openssl/ssl/bio_ssl.c
Matt Caswell b46fe860fe Fix BIO_pop for SSL BIOs
The BIO_pop implementation assumes that the rbio still equals the next BIO
in the chain. While this would normally be the case, it is possible that it
could have been changed directly by the application. It also does not
properly cater for the scenario where the buffering BIO is still in place
for the write BIO.

Most of the existing BIO_pop code for SSL BIOs can be replaced by a single
call to SSL_set_bio(). This is equivalent to the existing code but
additionally handles the scenario where the rbio has been changed or the
buffering BIO is still in place.

Reviewed-by: Rich Salz <rsalz@openssl.org>
2016-07-29 14:09:57 +01:00

529 lines
13 KiB
C

/*
* Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <openssl/crypto.h>
#include "internal/bio.h"
#include <openssl/err.h>
#include "ssl_locl.h"
static int ssl_write(BIO *h, const char *buf, int num);
static int ssl_read(BIO *h, char *buf, int size);
static int ssl_puts(BIO *h, const char *str);
static long ssl_ctrl(BIO *h, int cmd, long arg1, void *arg2);
static int ssl_new(BIO *h);
static int ssl_free(BIO *data);
static long ssl_callback_ctrl(BIO *h, int cmd, bio_info_cb *fp);
typedef struct bio_ssl_st {
SSL *ssl; /* The ssl handle :-) */
/* re-negotiate every time the total number of bytes is this size */
int num_renegotiates;
unsigned long renegotiate_count;
unsigned long byte_count;
unsigned long renegotiate_timeout;
unsigned long last_time;
} BIO_SSL;
static const BIO_METHOD methods_sslp = {
BIO_TYPE_SSL, "ssl",
ssl_write,
ssl_read,
ssl_puts,
NULL, /* ssl_gets, */
ssl_ctrl,
ssl_new,
ssl_free,
ssl_callback_ctrl,
};
const BIO_METHOD *BIO_f_ssl(void)
{
return (&methods_sslp);
}
static int ssl_new(BIO *bi)
{
BIO_SSL *bs = OPENSSL_zalloc(sizeof(*bs));
if (bs == NULL) {
BIOerr(BIO_F_SSL_NEW, ERR_R_MALLOC_FAILURE);
return (0);
}
BIO_set_init(bi, 0);
BIO_set_data(bi, bs);
/* Clear all flags */
BIO_clear_flags(bi, ~0);
return 1;
}
static int ssl_free(BIO *a)
{
BIO_SSL *bs;
if (a == NULL)
return (0);
bs = BIO_get_data(a);
if (bs->ssl != NULL)
SSL_shutdown(bs->ssl);
if (BIO_get_shutdown(a)) {
if (BIO_get_init(a))
SSL_free(bs->ssl);
/* Clear all flags */
BIO_clear_flags(a, ~0);
BIO_set_init(a, 0);
}
OPENSSL_free(bs);
return 1;
}
static int ssl_read(BIO *b, char *out, int outl)
{
int ret = 1;
BIO_SSL *sb;
SSL *ssl;
int retry_reason = 0;
int r = 0;
if (out == NULL)
return (0);
sb = BIO_get_data(b);
ssl = sb->ssl;
BIO_clear_retry_flags(b);
ret = SSL_read(ssl, out, outl);
switch (SSL_get_error(ssl, ret)) {
case SSL_ERROR_NONE:
if (ret <= 0)
break;
if (sb->renegotiate_count > 0) {
sb->byte_count += ret;
if (sb->byte_count > sb->renegotiate_count) {
