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openssl/demos/easy_tls/easy-tls.c
Matt Caswell 13c9bb3ece Client side version negotiation rewrite 
Continuing from the previous commit this changes the way we do client side
version negotiation. Similarly all of the s23* "up front" state machine code
has been avoided and again things now work much the same way as they already
did for DTLS, i.e. we just do most of the work in the
ssl3_get_server_hello() function.

Reviewed-by: Kurt Roeckx <kurt@openssl.org>
2015-05-16 09:20:31 +01:00

1308 lines
37 KiB
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/* -*- Mode: C; c-file-style: "bsd" -*- */
/*-
* easy-tls.c -- generic TLS proxy.
* $Id: easy-tls.c,v 1.4 2002/03/05 09:07:16 bodo Exp $
*/
/*-
(c) Copyright 1999 Bodo Moeller. All rights reserved.
This is free software; you can redistributed and/or modify it
unter the terms of either
- the GNU General Public License as published by the
Free Software Foundation, version 1, or (at your option)
any later version,
or
- the following license:
*/
/*-
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that each of the following
* conditions is met:
*
* 1. Redistributions qualify as "freeware" or "Open Source Software" under
* one of the following terms:
*
* (a) Redistributions are made at no charge beyond the reasonable cost of
* materials and delivery.
*
* (b) Redistributions are accompanied by a copy of the Source Code
* or by an irrevocable offer to provide a copy of the Source Code
* for up to three years at the cost of materials and delivery.
* Such redistributions must allow further use, modification, and
* redistribution of the Source Code under substantially the same
* terms as this license.
*
* 2. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 3. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 4. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by Bodo Moeller."
* (If available, substitute umlauted o for oe.)
*
* 5. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by Bodo Moeller."
*
* THIS SOFTWARE IS PROVIDED BY BODO MOELLER ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BODO MOELLER OR
* HIS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*-
* Attribution for OpenSSL library:
*
* This product includes cryptographic software written by Eric Young
* (eay@cryptsoft.com). This product includes software written by Tim
* Hudson (tjh@cryptsoft.com).
* This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.openssl.org/)
*/
static char const rcsid[] =
"$Id: easy-tls.c,v 1.4 2002/03/05 09:07:16 bodo Exp $";
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include <sys/select.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/utsname.h>
#include <unistd.h>
#include <openssl/crypto.h>
#include <openssl/dh.h>
#include <openssl/dsa.h>
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/opensslv.h>
#include <openssl/pem.h>
#include <openssl/rand.h>
#ifndef NO_RSA
# include <openssl/rsa.h>
#endif
#include <openssl/ssl.h>
#include <openssl/x509.h>
#include <openssl/x509_vfy.h>
#if OPENSSL_VERSION_NUMBER < 0x00904000L /* 0.9.4-dev */
# error "This program needs OpenSSL 0.9.4 or later."
#endif
#include "easy-tls.h" /* include after <openssl/ssl.h> if both are
* needed */
#if TLS_INFO_SIZE > PIPE_BUF
# if PIPE_BUF < 512
# error "PIPE_BUF < 512" /* non-POSIX */
# endif
# error "TLS_INFO_SIZE > PIPE_BUF"
#endif
/*****************************************************************************/
#ifdef TLS_APP
# include TLS_APP
#endif
/*-
* Applications can define:
* TLS_APP_PROCESS_INIT -- void ...(int fd, int client_p, void *apparg)
* TLS_CUMULATE_ERRORS
* TLS_ERROR_BUFSIZ
* TLS_APP_ERRFLUSH -- void ...(int child_p, char *, size_t, void *apparg)
