hiredis/ssl.c

468 lines
13 KiB
C

/*
* Copyright (c) 2009-2011, Salvatore Sanfilippo <antirez at gmail dot com>
* Copyright (c) 2010-2011, Pieter Noordhuis <pcnoordhuis at gmail dot com>
* Copyright (c) 2019, Redis Labs
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * 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.
* * Neither the name of Redis nor the names of its contributors may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS 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 THE COPYRIGHT OWNER OR 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.
*/
#include "hiredis.h"
#include "async.h"
#include <assert.h>
#include <errno.h>
#include <string.h>
#ifdef WIN32
#include <windows.h>
#else
#include <pthread.h>
#endif
#include <openssl/ssl.h>
#include <openssl/err.h>
#include "win32.h"
#include "async_private.h"
void __redisSetError(redisContext *c, int type, const char *str);
/* The SSL context is attached to SSL/TLS connections as a privdata. */
typedef struct redisSSLContext {
/**
* OpenSSL SSL_CTX; It is optional and will not be set when using
* user-supplied SSL.
*/
SSL_CTX *ssl_ctx;
/**
* OpenSSL SSL object.
*/
SSL *ssl;
/**
* SSL_write() requires to be called again with the same arguments it was
* previously called with in the event of an SSL_read/SSL_write situation
*/
size_t lastLen;
/** Whether the SSL layer requires read (possibly before a write) */
int wantRead;
/**
* Whether a write was requested prior to a read. If set, the write()
* should resume whenever a read takes place, if possible
*/
int pendingWrite;
} redisSSLContext;
/* Forward declaration */
redisContextFuncs redisContextSSLFuncs;
#ifdef HIREDIS_SSL_TRACE
/**
* Callback used for debugging
*/
static void sslLogCallback(const SSL *ssl, int where, int ret) {
const char *retstr;
int should_log = 0;
/* Ignore low-level SSL stuff */
if (where & SSL_CB_ALERT) {
should_log = 1;
}
if (where == SSL_CB_HANDSHAKE_START || where == SSL_CB_HANDSHAKE_DONE) {
should_log = 1;
}
if ((where & SSL_CB_EXIT) && ret == 0) {
should_log = 1;
}
if (!should_log) {
return;
}
retstr = SSL_alert_type_string(ret);
printf("ST(0x%x). %s. R(0x%x)%s\n", where, SSL_state_string_long(ssl), ret, retstr);
if (where == SSL_CB_HANDSHAKE_DONE) {
printf("Using SSL version %s. Cipher=%s\n", SSL_get_version(ssl), SSL_get_cipher_name(ssl));
}
}
#endif
/**
* OpenSSL global initialization and locking handling callbacks.
* Note that this is only required for OpenSSL < 1.1.0.
*/
#if OPENSSL_VERSION_NUMBER < 0x10100000L
#define HIREDIS_USE_CRYPTO_LOCKS
#endif
#ifdef HIREDIS_USE_CRYPTO_LOCKS
#ifdef WIN32
typedef CRITICAL_SECTION sslLockType;
static void sslLockInit(sslLockType* l) {
InitializeCriticalSection(l);
}
static void sslLockAcquire(sslLockType* l) {
EnterCriticalSection(l);
}
static void sslLockRelease(sslLockType* l) {
LeaveCriticalSection(l);
}
#else
typedef pthread_mutex_t sslLockType;
static void sslLockInit(sslLockType *l) {
pthread_mutex_init(l, NULL);
}
static void sslLockAcquire(sslLockType *l) {
pthread_mutex_lock(l);
}
static void sslLockRelease(sslLockType *l) {
pthread_mutex_unlock(l);
}
#endif
static sslLockType* ossl_locks;
static void opensslDoLock(int mode, int lkid, const char *f, int line) {
sslLockType *l = ossl_locks + lkid;
if (mode & CRYPTO_LOCK) {
sslLockAcquire(l);
} else {
sslLockRelease(l);
}
(void)f;
(void)line;
}
static void initOpensslLocks(void) {
unsigned ii, nlocks;
if (CRYPTO_get_locking_callback() != NULL) {
/* Someone already set the callback before us. Don't destroy it! */
return;
}
nlocks = CRYPTO_num_locks();
ossl_locks = hi_malloc(sizeof(*ossl_locks) * nlocks);
for (ii = 0; ii < nlocks; ii++) {
sslLockInit(ossl_locks + ii);
}
CRYPTO_set_locking_callback(opensslDoLock);
}
#endif /* HIREDIS_USE_CRYPTO_LOCKS */
/**
* SSL Connection initialization.
