ref: 49bd8a86f3a07c4f54df94838c07fa653d725afa
dir: /sys/src/libsec/port/desCBC.c/
#include "os.h" #include <libsec.h> // Because of the way that non multiple of 8 // buffers are handled, the decryptor must // be fed buffers of the same size as the // encryptor // If the length is not a multiple of 8, I encrypt // the overflow to be compatible with lacy's cryptlib void desCBCencrypt(uchar *p, int len, DESstate *s) { uchar *p2, *ip, *eip; for(; len >= 8; len -= 8){ p2 = p; ip = s->ivec; for(eip = ip+8; ip < eip; ) *p2++ ^= *ip++; block_cipher(s->expanded, p, 0); memmove(s->ivec, p, 8); p += 8; } if(len > 0){ ip = s->ivec; block_cipher(s->expanded, ip, 0); for(eip = ip+len; ip < eip; ) *p++ ^= *ip++; } } void desCBCdecrypt(uchar *p, int len, DESstate *s) { uchar *ip, *eip, *tp; uchar tmp[8]; for(; len >= 8; len -= 8){ memmove(tmp, p, 8); block_cipher(s->expanded, p, 1); tp = tmp; ip = s->ivec; for(eip = ip+8; ip < eip; ){ *p++ ^= *ip; *ip++ = *tp++; } } if(len > 0){ ip = s->ivec; block_cipher(s->expanded, ip, 0); for(eip = ip+len; ip < eip; ) *p++ ^= *ip++; } }