sb->byte_count = 0;
sb->num_renegotiates++;
SSL_renegotiate(ssl);
r = 1;
}
}
if ((sb->renegotiate_timeout > 0) && (!r)) {
unsigned long tm;
tm = (unsigned long)time(NULL);
if (tm > sb->last_time + sb->renegotiate_timeout) {
sb->last_time = tm;
sb->num_renegotiates++;
SSL_renegotiate(ssl);
}
}
break;
case SSL_ERROR_WANT_READ:
BIO_set_retry_read(b);
break;
case SSL_ERROR_WANT_WRITE:
BIO_set_retry_write(b);
break;
case SSL_ERROR_WANT_X509_LOOKUP:
BIO_set_retry_special(b);
retry_reason = BIO_RR_SSL_X509_LOOKUP;
break;
case SSL_ERROR_WANT_ACCEPT:
BIO_set_retry_special(b);
retry_reason = BIO_RR_ACCEPT;
break;
case SSL_ERROR_WANT_CONNECT:
BIO_set_retry_special(b);
retry_reason = BIO_RR_CONNECT;
break;
case SSL_ERROR_SYSCALL:
case SSL_ERROR_SSL:
case SSL_ERROR_ZERO_RETURN:
default:
break;
}
BIO_set_retry_reason(b, retry_reason);
return (ret);
}
static int ssl_write(BIO *b, const char *out, int outl)
{
int ret, r = 0;
int retry_reason = 0;
SSL *ssl;
BIO_SSL *bs;
if (out == NULL)
return (0);
bs = BIO_get_data(b);
ssl = bs->ssl;
BIO_clear_retry_flags(b);
/*
* ret=SSL_do_handshake(ssl); if (ret > 0)
*/
ret = SSL_write(ssl, out, outl);
switch (SSL_get_error(ssl, ret)) {
case SSL_ERROR_NONE:
if (ret <= 0)
break;
if (bs->renegotiate_count > 0) {
bs->byte_count += ret;
if (bs->byte_count > bs->renegotiate_count) {
bs->byte_count = 0;
bs->num_renegotiates++;
SSL_renegotiate(ssl);
r = 1;
}
}
if ((bs->renegotiate_timeout > 0) && (!r)) {
unsigned long tm;
tm = (unsigned long)time(NULL);
if (tm > bs->last_time + bs->renegotiate_timeout) {
bs->last_time = tm;
bs->num_renegotiates++;
SSL_renegotiate(ssl);
}
}
break;
case SSL_ERROR_WANT_WRITE:
BIO_set_retry_write(b);
break;
case SSL_ERROR_WANT_READ:
BIO_set_retry_read(b);
break;
case SSL_ERROR_WANT_X509_LOOKUP:
BIO_set_retry_special(b);
retry_reason = BIO_RR_SSL_X509_LOOKUP;
break;
case SSL_ERROR_WANT_CONNECT:
BIO_set_retry_special(b);
retry_reason = BIO_RR_CONNECT;
case SSL_ERROR_SYSCALL:
case SSL_ERROR_SSL:
default:
break;
}
BIO_set_retry_reason(b, retry_reason);
return ret;
}
static long ssl_ctrl(BIO *b, int cmd, long num, void *ptr)
{
SSL **sslp, *ssl;
BIO_SSL *bs, *dbs;
BIO *dbio, *bio;
long ret = 1;
BIO *next;
bs = BIO_get_data(b);
next = BIO_next(b);
ssl = bs->ssl;
if ((ssl == NULL) && (cmd != BIO_C_SET_SSL))
return (0);
switch (cmd) {
case BIO_CTRL_RESET:
SSL_shutdown(ssl);
if (ssl->handshake_func == ssl->method->ssl_connect)
SSL_set_connect_state(ssl);
else if (ssl->handshake_func == ssl->method->ssl_accept)
SSL_set_accept_state(ssl);
if (!SSL_clear(ssl)) {
ret = 0;
break;
}
if (next != NULL)
ret = BIO_ctrl(next, cmd, num, ptr);
else if (ssl->rbio != NULL)
ret = BIO_ctrl(ssl->rbio, cmd, num, ptr);
else
