/* rijndael-api-ref.c   v2.0   August '99
 * Reference ANSI C code
 * authors: Paulo Barreto
 *          Vincent Rijmen
 */
/*
                        ------------------------------
                        Rijndael ANSI C Reference Code
                        ------------------------------

                                October 24, 2000

                                  Disclaimer


This software package was submitted to the National Institute of Standards and
Technology (NIST) during the Advanced Encryption Standard (AES) development
effort by Joan Daemen and Vincent Rijmen, the developers of the Rijndael algorithm.

This software is distributed in compliance with export regulations (see below), and
it is intended for non-commercial use, only.   NIST does not support this software 
and does not provide any guarantees or warranties as to its performance, fitness 
for any particular application, or validation under the Cryptographic Module
Validation Program (CMVP) <http://csrc.nist.gov/cryptval/>.  NIST does not accept 
any liability associated with its use or misuse.  This software is provided as-is. 
By accepting this software the user agrees to the terms stated herein.

                            -----------------------

                              Export Restrictions


Implementations of cryptography are subject to United States Federal
Government export controls.  Export controls on commercial encryption products 
are administered by the Bureau of Export Administration (BXA) 
<http://www.bxa.doc.gov/Encryption/> in the U.S. Department of Commerce. 
Regulations governing exports of encryption are found in the Export 
Administration Regulations (EAR), 15 C.F.R. Parts 730-774.
*/

#include <stdlib.h>
#include <string.h>

#include "rijndael-alg-ref.h"
#include "rijndael-api-ref.h"


int makeKey(keyInstance *key, BYTE direction, int keyLen, char *keyMaterial)
{
	word8 k[4][MAXKC];
	int i, j, t;
	
	if (key == NULL) {
		return BAD_KEY_INSTANCE;
	}

	if ((direction == DIR_ENCRYPT) || (direction == DIR_DECRYPT)) {
		key->direction = direction;
	} else {
		return BAD_KEY_DIR;
	}

	if ((keyLen == 128) || (keyLen == 192) || (keyLen == 256)) { 
		key->keyLen = keyLen;
	} else {
		return BAD_KEY_MAT;
	}

	if ( keyMaterial ) {
		strncpy(key->keyMaterial, keyMaterial, keyLen/4);
	}

	/* initialize key schedule: */ 
 	for(i = 0; i < key->keyLen/8; i++) {
		t = key->keyMaterial[2*i];
		if ((t >= '0') && (t <= '9')) j = (t - '0') << 4;
		else if ((t >= 'a') && (t <= 'f')) j = (t - 'a' + 10) << 4; 
		else if ((t >= 'A') && (t <= 'F')) j = (t - 'A' + 10) << 4; 
		else return BAD_KEY_MAT;
		
		t = key->keyMaterial[2*i+1];
		if ((t >= '0') && (t <= '9')) j ^= (t - '0');
		else if ((t >= 'a') && (t <= 'f')) j ^= (t - 'a' + 10); 
		else if ((t >= 'A') && (t <= 'F')) j ^= (t - 'A' + 10); 
		else return BAD_KEY_MAT;
		
		k[i % 4][i / 4] = (word8) j; 
	}	
	
	rijndaelKeySched (k, key->keyLen, key->blockLen, key->keySched);
	
	return TRUE;
}

int cipherInit(cipherInstance *cipher, BYTE mode, char *IV)
{
	int i, j, t;
	
	if ((mode == MODE_ECB) || (mode == MODE_CBC) || (mode == MODE_CFB1)) {
		cipher->mode = mode;
	} else {
		return BAD_CIPHER_MODE;
	}
	
	if (IV != NULL) {
 		for(i = 0; i < cipher->blockLen/8; i++) {		
			t = IV[2*i];
			if ((t >= '0') && (t <= '9')) j = (t - '0') << 4;
			else if ((t >= 'a') && (t <= 'f')) j = (t - 'a' + 10) << 4; 
			else if ((t >= 'A') && (t <= 'F')) j = (t - 'A' + 10) << 4; 
			else return BAD_CIPHER_INSTANCE;
		
