Subversion Repositories planix.SVN

#include "os.h"
#include <libsec.h>

/*
 * Define by analogy with desCBCencrypt;  AES modes are not standardized yet.
 * Because of the way that non-multiple-of-16 buffers are handled,
 * the decryptor must be fed buffers of the same size as the encryptor.
 */
void
aesCBCencrypt(uchar *p, int len, AESstate *s)
{
        uchar *ip, *eip;

        if(((p-(uchar*)0) & 3) == 0){
                for(; len >= AESbsize; len -= AESbsize){
                        ip = s->ivec;
                        ((u32int*)ip)[0] ^= ((u32int*)p)[0];
                        ((u32int*)ip)[1] ^= ((u32int*)p)[1];
                        ((u32int*)ip)[2] ^= ((u32int*)p)[2];
                        ((u32int*)ip)[3] ^= ((u32int*)p)[3];

                        aes_encrypt(s->ekey, s->rounds, ip, ip);

                        ((u32int*)p)[0] = ((u32int*)ip)[0];
                        ((u32int*)p)[1] = ((u32int*)ip)[1];
                        ((u32int*)p)[2] = ((u32int*)ip)[2];
                        ((u32int*)p)[3] = ((u32int*)ip)[3];
                        p += AESbsize;
                }
        } else {
                for(; len >= AESbsize; len -= AESbsize){
                        ip = s->ivec;
                        for(eip = ip+AESbsize; ip < eip; )
                                *ip++ ^= *p++;
                        aes_encrypt(s->ekey, s->rounds, s->ivec, s->ivec);
                        memmove(p - AESbsize, s->ivec, AESbsize);
                }
        }

        if(len > 0){
                ip = s->ivec;
                aes_encrypt(s->ekey, s->rounds, ip, ip);
                for(eip = ip+len; ip < eip; )
                        *p++ ^= *ip++;
        }
}

void
aesCBCdecrypt(uchar *p, int len, AESstate *s)
{
        uchar *ip, *eip, *tp;
        u32int t[4];

        if(((p-(uchar*)0) & 3) == 0){
                for(; len >= AESbsize; len -= AESbsize){
                        t[0] = ((u32int*)p)[0];
                        t[1] = ((u32int*)p)[1];
                        t[2] = ((u32int*)p)[2];
                        t[3] = ((u32int*)p)[3];

                        aes_decrypt(s->dkey, s->rounds, p, p);

                        ip = s->ivec;
                        ((u32int*)p)[0] ^= ((u32int*)ip)[0];
                        ((u32int*)p)[1] ^= ((u32int*)ip)[1];
                        ((u32int*)p)[2] ^= ((u32int*)ip)[2];
                        ((u32int*)p)[3] ^= ((u32int*)ip)[3];
                        p += AESbsize;

                        ((u32int*)ip)[0] = t[0];
                        ((u32int*)ip)[1] = t[1];
                        ((u32int*)ip)[2] = t[2];
                        ((u32int*)ip)[3] = t[3];
                }
        } else {
                for(; len >= AESbsize; len -= AESbsize){
                        tp = (uchar*)t;
                        memmove(tp, p, AESbsize);
                        aes_decrypt(s->dkey, s->rounds, p, p);
                        ip = s->ivec;
                        for(eip = ip+AESbsize; ip < eip; ){
                                *p++ ^= *ip;
                                *ip++ = *tp++;
                        }
                }
        }

        if(len > 0){
                ip = s->ivec;
                aes_encrypt(s->ekey, s->rounds, ip, ip);
                for(eip = ip+len; ip < eip; )
                        *p++ ^= *ip++;
        }
}