*/
#ifndef TLS_APP_PROCESS_INIT
# define TLS_APP_PROCESS_INIT(fd, client_p, apparg) ((void) 0)
#endif
#ifndef TLS_ERROR_BUFSIZ
# define TLS_ERROR_BUFSIZ (10*160)
#endif
#if TLS_ERROR_BUFSIZ < 2 /* {'\n',0} */
# error "TLS_ERROR_BUFSIZE is too small."
#endif
#ifndef TLS_APP_ERRFLUSH
# define TLS_APP_ERRFLUSH tls_app_errflush
static void
tls_app_errflush(int child_p, char *errbuf, size_t num, void *apparg)
{
fputs(errbuf, stderr);
}
#endif
/*****************************************************************************/
#ifdef DEBUG_TLS
# define DEBUG_MSG(x) fprintf(stderr," %s\n",x)
# define DEBUG_MSG2(x,y) fprintf(stderr, " %s: %d\n",x,y)
static int tls_loop_count = 0;
static int tls_select_count = 0;
#else
# define DEBUG_MSG(x) (void)0
# define DEBUG_MSG2(x,y) (void)0
#endif
static void tls_rand_seed_uniquely(void);
static void tls_proxy(int clear_fd, int tls_fd, int info_fd, SSL_CTX *ctx,
int client_p);
static int tls_socket_nonblocking(int fd);
static int tls_child_p = 0;
static void *tls_child_apparg;
struct tls_start_proxy_args tls_start_proxy_defaultargs(void)
{
struct tls_start_proxy_args ret;
ret.fd = -1;
ret.client_p = -1;
ret.ctx = NULL;
ret.pid = NULL;
ret.infofd = NULL;
return ret;
}
/*-
* Slice in TLS proxy process at fd.
* Return value:
* 0 ok (*pid is set to child's PID if pid != NULL),
* < 0 look at errno
* > 0 other error
* (return value encodes place of error)
*
*/
int tls_start_proxy(struct tls_start_proxy_args a, void *apparg)
{
int fds[2] = { -1, -1 };
int infofds[2] = { -1, -1 };
int r, getfd, getfl;
int ret;
DEBUG_MSG2("tls_start_proxy fd", a.fd);
DEBUG_MSG2("tls_start_proxy client_p", a.client_p);
if (a.fd == -1 || a.client_p == -1 || a.ctx == NULL)
return 1;
if (a.pid != NULL) {
*a.pid = 0;
}
if (a.infofd != NULL) {
*a.infofd = -1;
}
r = socketpair(AF_UNIX, SOCK_STREAM, 0, fds);
if (r == -1)
return -1;
if (a.fd >= FD_SETSIZE || fds[0] >= FD_SETSIZE) {
ret = 2;
goto err;
}
if (a.infofd != NULL) {
r = pipe(infofds);
if (r == -1) {
ret = -3;
goto err;
}
}
r = fork();
if (r == -1) {
ret = -4;
goto err;
}
if (r == 0) {
DEBUG_MSG("fork");
tls_child_p = 1;
tls_child_apparg = apparg;
close(fds[1]);
if (infofds[0] != -1)
close(infofds[0]);
TLS_APP_PROCESS_INIT(a.fd, a.client_p, apparg);
DEBUG_MSG("TLS_APP_PROCESS_INIT");
tls_proxy(fds[0], a.fd, infofds[1], a.ctx, a.client_p);
exit(0);
}
if (a.pid != NULL)
*a.pid = r;
if (infofds[1] != -1) {
close(infofds[1]);
infofds[1] = -1;
}
/* install fds[1] in place of fd: */
close(fds[0]);
fds[0] = -1;
getfd = fcntl(a.fd, F_GETFD);
getfl = fcntl(a.fd, F_GETFL);
r = dup2(fds[1], a.fd);
close(fds[1]);
fds[1] = -1;
if (r == -1) {
ret = -5;
goto err;
}
if (getfd != 1)
fcntl(a.fd, F_SETFD, getfd);
if (getfl & O_NONBLOCK)
(void)tls_socket_nonblocking(a.fd);
if (a.infofd != NULL)
*a.infofd = infofds[0];
return 0;
err:
if (fds[0] != -1)
close(fds[0]);
if (fds[1] != -1)
close(fds[1]);
if (infofds[0] != -1)
close(infofds[0]);
if (infofds[1] != -1)
close(infofds[1]);
return ret;
}
/*****************************************************************************/
static char errbuf[TLS_ERROR_BUFSIZ];
static size_t errbuf_i = 0;
static void tls_errflush(void *apparg)
{
if (errbuf_i == 0)
return;
assert(errbuf_i < sizeof errbuf);
assert(errbuf[errbuf_i] == 0);
if (errbuf_i == sizeof errbuf - 1) {
/* make sure we have a newline, even if string has been truncated */
errbuf[errbuf_i - 1] = '\n';
}
/*
* TLS_APP_ERRFLUSH may modify the string as needed, e.g. substitute
* other characters for \n for convenience
*/
TLS_APP_ERRFLUSH(tls_child_p, errbuf, errbuf_i, apparg);
errbuf_i = 0;
}
static void tls_errprintf(int flush, void *apparg, const char *fmt, ...)
