[Mcrypt-modules] pmp5 mcrypt with 64 bit key issue

[kelly <ke...@se...>]

Hi,

 

This problem has been driving us crazy:

 

We are having trouble with interoperability when decrypting using
php5-mcrypt blowfish cbc with a 64 bit key(iv is 64 bits also), where the
encrypted data was encrypted using open ssl c libraries with blowfish cbc on
a centos5 box with the same 64 bit key and iv. 

 

Basically, encrypting the same data with the same 64bit key using both of
the libraries above(mcrypt php & open ssl c libraries) produces wildly
different encrypted data.

 

However, with a 128 bit key versus a 64 bit key(same 64 bit iv) on both
sides(php-mcrypt & openssl), they DO produce the same encrypted data.

 

Fyi: with the 64 bit key, each of these platforms can decrypt it own
encrypted data just fine. Also, we have tried this using the libmcrypt
2.5.8. 

 

We are stuck with using a 64 bit key on the system that uses the openssl
blowfish libraries to encrypt the data that the php script needs to decrypt
with mcrypt.

 

Could anyone provide insight or suggestions on how to solve the problem.

 

Thanks,

Bob C.