completed set 2 challenge 11

1 files changed, 46 insertions, 9 deletions

diff --git a/lib/lib2.c b/lib/lib2.c
index 49f7363..a28b7a5 100644
--- a/lib/lib2.c
+++ b/lib/lib2.c
@@ -59,7 +59,7 @@ int valid_pkcs7_padding(const char *in, int length_in, char *unpadded, int block
  * @param string_key key with which the content in in has been decrypted
  * @param iv initalization vector
  */
-int aes_cbc(char *in, int length_in, char *out, unsigned char *string_key, char *init_vector)
+int aes_cbc(char *in, int length_in, char *out, unsigned char *string_key, char *init_vector, int encrypt)
 {
 	char iv[16];
 	AES_KEY key;
@@ -69,22 +69,59 @@ int aes_cbc(char *in, int length_in, char *out, unsigned char *string_key, char
 	unsigned char tmp_after_aes[128+1];
 	unsigned char cleartext[128+1];
 	// set the key and bits
-	AES_set_decrypt_key(string_key, 128, &key);
+	if(encrypt)
+		AES_set_encrypt_key(string_key, 128, &key);
+	else
+		AES_set_decrypt_key(string_key, 128, &key);
 
 	memcpy(init_vector, iv, 16);
 
 	// implement cbc mode
 	for(i=0;i<number_blocks;i++) {
-		//do aes decryption
-		AES_decrypt(&in[i*16], tmp_after_aes, &key);
-		// xor
-		xor_string(iv, tmp_after_aes, &out[i*16], 16, 16);
-		// this ciphertext block is the next iv
-		for(j=0;j<16;j++) {
-			iv[j] = in[i*16+j];
+		if (!encrypt) {
+			//do aes decryption
+			AES_decrypt(&in[i*16], tmp_after_aes, &key);
+			// xor
+			xor_string(iv, tmp_after_aes, &out[i*16], 16, 16);
+			// this ciphertext block is the next iv
+			for(j=0;j<16;j++) {
+				iv[j] = in[i*16+j];
+			}
+		}
+		else {
+			// first xor
+			xor_string(iv, &in[i*16], tmp_after_aes, 16, 16);
+			// aes encrypt
+			AES_encrypt(tmp_after_aes, &out[i*16], &key);
+			// ciphertext is next iv
+			for(j=0;j<16;j++) {
+				iv[j] = out[i*16+j];
+			}
 		}
 	}
 
 	return 0;
 
 }
+
+int aes_ecb(char *in, int length_in, char *out, unsigned char *string_key,
+		int blocksize, int encrypt)
+{
+	AES_KEY key;
+	int number_blocks = length_in / blocksize;
+	int i;
+
+	if(encrypt)
+		AES_set_encrypt_key(string_key, blocksize, &key);
+	else
+		AES_set_decrypt_key(string_key, blocksize, &key);
+
+	for(i=0;i<number_blocks;i++) {
+		if(encrypt) {
+			AES_encrypt(&in[i*blocksize], &out[i*blocksize],&key);
+		}
+		else {
+			AES_decrypt(&in[i*blocksize], &out[i*blocksize],&key);
+		}
+	}
+}