{
va_list args;
int r;
if (errbuf_i < sizeof errbuf - 1) {
size_t n;
va_start(args, fmt);
n = (sizeof errbuf) - errbuf_i;
r = vsnprintf(errbuf + errbuf_i, n, fmt, args);
if (r >= n)
r = n - 1;
if (r >= 0) {
errbuf_i += r;
} else {
errbuf_i = sizeof errbuf - 1;
errbuf[errbuf_i] = '\0';
}
assert(errbuf_i < sizeof errbuf);
assert(errbuf[errbuf_i] == 0);
}
#ifndef TLS_CUMULATE_ERRORS
tls_errflush(apparg);
#else
if (flush)
tls_errflush(apparg);
#endif
}
/*
* app_prefix.. are for additional information provided by caller. If OpenSSL
* error queue is empty, print default_text ("???" if NULL).
*/
static char *tls_openssl_errors(const char *app_prefix_1,
const char *app_prefix_2,
const char *default_text, void *apparg)
{
static char reasons[255];
size_t reasons_i;
unsigned long err;
const char *file;
int line;
const char *data;
int flags;
char *errstring;
int printed_something = 0;
reasons_i = 0;
assert(app_prefix_1 != NULL);
assert(app_prefix_2 != NULL);
if (default_text == NULL)
default_text = "?" "?" "?";
while ((err = ERR_get_error_line_data(&file, &line, &data, &flags)) != 0) {
if (reasons_i < sizeof reasons) {
size_t n;
int r;
n = (sizeof reasons) - reasons_i;
r = snprintf(reasons + reasons_i, n, "%s%s",
(reasons_i > 0 ? ", " : ""),
ERR_reason_error_string(err));
if (r >= n)
r = n - 1;
if (r >= 0) {
reasons_i += r;
} else {
reasons_i = sizeof reasons;
}
assert(reasons_i <= sizeof reasons);
}
errstring = ERR_error_string(err, NULL);
assert(errstring != NULL);
tls_errprintf(0, apparg, "OpenSSL error%s%s: %s:%s:%d:%s\n",
app_prefix_1, app_prefix_2, errstring, file, line,
(flags & ERR_TXT_STRING) ? data : "");
printed_something = 1;
}
if (!printed_something) {
assert(reasons_i == 0);
snprintf(reasons, sizeof reasons, "%s", default_text);
tls_errprintf(0, apparg, "OpenSSL error%s%s: %s\n", app_prefix_1,
app_prefix_2, default_text);
}
#ifdef TLS_CUMULATE_ERRORS
tls_errflush(apparg);
#endif
assert(errbuf_i == 0);
return reasons;
}
/*****************************************************************************/
static int tls_init_done = 0;
static int tls_init(void *apparg)
{
if (tls_init_done)
return 0;
SSL_load_error_strings();
if (!SSL_library_init() /* aka SSLeay_add_ssl_algorithms() */ ) {
tls_errprintf(1, apparg, "SSL_library_init failed.\n");
return -1;
}
tls_init_done = 1;
tls_rand_seed();
return 0;
}
/*****************************************************************************/
static void tls_rand_seed_uniquely(void)
{
struct {
pid_t pid;
time_t time;
void *stack;
} data;
data.pid = getpid();
data.time = time(NULL);
data.stack = (void *)&data;
RAND_seed((const void *)&data, sizeof data);
}
void tls_rand_seed(void)
{
struct {
struct utsname uname;
int uname_1;
int uname_2;
uid_t uid;
uid_t euid;
gid_t gid;
gid_t egid;
} data;
data.uname_1 = uname(&data.uname);
data.uname_2 = errno; /* Let's hope that uname fails randomly :-) */
data.uid = getuid();
data.euid = geteuid();
data.gid = getgid();
data.egid = getegid();
RAND_seed((const void *)&data, sizeof data);
tls_rand_seed_uniquely();
}
static int tls_rand_seeded_p = 0;
#define my_MIN_SEED_BYTES 256 /* struct stat can be larger than 128 */
int tls_rand_seed_from_file(const char *filename, size_t n, void *apparg)
{
/*
* Seed OpenSSL's random number generator from file. Try to read n bytes
* if n > 0, whole file if n == 0.
*/
int r;
if (tls_init(apparg) == -1)
return -1;
tls_rand_seed();
r = RAND_load_file(filename,
(n > 0 && n < LONG_MAX) ? (long)n : LONG_MAX);
/*
* r is the number of bytes filled into the random number generator,
* which are taken from "stat(filename, ...)" in addition to the file
* contents.
