466 lines
11 KiB
C
466 lines
11 KiB
C
#include <sys/poll.h>
|
|
#include <openssl/ssl.h>
|
|
|
|
/*
|
|
* Demo 4: Client — Client Creates FD — Nonblocking
|
|
* ================================================
|
|
*
|
|
* This is an example of (part of) an application which uses libssl in an
|
|
* asynchronous, nonblocking fashion. The client is responsible for creating the
|
|
* socket and passing it to libssl. The functions show all interactions with
|
|
* libssl the application makes, and would hypothetically be linked into a
|
|
* larger application.
|
|
*/
|
|
typedef struct app_conn_st {
|
|
SSL *ssl;
|
|
int fd;
|
|
int rx_need_tx, tx_need_rx;
|
|
} APP_CONN;
|
|
|
|
/*
|
|
* The application is initializing and wants an SSL_CTX which it will use for
|
|
* some number of outgoing connections, which it creates in subsequent calls to
|
|
* new_conn. The application may also call this function multiple times to
|
|
* create multiple SSL_CTX.
|
|
*/
|
|
SSL_CTX *create_ssl_ctx(void)
|
|
{
|
|
SSL_CTX *ctx;
|
|
|
|
#ifdef USE_QUIC
|
|
ctx = SSL_CTX_new(OSSL_QUIC_client_method());
|
|
#else
|
|
ctx = SSL_CTX_new(TLS_client_method());
|
|
#endif
|
|
if (ctx == NULL)
|
|
return NULL;
|
|
|
|
/* Enable trust chain verification. */
|
|
SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER, NULL);
|
|
|
|
/* Load default root CA store. */
|
|
if (SSL_CTX_set_default_verify_paths(ctx) == 0) {
|
|
SSL_CTX_free(ctx);
|
|
return NULL;
|
|
}
|
|
|
|
return ctx;
|
|
}
|
|
|
|
/*
|
|
* The application wants to create a new outgoing connection using a given
|
|
* SSL_CTX.
|
|
*
|
|
* hostname is a string like "openssl.org" used for certificate validation.
|
|
*/
|
|
APP_CONN *new_conn(SSL_CTX *ctx, int fd, const char *bare_hostname)
|
|
{
|
|
APP_CONN *conn;
|
|
SSL *ssl;
|
|
#ifdef USE_QUIC
|
|
static const unsigned char alpn[] = {5, 'd', 'u', 'm', 'm', 'y'};
|
|
#endif
|
|
|
|
conn = calloc(1, sizeof(APP_CONN));
|
|
if (conn == NULL)
|
|
return NULL;
|
|
|
|
ssl = conn->ssl = SSL_new(ctx);
|
|
if (ssl == NULL) {
|
|
free(conn);
|
|
return NULL;
|
|
}
|
|
|
|
SSL_set_connect_state(ssl); /* cannot fail */
|
|
|
|
if (SSL_set_fd(ssl, fd) <= 0) {
|
|
SSL_free(ssl);
|
|
free(conn);
|
|
return NULL;
|
|
}
|
|
|
|
if (SSL_set1_host(ssl, bare_hostname) <= 0) {
|
|
SSL_free(ssl);
|
|
free(conn);
|
|
return NULL;
|
|
}
|
|
|
|
if (SSL_set_tlsext_host_name(ssl, bare_hostname) <= 0) {
|
|
SSL_free(ssl);
|
|
free(conn);
|
|
return NULL;
|
|
}
|
|
|
|
#ifdef USE_QUIC
|
|
/* Configure ALPN, which is required for QUIC. */
|
|
if (SSL_set_alpn_protos(ssl, alpn, sizeof(alpn))) {
|
|
/* Note: SSL_set_alpn_protos returns 1 for failure. */
|
|
SSL_free(ssl);
|
|
free(conn);
|
|
return NULL;
|
|
}
|
|
#endif
|
|
|
|
conn->fd = fd;
|
|
return conn;
|
|
}
|
|
|
|
/*
|
|
* Non-blocking transmission.
|
|
*
|
|
* Returns -1 on error. Returns -2 if the function would block (corresponds to
|
|
* EWOULDBLOCK).