ret = 1;
break;
case BIO_CTRL_INFO:
ret = 0;
break;
case BIO_C_SSL_MODE:
if (num) /* client mode */
SSL_set_connect_state(ssl);
else
SSL_set_accept_state(ssl);
break;
case BIO_C_SET_SSL_RENEGOTIATE_TIMEOUT:
ret = bs->renegotiate_timeout;
if (num < 60)
num = 5;
bs->renegotiate_timeout = (unsigned long)num;
bs->last_time = (unsigned long)time(NULL);
break;
case BIO_C_SET_SSL_RENEGOTIATE_BYTES:
ret = bs->renegotiate_count;
if ((long)num >= 512)
bs->renegotiate_count = (unsigned long)num;
break;
case BIO_C_GET_SSL_NUM_RENEGOTIATES:
ret = bs->num_renegotiates;
break;
case BIO_C_SET_SSL:
if (ssl != NULL) {
ssl_free(b);
if (!ssl_new(b))
return 0;
}
BIO_set_shutdown(b, num);
ssl = (SSL *)ptr;
bs->ssl = ssl;
bio = SSL_get_rbio(ssl);
if (bio != NULL) {
if (next != NULL)
BIO_push(bio, next);
BIO_set_next(b, bio);
BIO_up_ref(bio);
}
BIO_set_init(b, 1);
break;
case BIO_C_GET_SSL:
if (ptr != NULL) {
sslp = (SSL **)ptr;
*sslp = ssl;
} else
ret = 0;
break;
case BIO_CTRL_GET_CLOSE:
ret = BIO_get_shutdown(b);
break;
case BIO_CTRL_SET_CLOSE:
BIO_set_shutdown(b, (int)num);
break;
case BIO_CTRL_WPENDING:
ret = BIO_ctrl(ssl->wbio, cmd, num, ptr);
break;
case BIO_CTRL_PENDING:
ret = SSL_pending(ssl);
if (ret == 0)
ret = BIO_pending(ssl->rbio);
break;
case BIO_CTRL_FLUSH:
BIO_clear_retry_flags(b);
ret = BIO_ctrl(ssl->wbio, cmd, num, ptr);
BIO_copy_next_retry(b);
break;
case BIO_CTRL_PUSH:
if ((next != NULL) && (next != ssl->rbio)) {
/*
* We are going to pass ownership of next to the SSL object...but
* we don't own a reference to pass yet - so up ref
*/
BIO_up_ref(next);
SSL_set_bio(ssl, next, next);
}
break;
case BIO_CTRL_POP:
/* Only detach if we are the BIO explicitly being popped */
if (b == ptr) {
/* This will clear the reference we obtained during push */
SSL_set_bio(ssl, NULL, NULL);
}
break;
case BIO_C_DO_STATE_MACHINE:
BIO_clear_retry_flags(b);
BIO_set_retry_reason(b, 0);
ret = (int)SSL_do_handshake(ssl);
switch (SSL_get_error(ssl, (int)ret)) {
case SSL_ERROR_WANT_READ:
BIO_set_flags(b, BIO_FLAGS_READ | BIO_FLAGS_SHOULD_RETRY);
break;
case SSL_ERROR_WANT_WRITE:
BIO_set_flags(b, BIO_FLAGS_WRITE | BIO_FLAGS_SHOULD_RETRY);
break;
case SSL_ERROR_WANT_CONNECT:
BIO_set_flags(b, BIO_FLAGS_IO_SPECIAL | BIO_FLAGS_SHOULD_RETRY);
BIO_set_retry_reason(b, BIO_get_retry_reason(next));
break;
case SSL_ERROR_WANT_X509_LOOKUP:
BIO_set_retry_special(b);
BIO_set_retry_reason(b, BIO_RR_SSL_X509_LOOKUP);
break;
default:
break;
}
break;
case BIO_CTRL_DUP:
dbio = (BIO *)ptr;
dbs = BIO_get_data(dbio);
SSL_free(dbs->ssl);
dbs->ssl = SSL_dup(ssl);
dbs->num_renegotiates = bs->num_renegotiates;
dbs->renegotiate_count = bs->renegotiate_count;
dbs->byte_count = bs->byte_count;