*/
assert(1 < my_MIN_SEED_BYTES);
/*
* We need to detect at least those cases when the file does not exist at
* all. With current versions of OpenSSL, this should do it:
*/
if (n == 0)
n = my_MIN_SEED_BYTES;
if (r < n) {
tls_errprintf(1, apparg,
"rand_seed_from_file: could not read %d bytes from %s.\n",
n, filename);
return -1;
} else {
tls_rand_seeded_p = 1;
return 0;
}
}
void tls_rand_seed_from_memory(const void *buf, size_t n)
{
size_t i = 0;
while (i < n) {
size_t rest = n - i;
int chunk = rest < INT_MAX ? (int)rest : INT_MAX;
RAND_seed((const char *)buf + i, chunk);
i += chunk;
}
tls_rand_seeded_p = 1;
}
/*****************************************************************************/
struct tls_x509_name_string {
char str[100];
};
static void
tls_get_x509_subject_name_oneline(X509 *cert,
struct tls_x509_name_string *namestring)
{
X509_NAME *name;
if (cert == NULL) {
namestring->str[0] = '\0';
return;
}
name = X509_get_subject_name(cert); /* does not increment any reference
* counter */
assert(sizeof namestring->str >= 4); /* "?" or "...", plus 0 */
if (name == NULL) {
namestring->str[0] = '?';
namestring->str[1] = 0;
} else {
size_t len;
X509_NAME_oneline(name, namestring->str, sizeof namestring->str);
len = strlen(namestring->str);
assert(namestring->str[len] == 0);
assert(len < sizeof namestring->str);
if (len + 1 == sizeof namestring->str) {
/*
* (Probably something was cut off.) Does not really work --
* X509_NAME_oneline truncates after name components, we cannot
* tell from the result whether anything is missing.
*/
assert(namestring->str[len] == 0);
namestring->str[--len] = '.';
namestring->str[--len] = '.';
namestring->str[--len] = '.';
}
}
}
/*****************************************************************************/
/* to hinder OpenSSL from asking for passphrases */
static int no_passphrase_callback(char *buf, int num, int w, void *arg)
{
return -1;
}
#if OPENSSL_VERSION_NUMBER >= 0x00907000L
static int verify_dont_fail_cb(X509_STORE_CTX *c, void *unused_arg)
#else
static int verify_dont_fail_cb(X509_STORE_CTX *c)
#endif
{
int i;
i = X509_verify_cert(c); /* sets c->error */
#if OPENSSL_VERSION_NUMBER >= 0x00905000L /* don't allow unverified
* certificates -- they could
* survive session reuse, but
* OpenSSL < 0.9.5-dev does not
* preserve their verify_result */
if (i == 0)
return 1;
else
#endif
return i;
}
static DH *tls_dhe1024 = NULL; /* generating these takes a while, so do it
* just once */
void tls_set_dhe1024(int i, void *apparg)
{
DSA *dsaparams;
DH *dhparams;
const char *seed[] = { ";-) :-( :-) :-( ",
";-) :-( :-) :-( ",
"Random String no. 12",
";-) :-( :-) :-( ",
"hackers have even mo", /* from jargon file */
};
unsigned char seedbuf[20];
tls_init(apparg);
if (i >= 0) {
i %= sizeof seed / sizeof seed[0];
assert(strlen(seed[i]) == 20);
memcpy(seedbuf, seed[i], 20);
dsaparams =
DSA_generate_parameters(1024, seedbuf, 20, NULL, NULL, 0, NULL);
} else {
/* random parameters (may take a while) */
dsaparams =
DSA_generate_parameters(1024, NULL, 0, NULL, NULL, 0, NULL);
}
if (dsaparams == NULL) {
tls_openssl_errors("", "", NULL, apparg);
return;
}
dhparams = DSA_dup_DH(dsaparams);
DSA_free(dsaparams);
if (dhparams == NULL) {
tls_openssl_errors("", "", NULL, apparg);
return;
}
DH_free(tls_dhe1024);
tls_dhe1024 = dhparams;
}
struct tls_create_ctx_args tls_create_ctx_defaultargs(void)
{
struct tls_create_ctx_args ret;
ret.client_p = 0;
ret.certificate_file = NULL;
ret.key_file = NULL;
ret.ca_file = NULL;
ret.verify_depth = -1;
ret.fail_unless_verified = 0;
