys_count; i++) {
-						if (input.multisig.pubkeys[i].size == 33 && memcmp(input.multisig.pubkeys[i].bytes, pubkey, 33) == 0) {
-							pubkey_idx = i;
-							break;
-						}
-					}
-					if (pubkey_idx == -1) {
+					int pubkey_idx = cryptoMultisigPubkeyIndex(&(input.multisig), pubkey, 33);
+					if (pubkey_idx < 0) {
 						fsm_sendFailure(FailureType_Failure_Other, "Pubkey not found in multisig script");
 						signing_abort();
 						return;

firmware/transaction.c

@@ -149,8 +149,8 @@ uint32_t compile_script_multisig(const MultisigRedeemScriptType *multisig, uint8
 		out[r] = 0xAE; r++; // OP_CHECKMULTISIG
 	} else {
 		r++;
+		uint8_t dummy[8];
 		for (i = 0; i < n; i++) {
-			uint8_t dummy[8];
 			r += op_push(multisig->pubkeys[i].size, dummy);
 			r += multisig->pubkeys[i].size;
 		}
@@ -160,6 +160,36 @@ uint32_t compile_script_multisig(const MultisigRedeemScriptType *multisig, uint8
 	return r;
 }
 
+uint32_t compile_script_multisig_hash(const MultisigRedeemScriptType *multisig, uint8_t *hash)
+{
+	if (!multisig->has_m) return 0;
+	uint32_t m = multisig->m;
+	uint32_t n = multisig->pubkeys_count;
+	if (m < 2 || m > 3) return 0;
+	if (n < 2 || n > 3) return 0;
+
+	SHA256_CTX ctx;
+	sha256_Init(&ctx);
+
+	uint8_t d, dummy[8];
+	d = 0x50 + m;
+	sha256_Update(&ctx, &d, 1);
+	uint32_t i, r;
+	for (i = 0; i < n; i++) {
+		r = op_push(multisig->pubkeys[i].size, dummy);
+		sha256_Update(&ctx, dummy, r);
+		sha256_Update(&ctx, multisig->pubkeys[i].bytes, multisig->pubkeys[i].size);
+	}
+	d = 0x50 + n;
+	sha256_Update(&ctx, &d, 1);
+	d = 0xAE;
+	sha256_Update(&ctx, &d, 1);
+
+	sha256_Final(hash, &ctx);
+
+	return 1;
+}
+
 uint32_t serialize_script_sig(const uint8_t *signature, uint32_t signature_len, const uint8_t *pubkey, uint32_t pubkey_len, uint8_t *out)
 {
 	uint32_t r = 0;

firmware/transaction.h

@@ -43,6 +43,7 @@ typedef struct {
 
 uint32_t compile_script_sig(uint8_t address_type, const uint8_t *pubkeyhash, uint8_t *out);
 uint32_t compile_script_multisig(const MultisigRedeemScriptType *multisig, uint8_t *out);
+uint32_t compile_script_multisig_hash(const MultisigRedeemScriptType *multisig, uint8_t *hash);
 uint32_t serialize_script_sig(const uint8_t *signature, uint32_t signature_len, const uint8_t *pubkey, uint32_t pubkey_len, uint8_t *out);
 uint32_t serialize_script_multisig(const MultisigRedeemScriptType *multisig, uint8_t *out);
 int compile_output(const CoinType *coin, const HDNode *root, TxOutputType *in, TxOutputBinType *out, bool needs_confirm);