ref: 941d146cea7d0c2ce872e599622a5c9e01d37fe2
dir: /net.c/
#include <u.h> #include <libc.h> #include <ip.h> #include <mp.h> #include <libsec.h> #include <thread.h> #include <draw.h> #include <geometry.h> #include "dat.h" #include "fns.h" /* DHX */ void dhgenpg(ulong *p, ulong *g) { static ulong P = 97; static ulong G = 71; *p = P; *g = G; } /* * y = g^k mod p */ ulong dhgenkey(ulong g, ulong k, ulong p) { ulong r, y; y = 1; while(k > 0){ r = k % 2; if(r == 1) y = y*g % p; g = g*g % p; k /= 2; } return y; } /* NetConn */ NetConn * newnetconn(NCState s, Udphdr *u) { NetConn *nc; nc = emalloc(sizeof(NetConn)); memset(nc, 0, sizeof(NetConn)); if(u != nil) memmove(&nc->udp, u, Udphdrsize); nc->state = s; return nc; } void delnetconn(NetConn *nc) { free(nc); } /* Frame */ Frame * newframe(Udphdr *hdr, u8int type, u32int seq, u32int ack, u16int len, uchar *data) { Frame *f; f = emalloc(sizeof(Frame)+len); memset(f, 0, sizeof(Frame)); if(hdr != nil) memmove(&f->udp, hdr, Udphdrsize); f->id = ProtocolID; f->type = type; f->seq = seq; f->ack = ack; f->len = len; if(data != nil) memmove(f->data, data, f->len); return f; } void signframe(Frame *f, ulong key) { uchar k[sizeof(ulong)]; uchar h[MD5dlen]; uchar msg[MTU]; int n; k[0] = key; k[1] = key>>8; k[2] = key>>16; k[3] = key>>24; memset(f->sig, 0, MD5dlen); n = pack(msg, sizeof msg, "f", f); hmac_md5(msg, n, k, sizeof k, h, nil); memmove(f->sig, h, MD5dlen); } int verifyframe(Frame *f, ulong key) { uchar k[sizeof(ulong)]; uchar h0[MD5dlen], h1[MD5dlen]; uchar msg[MTU]; int n; k[0] = key; k[1] = key>>8; k[2] = key>>16; k[3] = key>>24; memmove(h0, f->sig, MD5dlen); memset(f->sig, 0, MD5dlen); n = pack(msg, sizeof msg, "f", f); hmac_md5(msg, n, k, sizeof k, h1, nil); return memcmp(h0, h1, MD5dlen) == 0; } void delframe(Frame *f) { free(f); }