com.lf.commons.crypto

Class CryptoUtils

java.lang.Object

com.lf.commons.crypto.CryptoUtils

public class CryptoUtils
extends java.lang.Object

Some common functionality to use the cryptographic classes.

Since:

1.6

Version:

$Revision: 1.54 $, $Date: 2016/01/01 15:43:01 $

Author:

Axel Schwolow

Constructor Summary

Constructors

Constructor and Description
CryptoUtils() Constructor method for i18n purposes only.

Method Summary

Methods

Modifier and Type	Method and Description
static java.lang.String	assembleUserID(java.lang.String realname, java.lang.String comment, java.lang.String email) Combines the user ID fields real name (optional), comment (optional), and e-mail.
static java.util.Date	calculateExpireDate(java.util.Date creation, int validdays) Computes the expiration date of a key.
static int	checkEncryptionASCIIFormat(byte[] encrypted) Checks the format of the given encrypted ASCII-armored data.
static java.lang.String	convertKeyID(long longkeyid) Converts the given key identifier to hexadecimal format as used for PGP.
static long	convertKeyID(java.lang.String keyid) Converts the given key identifier back to the numeric representation.
static byte[]	decryptAES(byte[] encrypted, byte[] aeskey, boolean armor) Encrypts the given data portion using the given AES key.
static boolean	decryptAES(java.io.InputStream istream, java.io.OutputStream ostream, byte[] aeskey) Decrypts the given data portion using the given AES key.
static byte[]	encryptAES(byte[] rawdata, byte[] aeskey, boolean armor) Encrypts the given data portion using the given AES key.
static boolean	encryptAES(java.io.InputStream istream, java.io.OutputStream ostream, byte[] aeskey) Encrypts the given data portion using the given AES key.
static java.lang.String	extractComment(java.lang.String userid) Extracts the comment from the given user ID.
static java.lang.String	extractEMail(java.lang.String userid) Extracts the email from the given user ID.
static java.lang.String	extractRealName(java.lang.String userid) Extracts the real name from the given user ID.
static java.lang.String	getChecksum(java.lang.String algo, byte[] data) Calculates a checksum for binary data.
static java.lang.String[]	getDefaultCompressionAlgos() Provides the default compression algorithms for key generation.
static java.lang.String[]	getDefaultHashingAlgos() Provides the default hashing algorithms for key generation.
static java.lang.String[]	getDefaultSymmetricKeyAlgos() Provides the default symmetric key algorithms for key generation.
static byte[]	getDetachedSignature(org.bouncycastle.openpgp.PGPSignature signature, boolean armor, java.lang.String version) Creates a binary representation of a given detached signature.
static java.lang.String[]	getEncryptionKeyIDs(java.io.InputStream istream) Reads the key IDs of the keys used for an encrypted file.
static java.lang.String	getMD5Checksum(byte[] data) Calculates a MD5 checksum for binary data.
static java.lang.String	getSHA1Checksum(byte[] data) Calculates a SHA-1 checksum for binary data.
static org.bouncycastle.openpgp.PGPSignature[]	loadDetachedSignatures(java.io.InputStream sigstream) Extracts detached signatures from a stream containing one or multiple detached signatures.
static java.util.Vector<java.lang.String>	loadDetachedSignaturesASCII(java.io.InputStream sigstream) Parses an ASCII-armored stream containing one or multiple detached signatures.
static void	main(java.lang.String[] arg) This may be used especially for debugging purposes.
static java.io.File	mapToDecryptedFile(java.io.File encrypted) Provides the appropriate name of a decrypted file based on the encrypted file name.
protected static PasswordDialog	showPasswordDialog(java.awt.Component parent, java.lang.String userid, boolean remember) Shows the password dialog to prompt the user for a valid PGP key passphrase.

Methods inherited from class java.lang.Object

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

Constructor Detail

CryptoUtils

public CryptoUtils()
            throws java.lang.InstantiationException

Constructor method for i18n purposes only.

Can only be used if beans design time is set (e.g. by external tools like the I18NExtractor).

Throws:

java.lang.InstantiationException - Error indication

Since:

1.6

Method Detail

getMD5Checksum

public static java.lang.String getMD5Checksum(byte[] data)

Calculates a MD5 checksum for binary data.

