6 void cookie(hash,key,keylen,date,addr,action)
16 unsigned char out[32];
21 step 1: create seed from key. note that this doesn't have to be
22 cryptographic; it simply has to avoid destroying the user's entropy.
23 if speed turns out to be a problem, switch to a CRC.
25 for (i = 0;i < 32;++i) seed[i] = 0;
26 for (j = 0;j < 4;++j) {
27 surfpcs_init(&s,seed);
28 surfpcs_add(&s,key,keylen);
30 for (i = 0;i < 32;++i) seed[i] = (seed[i] << 8) + out[i];
36 surfpcs_init(&s,seed);
37 surfpcs_add(&s,date,str_len(date) + 1);
38 surfpcs_add(&s,addr,str_len(addr) + 1);
39 surfpcs_add(&s,action,1);
43 step 3: extract a readable cookie from the SURF output.
45 for (i = 0;i < 20;++i)
46 hash[i] = 'a' + (out[i] & 15);