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server3.c (5423B)
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 #include "bloom.h"
10
11 int main(int ac, char **av){
12
13 setLogMode(LOG_FUNC);
14
15 if (not selInit()) ret 1;
16
17 // initialize bloomfilter for 45 million sessions, 10% false positive
18 struct bloom bloom;
19 u32 filterCount = 0;
20 bloom_init2(&bloom, 45000000, 0.1);
21
22 // generate id keys
23 newSignKeys();
24
25
26 // start event loop
27 int sock;
28 struct sockaddr_in server;
29 int mysock;
30 char buf[128*1024];
31 int rval;
32
33 sock = socket(AF_INET, SOCK_STREAM, 0);
34 if (sock < 0){
35 perror("Failed to create socket");
36 ret 1;
37 }
38
39 server.sin_family = AF_INET;
40 server.sin_addr.s_addr = INADDR_ANY;
41 server.sin_port = htons(5000);
42
43 if (bind(sock, (struct sockaddr *) &server, sizeof(server))){
44 perror("bind failed");
45 ret 1;
46 }
47
48 listen(sock, 5);
49
50 logI("Server started");
51 forever {
52 mysock = accept(sock, (struct sockaddr *)0, 0);
53 if (mysock == -1)
54 perror("accept failed");
55 else {
56
57 bool snd(void *buf, size_t sz) {
58 logVarG(sz);
59 if(send(mysock, buf, sz, 0) < 0){
60 perror("send failed");
61 close(mysock);
62 ret no;
63 }
64 ret yes;
65 }
66
67 bool rcv(void *buf, size_t sz) {
68 while (sz > 0) {
69 // TODO add timeout
70 rval = recv(mysock, buf, sz, MSG_WAITALL);
71 if (rval < 0) {
72 perror("reading message");
73 ret no;
74 }
75 else if (rval == 0) {
76 logI("Ending connection");
77 close(mysock);
78 ret no;
79 }
80 sz -= rval;
81 }
82 ret yes;
83 }
84
85 // public key for session
86 newKeys();
87 randombytes_buf(sessionKeys.nonce, sizeof(sessionKeys.nonce));
88
89 // store remote public key
90 u8 clientInfo[crypto_sign_BYTES + crypto_sign_PUBLICKEYBYTES + sizeof(keys.remotePublicKey)] = init0Var;
91 rcv(clientInfo, sizeof(clientInfo));
92
93 // check if the clientInfo is signed
94 bool is0 = yes;
95 range(i, crypto_sign_BYTES + crypto_sign_PUBLICKEYBYTES) {
96 if (clientInfo[i]) {
97 is0 = no;
98 break;
99 }
100 }
101
102 if (is0) {
103 logN("Client id not checked");
104 }
105 else {
106 // check client
107 // id key should already be known
108 u8 unsigned_message[crypto_sign_PUBLICKEYBYTES + sizeof(keys.remotePublicKey)] = init0Var;
109 unsigned long long unsigned_message_len;
110
111 if (crypto_sign_open(unsigned_message, &unsigned_message_len, clientInfo, sizeof(clientInfo), clientInfo + crypto_sign_BYTES) != 0) {
112 logE("Incorrect signature!");
113 }
114 else {
115 logP("Correct client signature");
116 }
117 }
118
119 memcpy(keys.remotePublicKey, clientInfo + crypto_sign_BYTES + crypto_sign_PUBLICKEYBYTES, sizeof(keys.remotePublicKey));
120
121 // check if key is in bloom filter
122 if (filterCount == bloom.entries) {
123 logD("Reseting bloom filter");
124 bloom_reset(&bloom);
125 filterCount = 0;
126 }
127 int bfr = bloom_check(&bloom, keys.remotePublicKey, sizeof(keys.remotePublicKey));
128 if (bfr == -1) {
129 logE("Bloom filter is not initialized");
130 }
131 elif (bfr == 1) {
132 logI("Client key already is already in bloom filter, request a new key");
133 }
134 elif (bfr == 0) {
135 // if not add it to the bloom filter
136 bloom_add(&bloom, keys.remotePublicKey, sizeof(keys.remotePublicKey));
137 inc filterCount;
138 }
139
140 logD("Remote public key");
141 loghex(keys.remotePublicKey, sizeof(keys.remotePublicKey));
142 put;
143
144 // send public key
145 u8 exchange[crypto_sign_PUBLICKEYBYTES + sizeof(keys.publicKey) + crypto_box_NONCEBYTES] = init0Var;
146 u8 signed_message[crypto_sign_BYTES + sizeof(exchange)] = init0Var;
147 unsigned long long signed_message_len = 0;
148
149 memcpy(exchange, identityKeys.publicKey, crypto_sign_PUBLICKEYBYTES);
150 memcpy(exchange + crypto_sign_PUBLICKEYBYTES, keys.publicKey, sizeof(keys.publicKey));
151 memcpy(exchange + crypto_sign_PUBLICKEYBYTES + sizeof(keys.publicKey), sessionKeys.nonce, sizeof(sessionKeys.nonce));
152
153 crypto_sign(signed_message, &signed_message_len, exchange, sizeof(exchange), identityKeys.secretKey);
154
155 if (!snd(signed_message, sizeof(signed_message))) continue;
156
157 // key exchange
158 if (not computeSharedKeys(SERVER_SESSION_KEYS)) {
159 logE("Invalid client key");
160 exit(1);
161 }
162
163 // get encrypted message
164 int len;
165 // *nonce is incremented by after sending or receiving a message
166 // *nonce is allowed to wrap from the max value
167 u64 *nonce = (u64*)sessionKeys.nonce;
168 if (!rcv(&len, sizeof(len))) continue;
169 rcv(buf, len);
170
171 u8 decrypted[1000];
172 logVarG(*nonce);
173 len = selDecrypt(decrypted, sizeof(decrypted), buf, len);
174 inc *nonce;
175
176 if (!len) {
177 logE("failed to decrypt");
178 close(mysock);
179 continue;
180 }
181
182 decrypted[len] = 0;
183
184 logI("decrypted: %s", decrypted);
185
186 // send encrypted response
187
188 char *msg = "OK";
189
190 logVarG(*nonce);
191 len = selEncrypt(buf, sizeof(buf), msg, strlen(msg));
192 inc *nonce;
193
194 logVarG(len);
195
196 snd(&len, sizeof(len));
197 snd(buf, len);
198
199 close(mysock);
200 }
201 }
202 bloom_free(&bloom);
203 }
204 // vim: set expandtab ts=2 sw=2: