Converts encrypted data (a binary byte stream)
to its original source format, and returns a MEMPTR containing the
decrypted data.
Note: You must use the same cryptographic
algorithm, initialization vector, and encryption key values to encrypt
and decrypt the same data instance.
Syntax
DECRYPT ( data-to-decrypt[ , encrypt-key[ , iv-value[ , algorithm]]] )
|
-
data-to-decrypt
- The encrypted data to decrypt. The value may be of type RAW
or MEMPTR.
-
encrypt-key
- An optional RAW expression that evaluates to the encryption key (a binary value)
originally used to encrypt the specified data. If you specify the Unknown value
(?), the current value of the SYMMETRIC-ENCRYPTION-KEY attribute is
used. If the value of the SYMMETRIC-ENCRYPTION-KEY attribute is also the Unknown value
(?), the AVM generates a run-time error.
The AVM compares the size
of the specified encryption key to the key size specified by the cryptographic
algorithm. If the key sizes are inconsistent, the AVM generates a run-time
error.
You can use the GENERATE-PBE-KEY function to regenerate the same encryption key
originally used to encrypt the specified data as long as you specify the same password
string, hash algorithm, number of iterations, and salt value.
Note: Do
not use the
GENERATE-RANDOM-KEY function to
generate this encryption key. The random key it generates will always be different
than the key originally used to encrypt the specified data.
You are
responsible for generating, storing, and transporting this value.
-
iv-value
- An optional RAW expression that evaluates to the initialization vector value to use
with the specified encryption key in the original encryption operation. If you specify
the Unknown value (?), the current value of the SYMMETRIC-ENCRYPTION-IV
attribute is used.
-
algorithm
- An optional CHARACTER expression that evaluates to the name of the symmetric
cryptographic algorithm originally used to encrypt the specified data instance. If you
specify the Unknown value (?), the current value of the
SYMMETRIC-ENCRYPTION-ALGORITHM attribute is used.
For a list the supported
cryptographic algorithms, see the SYMMETRIC-SUPPORT attribute
reference entry.
