MessageDigestSpi
abstract class MessageDigestSpi
| kotlin.Any | |
| ↳ | java.security.MessageDigestSpi |
This class defines the Service Provider Interface (SPI) for the MessageDigest class, which provides the functionality of a message digest algorithm, such as MD5 or SHA. Message digests are secure one-way hash functions that take arbitrary-sized data and output a fixed-length hash value.
All the abstract methods in this class must be implemented by a cryptographic service provider who wishes to supply the implementation of a particular message digest algorithm.
Implementations are free to implement the Cloneable interface.
Summary
| Public constructors | |
|---|---|
| Public methods | |
|---|---|
| open Any! |
clone()Returns a clone if the implementation is cloneable. |
| Protected methods | |
|---|---|
| abstract ByteArray! |
Completes the hash computation by performing final operations such as padding. |
| open Int |
engineDigest(buf: ByteArray!, offset: Int, len: Int)Completes the hash computation by performing final operations such as padding. |
| open Int |
Returns the digest length in bytes. |
| abstract Unit |
Resets the digest for further use. |
| abstract Unit |
engineUpdate(input: Byte)Updates the digest using the specified byte. |
| abstract Unit |
engineUpdate(input: ByteArray!, offset: Int, len: Int)Updates the digest using the specified array of bytes, starting at the specified offset. |
| open Unit |
engineUpdate(input: ByteBuffer!)Update the digest using the specified ByteBuffer. |
Public constructors
Public methods
clone
open fun clone(): Any!
Returns a clone if the implementation is cloneable.
| Return | |
|---|---|
Any! |
a clone if the implementation is cloneable. |
| Exceptions | |
|---|---|
java.lang.CloneNotSupportedException |
if the object's class does not support the Cloneable interface. Subclasses that override the clone method can also throw this exception to indicate that an instance cannot be cloned. |
java.lang.CloneNotSupportedException |
if this is called on an implementation that does not support Cloneable. |
Protected methods
engineDigest
protected abstract fun engineDigest(): ByteArray!
Completes the hash computation by performing final operations such as padding. Once engineDigest has been called, the engine should be reset (see engineReset). Resetting is the responsibility of the engine implementor.
| Return | |
|---|---|
ByteArray! |
the array of bytes for the resulting hash value. |
engineDigest
protected open fun engineDigest(
buf: ByteArray!,
offset: Int,
len: Int
): Int
Completes the hash computation by performing final operations such as padding. Once engineDigest has been called, the engine should be reset (see engineReset). Resetting is the responsibility of the engine implementor. This method should be abstract, but we leave it concrete for binary compatibility. Knowledgeable providers should override this method.
| Parameters | |
|---|---|
buf |
ByteArray!: the output buffer in which to store the digest |
offset |
Int: offset to start from in the output buffer |
len |
Int: number of bytes within buf allotted for the digest. Both this default implementation and the SUN provider do not return partial digests. The presence of this parameter is solely for consistency in our API's. If the value of this parameter is less than the actual digest length, the method will throw a DigestException. This parameter is ignored if its value is greater than or equal to the actual digest length. |
| Return | |
|---|---|
Int |
the length of the digest stored in the output buffer. |
| Exceptions | |
|---|---|
java.security.DigestException |
if an error occurs. |
engineGetDigestLength
protected open fun engineGetDigestLength(): Int
Returns the digest length in bytes.
This concrete method has been added to this previously-defined abstract class. (For backwards compatibility, it cannot be abstract.)
The default behavior is to return 0.
This method may be overridden by a provider to return the digest length.
| Return | |
|---|---|
Int |
the digest length in bytes. |
engineReset
protected abstract fun engineReset(): Unit
Resets the digest for further use.
engineUpdate
protected abstract fun engineUpdate(input: Byte): Unit
Updates the digest using the specified byte.
| Parameters | |
|---|---|
input |
Byte: the byte to use for the update. |
engineUpdate
protected abstract fun engineUpdate(
input: ByteArray!,
offset: Int,
len: Int
): Unit
Updates the digest using the specified array of bytes, starting at the specified offset.
| Parameters | |
|---|---|
input |
ByteArray!: the array of bytes to use for the update. |
offset |
Int: the offset to start from in the array of bytes. |
len |
Int: the number of bytes to use, starting at offset. |
engineUpdate
protected open fun engineUpdate(input: ByteBuffer!): Unit
Update the digest using the specified ByteBuffer. The digest is updated using the input.remaining() bytes starting at input.position(). Upon return, the buffer's position will be equal to its limit; its limit will not have changed.
| Parameters | |
|---|---|
input |
ByteBuffer!: the ByteBuffer |