1Shared Libraries 2================ 3 4## bitcoinconsensus 5 6The purpose of this library is to make the verification functionality that is critical to Bitcoin's consensus available to other applications, e.g. to language bindings. 7 8### API 9 10The interface is defined in the C header `bitcoinconsensus.h` located in `src/script/bitcoinconsensus.h`. 11 12#### Version 13 14`bitcoinconsensus_version` returns an `unsigned int` with the API version *(currently at an experimental `0`)*. 15 16#### Script Validation 17 18`bitcoinconsensus_verify_script` returns an `int` with the status of the verification. It will be `1` if the input script correctly spends the previous output `scriptPubKey`. 19 20##### Parameters 21- `const unsigned char *scriptPubKey` - The previous output script that encumbers spending. 22- `unsigned int scriptPubKeyLen` - The number of bytes for the `scriptPubKey`. 23- `const unsigned char *txTo` - The transaction with the input that is spending the previous output. 24- `unsigned int txToLen` - The number of bytes for the `txTo`. 25- `unsigned int nIn` - The index of the input in `txTo` that spends the `scriptPubKey`. 26- `unsigned int flags` - The script validation flags *(see below)*. 27- `bitcoinconsensus_error* err` - Will have the error/success code for the operation *(see below)*. 28 29##### Script Flags 30- `bitcoinconsensus_SCRIPT_FLAGS_VERIFY_NONE` 31- `bitcoinconsensus_SCRIPT_FLAGS_VERIFY_P2SH` - Evaluate P2SH ([BIP16](https://github.com/bitcoin/bips/blob/master/bip-0016.mediawiki)) subscripts 32- `bitcoinconsensus_SCRIPT_FLAGS_VERIFY_DERSIG` - Enforce strict DER ([BIP66](https://github.com/bitcoin/bips/blob/master/bip-0066.mediawiki)) compliance 33- `bitcoinconsensus_SCRIPT_FLAGS_VERIFY_NULLDUMMY` - Enforce NULLDUMMY ([BIP147](https://github.com/bitcoin/bips/blob/master/bip-0147.mediawiki)) 34- `bitcoinconsensus_SCRIPT_FLAGS_VERIFY_CHECKLOCKTIMEVERIFY` - Enable CHECKLOCKTIMEVERIFY ([BIP65](https://github.com/bitcoin/bips/blob/master/bip-0065.mediawiki)) 35- `bitcoinconsensus_SCRIPT_FLAGS_VERIFY_CHECKSEQUENCEVERIFY` - Enable CHECKSEQUENCEVERIFY ([BIP112](https://github.com/bitcoin/bips/blob/master/bip-0112.mediawiki)) 36- `bitcoinconsensus_SCRIPT_FLAGS_VERIFY_WITNESS` - Enable WITNESS ([BIP141](https://github.com/bitcoin/bips/blob/master/bip-0141.mediawiki)) 37 38##### Errors 39- `bitcoinconsensus_ERR_OK` - No errors with input parameters *(see the return value of `bitcoinconsensus_verify_script` for the verification status)* 40- `bitcoinconsensus_ERR_TX_INDEX` - An invalid index for `txTo` 41- `bitcoinconsensus_ERR_TX_SIZE_MISMATCH` - `txToLen` did not match with the size of `txTo` 42- `bitcoinconsensus_ERR_DESERIALIZE` - An error deserializing `txTo` 43- `bitcoinconsensus_ERR_AMOUNT_REQUIRED` - Input amount is required if WITNESS is used 44 45### Example Implementations 46- [NBitcoin](https://github.com/NicolasDorier/NBitcoin/blob/master/NBitcoin/Script.cs#L814) (.NET Bindings) 47- [node-libbitcoinconsensus](https://github.com/bitpay/node-libbitcoinconsensus) (Node.js Bindings) 48- [java-libbitcoinconsensus](https://github.com/dexX7/java-libbitcoinconsensus) (Java Bindings) 49- [bitcoinconsensus-php](https://github.com/Bit-Wasp/bitcoinconsensus-php) (PHP Bindings) 50