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server4.c (3876B)
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 // public key
19 newKeys();
20
21
22 const char* clientPublicFilename = "client4Public.bin";
23 u8 knownClientPublicKey[crypto_box_PUBLICKEYBYTES];
24 if (isPath(clientPublicFilename)) {
25 logI("Server found known client session key");
26 pError0(bLReadFile(clientPublicFilename, knownClientPublicKey, sizeof(knownClientPublicKey)));
27 }
28 else {
29 logE("known client key not found, run client4.c once before starting the server");
30 }
31
32
33 // start event loop
34 int sock;
35 struct sockaddr_in server;
36 int mysock;
37 char buf[128*1024];
38 int rval;
39
40 sock = socket(AF_INET, SOCK_STREAM, 0);
41 if (sock < 0){
42 perror("Failed to create socket");
43 ret 1;
44 }
45
46 server.sin_family = AF_INET;
47 server.sin_addr.s_addr = INADDR_ANY;
48 server.sin_port = htons(5000);
49
50 if (bind(sock, (struct sockaddr *) &server, sizeof(server))){
51 perror("bind failed");
52 ret 1;
53 }
54
55 listen(sock, 5);
56
57 logI("Server started");
58 forever {
59 mysock = accept(sock, (struct sockaddr *)0, 0);
60 if (mysock == -1)
61 perror("accept failed");
62 else {
63
64 bool snd(void *buf, size_t sz) {
65 logVarG(sz);
66 if(send(mysock, buf, sz, 0) < 0){
67 perror("send failed");
68 close(mysock);
69 ret no;
70 }
71 ret yes;
72 }
73
74 bool rcv(void *buf, size_t sz) {
75 while (sz > 0) {
76 // TODO add timeout
77 rval = recv(mysock, buf, sz, MSG_WAITALL);
78 if (rval < 0) {
79 perror("reading message");
80 ret no;
81 }
82 else if (rval == 0) {
83 logI("Ending connection");
84 close(mysock);
85 ret no;
86 }
87 sz -= rval;
88 }
89 ret yes;
90 }
91
92 // store remote public key
93 u8 clientInfo[1 + sizeof(keys.remotePublicKey) + sizeof(keys.nonce)] = init0Var;
94 rcv(clientInfo, sizeof(clientInfo));
95
96 // check if client public key is known
97 if (memcmp(knownClientPublicKey, clientInfo +1, sizeof(knownClientPublicKey))) {
98 logE("unknown client");
99 }
100
101 memcpy(keys.remotePublicKey, clientInfo + 1, sizeof(keys.remotePublicKey));
102 memcpy(keys.nonce, clientInfo + 1 + sizeof(keys.remotePublicKey), sizeof(keys.nonce));
103
104 logD("Remote public key");
105 loghex(keys.remotePublicKey, sizeof(keys.remotePublicKey));
106 put;
107
108 // send public key
109 if (clientInfo[0] == 0) {
110 logD("command 0 - send server public key");
111 u8 exchange[sizeof(keys.publicKey)] = init0Var;
112 memcpy(exchange, keys.publicKey, sizeof(keys.publicKey));
113 if (!snd(exchange, sizeof(exchange))) continue;
114 }
115
116 // key exchange
117 if (not computeSharedKeys(SERVER_SESSION_KEYS)) {
118 logE("Invalid client key");
119 exit(1);
120 }
121
122 // get encrypted message
123 int len;
124 // *nonce is incremented by after sending or receiving a message
125 // *nonce is allowed to wrap from the max value
126 u64 *nonce = (u64*)keys.nonce;
127 if (!rcv(&len, sizeof(len))) continue;
128 rcv(buf, len);
129
130 u8 decrypted[1000];
131 logVarG(*nonce);
132 len = selDecrypt(decrypted, sizeof(decrypted), buf, len);
133 inc *nonce;
134
135 if (!len) {
136 logE("failed to decrypt");
137 close(mysock);
138 continue;
139 }
140
141 decrypted[len] = 0;
142
143 logI("decrypted: %s", decrypted);
144
145 // send encrypted response
146
147 char *msg = "OK";
148
149 logVarG(*nonce);
150 len = selEncrypt(buf, sizeof(buf), msg, strlen(msg));
151 inc *nonce;
152
153 logVarG(len);
154
155 snd(&len, sizeof(len));
156 snd(buf, len);
157
158 close(mysock);
159 }
160 }
161 }
162 // vim: set expandtab ts=2 sw=2: