Arguments

 

context

   type:      longword integer (signed)
   access:    write only
   mechanism: by reference
   Context area initialized when ENCRYPT$INIT completes execution.
   The context argument is the address of a longword of unspecified
   interpretation that is used to convey context between encryption
   operations.
 

input

   type:      char_string
   access:    read only
   mechanism: by descriptor
   Plaintext record to encrypt. The input argument is the address
   of a descriptor pointing to a byte-aligned buffer containing the
   input record to the encryption operation.
 

output

   type:      char_string
   access:    write only by descriptor
   mechanism:
   Ciphertext record that results when ENCRYPT$ENCRYPT completes
   execution. The output argument is the address of a descriptor
   pointing to a byte-aligned buffer that will contain the output
   record from the encryption operation.

   If the descriptor is dynamic and insufficient space is allocated
   to contain the output record, storage is allocated from dynamic
   memory.

   ENCRYPT$ENCRYPT adjusts the length of the output descriptor,
   if possible, to reflect the actual length of the output string.
   If the descriptor type is not DSC$K_DTYPE_VS (varying string),
   DSC$K_DTYPE_V (varying), or DSC$K_DTYPE_D (dynamic), the routine
   takes the actual output count from the output-length argument.

   The output buffer must be able to accommodate a padded block to
   an increment of the block length. For AES this is 16 bytes and
   for DES, 8 bytes.
 

output-length

   type:      word integer
   access:    write only
   mechanism: by reference
   Optional argument. Number of bytes that ENCRYPT$ENCRYPT wrote to
   the output buffer. The output-length argument is the address of a
   word containing the number of bytes written to the output buffer.

   Some encryption algorithms have specific requirements for the
   length of the input and output strings. In particular, DESECB
   and DESCBC pad input data with from 1 to 7 bytes to form complete
   64-bit blocks for operation. The values of the pad characters are
   indeterminate.

   When you decrypt fewer than 8 bytes, preserve and present to
   ENCRYPT$DECRYPT the full 8 bytes resulting from ENCRYPT$ENCRYPT.
   Retain the byte count of the input data in order to strip
   trailing pad bytes after a subsequent decryption operation.

   Note that the AES block mode algorithms (AESCBCxxx and AESECBxxx)
   pad the data to even 16 byte block boundaries. For AES, one byte
   encrypts and decrypts to 16 bytes, 72 bytes to 80, and so forth.
   The AES padding character is a HEX number of bytes indicating the
   number of bytes padded. For example, the one-byte encrypted pad
   would decrypt to 15 characters of 0F following the one encrypted
   byte of data. For the 72 bytes of data, eight bytes of padding
   characters (08 08 ... 08), would follow the 72 bytes of encrypted
   data. DESECB and DESCBC modes always pad with characters of
   zeros. The character stream modes (AESCFBxxx, AESOFBxxx, DESCFB).
   In order that the output-length will match the actual number of
   data bytes, do not pad the data.
 

p1

   type:      quadword[1] (DES), quadword[2] (AES)
   access:    read only
   mechanism: by reference
   Optional argument. The p1 argument is the address of a quadword
   initialization vector used to seed the three modes (DESECB,
   DESCFB, and DESMAC) of the DES algorithm for which it is
   applicable. The DES IV initialization vector is a quadword
   reference, to an eight byte value.

   For AES, the optional P1 argument for the AES IV initialization
   vector is a reference to a 16 byte (two quadwords) value.

   If you omit this argument, the initialization vector used is
   the residue of the previous use of the specified context block.
   ENCRYPT$INIT initializes the context block with an initialization
   vector of zero.