ret.export_p = 0;
return ret;
}
SSL_CTX *tls_create_ctx(struct tls_create_ctx_args a, void *apparg)
{
int r;
static long context_num = 0;
SSL_CTX *ret;
const char *err_pref_1 = "", *err_pref_2 = "";
if (tls_init(apparg) == -1)
return NULL;
ret =
SSL_CTX_new((a.client_p ? TLS_client_method :
TLS_server_method) ());
if (ret == NULL)
goto err;
SSL_CTX_set_default_passwd_cb(ret, no_passphrase_callback);
SSL_CTX_set_mode(ret, SSL_MODE_ENABLE_PARTIAL_WRITE);
if ((a.certificate_file != NULL) || (a.key_file != NULL)) {
if (a.key_file == NULL) {
tls_errprintf(1, apparg, "Need a key file.\n");
goto err_return;
}
if (a.certificate_file == NULL) {
tls_errprintf(1, apparg, "Need a certificate chain file.\n");
goto err_return;
}
if (!SSL_CTX_use_PrivateKey_file(ret, a.key_file, SSL_FILETYPE_PEM))
goto err;
if (!tls_rand_seeded_p) {
/*
* particularly paranoid people may not like this -- so provide
* your own random seeding before calling this
*/
if (tls_rand_seed_from_file(a.key_file, 0, apparg) == -1)
goto err_return;
}
if (!SSL_CTX_use_certificate_chain_file(ret, a.certificate_file))
goto err;
if (!SSL_CTX_check_private_key(ret)) {
tls_errprintf(1, apparg,
"Private key \"%s\" does not match certificate \"%s\".\n",
a.key_file, a.certificate_file);
goto err_peek;
}
}
if ((a.ca_file != NULL) || (a.verify_depth > 0)) {
context_num++;
r = SSL_CTX_set_session_id_context(ret, (const void *)&context_num,
(unsigned int)sizeof context_num);
if (!r)
goto err;
SSL_CTX_set_verify(ret,
SSL_VERIFY_PEER | (a.fail_unless_verified ?
SSL_VERIFY_FAIL_IF_NO_PEER_CERT
: 0), 0);
if (!a.fail_unless_verified)
SSL_CTX_set_cert_verify_callback(ret, verify_dont_fail_cb, NULL);
if (a.verify_depth > 0)
SSL_CTX_set_verify_depth(ret, a.verify_depth);
if (a.ca_file != NULL) {
/* does not report failure if file does not exist ... */
/* NULL argument means no CA-directory */
r = SSL_CTX_load_verify_locations(ret, a.ca_file, NULL);
if (!r) {
err_pref_1 = " while processing certificate file ";
err_pref_2 = a.ca_file;
goto err;
}
if (!a.client_p) {
/*
* SSL_load_client_CA_file is a misnomer, it just creates a
* list of CNs.
*/
SSL_CTX_set_client_CA_list(ret,
SSL_load_client_CA_file
(a.ca_file));
/*
* SSL_CTX_set_client_CA_list does not have a return value;
* it does not really need one, but make sure (we really test
* if SSL_load_client_CA_file worked)
*/
if (SSL_CTX_get_client_CA_list(ret) == NULL) {
tls_errprintf(1, apparg,
"Could not set client CA list from \"%s\".\n",
a.ca_file);
goto err_peek;
}
}
}
}
if (!a.client_p) {
if (tls_dhe1024 == NULL) {
int i;
if (RAND_bytes((unsigned char *)&i, sizeof i) <= 0)
goto err_return;
/*
* make sure that i is non-negative -- pick one of the provided
* seeds
*/
if (i < 0)
i = -i;
if (i < 0)
i = 0;
tls_set_dhe1024(i, apparg);
if (tls_dhe1024 == NULL)
goto err_return;
}
if (!SSL_CTX_set_tmp_dh(ret, tls_dhe1024))
goto err;
/* avoid small subgroup attacks: */
SSL_CTX_set_options(ret, SSL_OP_SINGLE_DH_USE);
}
#ifndef NO_RSA
if (!a.client_p && a.export_p) {
RSA *tmpkey;
tmpkey = RSA_generate_key(512, RSA_F4, 0, NULL);
if (tmpkey == NULL)
goto err;
if (!SSL_CTX_set_tmp_rsa(ret, tmpkey)) {
RSA_free(tmpkey);
goto err;
}
RSA_free(tmpkey); /* SSL_CTX_set_tmp_rsa uses a duplicate. */
}
#endif
return ret;
err_peek:
if (!ERR_peek_error())
goto err_return;
err:
tls_openssl_errors(err_pref_1, err_pref_2, NULL, apparg);
err_return:
SSL_CTX_free(ret);
return NULL;
}
/*****************************************************************************/
static int tls_socket_nonblocking(int fd)
{
