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java.lang.Objectnet.rim.device.api.crypto.DecryptorFactory
public abstract class DecryptorFactory
Provides the user with a high-level means to decrypt data. The factory classes allow you to encrypt (see the class) and decrypt data without worrying about most of the minute details of the implementation. This class is suitable for developers with little cryptographic experience or, for decrypting data where the details of the implementation are not as important as the result.
The low-level alternative to using the DecryptorFactory
class is the
decryptor engine, such as the .
Note: When requesting a a block cipher in CFB mode you can specify the number of bits to be processed at a time. In our API there are two options allowed for CFB mode. You can either have 8bit mode (denoted by "CFB8") or full CFB mode (denoted simply by "CFB") which will process the full block length.
Note: When calling the getDecryptorInputStream functions, if you specify the algorithm as just "RSA", or just pass in an RSAPrivateKey, then what will be created is "RSA/PKCS1". This is because there are alot of problems with using RSA, by itself, with block encryption/decryption. To use the basic RSA function by itself, use the engine directly.
Note: When using the ElGamal Decryption algorithm it will expect the ephemeral public key from the encryption to have been prepended to the beginning of the ciphertext in the MPI format described in PGP. If this is not the case, it will be unable to properly decrypt your message. For other variations of using ElGamal please use the engine directly.
For more information on the cryptographic algorithms supported by this factory, see Crypto Algorithms.
RSADecryptorEngine
,
ElGamalDecryptorEngine
,
EncryptorFactory
,
DecryptorInputStream
Constructor Summary | ||
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protected |
DecryptorFactory()
Creates a new DecryptorFactory object. |
Method Summary | ||
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protected abstract Object |
create(String algorithm,
String nextAlgorithm,
Key key,
InputStream stream,
InitializationVector iv)
Creates an instance of the DecryptorFactory class given the
specified parameters. |
|
static Enumeration |
getAlgorithms()
Returns an Enumeration of String representing all of the
registered algorithms with this factory. |
|
static BlockDecryptorEngine |
getBlockDecryptorEngine(Key key)
Returns the block decryptor engine using the symmetric key as an argument. |
|
static BlockDecryptorEngine |
getBlockDecryptorEngine(Key key,
String algorithm)
Returns the block decryptor engine using the symmetric key as an argument. |
|
static BlockDecryptorEngine |
getBlockDecryptorEngine(Key key,
String algorithm,
InitializationVector iv)
Returns the block decryptor engine using the symmetric key as an argument. |
|
static DecryptorInputStream |
getDecryptorInputStream(Key key,
InputStream stream)
Returns the decrypted input stream using the symmetric key and input stream as arguments. |
|
static DecryptorInputStream |
getDecryptorInputStream(Key key,
InputStream stream,
String algorithm)
Returns the decrypted input stream using the symmetric key, input stream and algorithm name as arguments. |
|
static DecryptorInputStream |
getDecryptorInputStream(Key key,
InputStream stream,
String algorithm,
InitializationVector iv)
Returns the decrypted input stream using the initialization vector as an additonal argument. |
|
protected abstract String[] |
getFactoryAlgorithms()
Returns a string representing the name of the decryptor algorithm, for example "DES", used to decrypt the data. |
|
static void |
register(DecryptorFactory factory)
Registers the specified factory. |
Methods inherited from class java.lang.Object |
---|
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Constructor Detail |
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protected DecryptorFactory()
DecryptorFactory
object.
Method Detail |
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public static DecryptorInputStream getDecryptorInputStream(Key key, InputStream stream) throws NoSuchAlgorithmException, CryptoTokenException, CryptoUnsupportedOperationException, CryptoException, IOException
key
- The key used to encrypt and decrypt the data.stream
- The input stream.
NoSuchAlgorithmException
- Occurs when the specified algorithm is invalid.
CryptoTokenException
- Occurs when the crypto token is invalid.
CryptoUnsupportedOperationException
- Thrown if a call is made to
an unsupported operation.
CryptoException
IOException
public static DecryptorInputStream getDecryptorInputStream(Key key, InputStream stream, String algorithm) throws NoSuchAlgorithmException, CryptoTokenException, CryptoUnsupportedOperationException, CryptoException, IOException
key
- The key used to encrypt and decrypt the data.stream
- The input stream.algorithm
- A string that represents the algorithm along with the
details of the decryption. eg, "RC5_64_64" ("RC5_" + keyBitLength + "_" +
blockBitLength).
The string, consisting of one or more substrings, is read from right to
left with the left-most sub-string representing the name of the
algorithm. The two substrings to the right of the algorithm specify the
length of the key in bits and the block length of the data in bits.
If a substring is not defined, the default value is substituted instead.
NoSuchAlgorithmException
- Occurs when the specified algorithm is invalid.
CryptoTokenException
- Occurs when the crypto token is invalid.
CryptoUnsupportedOperationException
- Thrown if a call is made to
an unsupported operation.
