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 <mbedtls/ssl.h>
  14 #include <mbedtls/entropy.h>
  15 #include <mbedtls/ctr_drbg.h>
  16 #include <mbedtls/net_sockets.h>
  17
  18 struct conn {
  19         int fd;
  20         int tls;
  21         mbedtls_ssl_context ssl;
  22         mbedtls_ssl_session ssn;
  23         mbedtls_ctr_drbg_context ctr_drbg;
  24         mbedtls_x509_crt cert;
  25         mbedtls_ssl_config conf;
  26 };
  27
  28 int conn_read(struct conn *conn, char *buf, int len)
  29 {
  30         if (conn->tls)
  31                 return mbedtls_ssl_read(&conn->ssl, (unsigned char *) buf, len);
  32         return read(conn->fd, buf, len);
  33 }
  34
  35 int conn_write(struct conn *conn, char *buf, int len)
  36 {
  37         if (conn->tls)
  38                 return mbedtls_ssl_write(&conn->ssl, (unsigned char *) buf, len);
  39         return write(conn->fd, buf, len);
  40 }
  41
  42 int conn_tls(struct conn *conn, char *certfile)
  43 {
  44         mbedtls_entropy_context entropy;
  45         mbedtls_entropy_init(&entropy);
  46         mbedtls_ctr_drbg_init(&conn->ctr_drbg);
  47         mbedtls_ssl_init(&conn->ssl);
  48         mbedtls_ssl_config_init(&conn->conf);
  49         mbedtls_ctr_drbg_seed(&conn->ctr_drbg, mbedtls_entropy_func, &entropy, NULL, 0);
  50         mbedtls_ssl_config_defaults(&conn->conf, MBEDTLS_SSL_IS_CLIENT,
  51                         MBEDTLS_SSL_TRANSPORT_STREAM, MBEDTLS_SSL_PRESET_DEFAULT);
  52         mbedtls_ssl_conf_rng(&conn->conf, mbedtls_ctr_drbg_random, &conn->ctr_drbg);
  53         if (certfile) {
  54                 mbedtls_x509_crt_parse_file(&conn->cert, certfile);
  55                 mbedtls_ssl_conf_ca_chain(&conn->conf, &conn->cert, NULL);
  56                 mbedtls_ssl_conf_authmode(&conn->conf, MBEDTLS_SSL_VERIFY_REQUIRED);
  57                 mbedtls_ssl_conf_ca_chain(&conn->conf, &conn->cert, NULL);
  58         } else {
  59                 mbedtls_ssl_conf_authmode(&conn->conf, MBEDTLS_SSL_VERIFY_NONE);
  60         }
  61         if (mbedtls_ssl_setup(&conn->ssl, &conn->conf))
  62                 return 1;
  63         mbedtls_ssl_set_bio(&conn->ssl, &conn->fd, mbedtls_net_send, mbedtls_net_recv, NULL);
  64         conn->tls = 1;
  65         return mbedtls_ssl_handshake(&conn->ssl);
  66 }
  67
  68 struct conn *conn_connect(char *addr, char *port, char *certfile)
  69 {
  70         struct addrinfo hints, *addrinfo;
  71         struct conn *conn;
  72         int fd;
  73
  74         memset(&hints, 0, sizeof(hints));
  75         hints.ai_family = AF_UNSPEC;
  76         hints.ai_socktype = SOCK_STREAM;
  77         hints.ai_flags = AI_PASSIVE;
  78
  79         if (getaddrinfo(addr, port, &hints, &addrinfo))
  80                 return NULL;
  81         fd = socket(addrinfo->ai_family, addrinfo->ai_socktype,
  82                         addrinfo->ai_protocol);
  83
  84         if (connect(fd, addrinfo->ai_addr, addrinfo->ai_addrlen) == -1) {
  85                 close(fd);
  86                 freeaddrinfo(addrinfo);
  87                 return NULL;
  88         }
  89         freeaddrinfo(addrinfo);
  90
  91         conn = malloc(sizeof(*conn));
  92         memset(conn, 0, sizeof(*conn));
  93         conn->fd = fd;
  94         return conn;
  95 }
  96
  97 int conn_close(struct conn *conn)
  98 {
  99         if (conn->tls) {
 100                 mbedtls_ssl_close_notify(&conn->ssl);
 101                 mbedtls_x509_crt_free(&conn->cert);
 102                 mbedtls_ssl_free(&conn->ssl);
 103                 mbedtls_ssl_config_free(&conn->conf);
 104                 mbedtls_ctr_drbg_free(&conn->ctr_drbg);
 105         }
 106         close(conn->fd);
 107         free(conn);
 108         return 0;
 109 }