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Description:

crypto keys

A library for doing cryptographic signing/verifying and encrypting/decrypting.
It uses pointycastle under the hood, but exposes a more convenient
api.
Usage #
Signing #
A simple usage example:
import 'package:crypto_keys/crypto_keys.dart';
import 'dart:typed_data';

main() {
// Create a key pair from a JWK representation
var keyPair = new KeyPair.fromJwk({
"kty": "oct",
"k": "AyM1SysPpbyDfgZld3umj1qzKObwVMkoqQ-EstJQLr_T-1qS0gZH75"
"aKtMN3Yj0iPS4hcgUuTwjAzZr1Z9CAow"
});

// A key pair has a private and public key, possibly one of them is null, if
// required info was not available when construction
// The private key can be used for signing
var privateKey = keyPair.privateKey;

// Create a signer for the key using the HMAC/SHA-256 algorithm
var signer = privateKey.createSigner(algorithms.signing.hmac.sha256);

// Sign some content, to be integrity protected
var content = "It's me, really me";
var signature = signer.sign("It's me, really me".codeUnits);

print("Signing '$content'");
print("Signature: ${signature.data}");

// The public key can be used for verifying the signature
var publicKey = keyPair.publicKey;

// Create a verifier for the key using the specified algorithm
var verifier = publicKey.createVerifier(algorithms.signing.hmac.sha256);

var verified =
verifier.verify(new Uint8List.fromList(content.codeUnits), signature);
if (verified)
print("Verification succeeded");
else
print("Verification failed");
}
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Encryption #
A simple usage example:

import 'package:crypto_keys/crypto_keys.dart';
import 'dart:typed_data';

main() {
// Generate a new random symmetric key pair
var keyPair = new KeyPair.generateSymmetric(128);

// Use the public key to create an encrypter with the AES/GCM algorithm
var encrypter =
keyPair.publicKey.createEncrypter(algorithms.encryption.aes.gcm);

// Encrypt the content with an additional authentication data for integrity
// protection
var content = "A very secret text";
var aad = "It is me";
var v = encrypter.encrypt(new Uint8List.fromList(content.codeUnits),
additionalAuthenticatedData: new Uint8List.fromList(aad.codeUnits));

print("Encrypting '$content'");
print("Ciphertext: ${v.data}");
print("Authentication tag: ${v.authenticationTag}");

// Use the private key to create the decrypter
var decrypter =
keyPair.privateKey.createEncrypter(algorithms.encryption.aes.gcm);

// Decrypt and verify authentication tag
var decrypted = decrypter.decrypt(v);

print("Decrypted text: '${new String.fromCharCodes(decrypted)}'");
}

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Features and bugs #
Please file feature requests and bugs at the issue tracker.