int v, r;
v = fcntl(fd, F_GETFL, 0);
if (v == -1) {
if (errno == EINVAL)
return 0; /* already shut down -- ignore */
return -1;
}
r = fcntl(fd, F_SETFL, v | O_NONBLOCK);
if (r == -1) {
if (errno == EINVAL)
return 0; /* already shut down -- ignore */
return -1;
}
return 0;
}
static int max(int a, int b)
{
return a > b ? a : b;
}
/* timeout, -1 means no timeout */
static void
tls_sockets_select(int read_select_1, int read_select_2, int write_select_1,
int write_select_2, int seconds)
{
int maxfd, n;
fd_set reads, writes;
struct timeval timeout;
struct timeval *timeout_p;
assert(read_select_1 >= -1 && read_select_2 >= -1 && write_select_1 >= -1
&& write_select_2 >= -1);
assert(read_select_1 < FD_SETSIZE && read_select_2 < FD_SETSIZE - 1
&& write_select_1 < FD_SETSIZE - 1
&& write_select_2 < FD_SETSIZE - 1);
maxfd =
max(max(read_select_1, read_select_2),
max(write_select_1, write_select_2));
assert(maxfd >= 0);
FD_ZERO(&reads);
FD_ZERO(&writes);
for (n = 0; n < 4; ++n) {
int i = n % 2;
int w = n >= 2;
/* loop over all (i, w) in {0,1}x{0,1} */
int fd;
if (i == 0 && w == 0)
fd = read_select_1;
else if (i == 1 && w == 0)
fd = read_select_2;
else if (i == 0 && w == 1)
fd = write_select_1;
else {
assert(i == 1 && w == 1);
fd = write_select_2;
}
if (fd >= 0) {
if (w == 0)
FD_SET(fd, &reads);
else /* w == 1 */
FD_SET(fd, &writes);
}
}
if (seconds >= 0) {
timeout.tv_sec = seconds;
timeout.tv_usec = 0;
timeout_p = &timeout;
} else
timeout_p = NULL;
DEBUG_MSG2("select no.", ++tls_select_count);
select(maxfd + 1, &reads, &writes, (fd_set *) NULL, timeout_p);
DEBUG_MSG("cont.");
}
/*****************************************************************************/
#define TUNNELBUFSIZE (16*1024)
struct tunnelbuf {
char buf[TUNNELBUFSIZE];
size_t len;
size_t offset;
};
static int tls_connect_attempt(SSL *, int *write_select, int *read_select,
int *closed, int *progress,
const char **err_pref);
static int tls_accept_attempt(SSL *, int *write_select, int *read_select,
int *closed, int *progress,
const char **err_pref);
static int tls_write_attempt(SSL *, struct tunnelbuf *, int *write_select,
int *read_select, int *closed, int *progress,
const char **err_pref);
static int tls_read_attempt(SSL *, struct tunnelbuf *, int *write_select,
int *read_select, int *closed, int *progress,
const char **err_pref);
static int write_attempt(int fd, struct tunnelbuf *, int *select, int *closed,
int *progress);
static int read_attempt(int fd, struct tunnelbuf *, int *select, int *closed,
int *progress);
static void write_info(SSL *ssl, int *info_fd)
{
if (*info_fd != -1) {
long v;
int v_ok;
struct tls_x509_name_string peer;
char infobuf[TLS_INFO_SIZE];
int r;
DEBUG_MSG("write_info");
v = SSL_get_verify_result(ssl);
v_ok = (v == X509_V_OK) ? 'A' : 'E'; /* Auth./Error */
{
X509 *peercert;
peercert = SSL_get_peer_certificate(ssl);
tls_get_x509_subject_name_oneline(peercert, &peer);
X509_free(peercert);
}
if (peer.str[0] == '\0')
v_ok = '0'; /* no cert at all */
else if (strchr(peer.str, '\n')) {
/* should not happen, but make sure */
*strchr(peer.str, '\n') = '\0';
}
r = snprintf(infobuf, sizeof infobuf, "%c:%s\n%s\n", v_ok,
X509_verify_cert_error_string(v), peer.str);
DEBUG_MSG2("snprintf", r);
if (r == -1 || r >= sizeof infobuf)
r = sizeof infobuf - 1;
write(*info_fd, infobuf, r);
close(*info_fd);
*info_fd = -1;
}
}
/* tls_proxy expects that all fds are closed after return */
static void
tls_proxy(int clear_fd, int tls_fd, int info_fd, SSL_CTX *ctx, int client_p)
{
struct tunnelbuf clear_to_tls, tls_to_clear;
