ref: 9ff908d2e99557534056889b6673d7710c37a4c7
dir: /libsec/aesCBC.c/
#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 *p2, *ip, *eip; uchar q[AESbsize]; for(; len >= AESbsize; len -= AESbsize){ p2 = p; ip = s->ivec; for(eip = ip+AESbsize; ip < eip; ) *p2++ ^= *ip++; aes_encrypt(s->ekey, s->rounds, p, q); memmove(s->ivec, q, AESbsize); memmove(p, q, AESbsize); p += AESbsize; } if(len > 0){ ip = s->ivec; aes_encrypt(s->ekey, s->rounds, ip, q); memmove(s->ivec, q, AESbsize); for(eip = ip+len; ip < eip; ) *p++ ^= *ip++; } } void aesCBCdecrypt(uchar *p, int len, AESstate *s) { uchar *ip, *eip, *tp; uchar tmp[AESbsize], q[AESbsize]; for(; len >= AESbsize; len -= AESbsize){ memmove(tmp, p, AESbsize); aes_decrypt(s->dkey, s->rounds, p, q); memmove(p, q, AESbsize); tp = tmp; 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, q); memmove(s->ivec, q, AESbsize); for(eip = ip+len; ip < eip; ) *p++ ^= *ip++; } }