(module blowfish
	(blowfish-init make-blowfish-encryptor make-blowfish-decryptor)
	(import scheme chicken foreign)

#>
#include "blowfish/blowfish.c"
#define BLOWFISH_CTX_SIZE sizeof(BLOWFISH_CTX)
typedef unsigned long block_type;
<#

(define BLOWFISH-CTX-SIZE (foreign-value "BLOWFISH_CTX_SIZE" int))

(define c-blowfish-init
	(foreign-lambda* void ((scheme-pointer ctx) (scheme-pointer key) (int len))
	"Blowfish_Init(ctx,key,len);"))

(define c-blowfish-encrypt
        (foreign-lambda* void ((scheme-pointer ctx) (scheme-pointer input) (scheme-pointer result) (int offset))
	"block_type* in;
	block_type* out;
        in = (block_type*) ((char*)input + offset);
        out = (block_type*) ((char*)result + offset);
	out[0] = in[0];
	out[1] = in[1];
	Blowfish_Encrypt(ctx,&out[0],&out[1]);"))

(define c-blowfish-decrypt
        (foreign-lambda* void ((scheme-pointer ctx) (scheme-pointer input) (scheme-pointer result) (int offset))
	"block_type* in;
	block_type* out;
        in = (block_type*) ((char*)input + offset);
        out = (block_type*) ((char*)result + offset);
	out[0] = in[0];
	out[1] = in[1];
	Blowfish_Decrypt(ctx,&out[0],&out[1]);"))


(define (blowfish-init key len)
    (or (and (<= 4 len) (<= len 56))
        (error "blowfish invalid key length" len))
	(let ((ctx (make-blob BLOWFISH-CTX-SIZE)))
		(c-blowfish-init ctx key len)
		ctx))

(define (make-blowfish-encryptor key)
	(let ((ctx (blowfish-init key (blob-size key))))
                (lambda (input)
                  (let loop ((i 0)
                             (e (blob-size input))
                             (result (make-blob (blob-size input))))
                    (when (< i e)
                      (or
                        (<= 8 (- e i))
                        (error "blowfish invalid encryptor block size" (blob-size input)))
                      (c-blowfish-encrypt ctx input result i)
                      (loop (+ i 8) e result))
                    result))))

(define (make-blowfish-decryptor key)
	(let ((ctx (blowfish-init key (blob-size key))))
                (lambda (input)
                  (let loop ((i 0)
                             (e (blob-size input))
                             (result (make-blob (blob-size input))))
                    (when (< i e)
                      (or
                        (<= 8 (- e i))
                        (error "blowfish invalid decryptor block size" (blob-size input)))
                      (c-blowfish-decrypt ctx input result i)
                      (loop (+ i 8) e result))
                    result))))

);module blowfish