This is a Java fork of ecdsa-python
It is compatible with OpenSSL and is fast. It uses some elegant math as Jacobian Coordinates to speed up the ECDSA.
We currently support secp256k1, but it's super easy to add more curves to the project. Just add them on Curve.java
How to use it:
// Generate Keys
PrivateKey privateKey = new PrivateKey();
PublicKey publicKey = privateKey.publicKey();
String message = "My test message";
// Generate Signature
Signature signature = Ecsda.sign(message, privateKey);
// Verify if signature is valid
System.out.println(Ecsda.verify(message, signature, publicKey));This library is compatible with OpenSSL, so you can use it to generate keys:
openssl ecparam -name secp256k1 -genkey -out privateKey.pem
openssl ec -in privateKey.pem -pubout -out publicKey.pem
Create a message.txt file and sign it:
openssl dgst -sha256 -sign privateKey.pem -out signatureBinary.txt message.txt
It's time to verify:
String publicKeyPem = new String(Files.readAllBytes(Path.get("publicKey.pem")));
byte[] signatureBin = Files.readAllBytes(Path.get("signatureBinary.txt"));
String message = new String(Files.readAllBytes(Path.get("message.txt")));
PublicKey publicKey = PublicKey.fromPem(publicKeyPem);
Signature signature = Signature.fromDer(signatureBin);
System.out.println(Ecdsa.verify(message, signature, publicKey));You can also verify it on terminal:
openssl dgst -sha256 -verify publicKey.pem -signature signatureBinary.txt message.txt
NOTE: If you want to create a Digital Signature to use in the Stark Bank, you need to convert the binary signature to base64.
openssl base64 -in signatureBinary.txt -out signatureBase64.txt
With this library, you can do it:
byte[] signatureBin = Files.readAllBytes(Path.get("signatureBinary.txt"));
Signature signature = Signature.fromDer(new ByteString(signatureBin));
System.out.println(signature.toBase64());<dependency>
<groupId>com.github.starkbank</groupId>
<artifactId>ecdsa-java</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>gradle test