SSL *ssl;
BIO *rbio, *wbio;
int closed, in_handshake;
const char *err_pref_1 = "", *err_pref_2 = "";
const char *err_def = NULL;
assert(clear_fd != -1);
assert(tls_fd != -1);
assert(clear_fd < FD_SETSIZE);
assert(tls_fd < FD_SETSIZE);
/* info_fd may be -1 */
assert(ctx != NULL);
tls_rand_seed_uniquely();
tls_socket_nonblocking(clear_fd);
DEBUG_MSG2("clear_fd", clear_fd);
tls_socket_nonblocking(tls_fd);
DEBUG_MSG2("tls_fd", tls_fd);
ssl = SSL_new(ctx);
if (ssl == NULL)
goto err;
DEBUG_MSG("SSL_new");
if (!SSL_set_fd(ssl, tls_fd))
goto err;
rbio = SSL_get_rbio(ssl);
wbio = SSL_get_wbio(ssl); /* should be the same, but who cares */
assert(rbio != NULL);
assert(wbio != NULL);
if (client_p)
SSL_set_connect_state(ssl);
else
SSL_set_accept_state(ssl);
closed = 0;
in_handshake = 1;
tls_to_clear.len = 0;
tls_to_clear.offset = 0;
clear_to_tls.len = 0;
clear_to_tls.offset = 0;
err_def = "I/O error";
/*
* loop finishes as soon as we detect that one side closed; when all
* (program and OS) buffers have enough space, the data from the last
* successful read in each direction is transferred before close
*/
do {
int clear_read_select = 0, clear_write_select = 0,
tls_read_select = 0, tls_write_select = 0, progress = 0;
int r;
unsigned long num_read = BIO_number_read(rbio),
num_written = BIO_number_written(wbio);
DEBUG_MSG2("loop iteration", ++tls_loop_count);
if (in_handshake) {
DEBUG_MSG("in_handshake");
if (client_p)
r = tls_connect_attempt(ssl, &tls_write_select,
&tls_read_select, &closed, &progress,
&err_pref_1);
else
r = tls_accept_attempt(ssl, &tls_write_select,
&tls_read_select, &closed, &progress,
&err_pref_1);
if (r != 0) {
write_info(ssl, &info_fd);
goto err;
}
if (closed)
goto err_return;
if (!SSL_in_init(ssl)) {
in_handshake = 0;
write_info(ssl, &info_fd);
}
}
if (clear_to_tls.len != 0 && !in_handshake) {
assert(!closed);
r = tls_write_attempt(ssl, &clear_to_tls, &tls_write_select,
&tls_read_select, &closed, &progress,
&err_pref_1);
if (r != 0)
goto err;
if (closed) {
assert(progress);
tls_to_clear.offset = 0;
tls_to_clear.len = 0;
}
}
if (tls_to_clear.len != 0) {
assert(!closed);
r = write_attempt(clear_fd, &tls_to_clear, &clear_write_select,
&closed, &progress);
if (r != 0)
goto err_return;
if (closed) {
assert(progress);
clear_to_tls.offset = 0;
clear_to_tls.len = 0;
}
}
if (!closed) {
if (clear_to_tls.offset + clear_to_tls.len <
sizeof clear_to_tls.buf) {
r = read_attempt(clear_fd, &clear_to_tls, &clear_read_select,
&closed, &progress);
if (r != 0)
goto err_return;
if (closed) {
r = SSL_shutdown(ssl);
DEBUG_MSG2("SSL_shutdown", r);
}
}
}
if (!closed && !in_handshake) {
if (tls_to_clear.offset + tls_to_clear.len <
sizeof tls_to_clear.buf) {
r = tls_read_attempt(ssl, &tls_to_clear, &tls_write_select,
&tls_read_select, &closed, &progress,
&err_pref_1);
if (r != 0)
goto err;
if (closed) {
r = SSL_shutdown(ssl);
DEBUG_MSG2("SSL_shutdown", r);
}
}
}
if (!progress) {
DEBUG_MSG("!progress?");
if (num_read != BIO_number_read(rbio)
|| num_written != BIO_number_written(wbio))
progress = 1;
if (!progress) {
DEBUG_MSG("!progress");
assert(clear_read_select || tls_read_select
|| clear_write_select || tls_write_select);
tls_sockets_select(clear_read_select ? clear_fd : -1,
tls_read_select ? tls_fd : -1,
clear_write_select ? clear_fd : -1,
tls_write_select ? tls_fd : -1, -1);
}
}
} while (!closed);
return;
err:
tls_openssl_errors(err_pref_1, err_pref_2, err_def, tls_child_apparg);
err_return:
return;
}
static int
tls_get_error(SSL *ssl, int r, int *write_select, int *read_select,