			t = IV[2*i+1];
			if ((t >= '0') && (t <= '9')) j ^= (t - '0');
			else if ((t >= 'a') && (t <= 'f')) j ^= (t - 'a' + 10); 
			else if ((t >= 'A') && (t <= 'F')) j ^= (t - 'A' + 10); 
			else return BAD_CIPHER_INSTANCE;
			
			cipher->IV[i] = (BYTE) j;
		} 
	}

	return TRUE;
}


int blockEncrypt(cipherInstance *cipher,
	keyInstance *key, BYTE *input, int inputLen, BYTE *outBuffer)
{
	int i, j, t, numBlocks;
	word8 block[4][MAXBC];

	
        /* check parameter consistency: */
        if (key == NULL ||
                key->direction != DIR_ENCRYPT ||
                (key->keyLen != 128 && key->keyLen != 192 && key->keyLen != 256)) {
                return BAD_KEY_MAT;
        }
        if (cipher == NULL ||
                (cipher->mode != MODE_ECB && cipher->mode != MODE_CBC && cipher->mode != MODE_CFB1) ||
                (cipher->blockLen != 128 && cipher->blockLen != 192 && cipher->blockLen != 256)) {
                return BAD_CIPHER_STATE;
        }


	numBlocks = inputLen/cipher->blockLen;
	
	switch (cipher->mode) {
	case MODE_ECB: 
		for (i = 0; i < numBlocks; i++) {
			for (j = 0; j < cipher->blockLen/32; j++) {
				for(t = 0; t < 4; t++)
				/* parse input stream into rectangular array */
					block[t][j] = input[4*j+t] & 0xFF;
			}
			rijndaelEncrypt (block, key->keyLen, cipher->blockLen, key->keySched);
			for (j = 0; j < cipher->blockLen/32; j++) {
				/* parse rectangular array into output ciphertext bytes */
				for(t = 0; t < 4; t++)
					outBuffer[4*j+t] = (BYTE) block[t][j];
			}
		}
		break;
		
	case MODE_CBC:
		for (j = 0; j < cipher->blockLen/32; j++) {
			for(t = 0; t < 4; t++)
			/* parse initial value into rectangular array */
					block[t][j] = cipher->IV[t+4*j] & 0xFF;
			}
		for (i = 0; i < numBlocks; i++) {
			for (j = 0; j < cipher->blockLen/32; j++) {
				for(t = 0; t < 4; t++)
				/* parse input stream into rectangular array and exor with 
				   IV or the previous ciphertext */
					block[t][j] ^= input[4*j+t] & 0xFF;
			}
			rijndaelEncrypt (block, key->keyLen, cipher->blockLen, key->keySched);
			for (j = 0; j < cipher->blockLen/32; j++) {
				/* parse rectangular array into output ciphertext bytes */
				for(t = 0; t < 4; t++)
					outBuffer[4*j+t] = (BYTE) block[t][j];
			}
		}
		break;
	
	default: return BAD_CIPHER_STATE;
	}
	
	return numBlocks*cipher->blockLen;
}

int blockDecrypt(cipherInstance *cipher,
	keyInstance *key, BYTE *input, int inputLen, BYTE *outBuffer)
{
	int i, j, t, numBlocks;
	word8 block[4][MAXBC];

	if (cipher == NULL ||
		key == NULL ||
		key->direction == DIR_ENCRYPT ||
		cipher->blockLen != key->blockLen) {
		return BAD_CIPHER_STATE;
	}