Parameters:

data - Binary data

Returns:

MD5 checksum, else null

Since:

1.6

getSHA1Checksum

public static java.lang.String getSHA1Checksum(byte[] data)

Calculates a SHA-1 checksum for binary data.

Parameters:

data - Binary data

Returns:

SHA-1 checksum, else null

Since:

1.6

getChecksum

public static java.lang.String getChecksum(java.lang.String algo,
                           byte[] data)

Calculates a checksum for binary data.

Parameters:

algo - The algorithm like "MD5"

data - Binary data

Returns:

MD5 checksum, else null

Since:

1.6

convertKeyID

public static java.lang.String convertKeyID(long longkeyid)

Converts the given key identifier to hexadecimal format as used for PGP.

Parameters:

longkeyid - Binary data

Returns:

Hexadecimal representation, null otherwise

See Also:

convertKeyID(String)

convertKeyID

public static long convertKeyID(java.lang.String keyid)

Converts the given key identifier back to the numeric representation.

Parameters:

keyid - Display data like 0xaabbccdd

Returns:

Numeric representation, -1 otherwise

See Also:

convertKeyID(long)

mapToDecryptedFile

public static java.io.File mapToDecryptedFile(java.io.File encrypted)

Provides the appropriate name of a decrypted file based on the encrypted file name.

If the encrypted file has a ".txt" extension then this extension is simply cut off the name. The extension ".decrypted" is applied otherwise.

Parameters:

encrypted - The encrypted file

Returns:

Reference of the

Since:

1.6

getEncryptionKeyIDs

public static java.lang.String[] getEncryptionKeyIDs(java.io.InputStream istream)

Reads the key IDs of the keys used for an encrypted file.

This method can be applied to a PGP encrypted file directly (both ASCII armored or binary) to get the list of keys required to decrypt the file.

Parameters:

istream - The encrypted data stream to be analyzed, never closed

Returns:

List of key IDs, null indicates error

Since:

1.6

See Also:

convertKeyID(String)

extractRealName

public static java.lang.String extractRealName(java.lang.String userid)

Extracts the real name from the given user ID.

Typical user IDs look like "Digester 1.6.x Server (Comment) " where "Digester 1.6.x Server" is the real name part.

Parameters:

userid - The user ID to be analyzed

Returns:

The real name, may be null

Since:

1.6

extractComment

public static java.lang.String extractComment(java.lang.String userid)

Extracts the comment from the given user ID.

Typical user IDs look like "Digester 1.6.x Server (Comment) " where "Comment" is the comment part embedded in round brackets.

Parameters:

userid - The user ID to be analyzed

Returns:

The comment, may be null

Since:

1.6

extractEMail

public static java.lang.String extractEMail(java.lang.String userid)

Extracts the email from the given user ID.

Typical user IDs look like "Digester 1.6.x Server (Comment) " where the email part is embedded in tag brackets.

Parameters:

userid - The user ID to be analyzed

Returns:

The real name, may be null

Since:

1.6

encryptAES

public static byte[] encryptAES(byte[] rawdata,
                byte[] aeskey,
                boolean armor)

Encrypts the given data portion using the given AES key.

Parameters:

rawdata - The data to be encrypted

aeskey - The key to use (128, 192, or 256 length)

armor - ASCII-armored?

Returns:

Decrypted data, null indicates error

Since:

1.6

encryptAES

public static boolean encryptAES(java.io.InputStream istream,
                 java.io.OutputStream ostream,
                 byte[] aeskey)

Encrypts the given data portion using the given AES key.

Found it here: http://www.itcsolutions.eu/2010/12/28/how-to-encrypt-decrypt-with-aes-from-bouncy-castle-api-in-j2me-applications/

Parameters:

istream - The data to be encrypted, never closed

ostream - The encrypted data, never closed

aeskey - The key to use (128, 192, or 256 bits length)

Returns:

Successful?

Since:

1.6

decryptAES

public static byte[] decryptAES(byte[] encrypted,
                byte[] aeskey,
                boolean armor)

Encrypts the given data portion using the given AES key.

