Oct 04, 2019 ECDSA with secp256k1 in Java: generate ECC keys, sign, verify - ECDSA-secp256k1-example.java. Sep 11, 2012 This site uses cookies for analytics, personalized content and ads. By continuing to browse this site, you agree to this use.
Generate Public Key From Private Key Ecdsa Encryption Java Server
| importorg.bouncycastle.util.encoders.Hex; |
| importorg.web3j.crypto.*; |
| importjava.math.BigInteger; |
| publicclassECCExample { |
| publicstaticStringcompressPubKey(BigIntegerpubKey) { |
| String pubKeyYPrefix = pubKey.testBit(0) ?'03':'02'; |
| String pubKeyHex = pubKey.toString(16); |
| String pubKeyX = pubKeyHex.substring(0, 64); |
| return pubKeyYPrefix + pubKeyX; |
| } |
| publicstaticvoidmain(String[] args) throwsException { |
| //BigInteger privKey = Keys.createEcKeyPair().getPrivateKey(); |
| BigInteger privKey =newBigInteger('97ddae0f3a25b92268175400149d65d6887b9cefaf28ea2c078e05cdc15a3c0a', 16); |
| BigInteger pubKey =Sign.publicKeyFromPrivate(privKey); |
| ECKeyPair keyPair =newECKeyPair(privKey, pubKey); |
| System.out.println('Private key: '+ privKey.toString(16)); |
| System.out.println('Public key: '+ pubKey.toString(16)); |
| System.out.println('Public key (compressed): '+ compressPubKey(pubKey)); |
| String msg ='Message for signing'; |
| byte[] msgHash =Hash.sha3(msg.getBytes()); |
| Sign.SignatureData signature =Sign.signMessage(msgHash, keyPair, false); |
| System.out.println('Msg: '+ msg); |
| System.out.println('Msg hash: '+Hex.toHexString(msgHash)); |
| System.out.printf('Signature: [v = %d, r = %s, s = %s]n', |
| signature.getV() -27, |
| Hex.toHexString(signature.getR()), |
| Hex.toHexString(signature.getS())); |
| System.out.println(); |
| BigInteger pubKeyRecovered =Sign.signedMessageToKey(msg.getBytes(), signature); |
| System.out.println('Recovered public key: '+ pubKeyRecovered.toString(16)); |
| boolean validSig = pubKey.equals(pubKeyRecovered); |
| System.out.println('Signature valid? '+ validSig); |
| } |
| } |
| <?xml version='1.0' encoding='UTF-8'?> |
| <projectxmlns='http://maven.apache.org/POM/4.0.0' |
| xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' |
| xsi:schemaLocation='http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd'> |
| <modelVersion>4.0.0</modelVersion> |
| <groupId>bc-examples</groupId> |
| <artifactId>bc-examples</artifactId> |
| <version>1.0-SNAPSHOT</version> |
| <dependencies> |
| <dependency> |
| <groupId>org.web3j</groupId> |
| <artifactId>crypto</artifactId> |
| <version>3.3.1</version> |
| </dependency> |
| </dependencies> |
| </project> |
commented Apr 5, 2018
The expected output is as follows: |
commented Sep 16, 2018
java.security package contains ECDSA classes for generating the key pair, signing and verifying signatures. (Disclaimer)I recently used this solution to remote log in to new deployed VM images on GCE.Tools used:.Steps to perform:. Ssh-rsa AAAA./VqDjtS5 ubuntu@ubuntuFor keys that were added to the SSH Agent (a program that runs in the background and avoids the need for re-entering the keyfile passphrase over and over again), you can use the ssh-add -L command to list the public keys for keys that were added to the agent (via ssh-add -l). Generate a public/private key pair using puttygen. This is a solution is specifically for users using Windows to SSH into their remote machines, including cloud images on Amazon AWS and GCE. This is useful when the SSH key is stored on a smart card (and access to the private key file is not possible). |
