server2.c (4577B)
1 #! /usr/bin/env sheepy
2
3 #include "libsheepyObject.h"
4
5 #include <sys/socket.h>
6 #include <netinet/in.h>
7
8 #include "sel.h"
9
10 int main(int ac, char **av){
11
12 setLogMode(LOG_FUNC);
13
14 if (not selInit()) ret 1;
15
16 // generate id keys
17 newSignKeys();
18
19
20 // start event loop
21 int sock;
22 struct sockaddr_in server;
23 int mysock;
24 char buf[128*1024];
25 int rval;
26
27 sock = socket(AF_INET, SOCK_STREAM, 0);
28 if (sock < 0){
29 perror("Failed to create socket");
30 ret 1;
31 }
32
33 server.sin_family = AF_INET;
34 server.sin_addr.s_addr = INADDR_ANY;
35 server.sin_port = htons(5000);
36
37 if (bind(sock, (struct sockaddr *) &server, sizeof(server))){
38 perror("bind failed");
39 ret 1;
40 }
41
42 listen(sock, 5);
43
44 logI("Server started");
45 forever {
46 mysock = accept(sock, (struct sockaddr *)0, 0);
47 if (mysock == -1)
48 perror("accept failed");
49 else {
50
51 bool snd(void *buf, size_t sz) {
52 logVarG(sz);
53 if(send(mysock, buf, sz, 0) < 0){
54 perror("send failed");
55 close(mysock);
56 ret no;
57 }
58 ret yes;
59 }
60
61 bool rcv(void *buf, size_t sz) {
62 while (sz > 0) {
63 // TODO add timeout
64 rval = recv(mysock, buf, sz, MSG_WAITALL);
65 if (rval < 0) {
66 perror("reading message");
67 ret no;
68 }
69 else if (rval == 0) {
70 logI("Ending connection");
71 close(mysock);
72 ret no;
73 }
74 sz -= rval;
75 }
76 ret yes;
77 }
78
79 // public key for session
80 newKeys();
81 randombytes_buf(sessionKeys.nonce, sizeof(sessionKeys.nonce));
82
83 // store remote public key
84 u8 clientInfo[crypto_sign_BYTES + crypto_sign_PUBLICKEYBYTES + sizeof(keys.remotePublicKey)] = init0Var;
85 rcv(clientInfo, sizeof(clientInfo));
86
87 // check if the clientInfo is signed
88 bool is0 = yes;
89 range(i, crypto_sign_BYTES + crypto_sign_PUBLICKEYBYTES) {
90 if (clientInfo[i]) {
91 is0 = no;
92 break;
93 }
94 }
95
96 if (is0) {
97 logN("Client id not checked");
98 }
99 else {
100 // check client
101 // id key should already be known
102 u8 unsigned_message[crypto_sign_PUBLICKEYBYTES + sizeof(keys.remotePublicKey)] = init0Var;
103 unsigned long long unsigned_message_len;
104
105 if (crypto_sign_open(unsigned_message, &unsigned_message_len, clientInfo, sizeof(clientInfo), clientInfo + crypto_sign_BYTES) != 0) {
106 logE("Incorrect signature!");
107 }
108 else {
109 logP("Correct client signature");
110 }
111 }
112
113 memcpy(keys.remotePublicKey, clientInfo + crypto_sign_BYTES + crypto_sign_PUBLICKEYBYTES, sizeof(keys.remotePublicKey));
114
115 logD("Remote public key");
116 loghex(keys.remotePublicKey, sizeof(keys.remotePublicKey));
117 put;
118
119 // send public key
120 u8 exchange[crypto_sign_PUBLICKEYBYTES + sizeof(keys.publicKey) + crypto_box_NONCEBYTES] = init0Var;
121 u8 signed_message[crypto_sign_BYTES + sizeof(exchange)] = init0Var;
122 unsigned long long signed_message_len = 0;
123
124 memcpy(exchange, identityKeys.publicKey, crypto_sign_PUBLICKEYBYTES);
125 memcpy(exchange + crypto_sign_PUBLICKEYBYTES, keys.publicKey, sizeof(keys.publicKey));
126 memcpy(exchange + crypto_sign_PUBLICKEYBYTES + sizeof(keys.publicKey), sessionKeys.nonce, sizeof(sessionKeys.nonce));
127
128 crypto_sign(signed_message, &signed_message_len, exchange, sizeof(exchange), identityKeys.secretKey);
129
130 if (!snd(signed_message, sizeof(signed_message))) continue;
131
132 // key exchange
133 if (not computeSharedKeys(SERVER_SESSION_KEYS)) {
134 logE("Invalid client key");
135 exit(1);
136 }
137
138 // get encrypted message
139 int len;
140 // *nonce is incremented by after sending or receiving a message
141 // *nonce is allowed to wrap from the max value
142 u64 *nonce = (u64*)sessionKeys.nonce;
143 if (!rcv(&len, sizeof(len))) continue;
144 rcv(buf, len);
145
146 u8 decrypted[1000];
147 logVarG(*nonce);
148 len = selDecrypt(decrypted, sizeof(decrypted), buf, len);
149 inc *nonce;
150
151 if (!len) {
152 logE("failed to decrypt");
153 close(mysock);
154 continue;
155 }
156
157 decrypted[len] = 0;
158
159 logI("decrypted: %s", decrypted);
160
161 // send encrypted response
162
163 char *msg = "OK";
164
165 logVarG(*nonce);
166 len = selEncrypt(buf, sizeof(buf), msg, strlen(msg));
167 inc *nonce;
168
169 logVarG(len);
170
171 snd(&len, sizeof(len));
172 snd(buf, len);
173
174 close(mysock);
175 }
176 }
177 }
178 // vim: set expandtab ts=2 sw=2: