wally: Remove unused sha256_tx_for_sig function

Signed-off-by: Christian Decker <decker.christian@gmail.com>

bitcoin/tx.c

@@ -13,8 +13,6 @@
 
 #define SEGREGATED_WITNESS_FLAG 0x1
 
-static struct sha256_double all_zeroes;
-
 int bitcoin_tx_add_output(struct bitcoin_tx *tx, u8 *script,
 			  struct amount_sat *amount)
 {
@@ -208,148 +206,6 @@ static void push_sha(const void *data, size_t len, void *shactx_)
 	sha256_update(ctx, memcheck(data, len), len);
 }
 
-static void hash_prevouts(struct sha256_double *h, const struct bitcoin_tx *tx,
-			  enum sighash_type sighash_type)
-{
-	struct sha256_ctx ctx;
-	size_t i;
-
-	/* BIP143: If the ANYONECANPAY flag is not set, hashPrevouts is the
-	 * double SHA256 of the serialization of all input
-	 * outpoints; Otherwise, hashPrevouts is a uint256 of 0x0000......0000.
-	 */
-	if (sighash_anyonecanpay(sighash_type)) {
-		*h = all_zeroes;
-		return;
-	}
-
-	sha256_init(&ctx);
-	for (i = 0; i < tal_count(tx->input); i++) {
-		push_sha(&tx->input[i].txid, sizeof(tx->input[i].txid), &ctx);
-		push_le32(tx->input[i].index, push_sha, &ctx);
-	}
-	sha256_double_done(&ctx, h);
-}
-
-static void hash_sequence(struct sha256_double *h, const struct bitcoin_tx *tx,
-			  enum sighash_type sighash_type)
-{
-	struct sha256_ctx ctx;
-	size_t i;
-
-	/* BIP143: If none of the ANYONECANPAY, SINGLE, NONE sighash type is
-	 * set, hashSequence is the double SHA256 of the serialization of
-	 * nSequence of all inputs; Otherwise, hashSequence is a uint256 of
-	 * 0x0000......0000. */
-	if (sighash_anyonecanpay(sighash_type) || sighash_single(sighash_type)) {
-		*h = all_zeroes;
-		return;
-	}
-
-	sha256_init(&ctx);
-	for (i = 0; i < tal_count(tx->input); i++)
-		push_le32(tx->input[i].sequence_number, push_sha, &ctx);
-
-	sha256_double_done(&ctx, h);
-}
-
-/* If the sighash type is neither SINGLE nor NONE, hashOutputs is the double
- * SHA256 of the serialization of all output value (8-byte little endian) with
- * scriptPubKey (varInt for the length + script); If sighash type is SINGLE
- * and the input index is smaller than the number of outputs, hashOutputs is
- * the double SHA256 of the output amount with scriptPubKey of the same index
- * as the input; */
-static void hash_outputs(struct sha256_double *h, const struct bitcoin_tx *tx,
-			 enum sighash_type sighash_type, unsigned int input_num)
-{
-	struct sha256_ctx ctx;
-	size_t i;
-
-	sha256_init(&ctx);
-	for (i = 0; i < tal_count(tx->output); i++) {
-		if (sighash_single(sighash_type) && i != input_num)
-			continue;
-
-		push_amount_sat(tx->output[i].amount, push_sha, &ctx);
-		push_varint_blob(tx->output[i].script, push_sha, &ctx);
-	}
-
-	sha256_double_done(&ctx, h);
-}
-
-static void hash_for_segwit(struct sha256_ctx *ctx,
-			    const struct bitcoin_tx *tx,
-			    unsigned int input_num,
-			    const u8 *witness_script,
-			    enum sighash_type sighash_type)
-{
-	struct sha256_double h;
-
-	/* BIP143:
-	 *
-	 * Double SHA256 of the serialization of:
-	 *     1. nVersion of the transaction (4-byte little endian)
-	 */
-	push_le32(tx->wtx->version, push_sha, ctx);
-
-	/*     2. hashPrevouts (32-byte hash) */
-	hash_prevouts(&h, tx, sighash_type);
-	push_sha(&h, sizeof(h), ctx);
-
-	/*     3. hashSequence (32-byte hash) */
-	hash_sequence(&h, tx, sighash_type);
-	push_sha(&h, sizeof(h), ctx);
-
-	/*     4. outpoint (32-byte hash + 4-byte little endian)  */
-	push_sha(&tx->input[input_num].txid, sizeof(tx->input[input_num].txid),
-		ctx);
-	push_le32(tx->input[input_num].index, push_sha, ctx);
-
-	/*     5. scriptCode of the input (varInt for the length + script) */
-	push_varint_blob(witness_script, push_sha, ctx);
-
-	/*     6. value of the output spent by this input (8-byte little end) */
-	push_amount_sat(*tx->input_amounts[input_num], push_sha, ctx);
-
-	/*     7. nSequence of the input (4-byte little endian) */
-	push_le32(tx->input[input_num].sequence_number, push_sha, ctx);
-
-	/*     8. hashOutputs (32-byte hash) */
-	hash_outputs(&h, tx, sighash_type, input_num);
-	push_sha(&h, sizeof(h), ctx);
-
-	/*     9. nLocktime of the transaction (4-byte little endian) */
-	push_le32(tx->wtx->locktime, push_sha, ctx);
-}
-
-void sha256_tx_for_sig(struct sha256_double *h, const struct bitcoin_tx *tx,
-		       unsigned int input_num,
-		       const u8 *script,
-		       const u8 *witness_script,
-		       enum sighash_type sighash_type)
-{
-	struct sha256_ctx ctx = SHA256_INIT;
-
-	assert(input_num < tal_count(tx->input));
-
-	if (witness_script) {
-		/* Only implemented and tested these two! */
-		assert(sighash_type == SIGHASH_ALL
-		       || sighash_type == (SIGHASH_SINGLE|SIGHASH_ANYONECANPAY));
-		/* BIP143 hashing if OP_CHECKSIG is inside witness. */
-		hash_for_segwit(&ctx, tx, input_num, witness_script,
-				sighash_type);
-	} else {
-		/* Never implemented anything else for old scheme. */
-		assert(sighash_type == SIGHASH_ALL);
-		/* Otherwise signature hashing never includes witness. */
-		push_tx(tx, script, input_num, push_sha, &ctx, false);
-	}
-
-	sha256_le32(&ctx, sighash_type);
-	sha256_double_done(&ctx, h);
-}
-
 static void push_linearize(const void *data, size_t len, void *pptr_)
 {
 	u8 **pptr = pptr_;

bitcoin/tx.h

@@ -50,14 +50,6 @@ struct bitcoin_tx_input {
 /* SHA256^2 the tx: simpler than sha256_tx */
 void bitcoin_txid(const struct bitcoin_tx *tx, struct bitcoin_txid *txid);
 
-/* Useful for signature code.  Only supports SIGHASH_ALL and
- * (for segwit) SIGHASH_SINGLE|SIGHASH_ANYONECANPAY. */
-void sha256_tx_for_sig(struct sha256_double *h, const struct bitcoin_tx *tx,
-		       unsigned int input_num,
-		       const u8 *script,
-		       const u8 *witness_script,
-		       enum sighash_type sighash_type);
-
 /* Linear bytes of tx. */
 u8 *linearize_tx(const tal_t *ctx, const struct bitcoin_tx *tx);