[openssl-users] OpenSSL 1.1.0 assertion failure: ssl_free_wbio_buffer()
Hello,
we encountered a strange behaviour of OpenSSL 1.1.0 when our test with "sslscan" provokes an unfinished
handshake. The problem exists since OpenSSL 1.1.0 - there were no problems with OpenSSL 1.0.2x.
Our asynchronous communication approach uses memory BIOs in order to read/write data from other
communication layers into the SSL object. After the read/write operations are done, the BIOs are freed.
Our example code is basically as follows:
---
err = SSL_accept (ssl);
BIO *rBIO = BIO_new(BIO_s_mem());
BIO *wBIO = BIO_new(BIO_s_mem());
SSL_set_bio(ssl, rBIO, wBIO);
// ... operate with read / write BIOs and SSL_read/SSL_write
SSL_set_bio(ssl, NULL, NULL); // free BIOs when finished
SSL_free(ssl);
---
When calling SSL_free() after a complete handshake, everything is fine, but when calling SSL_free() after an
unfinished handshake, the assertion "assert(s->wbio != NULL);" in ssl_free_wbio_buffer() fails:
---
void ssl_free_wbio_buffer(SSL *s)
{
/* callers ensure s is never null */
if (s->bbio == NULL)
return;
s->wbio = BIO_pop(s->wbio);
assert(s->wbio != NULL); /* <- this assertion fails! */
BIO_free(s->bbio);
s->bbio = NULL;
}
---
With a complete handshake the new attribute “bbio” is freed by calling the method tls_finish_handshake(),
which itself calls ssl_free_wbio_buffer(). When the handshake is not finished successfully, the “bbio” is not freed, and
therefore when calling SSL_free() the assert in ssl_free_wbio_buffer() fails.
Is this a faulty behavior of OpenSSL 1.1.0 or is the fault on my side?
Thank you for your help!
Best regards,
Marcus
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[openssl-users] Assertion in ssl_free_wbio_buffer() fails after unfinished handshake since OpenSSL 1.1.0
Hello,
we encountered a strange behaviour of OpenSSL 1.1.0 when our test with "sslscan" provokes an unfinished
handshake.
Our asynchronous communication approach uses memory BIOs in order to read/write data from other
communication layers into the SSL object. After the read/write operations are done the BIOs are freed.
Our example code is basically as follows:
---
err = SSL_accept (ssl);
BIO *rBIO = BIO_new(BIO_s_mem());
BIO *wBIO = BIO_new(BIO_s_mem());
SSL_set_bio(ssl, rBIO, wBIO);
// ... operate with read / write BIOs and SSL_read/SSL_write
SSL_set_bio(ssl, NULL, NULL); // free BIOs when finished
SSL_free(ssl);
---
When calling SSL_free() after a complete handshake, everything is fine, but when calling SSL_free() after an
unfinished handshake, the assertion "assert(s->wbio != NULL);" in ssl_free_wbio_buffer() fails:
---
void ssl_free_wbio_buffer(SSL *s)
{
/* callers ensure s is never null */
if (s->bbio == NULL)
return;
s->wbio = BIO_pop(s->wbio);
assert(s->wbio != NULL);/* <- this assertion fails! */
BIO_free(s->bbio);
s->bbio = NULL;
}
---
With a complete handshake the new attribute “bbio” is freed by calling the method tls_finish_handshake(),
which itself calls ssl_free_wbio_buffer(). When the handshake is not finished successfully, the “bbio” is not freed, and
therefore when calling SSL_free() the assert in ssl_free_wbio_buffer() fails.
The problem exists since OpenSSL 1.1.0 - there were no problems with OpenSSL 1.0.2x.
Is this a faulty behavior of the OpenSSL 1.1.0?
Thank you for your help!
Best regards,
Marcus
--
openssl-users mailing list
To unsubscribe: https://mta.openssl.org/mailman/listinfo/openssl-users
[openssl-users] Deactivation of client renegotiation particularily in OpenSSL 1.1.0
Hello, I am referring to the DoS via repeated SSL session renegotiations (http://kalilinuxtutorials.com/thc-ssl-dos/). Prior to OpenSSL 1.1.0 the approach to deactivate client renegotiation was to set the corresponding flag via a callback function, e.g. : --- SSL *connection; ... connection->s3->flags |= SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS; --- The problem now is, that this approach does not work for OpenSSL 1.1.0, because the "flags" are not accessible any longer. It also seems that there is no *_set_flags() function for deactivating client renegotiation. 1) How can the client-renegotiation in OpenSSL generally be deactivated, preferably without accessing internal data structures as in the approach above? 2) Is it possible in OpenSSL 1.1.0 to access attributes like "flags" above? It seems that there is no dedicated API function for that. Thank you for your help! Best regards, Marcus -- openssl-users mailing list To unsubscribe: https://mta.openssl.org/mailman/listinfo/openssl-users