Parameters:

encrypted - The encrypted data

aeskey - The key to use (128, 192, or 256 length)

armor - Expect ASCII-armored?

Returns:

Decrypted data, null indicates error

Since:

1.6

decryptAES

public static boolean decryptAES(java.io.InputStream istream,
                 java.io.OutputStream ostream,
                 byte[] aeskey)

Decrypts the given data portion using the given AES key.

Found it here: http://www.itcsolutions.eu/2010/12/28/how-to-encrypt-decrypt-with-aes-from-bouncy-castle-api-in-j2me-applications/

Parameters:

istream - The data to be decrypted, never closed

ostream - The decrypted data, never closed

aeskey - The key to use (128, 192, or 256 bits length)

Returns:

Successful?

Since:

1.6

checkEncryptionASCIIFormat

public static int checkEncryptionASCIIFormat(byte[] encrypted)

Checks the format of the given encrypted ASCII-armored data.

Parameters:

encrypted - The encrypted ASCII-armored data

Returns:

The type CryptoConstants.FORMAT_PGP_ARMOR, ...

Since:

1.6

calculateExpireDate

public static java.util.Date calculateExpireDate(java.util.Date creation,
                                 int validdays)

Computes the expiration date of a key.

Parameters:

creation - The key creation date

validdays - Number of days the key is valid

Returns:

The expire date, null = key does never expire

assembleUserID

public static java.lang.String assembleUserID(java.lang.String realname,
                              java.lang.String comment,
                              java.lang.String email)

Combines the user ID fields real name (optional), comment (optional), and e-mail.

Typical user IDs look like "Digester 1.6.x Server (Comment) " where "Digester 1.6.x Server" is the real name part.

Parameters:

realname - The real name (optional)

comment - The comment (optional)

email - The e-mail address

Returns:

The real name, may be null

Throws:

java.lang.NullPointerException - If a parameter is null

Since:

1.6

getDefaultHashingAlgos

public static java.lang.String[] getDefaultHashingAlgos()

Provides the default hashing algorithms for key generation.

Returns:

The defaults

Since:

1.6

getDefaultCompressionAlgos

public static java.lang.String[] getDefaultCompressionAlgos()

Provides the default compression algorithms for key generation.

Returns:

The defaults

Since:

1.6

getDefaultSymmetricKeyAlgos

public static java.lang.String[] getDefaultSymmetricKeyAlgos()

Provides the default symmetric key algorithms for key generation.

Returns:

The defaults

Since:

1.6

showPasswordDialog

protected static PasswordDialog showPasswordDialog(java.awt.Component parent,
                                java.lang.String userid,
                                boolean remember)

Shows the password dialog to prompt the user for a valid PGP key passphrase.

Parameters:

parent - The GUI parent for the dialog

userid - The key ID to print

remember - Remember the passphrase for the next time?

Returns:

The dialog or null if not available

Since:

1.6

loadDetachedSignaturesASCII

public static java.util.Vector<java.lang.String> loadDetachedSignaturesASCII(java.io.InputStream sigstream)

Parses an ASCII-armored stream containing one or multiple detached signatures.

Parameters:

sigstream - The signature stream, closed here

Returns:

Container with ASCII-armored signatures, may be empty

Since:

1.6

loadDetachedSignatures

public static org.bouncycastle.openpgp.PGPSignature[] loadDetachedSignatures(java.io.InputStream sigstream)

Extracts detached signatures from a stream containing one or multiple detached signatures.

The input stream may be either ASCII-armored or binary signature data.

Parameters:

sigstream - The signature stream

Returns:

The signatures, may have zero length

Since:

1.6

getDetachedSignature

public static byte[] getDetachedSignature(org.bouncycastle.openpgp.PGPSignature signature,
                          boolean armor,
                          java.lang.String version)

Creates a binary representation of a given detached signature.

Parameters:

signature - The pre-processed signature object

armor - Generate ASCII format

version - The version info (optional)

Returns:

The signature data, null indicates error

Since:

1.6

main

public static void main(java.lang.String[] arg)
                 throws java.lang.Exception

This may be used especially for debugging purposes.

Parameters:

arg - Array of String objects with console params

Throws:

java.lang.Exception - Error indication

Since:

1.6