1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
|
/* cli.cpp - Minimal ssleay client for Unix
30.9.1996, Sampo Kellomaki <sampo@iki.fi> */
/* mangled to work with SSLeay-0.9.0b and OpenSSL 0.9.2b
Simplified to be even more minimal
12/98 - 4/99 Wade Scholine <wades@mail.cybg.com> */
#include <stdio.h>
#include <memory.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <openssl/crypto.h>
#include <openssl/x509.h>
#include <openssl/pem.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
#define CHK_NULL(x) if ((x)==NULL) exit (1)
#define CHK_ERR(err,s) if ((err)==-1) { perror(s); exit(1); }
#define CHK_SSL(err) if ((err)==-1) { ERR_print_errors_fp(stderr); exit(2); }
void main ()
{
int err;
int sd;
struct sockaddr_in sa;
SSL_CTX* ctx;
SSL* ssl;
X509* server_cert;
char* str;
char buf [4096];
SSL_METHOD *meth;
SSLeay_add_ssl_algorithms();
meth = SSLv23_client_method();
SSL_load_error_strings();
ctx = SSL_CTX_new (meth); CHK_NULL(ctx);
/* ----------------------------------------------- */
/* Create a socket and connect to server using normal socket calls. */
sd = socket (AF_INET, SOCK_STREAM, 0); CHK_ERR(sd, "socket");
memset(&sa, 0, sizeof(sa));
sa.sin_family = AF_INET;
sa.sin_addr.s_addr = inet_addr ("127.0.0.1"); /* Server IP */
sa.sin_port = htons (1111); /* Server Port number */
err = connect(sd, (struct sockaddr*) &sa,
sizeof(sa)); CHK_ERR(err, "connect");
/* ----------------------------------------------- */
/* Now we have TCP conncetion. Start SSL negotiation. */
ssl = SSL_new (ctx); CHK_NULL(ssl);
SSL_set_fd (ssl, sd);
err = SSL_connect (ssl); CHK_SSL(err);
/* Following two steps are optional and not required for
data exchange to be successful. */
/* Get the cipher - opt */
printf ("SSL connection using %s\n", SSL_get_cipher (ssl));
/* Get server's certificate (note: beware of dynamic allocation) - opt */
server_cert = SSL_get_peer_certificate (ssl); CHK_NULL(server_cert);
printf ("Server certificate:\n");
str = X509_NAME_oneline (X509_get_subject_name (server_cert),0,0);
CHK_NULL(str);
printf ("\t subject: %s\n", str);
OPENSSL_free (str);
str = X509_NAME_oneline (X509_get_issuer_name (server_cert),0,0);
CHK_NULL(str);
printf ("\t issuer: %s\n", str);
OPENSSL_free (str);
/* We could do all sorts of certificate verification stuff here before
deallocating the certificate. */
X509_free (server_cert);
/* --------------------------------------------------- */
/* DATA EXCHANGE - Send a message and receive a reply. */
err = SSL_write (ssl, "Hello World!", strlen("Hello World!")); CHK_SSL(err);
err = SSL_read (ssl, buf, sizeof(buf) - 1); CHK_SSL(err);
buf[err] = '\0';
printf ("Got %d chars:'%s'\n", err, buf);
SSL_shutdown (ssl); /* send SSL/TLS close_notify */
/* Clean up. */
close (sd);
SSL_free (ssl);
SSL_CTX_free (ctx);
}
/* EOF - cli.cpp */
|
