/**
* Create a clear sign signature over the input data. (Not detached)
*
* @param input the content to be signed
* @param keyring the keyring
* @param keyId the 4 bytes identifier of the key, in hexadecimal format
* @param passphrase the passphrase to retrieve the private key
* @param output the output destination of the signature
*/
public static void clearSign(
InputStream input, InputStream keyring, String keyId, String passphrase, OutputStream output)
throws IOException, PGPException, GeneralSecurityException {
PGPSecretKey secretKey = getSecretKey(keyring, keyId);
PGPPrivateKey privateKey =
secretKey.extractPrivateKey(
new BcPBESecretKeyDecryptorBuilder(new BcPGPDigestCalculatorProvider())
.build(passphrase.toCharArray()));
int digest = PGPUtil.SHA1;
PGPSignatureGenerator signatureGenerator =
new PGPSignatureGenerator(
new BcPGPContentSignerBuilder(secretKey.getPublicKey().getAlgorithm(), digest));
signatureGenerator.init(PGPSignature.CANONICAL_TEXT_DOCUMENT, privateKey);
ArmoredOutputStream armoredOutput = new ArmoredOutputStream(output);
armoredOutput.beginClearText(digest);
BufferedReader reader = new BufferedReader(new InputStreamReader(input));
String line;
while ((line = reader.readLine()) != null) {
// trailing spaces must be removed for signature calculation (see
// http://tools.ietf.org/html/rfc4880#section-7.1)
byte[] data = trim(line).getBytes("UTF-8");
armoredOutput.write(data);
armoredOutput.write(EOL);
signatureGenerator.update(data);
signatureGenerator.update(EOL);
}
armoredOutput.endClearText();
PGPSignature signature = signatureGenerator.generate();
signature.encode(new BCPGOutputStream(armoredOutput));
armoredOutput.close();
}
/**
* Encodes the provided message with the private key and pass phrase set in configuration
*
* @param message Message to encode
* @return Encoded message
* @throws LRException SIGNING_FAILED if the document cannot be signed, NO_KEY if the key cannot
* be obtained
*/
private String signEnvelopeData(String message) throws LRException {
// Get an InputStream for the private key
InputStream privateKeyStream = getPrivateKeyStream(privateKey);
// Get an OutputStream for the result
ByteArrayOutputStream result = new ByteArrayOutputStream();
ArmoredOutputStream aOut = new ArmoredOutputStream(result);
// Get the pass phrase
char[] privateKeyPassword = passPhrase.toCharArray();
try {
// Get the private key from the InputStream
PGPSecretKey sk = readSecretKey(privateKeyStream);
PGPPrivateKey pk = sk.extractPrivateKey(privateKeyPassword, "BC");
PGPSignatureGenerator pgp =
new PGPSignatureGenerator(sk.getPublicKey().getAlgorithm(), PGPUtil.SHA256, "BC");
PGPSignatureSubpacketGenerator spGen = new PGPSignatureSubpacketGenerator();
// Clear sign the message
java.util.Iterator it = sk.getPublicKey().getUserIDs();
if (it.hasNext()) {
spGen.setSignerUserID(false, (String) it.next());
pgp.setHashedSubpackets(spGen.generate());
}
aOut.beginClearText(PGPUtil.SHA256);
pgp.initSign(PGPSignature.CANONICAL_TEXT_DOCUMENT, pk);
byte[] msg = message.getBytes();
pgp.update(msg, 0, msg.length);
aOut.write(msg, 0, msg.length);
BCPGOutputStream bOut = new BCPGOutputStream(aOut);
aOut.endClearText();
pgp.generate().encode(bOut);
String strResult = result.toString("utf8");
return strResult;
} catch (Exception e) {
throw new LRException(LRException.SIGNING_FAILED);
} finally {
try {
if (privateKeyStream != null) {
privateKeyStream.close();
}
aOut.close();
result.close();
} catch (IOException e) {
// Could not close the streams
}
}
}