conn_mbedtls.c

   1 #include <arpa/inet.h>
   2 #include <netinet/in.h>
   3 #include <netdb.h>
   4 #include <signal.h>
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <string.h>
   8 #include <sys/socket.h>
   9 #include <sys/stat.h>
  10 #include <sys/types.h>
  11 #include <time.h>
  12 #include <unistd.h>
  13 #include <polarssl/ssl.h>
  14 #include <polarssl/entropy.h>
  15 #include <polarssl/ctr_drbg.h>
  16
  17 struct conn {
  18         int fd;
  19         int tls;
  20         ssl_context ssl;
  21         ssl_session ssn;
  22         ctr_drbg_context ctr_drbg;
  23         x509_crt cert;
  24 };
  25
  26 static int ps_send(void *ctx, const unsigned char *buf, size_t len)
  27 {
  28         return write(*(int *) ctx, buf, len);
  29 }
  30
  31 static int ps_recv(void *ctx, unsigned char *buf, size_t len)
  32 {
  33         return read(*(int *) ctx, buf, len);
  34 }
  35
  36 int conn_read(struct conn *conn, char *buf, int len)
  37 {
  38         if (conn->tls)
  39                 return ssl_read(&conn->ssl, (unsigned char *) buf, len);
  40         return read(conn->fd, buf, len);
  41 }
  42
  43 int conn_write(struct conn *conn, char *buf, int len)
  44 {
  45         if (conn->tls)
  46                 return ssl_write(&conn->ssl, (unsigned char *) buf, len);
  47         return write(conn->fd, buf, len);
  48 }
  49
  50 int conn_tls(struct conn *conn, char *certfile)
  51 {
  52         entropy_context entropy;
  53         entropy_init(&entropy);
  54         ctr_drbg_init(&conn->ctr_drbg, entropy_func, &entropy, NULL, 0);
  55         if (ssl_init(&conn->ssl))
  56                 return 1;
  57         ssl_set_endpoint(&conn->ssl, SSL_IS_CLIENT);
  58         if (certfile) {
  59                 x509_crt_parse_file(&conn->cert, certfile);
  60                 ssl_set_ca_chain(&conn->ssl, &conn->cert, NULL, NULL);
  61                 ssl_set_authmode(&conn->ssl, SSL_VERIFY_REQUIRED);
  62         } else{
  63                 ssl_set_authmode(&conn->ssl, SSL_VERIFY_NONE);
  64         }
  65         ssl_set_rng(&conn->ssl, ctr_drbg_random, &conn->ctr_drbg);
  66         ssl_set_bio(&conn->ssl, ps_recv, &conn->fd, ps_send, &conn->fd);
  67         ssl_set_ciphersuites(&conn->ssl, ssl_list_ciphersuites());
  68         ssl_set_session(&conn->ssl, &conn->ssn);
  69         conn->tls = 1;
  70         return ssl_handshake(&conn->ssl);
  71 }
  72
  73 struct conn *conn_connect(char *addr, char *port, char *certfile)
  74 {
  75         struct addrinfo hints, *addrinfo;
  76         struct conn *conn;
  77         int fd;
  78
  79         memset(&hints, 0, sizeof(hints));
  80         hints.ai_family = AF_UNSPEC;
  81         hints.ai_socktype = SOCK_STREAM;
  82         hints.ai_flags = AI_PASSIVE;
  83
  84         if (getaddrinfo(addr, port, &hints, &addrinfo))
  85                 return NULL;
  86         fd = socket(addrinfo->ai_family, addrinfo->ai_socktype,
  87                         addrinfo->ai_protocol);
  88
  89         if (connect(fd, addrinfo->ai_addr, addrinfo->ai_addrlen) == -1) {
  90                 close(fd);
  91                 freeaddrinfo(addrinfo);
  92                 return NULL;
  93         }
  94         freeaddrinfo(addrinfo);
  95
  96         conn = malloc(sizeof(*conn));
  97         memset(conn, 0, sizeof(*conn));
  98         conn->fd = fd;
  99         return conn;
 100 }
 101
 102 int conn_close(struct conn *conn)
 103 {
 104         if (conn->tls) {
 105                 ssl_close_notify(&conn->ssl);
 106                 x509_crt_free(&conn->cert);
 107                 ssl_free(&conn->ssl);
 108         }
 109         close(conn->fd);
 110         free(conn);
 111         return 0;
 112 }