Signature failed to verify
Hi there,
I'm having a problem verify a signature using my public key. I get the following error when I run call the method verifies from Signature object:
Verifies = false
My code below any help is much appreciated:
publicstaticvoid main(String[] args)throws Exception{
FileInputStream fis =new FileInputStream("C:\\test.txt");
String strTXT = doLookup("123._cisco.com");
String strPublicKey = strTXT.replaceAll("(?s)^.*p\\=([^;]*);?.*\"$","$1").replaceAll("(?s)\\s","");
System.out.println("strTxt: " + strTXT);
System.out.println("strPublicKey is: " + strPublicKey);
byte [] publicKey = Base64.decode(strPublicKey);
byte [] signature = Base64.decode("dXj0ycQM1ekdhlfO0GfhSXZQsfG0S7jrTv6s0aCFLQLduPW4CwC8UNYnHN6fE5pZU3MPpiYYmmJabR7yg3MQb7AM5HQzm0q+HrJFX86V/SB9Zuhkl37DJegPK8TPMZ0Bsynrp=");
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
X509EncodedKeySpec publicKeySpec =new X509EncodedKeySpec(publicKey);
PublicKey specPublicKey = keyFactory.generatePublic(publicKeySpec);
System.out.println("public key is: " + specPublicKey.getFormat());
System.out.println("pub key algorithm is: " + specPublicKey.getAlgorithm());
//Need to create a Signature object that uses the same signature algorithm to generate
//the signature.
Signature rsa = Signature.getInstance("SHA1WITHRSA");
//initialize the Signature object.
rsa.initVerify(specPublicKey);
System.out.println("publicKey is: " + specPublicKey.toString());
System.out.println("Calling rsa.verify");
/*Supply the Signature Object With the Data to be Verified*/
BufferedInputStream bufins =new BufferedInputStream(fis);
byte[] buffer =newbyte[1024];
int len;
while(bufins.available() !=0){
len = bufins.read(buffer);
rsa.update(buffer, 0, len);
};
bufins.close();
boolean verifies = rsa.verify(signature);
System.out.println("Verifies = " + Boolean.toString(verifies));
Code output:
strTxt: TXT: "g=*; k=rsa; t=y; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCg8yo6rDhsNiwUfVR37HgF4bWqoG13Nd9XLT+Z0VLzCkWJZOdzGNQnnm7ujoQ8gbxeDvIo9RG5I3eZteBwD91Nf6P/E9lvJQDL2Qnz4EXH/CVW9DeEfvY1UJN9kc6q6KkYEPWssvVvlDOp2slbEKZCJtaPvVuGCAqfaps8J0FjOQIDAQAB"
strPublicKey is: MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCg8yo6rDhsNiwUfVR37HgF4bWqoG13Nd9XLT+Z0VLzCkWJZOdzGNQnnm7ujoQ8gbxeDvIo9RG5I3eZteBwD91Nf6P/E9lvJQDL2Qnz4EXH/CVW9DeEfvY1UJN9kc6q6KkYEPWssvVvlDOp2slbEKZCJtaPvVuGCAqfaps8J0FjOQIDAQAB
public key is: X.509
pub key algorithm is: RSA
publicKey is: Sun RSA public key, 1024 bits
Calling rsa.verify
Verifies = false
