We discovered a problem running openssl with our application on WinNT4.0 and
using Visual C++ 6.0.
When we run our application, it makes a call to SSL_write, then an access
violation occurs executing fwrite within the function file_write of openSSL.
Upon closer inspection, we found the culprit to be stdout. From within our
application, while initializing openSSL, b->ptr (b is type BIO) is set to
stdout. Just before the crash within openSSL, b->ptr is still pointing to
that
address; however, if a variable is set within openSSL to stdout, that
variable
points to a different address.
In other words: If a variable is set to stdout in our application, and a
variable is set to stdout within openSSL, the two point to different
addresses
in NT--in Unix, both point to the same address. In NT, if an attempt is made
to
use the stdout address set in the calling from application within openSSL, a
crash occurs.
An earlier message on the listserv indicated a similar problem (see "App
crash
on NT"); the solution suggested using the multithreaded dll version of the
run-time libraries. We verified that the correct libraries are indeed being
used. Someone else suggested that the library containing the standard
implentation for a console app was missing; we verified that it was included
within our application as well as openssl.
The solution we developed is to create a function within openssl that simply
returns the pointer to stdout. This way, the pointer to stdout is correct in
whatever environment it resides. Our application can then use this to set
b->ptr to the correct address of stdout.
We made the following changes to the NT version:
1) Within
openssl-0.9.4\inc32\openssl\ssl.h
openssl-0.9.4\ssl\ssl.h
the following prototype was added:
FILE *SSLGetSSLstdout(void);
2) Within
openssl-0.9.4\ssl\ssl_lib.c
the following function was added:
FILE *SSLGetSSLstdout(void)
{
return (stdout);
}
3) Within
openssl-0.9.4\ms\ssleay32.def
the following line was added under "EXPORTS":
SSLGetSSLstdout
If we are missing something, please let us know. Thanks!
Paul Kudlawiec
Software Engineer
[EMAIL PROTECTED]
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