@CHIP-RTOS C Library - TCP/IP API

Crypt_Blowfish_MakeKey

Generate the Blowfish subkey arrays.

int far Crypt_Blowfish_MakeKey (
             Crypt_BlowfishKeyS far * subkeys,
             int len,
             const unsigned char far * key ) ;

Parameters

subkeys

[out]   Pointer to a Crypt_BlowfishKeyS structure to be initialized by this API.   The generated subkey arrays are written here.

len

[in]   Number of bytes key material provided at key.

key

[in]   This is the secret, typically some random data.

Return Value

0 constant (provisional error code)

Comments

This API performs some preprocessing on the key to generate the Blowfish subkey arrays based on the supplied key.   These subkey arrays will then be used by the Blowfish encryption and decryption API.

The amount of key material supplied may be any non-zero number of bytes.   Up to 72 bytes from these will be used for subkey generation.   Any additional key bytes will be ignored.

No presetting of the memory at subkeys is required by the caller.   This API fully initializes this block of memory with the Blowfish subkeys based on the provided key material.

The BLOWFISH cipher is the fastest cipher offered by the @CHIP-RTOS-x86 API.
And the variable size key range allows a larger key (more bits) then any of the other API.   The encryption/decryption speed can be significantly improved by allocating the Crypt_BlowfishKeyS object from the system's fast RAM heap area.

Go here for a summary of cipher method execution times.

See Also

Crypt_Blowfish_Decrypt        Crypt_Blowfish_Encrypt        

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