|
|
*/
|
|
int tx(APP_CONN *conn, const void *buf, int buf_len)
|
|
{
|
|
int rc, l;
|
|
|
|
conn->tx_need_rx = 0;
|
|
|
|
l = SSL_write(conn->ssl, buf, buf_len);
|
|
if (l <= 0) {
|
|
rc = SSL_get_error(conn->ssl, l);
|
|
switch (rc) {
|
|
case SSL_ERROR_WANT_READ:
|
|
conn->tx_need_rx = 1;
|
|
case SSL_ERROR_WANT_CONNECT:
|
|
case SSL_ERROR_WANT_WRITE:
|
|
return -2;
|
|
default:
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
return l;
|
|
}
|
|
|
|
/*
|
|
* Non-blocking reception.
|
|
*
|
|
* Returns -1 on error. Returns -2 if the function would block (corresponds to
|
|
* EWOULDBLOCK).
|
|
*/
|
|
int rx(APP_CONN *conn, void *buf, int buf_len)
|
|
{
|
|
int rc, l;
|
|
|
|
conn->rx_need_tx = 0;
|
|
|
|
l = SSL_read(conn->ssl, buf, buf_len);
|
|
if (l <= 0) {
|
|
rc = SSL_get_error(conn->ssl, l);
|
|
switch (rc) {
|
|
case SSL_ERROR_WANT_WRITE:
|
|
conn->rx_need_tx = 1;
|
|
case SSL_ERROR_WANT_READ:
|
|
return -2;
|
|
default:
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
return l;
|
|
}
|
|
|
|
/*
|
|
* The application wants to know a fd it can poll on to determine when the
|
|
* SSL state machine needs to be pumped.
|
|
*
|
|
* If the fd returned has:
|
|
*
|
|
* POLLIN: SSL_read *may* return data;
|
|
* if application does not want to read yet, it should call pump().
|
|
*
|
|
* POLLOUT: SSL_write *may* accept data
|
|
*
|
|
* POLLERR: An application should call pump() if it is not likely to call
|
|
* SSL_read or SSL_write soon.
|
|
*
|
|
*/
|
|
int get_conn_fd(APP_CONN *conn)
|
|
{
|
|
return conn->fd;
|
|
}
|
|
|
|
/*
|
|
* These functions returns zero or more of:
|
|
*
|
|
* POLLIN: The SSL state machine is interested in socket readability events.
|
|
*
|
|
* POLLOUT: The SSL state machine is interested in socket writeability events.
|
|
*
|
|
* POLLERR: The SSL state machine is interested in socket error events.
|
|
*
|
|
* get_conn_pending_tx returns events which may cause SSL_write to make
|
|
* progress and get_conn_pending_rx returns events which may cause SSL_read
|
|
* to make progress.
|
|
*/
|
|
int get_conn_pending_tx(APP_CONN *conn)
|
|
{
|
|
#ifdef USE_QUIC
|
|
return (SSL_net_read_desired(conn->ssl) ? POLLIN : 0)
|
|
| (SSL_net_write_desired(conn->ssl) ? POLLOUT : 0)
|
|
| POLLERR;
|
|
#else
|
|
return (conn->tx_need_rx ? POLLIN : 0) | POLLOUT | POLLERR;
|
|
#endif
|
|
}
|
|
|
|
int get_conn_pending_rx(APP_CONN *conn)
|
|
{
|
|
return get_conn_pending_tx(conn);
|
|
}
|
|
|
|
#ifdef USE_QUIC
|
|
/*
|
|
* Returns the number of milliseconds after which some call to libssl must be
|
|
* made. Any call (SSL_read/SSL_write/SSL_pump) will do. Returns -1 if there is
|
|
* no need for such a call. This may change after the next call
|
|
* to libssl.