dbs->renegotiate_timeout = bs->renegotiate_timeout;
dbs->last_time = bs->last_time;
ret = (dbs->ssl != NULL);
break;
case BIO_C_GET_FD:
ret = BIO_ctrl(ssl->rbio, cmd, num, ptr);
break;
case BIO_CTRL_SET_CALLBACK:
{
#if 0 /* FIXME: Should this be used? -- Richard
* Levitte */
SSLerr(SSL_F_SSL_CTRL, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
ret = -1;
#else
ret = 0;
#endif
}
break;
case BIO_CTRL_GET_CALLBACK:
{
void (**fptr) (const SSL *xssl, int type, int val);
fptr = (void (**)(const SSL *xssl, int type, int val))ptr;
*fptr = SSL_get_info_callback(ssl);
}
break;
default:
ret = BIO_ctrl(ssl->rbio, cmd, num, ptr);
break;
}
return (ret);
}
static long ssl_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
{
SSL *ssl;
BIO_SSL *bs;
long ret = 1;
bs = BIO_get_data(b);
ssl = bs->ssl;
switch (cmd) {
case BIO_CTRL_SET_CALLBACK:
{
/*
* FIXME: setting this via a completely different prototype seems
* like a crap idea
*/
SSL_set_info_callback(ssl, (void (*)(const SSL *, int, int))fp);
}
break;
default:
ret = BIO_callback_ctrl(ssl->rbio, cmd, fp);
break;
}
return (ret);
}
static int ssl_puts(BIO *bp, const char *str)
{
int n, ret;
n = strlen(str);
ret = BIO_write(bp, str, n);
return (ret);
}
BIO *BIO_new_buffer_ssl_connect(SSL_CTX *ctx)
{
#ifndef OPENSSL_NO_SOCK
BIO *ret = NULL, *buf = NULL, *ssl = NULL;
if ((buf = BIO_new(BIO_f_buffer())) == NULL)
return (NULL);
if ((ssl = BIO_new_ssl_connect(ctx)) == NULL)
goto err;
if ((ret = BIO_push(buf, ssl)) == NULL)
goto err;
return (ret);
err:
BIO_free(buf);
BIO_free(ssl);
#endif
return (NULL);
}
BIO *BIO_new_ssl_connect(SSL_CTX *ctx)
{
#ifndef OPENSSL_NO_SOCK
BIO *ret = NULL, *con = NULL, *ssl = NULL;
if ((con = BIO_new(BIO_s_connect())) == NULL)
return (NULL);
if ((ssl = BIO_new_ssl(ctx, 1)) == NULL)
goto err;
if ((ret = BIO_push(ssl, con)) == NULL)
goto err;
return (ret);
err:
BIO_free(con);
#endif
return (NULL);
}
BIO *BIO_new_ssl(SSL_CTX *ctx, int client)
{
BIO *ret;
SSL *ssl;
if ((ret = BIO_new(BIO_f_ssl())) == NULL)
return (NULL);
if ((ssl = SSL_new(ctx)) == NULL) {
BIO_free(ret);
return (NULL);
}
if (client)
SSL_set_connect_state(ssl);
else
SSL_set_accept_state(ssl);
BIO_set_ssl(ret, ssl, BIO_CLOSE);
return (ret);
}
int BIO_ssl_copy_session_id(BIO *t, BIO *f)
{
BIO_SSL *tdata, *fdata;
t = BIO_find_type(t, BIO_TYPE_SSL);
f = BIO_find_type(f, BIO_TYPE_SSL);
if ((t == NULL) || (f == NULL))
return 0;
tdata = BIO_get_data(t);
fdata = BIO_get_data(f);
if ((tdata->ssl == NULL) || (fdata->ssl == NULL))
return (0);
if (!SSL_copy_session_id(tdata->ssl, (fdata->ssl)))
return 0;
return (1);
}
void BIO_ssl_shutdown(BIO *b)
{
SSL *s;
b = BIO_find_type(b, BIO_TYPE_SSL);
if (b == NULL)
return;
s = BIO_get_data(b);
SSL_shutdown(s);
}