        /* check parameter consistency: */
        if (key == NULL ||
                key->direction != DIR_DECRYPT ||
                (key->keyLen != 128 && key->keyLen != 192 && key->keyLen != 256)) {
                return BAD_KEY_MAT;
        }
        if (cipher == NULL ||
                (cipher->mode != MODE_ECB && cipher->mode != MODE_CBC && cipher->mode != MODE_CFB1) ||
                (cipher->blockLen != 128 && cipher->blockLen != 192 && cipher->blockLen != 256)) {
                return BAD_CIPHER_STATE;
        }
	

	numBlocks = inputLen/cipher->blockLen;
	
	switch (cipher->mode) {
	case MODE_ECB: 
		for (i = 0; i < numBlocks; i++) {
			for (j = 0; j < cipher->blockLen/32; j++) {
				for(t = 0; t < 4; t++)
				/* parse input stream into rectangular array */
					block[t][j] = input[4*j+t] & 0xFF;
			}
			rijndaelDecrypt (block, key->keyLen, cipher->blockLen, key->keySched);
			for (j = 0; j < cipher->blockLen/32; j++) {
				/* parse rectangular array into output ciphertext bytes */
				for(t = 0; t < 4; t++)
					outBuffer[4*j+t] = (BYTE) block[t][j];
			}
		}
		break;
		
	case MODE_CBC:
		/* first block */
		for (j = 0; j < cipher->blockLen/32; j++) {
			for(t = 0; t < 4; t++)
			/* parse input stream into rectangular array */
				block[t][j] = input[4*j+t] & 0xFF;
		}
		rijndaelDecrypt (block, key->keyLen, cipher->blockLen, key->keySched);
		
		for (j = 0; j < cipher->blockLen/32; j++) {
			/* exor the IV and parse rectangular array into output ciphertext bytes */
			for(t = 0; t < 4; t++)
				outBuffer[4*j+t] = (BYTE) (block[t][j] ^ cipher->IV[t+4*j]);
		}
		
		/* next blocks */
		for (i = 1; i < numBlocks; i++) {
			for (j = 0; j < cipher->blockLen/32; j++) {
				for(t = 0; t < 4; t++)
				/* parse input stream into rectangular array */
					block[t][j] = input[cipher->blockLen/8+4*j+t] & 0xFF;
			}
			rijndaelDecrypt (block, key->keyLen, cipher->blockLen, key->keySched);
			
			for (j = 0; j < cipher->blockLen/32; j++) {
				/* exor previous ciphertext block and parse rectangular array 
				       into output ciphertext bytes */
				for(t = 0; t < 4; t++)
					outBuffer[cipher->blockLen/8+4*j+t] = (BYTE) (block[t][j] ^ 
						input[4*j+t-4*cipher->blockLen/32]);
			}
		}
		break;
	
	default: return BAD_CIPHER_STATE;
	}
	
	return numBlocks*cipher->blockLen;
}


/**
 *	cipherUpdateRounds:
 *
 *	Encrypts/Decrypts exactly one full block a specified number of rounds.
 *	Only used in the Intermediate Value Known Answer Test.	
 *
 *	Returns:
 *		TRUE - on success
 *		BAD_CIPHER_STATE - cipher in bad state (e.g., not initialized)
 */
int cipherUpdateRounds(cipherInstance *cipher,
	keyInstance *key, BYTE *input, int inputLen, BYTE *outBuffer, int rounds)
{
	int j, t;
	word8 block[4][MAXBC];

	if (cipher == NULL ||
		key == NULL ||
		cipher->blockLen != key->blockLen) {
		return BAD_CIPHER_STATE;
	}

	for (j = 0; j < cipher->blockLen/32; j++) {
		for(t = 0; t < 4; t++)
			/* parse input stream into rectangular array */
			block[t][j] = input[4*j+t] & 0xFF;
	}
	switch (key->direction) {
	case DIR_ENCRYPT:
		rijndaelEncryptRound (block, key->keyLen, cipher->blockLen, 
				key->keySched, rounds);
	break;
		
	case DIR_DECRYPT:
		rijndaelDecryptRound (block, key->keyLen, cipher->blockLen, 
				key->keySched, rounds);
	break;
		
	default: return BAD_KEY_DIR;
	} 
	for (j = 0; j < cipher->blockLen/32; j++) {
		/* parse rectangular array into output ciphertext bytes */
		for(t = 0; t < 4; t++)
			outBuffer[4*j+t] = (BYTE) block[t][j];
	}
	
	return TRUE;
}