|
|
*/
|
|
static inline int timeval_to_ms(const struct timeval *t);
|
|
|
|
int get_conn_pump_timeout(APP_CONN *conn)
|
|
{
|
|
struct timeval tv;
|
|
int is_infinite;
|
|
|
|
if (!SSL_get_event_timeout(conn->ssl, &tv, &is_infinite))
|
|
return -1;
|
|
|
|
return is_infinite ? -1 : timeval_to_ms(&tv);
|
|
}
|
|
|
|
/*
|
|
* Called to advance internals of libssl state machines without having to
|
|
* perform an application-level read/write.
|
|
*/
|
|
void pump(APP_CONN *conn)
|
|
{
|
|
SSL_handle_events(conn->ssl);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* The application wants to close the connection and free bookkeeping
|
|
* structures.
|
|
*/
|
|
void teardown(APP_CONN *conn)
|
|
{
|
|
SSL_shutdown(conn->ssl);
|
|
SSL_free(conn->ssl);
|
|
free(conn);
|
|
}
|
|
|
|
/*
|
|
* The application is shutting down and wants to free a previously
|
|
* created SSL_CTX.
|
|
*/
|
|
void teardown_ctx(SSL_CTX *ctx)
|
|
{
|
|
SSL_CTX_free(ctx);
|
|
}
|
|
|
|
/*
|
|
* ============================================================================
|
|
* Example driver for the above code. This is just to demonstrate that the code
|
|
* works and is not intended to be representative of a real application.
|
|
*/
|
|
#include <sys/types.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/signal.h>
|
|
#ifdef USE_QUIC
|
|
# include <sys/time.h>
|
|
#endif
|
|
#include <netdb.h>
|
|
#include <unistd.h>
|
|
#include <fcntl.h>
|
|
|
|
#ifdef USE_QUIC
|
|
|
|
static inline void ms_to_timeval(struct timeval *t, int ms)
|
|
{
|
|
t->tv_sec = ms < 0 ? -1 : ms/1000;
|
|
t->tv_usec = ms < 0 ? 0 : (ms%1000)*1000;
|
|
}
|
|
|
|
static inline int timeval_to_ms(const struct timeval *t)
|
|
{
|
|
return t->tv_sec*1000 + t->tv_usec/1000;
|
|
}
|
|
|
|
#endif
|
|
|
|
int main(int argc, char **argv)
|
|
{
|
|
int rc, fd = -1, res = 1;
|
|
static char tx_msg[300];
|
|
const char *tx_p = tx_msg;
|
|
char rx_buf[2048];
|
|
int l, tx_len;
|
|
#ifdef USE_QUIC
|
|
struct timeval timeout;
|
|
#else
|
|
int timeout = 2000 /* ms */;
|
|
#endif
|
|
APP_CONN *conn = NULL;
|
|
struct addrinfo hints = {0}, *result = NULL;
|
|
SSL_CTX *ctx = NULL;
|
|
|
|
#ifdef USE_QUIC
|
|
ms_to_timeval(&timeout, 2000);
|
|
#endif
|
|
|
|
if (argc < 3) {
|
|
fprintf(stderr, "usage: %s host port\n", argv[0]);
|
|
goto fail;
|
|
}
|
|
|
|
tx_len = snprintf(tx_msg, sizeof(tx_msg),
|
|
"GET / HTTP/1.0\r\nHost: %s\r\n\r\n", argv[1]);
|
|
|
|
ctx = create_ssl_ctx();
|
|
if (ctx == NULL) {
|
|
fprintf(stderr, "cannot create SSL context\n");
|
|
goto fail;
|
|
}
|
|
|
|
hints.ai_family = AF_INET;
|
|
hints.ai_socktype = SOCK_STREAM;
|
|
hints.ai_flags = AI_PASSIVE;
|
|
rc = getaddrinfo(argv[1], argv[2], &hints, &result);
|
|
if (rc < 0) {
|
|
fprintf(stderr, "cannot resolve\n");
|
|
goto fail;
|
|
}
|
|
|
|
signal(SIGPIPE, SIG_IGN);