*/
static int redisSSLConnect(redisContext *c, SSL_CTX *ssl_ctx, SSL *ssl) {
if (c->privdata) {
__redisSetError(c, REDIS_ERR_OTHER, "redisContext was already associated");
return REDIS_ERR;
}
c->privdata = calloc(1, sizeof(redisSSLContext));
c->funcs = &redisContextSSLFuncs;
redisSSLContext *rssl = c->privdata;
rssl->ssl_ctx = ssl_ctx;
rssl->ssl = ssl;
SSL_set_mode(rssl->ssl, SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
SSL_set_fd(rssl->ssl, c->fd);
SSL_set_connect_state(rssl->ssl);
ERR_clear_error();
int rv = SSL_connect(rssl->ssl);
if (rv == 1) {
return REDIS_OK;
}
rv = SSL_get_error(rssl->ssl, rv);
if (((c->flags & REDIS_BLOCK) == 0) &&
(rv == SSL_ERROR_WANT_READ || rv == SSL_ERROR_WANT_WRITE)) {
return REDIS_OK;
}
if (c->err == 0) {
char err[512];
if (rv == SSL_ERROR_SYSCALL)
snprintf(err,sizeof(err)-1,"SSL_connect failed: %s",strerror(errno));
else {
unsigned long e = ERR_peek_last_error();
snprintf(err,sizeof(err)-1,"SSL_connect failed: %s",
ERR_reason_error_string(e));
}
__redisSetError(c, REDIS_ERR_IO, err);
}
return REDIS_ERR;
}
int redisInitiateSSL(redisContext *c, SSL *ssl) {
return redisSSLConnect(c, NULL, ssl);
}
int redisSecureConnection(redisContext *c, const char *capath,
const char *certpath, const char *keypath, const char *servername) {
SSL_CTX *ssl_ctx = NULL;
SSL *ssl = NULL;
/* Initialize global OpenSSL stuff */
static int isInit = 0;
if (!isInit) {
isInit = 1;
SSL_library_init();
#ifdef HIREDIS_USE_CRYPTO_LOCKS
initOpensslLocks();
#endif
}
ssl_ctx = SSL_CTX_new(SSLv23_client_method());
if (!ssl_ctx) {
__redisSetError(c, REDIS_ERR_OTHER, "Failed to create SSL_CTX");
goto error;
}
#ifdef HIREDIS_SSL_TRACE
SSL_CTX_set_info_callback(ssl_ctx, sslLogCallback);
#endif
SSL_CTX_set_options(ssl_ctx, SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3);
SSL_CTX_set_verify(ssl_ctx, SSL_VERIFY_PEER, NULL);
if ((certpath != NULL && keypath == NULL) || (keypath != NULL && certpath == NULL)) {
__redisSetError(c, REDIS_ERR_OTHER, "certpath and keypath must be specified together");
goto error;
}
if (capath) {
if (!SSL_CTX_load_verify_locations(ssl_ctx, capath, NULL)) {
__redisSetError(c, REDIS_ERR_OTHER, "Invalid CA certificate");
goto error;
}
}
if (certpath) {
if (!SSL_CTX_use_certificate_chain_file(ssl_ctx, certpath)) {
__redisSetError(c, REDIS_ERR_OTHER, "Invalid client certificate");
goto error;
}
if (!SSL_CTX_use_PrivateKey_file(ssl_ctx, keypath, SSL_FILETYPE_PEM)) {
__redisSetError(c, REDIS_ERR_OTHER, "Invalid client key");
goto error;
}
}
ssl = SSL_new(ssl_ctx);
if (!ssl) {
__redisSetError(c, REDIS_ERR_OTHER, "Couldn't create new SSL instance");
goto error;
}
if (servername) {
if (!SSL_set_tlsext_host_name(ssl, servername)) {
__redisSetError(c, REDIS_ERR_OTHER, "Couldn't set server name indication");
goto error;
}
}
return redisSSLConnect(c, ssl_ctx, ssl);
error:
if (ssl) SSL_free(ssl);
if (ssl_ctx) SSL_CTX_free(ssl_ctx);
return REDIS_ERR;
}
static int maybeCheckWant(redisSSLContext *rssl, int rv) {
/**
* If the error is WANT_READ or WANT_WRITE, the appropriate flags are set
* and true is returned. False is returned otherwise
*/
if (rv == SSL_ERROR_WANT_READ) {
rssl->wantRead = 1;
return 1;
} else if (rv == SSL_ERROR_WANT_WRITE) {
rssl->pendingWrite = 1;
return 1;
} else {
return 0;
}
}
/**
* Implementation of redisContextFuncs for SSL connections.