int *closed, int *progress)
{
int err = SSL_get_error(ssl, r);
if (err == SSL_ERROR_NONE) {
assert(r > 0);
*progress = 1;
return 0;
}
assert(r <= 0);
switch (err) {
case SSL_ERROR_ZERO_RETURN:
assert(r == 0);
*closed = 1;
*progress = 1;
return 0;
case SSL_ERROR_WANT_WRITE:
*write_select = 1;
return 0;
case SSL_ERROR_WANT_READ:
*read_select = 1;
return 0;
}
return -1;
}
static int
tls_connect_attempt(SSL *ssl, int *write_select, int *read_select,
int *closed, int *progress, const char **err_pref)
{
int n, r;
DEBUG_MSG("tls_connect_attempt");
n = SSL_connect(ssl);
DEBUG_MSG2("SSL_connect", n);
r = tls_get_error(ssl, n, write_select, read_select, closed, progress);
if (r == -1)
*err_pref = " during SSL_connect";
return r;
}
static int
tls_accept_attempt(SSL *ssl, int *write_select, int *read_select, int *closed,
int *progress, const char **err_pref)
{
int n, r;
DEBUG_MSG("tls_accept_attempt");
n = SSL_accept(ssl);
DEBUG_MSG2("SSL_accept", n);
r = tls_get_error(ssl, n, write_select, read_select, closed, progress);
if (r == -1)
*err_pref = " during SSL_accept";
return r;
}
static int
tls_write_attempt(SSL *ssl, struct tunnelbuf *buf, int *write_select,
int *read_select, int *closed, int *progress,
const char **err_pref)
{
int n, r;
DEBUG_MSG("tls_write_attempt");
n = SSL_write(ssl, buf->buf + buf->offset, buf->len);
DEBUG_MSG2("SSL_write", n);
r = tls_get_error(ssl, n, write_select, read_select, closed, progress);
if (n > 0) {
buf->len -= n;
assert(buf->len >= 0);
if (buf->len == 0)
buf->offset = 0;
else
buf->offset += n;
}
if (r == -1)
*err_pref = " during SSL_write";
return r;
}
static int
tls_read_attempt(SSL *ssl, struct tunnelbuf *buf, int *write_select,
int *read_select, int *closed, int *progress,
const char **err_pref)
{
int n, r;
size_t total;
DEBUG_MSG("tls_read_attempt");
total = buf->offset + buf->len;
assert(total < sizeof buf->buf);
n = SSL_read(ssl, buf->buf + total, (sizeof buf->buf) - total);
DEBUG_MSG2("SSL_read", n);
r = tls_get_error(ssl, n, write_select, read_select, closed, progress);
if (n > 0) {
buf->len += n;
assert(buf->offset + buf->len <= sizeof buf->buf);
}
if (r == -1)
*err_pref = " during SSL_read";
return r;
}
static int get_error(int r, int *select, int *closed, int *progress)
{
if (r >= 0) {
*progress = 1;
if (r == 0)
*closed = 1;
return 0;
} else {
assert(r == -1);
if (errno == EAGAIN || errno == EWOULDBLOCK) {
*select = 1;
return 0;
} else if (errno == EPIPE) {
*progress = 1;
*closed = 1;
return 0;
} else
return -1;
}
}
static int write_attempt(int fd, struct tunnelbuf *buf, int *select,
int *closed, int *progress)
{
int n, r;
DEBUG_MSG("write_attempt");
n = write(fd, buf->buf + buf->offset, buf->len);
DEBUG_MSG2("write", n);
r = get_error(n, select, closed, progress);
if (n > 0) {
buf->len -= n;
assert(buf->len >= 0);
if (buf->len == 0)
buf->offset = 0;
else
buf->offset += n;
}
if (r == -1)
tls_errprintf(1, tls_child_apparg, "write error: %s\n",
strerror(errno));
return r;
}
static int
read_attempt(int fd, struct tunnelbuf *buf, int *select, int *closed,
int *progress)
{
int n, r;
size_t total;
DEBUG_MSG("read_attempt");
total = buf->offset + buf->len;
assert(total < sizeof buf->buf);
n = read(fd, buf->buf + total, (sizeof buf->buf) - total);
DEBUG_MSG2("read", n);
r = get_error(n, select, closed, progress);
if (n > 0) {
buf->len += n;
assert(buf->offset + buf->len <= sizeof buf->buf);
}
if (r == -1)
tls_errprintf(1, tls_child_apparg, "read error: %s\n",
strerror(errno));
return r;
}
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