org.apache.hadoop.security.authentication.util
Class Signer

java.lang.Object
  org.apache.hadoop.security.authentication.util.Signer

public class Signer
extends Object

Signs strings and verifies signed strings using a SHA digest.

Constructor Summary

Signer(SignerSecretProvider secretProvider)
Creates a Signer instance using the specified SignerSecretProvider.

Method Summary

protected void	checkSignatures(String rawValue, String originalSignature)
protected String	computeSignature(byte[] secret, String str) Returns then signature of a string.
String	sign(String str) Returns a signed string.
String	verifyAndExtract(String signedStr) Verifies a signed string and extracts the original string.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Signer

public Signer(SignerSecretProvider secretProvider)

Creates a Signer instance using the specified SignerSecretProvider. The SignerSecretProvider should already be initialized.

Parameters:

secretProvider - The SignerSecretProvider to use

Method Detail

sign

public String sign(String str)

Returns a signed string.

The signature '&s=SIGNATURE' is appended at the end of the string.

Parameters:

str - string to sign.

Returns:

the signed string.

verifyAndExtract

public String verifyAndExtract(String signedStr)
                        throws SignerException

Verifies a signed string and extracts the original string.

Parameters:

signedStr - the signed string to verify and extract.

Returns:

the extracted original string.

Throws:

SignerException - thrown if the given string is not a signed string or if the signature is invalid.

computeSignature

protected String computeSignature(byte[] secret,
                                  String str)

Returns then signature of a string.

Parameters:

secret - The secret to use

str - string to sign.

Returns:

the signature for the string.

checkSignatures

protected void checkSignatures(String rawValue,
                               String originalSignature)
                        throws SignerException

Throws:

SignerException