|
|
|
|
#ifdef USE_QUIC
|
|
fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
|
|
#else
|
|
fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
|
|
#endif
|
|
if (fd < 0) {
|
|
fprintf(stderr, "cannot create socket\n");
|
|
goto fail;
|
|
}
|
|
|
|
rc = connect(fd, result->ai_addr, result->ai_addrlen);
|
|
if (rc < 0) {
|
|
fprintf(stderr, "cannot connect\n");
|
|
goto fail;
|
|
}
|
|
|
|
rc = fcntl(fd, F_SETFL, O_NONBLOCK);
|
|
if (rc < 0) {
|
|
fprintf(stderr, "cannot make socket nonblocking\n");
|
|
goto fail;
|
|
}
|
|
|
|
conn = new_conn(ctx, fd, argv[1]);
|
|
if (conn == NULL) {
|
|
fprintf(stderr, "cannot establish connection\n");
|
|
goto fail;
|
|
}
|
|
|
|
/* TX */
|
|
while (tx_len != 0) {
|
|
l = tx(conn, tx_p, tx_len);
|
|
if (l > 0) {
|
|
tx_p += l;
|
|
tx_len -= l;
|
|
} else if (l == -1) {
|
|
fprintf(stderr, "tx error\n");
|
|
goto fail;
|
|
} else if (l == -2) {
|
|
#ifdef USE_QUIC
|
|
struct timeval start, now, deadline, t;
|
|
#endif
|
|
struct pollfd pfd = {0};
|
|
|
|
#ifdef USE_QUIC
|
|
ms_to_timeval(&t, get_conn_pump_timeout(conn));
|
|
if (t.tv_sec < 0 || timercmp(&t, &timeout, >))
|
|
t = timeout;
|
|
|
|
gettimeofday(&start, NULL);
|
|
timeradd(&start, &timeout, &deadline);
|
|
#endif
|
|
|
|
pfd.fd = get_conn_fd(conn);
|
|
pfd.events = get_conn_pending_tx(conn);
|
|
#ifdef USE_QUIC
|
|
if (poll(&pfd, 1, timeval_to_ms(&t)) == 0)
|
|
#else
|
|
if (poll(&pfd, 1, timeout) == 0)
|
|
#endif
|
|
{
|
|
#ifdef USE_QUIC
|
|
pump(conn);
|
|
|
|
gettimeofday(&now, NULL);
|
|
if (timercmp(&now, &deadline, >=))
|
|
#endif
|
|
{
|
|
fprintf(stderr, "tx timeout\n");
|
|
goto fail;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* RX */
|
|
for (;;) {
|
|
l = rx(conn, rx_buf, sizeof(rx_buf));
|
|
if (l > 0) {
|
|
fwrite(rx_buf, 1, l, stdout);
|
|
} else if (l == -1) {
|
|
break;
|
|
} else if (l == -2) {
|
|
#ifdef USE_QUIC
|
|
struct timeval start, now, deadline, t;
|
|
#endif
|
|
struct pollfd pfd = {0};
|
|
|
|
#ifdef USE_QUIC
|
|
ms_to_timeval(&t, get_conn_pump_timeout(conn));
|
|
if (t.tv_sec < 0 || timercmp(&t, &timeout, >))
|
|
t = timeout;
|
|
|
|
gettimeofday(&start, NULL);
|
|
timeradd(&start, &timeout, &deadline);
|
|
#endif
|
|
|
|
pfd.fd = get_conn_fd(conn);
|
|
pfd.events = get_conn_pending_rx(conn);
|
|
#ifdef USE_QUIC
|
|
if (poll(&pfd, 1, timeval_to_ms(&t)) == 0)
|
|
#else
|
|
if (poll(&pfd, 1, timeout) == 0)
|
|
#endif
|
|
{
|
|
#ifdef USE_QUIC
|
|
pump(conn);
|
|
gettimeofday(&now, NULL);
|
|
if (timercmp(&now, &deadline, >=))
|
|
#endif
|
|
{
|
|
fprintf(stderr, "rx timeout\n");
|
|
goto fail;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
res = 0;
|
|
fail:
|
|
if (conn != NULL)
|
|
teardown(conn);
|
|
if (ctx != NULL)
|
|
teardown_ctx(ctx);
|
|
if (result != NULL)
|
|
freeaddrinfo(result);
|
|
return res;
|
|
}
|