mvAesAlg.h File Reference

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Macros
#define	MAXBC   (128/32)
#define	MAXKC   (256/32)
#define	MAXROUNDS   14

Functions
int	rijndaelKeySched (MV_U8 k[4][MAXKC], int keyBits, int blockBits, MV_U8 rk[MAXROUNDS+1][4][MAXBC])
int	rijndaelEncrypt128 (MV_U8 a[4][MAXBC], MV_U8 rk[MAXROUNDS+1][4][MAXBC], int rounds)
int	rijndaelDecrypt128 (MV_U8 a[4][MAXBC], MV_U8 rk[MAXROUNDS+1][4][MAXBC], int rounds)

Macro Definition Documentation

MAXBC

#define MAXBC   (128/32)

Definition at line 9 of file mvAesAlg.h.

MAXKC

#define MAXKC   (256/32)

Definition at line 10 of file mvAesAlg.h.

MAXROUNDS

#define MAXROUNDS   14

Definition at line 11 of file mvAesAlg.h.

Function Documentation

rijndaelDecrypt128()

int rijndaelDecrypt128	(	MV_U8	a[4][MAXBC],
		MV_U8	rk[MAXROUNDS+1][4][MAXBC],
		int	rounds
	)

Definition at line 277 of file mvAesAlg.c.

{
    int r, BC, ROUNDS;
 
    BC = 4;
    ROUNDS = rounds;
 
    /* To decrypt: apply the inverse operations of the encrypt routine,
     *             in opposite order
     *
     * (KeyAddition is an involution: it 's equal to its inverse)
     * (the inverse of Substitution with table S is Substitution with the inverse table of S)
     * (the inverse of Shiftrow is Shiftrow over a suitable distance)
     */
 
        /* First the special round:
     *   without InvMixColumn
     *   with extra KeyAddition
     */
    KeyAddition(a,rk[ROUNDS],BC);
    ShiftRow128Dec(a);
    Substitution(a,Si);
 
    /* ROUNDS-1 ordinary rounds
     */
    for(r = ROUNDS-1; r > 0; r--) {
        KeyAddition(a,rk[r],BC);
        InvMixColumn(a);
        ShiftRow128Dec(a);
        Substitution(a,Si);
 
    }
 
    /* End with the extra key addition
     */
 
    KeyAddition(a,rk[0],BC);
 
    return 0;
}

rijndaelEncrypt128()

int rijndaelEncrypt128	(	MV_U8	a[4][MAXBC],
		MV_U8	rk[MAXROUNDS+1][4][MAXBC],
		int	rounds
	)

Definition at line 244 of file mvAesAlg.c.

{
    /* Encryption of one block.
     */
    int r, BC, ROUNDS;
 
    BC = 4;
    ROUNDS = rounds;
 
    /* begin with a key addition
     */
 
    KeyAddition(a,rk[0],BC);
 
    /* ROUNDS-1 ordinary rounds
     */
    for(r = 1; r < ROUNDS; r++) {
        Substitution(a,S);
        ShiftRow128Enc(a);
        MixColumn(a, rk[r]);
        /*KeyAddition(a,rk[r],BC);*/
    }
 
    /* Last round is special: there is no MixColumn
     */
    Substitution(a,S);
    ShiftRow128Enc(a);
    KeyAddition(a,rk[ROUNDS],BC);
 
    return 0;
}

rijndaelKeySched()

int rijndaelKeySched	(	MV_U8	k[4][MAXKC],
		int	keyBits,
		int	blockBits,
		MV_U8	rk[MAXROUNDS+1][4][MAXBC]
	)

Definition at line 179 of file mvAesAlg.c.

{
    /* Calculate the necessary round keys
     * The number of calculations depends on keyBits and blockBits
     */
    int KC, BC, ROUNDS;
    int i, j, t, rconpointer = 0;
    MV_U8 tk[4][MAXKC];
 
    switch (keyBits) {
    case 128: KC = 4; break;
    case 192: KC = 6; break;
    case 256: KC = 8; break;
    default : return (-1);
    }
 
    switch (blockBits) {
    case 128: BC = 4; break;
    case 192: BC = 6; break;
    case 256: BC = 8; break;
    default : return (-2);
    }
 
    switch (keyBits >= blockBits ? keyBits : blockBits) {
    case 128: ROUNDS = 10; break;
    case 192: ROUNDS = 12; break;
    case 256: ROUNDS = 14; break;
    default : return (-3); /* this cannot happen */
    }
 
 
    for(j = 0; j < KC; j++)
        for(i = 0; i < 4; i++)
            tk[i][j] = k[i][j];
    t = 0;
    /* copy values into round key array */
    for(j = 0; (j < KC) && (t < (ROUNDS+1)*BC); j++, t++)
        for(i = 0; i < 4; i++) W[t / BC][i][t % BC] = tk[i][j];
 
    while (t < (ROUNDS+1)*BC) { /* while not enough round key material calculated */
        /* calculate new values */
        for(i = 0; i < 4; i++)
            tk[i][0] ^= S[tk[(i+1)%4][KC-1]];
        tk[0][0] ^= rcon[rconpointer++];
 
        if (KC != 8)
            for(j = 1; j < KC; j++)
                for(i = 0; i < 4; i++) tk[i][j] ^= tk[i][j-1];
        else {
            for(j = 1; j < KC/2; j++)
                for(i = 0; i < 4; i++) tk[i][j] ^= tk[i][j-1];
            for(i = 0; i < 4; i++) tk[i][KC/2] ^= S[tk[i][KC/2 - 1]];
            for(j = KC/2 + 1; j < KC; j++)
                for(i = 0; i < 4; i++) tk[i][j] ^= tk[i][j-1];
    }
    /* copy values into round key array */
    for(j = 0; (j < KC) && (t < (ROUNDS+1)*BC); j++, t++)
        for(i = 0; i < 4; i++) W[t / BC][i][t % BC] = tk[i][j];
    }
 
    return 0;
}