Crypto API

[inferno_gogo]

Hi there,
I am working on a homework that has to do with encryption. I want to be able to encrypt a string of characters. I have been reading about the Crypto API over the last few days, and I managed to get some code, but It doesn't work properly. This is just a test, once I know its working I will added it to the rest of my code. Here I am setting a password, encrypting a string, decrypting and then I expect to see the same string, but It doesn't work out.

        char me[5] = "nice";    // set the password
	struct crypto_tfm *tfm;    // crypto pointer
	struct scatterlist src, dst, dst2;
	char str1[5] = "whic";
	char str2[5];
	char str3[5];
	
	src.page = virt_to_page(str1);
	src.offset = offset_in_page(str1);
	src.length = 5;
	
	dst.page = virt_to_page(str2);
	dst.offset = offset_in_page(str2);
	dst.length = 5;
	
	dst2.page = virt_to_page(str3);
	dst2.offset = offset_in_page(str3);
	dst2.length = 5;
	
	tfm = crypto_alloc_tfm("blowfish", CRYPTO_TFM_MODE_ECB);   // initialize with blowfish
	crypto_cipher_setkey(tfm, me, 4);    // set the key
	crypto_cipher_encrypt(tfm, &dst, &src, 1); // (tfm, dest, source)
	crypto_cipher_decrypt(tfm, &dst2, &dst, 1); // (tfm, dest, source)
	crypto_free_tfm(tfm);
	
	*(str1+4) = '\0';
 	*(str2+4) = '\0';
 	*(str3+4) = '\0';
 	printk("%s\n",str1);
 	printk("%s\n",str2);
 	printk("%s\n",str3);

Any suggestions on what I might be doing wrong?

Thank you,

-George

[Skvr]

tfm = crypto_alloc_tfm("blowfish", CRYPTO_TFM_MODE_ECB); // initialize with blowfish


Haven´t tested this or nothing just throwing a couple of thoughts in the air.

Is tfm really initialized with blowfish, maybe a check would be good?

Isn´t the ECB automatically be used with blowfish, how about :
tfm=crypto_alloc_tfm("blowfish,0");

Also is crypto_cipher_setkey(tfm, me, 4); returning succesfully value.?

I know that you are testing things at this point, but ain´t it important to check is something being successfully initialized to see is everything going as planned.