@CHIP-RTOS C Library - TCP/IP API

Crypt_Blowfish_Decrypt

Decrypt one cipher block of data using BLOWFISH decryption method.

int far Crypt_Blowfish_Decrypt (
             const Crypt_BlowfishKeyS far *subkeys,
             const void far *in,
                   void far *out ) ;

Parameters

subkeys

Pointer to BLOWFISH subkey schedule generated by Crypt_Blowfish_MakeKey().

in

Pointer to 8 byte clear text to be encrypted

out

Pointer to 8 byte buffer where the resulting decrypted clear text will be written by this API.

Return Value

0 constant (provisional error code)

Comments

This API uses the BLOWFISH algorithm to convert one 8 byte cipher block of encrypted data back to plain text.   It can be called repeatedly until your entire message has been recovered.   When your message is not an integral number of 8 byte blocks in length, then you will obtain on the final call the pad bytes that were appended to the original message at the encryption step.

This implementation of BLOWFISH uses 16 rounds.

Blowfish treats data as big endian ("network byte order") long words.   Any required data endian handling is done inside this API, so the caller must not perform any such endian swapping on their side.

The in and out parameters may reference the same location.

Go here for a summary of cipher method execution times.

See Also

Crypt_Blowfish_Encrypt        Crypt_Blowfish_MakeKey        

RTOS API

On the first call, this library function invokes a software interrupt which modifies the code at the calling site inside your application program.   A direct FAR JMP into the @CHIP-RTOS-x86 implementation for this function is installed so that on return and on any subsequent calls to this API this dynamic link reaches the function's implementation directly.

Supported since or modified in @CHIP-RTOS version

SC12	SC13	SC11	SC1x3	SC2x
n/a	n/a	n/a	V1.35	V1.35

Supported by @CHIP-RTOS C Library since version

CLIB
V2.19