CryptoException
IOException
public static DecryptorInputStream getDecryptorInputStream(Key key, InputStream stream, String algorithm, InitializationVector iv) throws NoSuchAlgorithmException, CryptoTokenException, CryptoUnsupportedOperationException, CryptoException, IOException
key
- The key used to encrypt and decrypt the data.stream
- The input stream.algorithm
- A string that represents the algorithm along with the
details of the decryption. eg, "RC5_64_64" ("RC5_" + keyBitLength + "_" +
blockBitLength).
The string, consisting of one or more substrings, is read from right to
left with the left-most sub-string representing the name of the
algorithm. The two substrings to the right of the algorithm specify the
length of the key in bits and the block length of the data in bits.
If a substring is not defined, the default value is substituted instead.
iv
- The initialization vector used to decrypt the data.
NoSuchAlgorithmException
- Occurs when the specified algorithm is invalid.
CryptoTokenException
- Occurs when the crypto token is invalid.
CryptoUnsupportedOperationException
- Thrown if a call is made to
an unsupported operation.
CryptoException
IOException
public static BlockDecryptorEngine getBlockDecryptorEngine(Key key) throws NoSuchAlgorithmException, CryptoTokenException, CryptoUnsupportedOperationException, CryptoException
key
- The key used to encrypt and decrypt the data.
NoSuchAlgorithmException
- Occurs when the specified algorithm is invalid.
CryptoTokenException
- Occurs when the crypto token is invalid.
CryptoUnsupportedOperationException
- Thrown if a call is made to
an unsupported operation.
CryptoException
public static BlockDecryptorEngine getBlockDecryptorEngine(Key key, String algorithm) throws NoSuchAlgorithmException, CryptoTokenException, CryptoUnsupportedOperationException, CryptoException
key
- The key used to encrypt and decrypt the data.algorithm
- A string that represents the algorithm along with the
details of the decryption. eg, "RC5_64_64" ("RC5_" + keyBitLength + "_" +
blockBitLength).
The string, consisting of one or more substrings, is read from right to
left with the left-most sub-string representing the name of the
algorithm. The two substrings to the right of the algorithm specify the
length of the key in bits and the block length of the data in bits.
If a substring is not defined, the default value is substituted instead.
NoSuchAlgorithmException
- Occurs when the specified algorithm is invalid.
CryptoTokenException
- Occurs when the crypto token is invalid.
CryptoUnsupportedOperationException
- Thrown if a call is made to
an unsupported operation.
CryptoException
public static BlockDecryptorEngine getBlockDecryptorEngine(Key key, String algorithm, InitializationVector iv) throws NoSuchAlgorithmException, CryptoTokenException, CryptoUnsupportedOperationException, CryptoException
key
- The key used to encrypt and decrypt the data.algorithm
- A string that represents the algorithm along with the
details of the decryption. eg, "RC5_64_64" ("RC5_" + keyBitLength + "_" +
blockBitLength).
The string, consisting of one or more substrings, is read from right to
left with the left-most sub-string representing the name of the
algorithm. The two substrings to the right of the algorithm specify the
length of the key in bits and the block length of the data in bits.
If a substring is not defined, the default value is substituted instead.
iv
- The initialization vector used to decrypt the data.
NoSuchAlgorithmException
- Occurs when the specified algorithm is invalid.
CryptoTokenException
- Occurs when the crypto token is invalid.
CryptoUnsupportedOperationException
- Thrown if a call is made to
an unsupported operation.
CryptoException
public static void register(DecryptorFactory factory)
factory
- The decryptor factory to be registered.public static Enumeration getAlgorithms()
String
representing all of the
registered algorithms with this factory.
protected abstract String[] getFactoryAlgorithms()
protected abstract Object create(String algorithm, String nextAlgorithm, Key key, InputStream stream, InitializationVector iv) throws NoSuchAlgorithmException, ClassCastException, CryptoTokenException, CryptoUnsupportedOperationException, CryptoException, IOException
DecryptorFactory
class given the
specified parameters.
algorithm
- String that specifies the details of the encryption
scheme. The string is composed of three separate strings concatenated
together and delimited by forward slashes. For example
DES/CBC/OAEP
represents a valid string that specifies the
cipher, the mode and the unformatterengine that will be used to decrypt
the data. The algorithm
parameter corresponds to the
rightmost substring. The null
value is passed if an element
is not specified. The null value specifies that the default value be used.nextAlgorithm
- String that represents the next substring to the
left of the initial algorithm
parameter specified above.key
- The key used to decrypt the data.stream
- The InputStream
that contains the ciphertext
of the initial message.iv
- The initialization vector initially used by the encryptor
engine to randomize the data.
NoSuchAlgorithmException
- Occurs when the specified algorithm is invalid.
ClassCastException
- Occurs when an object is improperly cast.
CryptoTokenException
- Occurs when the crypto token is invalid.
CryptoUnsupportedOperationException
- Thrown if a call is made to
an unsupported operation.
CryptoException
IOException
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