com.ibm.tivoli.nm.collectors.framework.utils

Class AESCrypto

java.lang.Object

com.ibm.tivoli.nm.collectors.framework.utils.AESCrypto

public class AESCrypto
extends java.lang.Object

Method Summary

Modifier and Type	Method and Description
java.lang.String	decrypt(java.lang.String encryptedText) Method that decrypts the specified encrypted string using the key from a file provided when obtaining reference to AESCrypto instance using getCryptoInstance(String) method and removes any padding added to the encrypted string by the encrypt method.
java.lang.String	encrypt(java.lang.String clearText) Method that encrypts the specified string using the key from a file provided when obtaining reference to AESCrypto instance using getCryptoInstance(String) method.
static AESCrypto	getCryptoInstance(java.lang.String keyLocation) Returns new instance of AESCrypto.
static AESCrypto	getCryptoInstance(java.lang.String keyLocation, int keySizeInBits) Returns new instance of AESCrypto.
static java.lang.Boolean	getIsEncrypted()
static java.lang.String	getKeyFile() Constructs and returns the full path to the key file based on the configured `nchome`, `keyLocation`, and `keyFileName` values.
static java.lang.String	getProviderName()
static java.lang.String	getSecurityProviderName() FIPS (Federal Information Processing Standards) Provider is setting from PrecisionConstants
static void	setIsEncrypted(java.lang.String isEncrypted)
void	writeKeyFile(java.lang.String keyFileName) Instance method that writes a new AES key to the specified file.

Methods inherited from class java.lang.Object

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

Method Detail

getCryptoInstance

public static AESCrypto getCryptoInstance(java.lang.String keyLocation)
                                   throws java.lang.Exception

Returns new instance of AESCrypto. Instances are cached based on keyLocation parameter, there is always single instance of AESCrypto class for each value of keyLocation requested. If keyLocation exists, the instance will attempt to read a key from it and use it. If not, it will attempt to create a file of that name and store a random 128-bit key in it.

Parameters:

keyLocation - path to a file containing cryptographic key

Returns:

instance

Throws:

java.lang.Exception - if security engine cannot be initialised

getIsEncrypted

public static java.lang.Boolean getIsEncrypted()

setIsEncrypted

public static void setIsEncrypted(java.lang.String isEncrypted)

getCryptoInstance

public static AESCrypto getCryptoInstance(java.lang.String keyLocation,
                                          int keySizeInBits)
                                   throws java.lang.Exception

Returns new instance of AESCrypto. Instances are cached based on keyLocation parameter, there is always single instance of AESCrypto class for each value of keyLocation requested.

Parameters:

keyLocation - path to a file containing cryptographic key

keySizeInBits - 128, 192 or 256

Returns:

instance of AESCrypto

Throws:

java.lang.Exception - if security engine cannot be initialised

getSecurityProviderName

public static java.lang.String getSecurityProviderName()

FIPS (Federal Information Processing Standards) Provider is setting from PrecisionConstants

Returns:

getKeyFile

public static java.lang.String getKeyFile()

Constructs and returns the full path to the key file based on the configured `nchome`, `keyLocation`, and `keyFileName` values.

Returns:

the full file path to the key file as a String, or null if nchome is null or empty.

getProviderName

public static java.lang.String getProviderName()

Returns:

encrypt

public java.lang.String encrypt(java.lang.String clearText)
                         throws java.lang.Exception

Method that encrypts the specified string using the key from a file provided when obtaining reference to AESCrypto instance using getCryptoInstance(String) method. The method manually pads to clearText bytes to the expected 16 byte block size by invoking the padByteArray(byte[], int) method. The decrypt(String) method automatically unpads the byte-array but be aware that if not using this classes decrypt method that padding will need to be manually removed.

Parameters:

clearText - to be encrypted.

Returns:

String of encrypted text.

Throws:

java.lang.Exception - if encryption fails.

decrypt

public java.lang.String decrypt(java.lang.String encryptedText)
                         throws java.lang.Exception

Method that decrypts the specified encrypted string using the key from a file provided when obtaining reference to AESCrypto instance using getCryptoInstance(String) method and removes any padding added to the encrypted string by the encrypt method.

Parameters:

encryptedText - encrypted String to decrypt.

Returns:

String of decrypted data.

Throws:

java.lang.Exception - if the decryption fails.

writeKeyFile

public void writeKeyFile(java.lang.String keyFileName)
                  throws java.lang.Exception

Instance method that writes a new AES key to the specified file.

Parameters:

keyFileName - full name and path of the file to write.

Throws:

java.lang.Exception - if the file could not be written.