Cryptographic Token Interface Standard

PKCS#11

Blowfish -CBC

Blowfish-CBC, denoted CKM_BLOWFISH_CBC, is a mechanism for single- and multiple-part encryption and decryption; key wrapping; and key unwrapping.

It has a parameter, a 8-byte initialization vector.

This mechanism can wrap and unwrap any secret key. For wrapping, the mechanism encrypts the value of the CKA_VALUE attribute of the key that is wrapped, padded on the trailing end with up to block size minus one null bytes so that the resulting length is a multiple of the block size. The output data is the same length as the padded input data. It does not wrap the key type, key length, or any other information about the key; the application must convey these separately.

For unwrapping, the mechanism decrypts the wrapped key, and truncates the result according to the CKA_KEY_TYPE attribute of the template and, if it has one, and the key type supports it, the CKA_VALUE_LEN attribute of the template. The mechanism contributes the result as the CKA_VALUE attribute of the new key; other attributes required by the key type must be specified in the template.

Constraints on key types and the length of data are summarized in the following table: 




 Table 22, BLOWFISH-CBC: Key And Data Length   
Function  Key type  

Input lenght 

 

Output lenght 

   


C_Encrypt BLOWFISH 

multiple of block size

 

same as input length

   


C_Decrypt BLOWFISH 

multiple of block size

 

same as input length

   


C_WrapKey BLOWFISH 

any

 

input length rounded up to multiple of the block size 

    


C_UnwrapKey BLOWFISH 

multiple of block size

 

determined by type of key being unwrapped or CKA_VALUE_LEN

  

 



For this mechanism, the ulMinKeySize and ulMaxKeySize fields of the CK_MECHANISM_INFO  structure specify the supported range of BLOWFISH key sizes, in bytes.


 
 



RSA Security Inc. Public-Key Cryptography Standards - 
PKCS#11 - v230