*/
static void redisSSLFreeContext(void *privdata){
redisSSLContext *rsc = privdata;
if (!rsc) return;
if (rsc->ssl) {
SSL_free(rsc->ssl);
rsc->ssl = NULL;
}
if (rsc->ssl_ctx) {
SSL_CTX_free(rsc->ssl_ctx);
rsc->ssl_ctx = NULL;
}
free(rsc);
}
static int redisSSLRead(redisContext *c, char *buf, size_t bufcap) {
redisSSLContext *rssl = c->privdata;
int nread = SSL_read(rssl->ssl, buf, bufcap);
if (nread > 0) {
return nread;
} else if (nread == 0) {
__redisSetError(c, REDIS_ERR_EOF, "Server closed the connection");
return -1;
} else {
int err = SSL_get_error(rssl->ssl, nread);
if (c->flags & REDIS_BLOCK) {
/**
* In blocking mode, we should never end up in a situation where
* we get an error without it being an actual error, except
* in the case of EINTR, which can be spuriously received from
* debuggers or whatever.
*/
if (errno == EINTR) {
return 0;
} else {
const char *msg = NULL;
if (errno == EAGAIN) {
msg = "Resource temporarily unavailable";
}
__redisSetError(c, REDIS_ERR_IO, msg);
return -1;
}
}
/**
* We can very well get an EWOULDBLOCK/EAGAIN, however
*/
if (maybeCheckWant(rssl, err)) {
return 0;
} else {
__redisSetError(c, REDIS_ERR_IO, NULL);
return -1;
}
}
}
static int redisSSLWrite(redisContext *c) {
redisSSLContext *rssl = c->privdata;
size_t len = rssl->lastLen ? rssl->lastLen : sdslen(c->obuf);
int rv = SSL_write(rssl->ssl, c->obuf, len);
if (rv > 0) {
rssl->lastLen = 0;
} else if (rv < 0) {
rssl->lastLen = len;
int err = SSL_get_error(rssl->ssl, rv);
if ((c->flags & REDIS_BLOCK) == 0 && maybeCheckWant(rssl, err)) {
return 0;
} else {
__redisSetError(c, REDIS_ERR_IO, NULL);
return -1;
}
}
return rv;
}
static void redisSSLAsyncRead(redisAsyncContext *ac) {
int rv;
redisSSLContext *rssl = ac->c.privdata;
redisContext *c = &ac->c;
rssl->wantRead = 0;
if (rssl->pendingWrite) {
int done;
/* This is probably just a write event */
rssl->pendingWrite = 0;
rv = redisBufferWrite(c, &done);
if (rv == REDIS_ERR) {
__redisAsyncDisconnect(ac);
return;
} else if (!done) {
_EL_ADD_WRITE(ac);
}
}
rv = redisBufferRead(c);
if (rv == REDIS_ERR) {
__redisAsyncDisconnect(ac);
} else {
_EL_ADD_READ(ac);
redisProcessCallbacks(ac);
}
}
static void redisSSLAsyncWrite(redisAsyncContext *ac) {
int rv, done = 0;
redisSSLContext *rssl = ac->c.privdata;
redisContext *c = &ac->c;
rssl->pendingWrite = 0;
rv = redisBufferWrite(c, &done);
if (rv == REDIS_ERR) {
__redisAsyncDisconnect(ac);
return;
}
if (!done) {
if (rssl->wantRead) {
/* Need to read-before-write */
rssl->pendingWrite = 1;
_EL_DEL_WRITE(ac);
} else {
/* No extra reads needed, just need to write more */
_EL_ADD_WRITE(ac);
}
} else {
/* Already done! */
_EL_DEL_WRITE(ac);
}
/* Always reschedule a read */
_EL_ADD_READ(ac);
}
redisContextFuncs redisContextSSLFuncs = {
.free_privdata = redisSSLFreeContext,
.async_read = redisSSLAsyncRead,
.async_write = redisSSLAsyncWrite,
.read = redisSSLRead,
.write = redisSSLWrite
};