Constructs a secret key from the given byte array, using the first
len
bytes of key
, starting at
offset
inclusive.
The bytes that constitute the secret key are
those between key[offset]
and
key[offset+len-1]
inclusive.
This constructor does not check if the given bytes indeed specify a
secret key of the specified algorithm. For example, if the algorithm is
DES, this constructor does not check if key
is 8 bytes
long, and also does not check for weak or semi-weak keys.
In order for those checks to be performed, an algorithm-specific key
specification class (in this case:
DESKeySpec
)
must be used.
key | the key material of the secret key. The first
len bytes of the array beginning at
offset inclusive are copied to protect
against subsequent modification. | |
offset | the offset in key where the key material
starts. | |
len | the length of the key material. | |
algorithm | the name of the secret-key algorithm to be associated with the given key material. See the Java Security Standard Algorithm Names document for information about standard algorithm names. |
IllegalArgumentException | if algorithm
is null or key is null, empty, or too short,
i.e. key.length-offset<len . | |
ArrayIndexOutOfBoundsException | is thrown if
offset or len index bytes outside the
key . |
Diagram: Key