problem with closing file descriptors while loading certificate in sign

[stanislav kimov]

Hi, thanks for developing openssl. It's realy a lifesaver!
But sometimes it gets difficult for me to understand it. I have made my own
realisation of SIGN by using functions from smime.c and encountered a big
problem while testing it for memory leaks. My realisation works correctly,
but when I called it for 10,000 times in one cycle I got such a run-time
error:
Error opening signer certificate user.cert
3075159688:error:02001018:system library:fopen:Too many open
files:bss_file.c:355:fopen('user.cert','r')
3075159688:error:20074002:BIO routines:FILE_CTRL:system lib:bss_file.c:357:
unable to load certificate

I'm using linux Ubuntu distribution and openssl-1.0.0-beta5 version.
Error occured on 1020 iteration, and each iteration number of opened file
descriptors and iteration number were equal.
It seems to me that file descriptor that load_cert() function opens for
reading certificate from file stays unclosed. I checked a link of function
calls by debugging "smime sign" called from openssl command line. I use same
functions in same order. And I clean everything in the end. I call
"X509_free(cert);" for certificate.
I load certificate like that:
cert = load_cert(bio_err, signerfile, FORMAT_PEM, NULL, e, "signer
certificate");

Thanks in advance for your help. I wait for reply very much, because I've
already broken my brains trying to solve it.