OpenSSL error on loading metadata certificate in shibd 3.0.2

[Rainer Hoerbe]

Shibd cannot load the certificate on startup:

2018-11-07 10:35:13 INFO XMLTooling.SecurityHelper : loading certificate(s) from file (/etc/shibboleth/metadata_crt.pem)
2018-11-07 10:35:13 ERROR OpenSSL : error code: 33558530 in bss_file.c, line 402
2018-11-07 10:35:13 ERROR OpenSSL : error data: fopen('/etc/shibboleth/metadata_crt.pem','r')
2018-11-07 10:35:13 ERROR OpenSSL : error code: 537346050 in bss_file.c, line 404

I can successfully use the locally installed OpenSSL (1.0.2k on CentoOS7) to read the certificate with the shibd user (`openssl x509 …`)

I am stuck in finding the relevant bss_file.c form the OpenSSL repository to understand what the error code means. How can I find out what version on OpenSSL is contained in the shibd RPM?

Thanks, Rainer