- size_t mykeylen = cipher_keylength(&c->incipher);
- size_t hiskeylen = cipher_keylength(&c->outcipher);
-
- char *mykey;
- char *hiskey;
- char *seed;
-
- if(strcmp(myself->name, c->name) < 0) {
- mykey = key;
- hiskey = key + mykeylen * 2;
- xasprintf(&seed, "tinc TCP key expansion %s %s", myself->name, c->name);
- } else {
- mykey = key + hiskeylen * 2;
- hiskey = key;
- xasprintf(&seed, "tinc TCP key expansion %s %s", c->name, myself->name);
- }
-
- if(!prf(shared, ECDH_SHARED_SIZE, seed, strlen(seed), key, hiskeylen * 2 + mykeylen * 2))
- return false;
-
- free(seed);
-
- cipher_set_key(&c->incipher, mykey, false);
- digest_set_key(&c->indigest, mykey + mykeylen, mykeylen);
-
- cipher_set_key(&c->outcipher, hiskey, true);
- digest_set_key(&c->outdigest, hiskey + hiskeylen, hiskeylen);
-
- c->status.decryptin = true;
- c->status.encryptout = true;
- c->allow_request = CHALLENGE;
-
- return send_challenge(c);