Dev Stack Source

Answer : PFX files are PKCS#12 Personal Information Exchange Syntax Standard bundles. They can include arbitrary number of private keys with accompanying X.509 certificates and a certificate authority chain (set certificates). If you want to extract client certificates, you can use OpenSSL's PKCS12 tool. openssl pkcs12 -in input.pfx -out mycerts.crt -nokeys -clcerts The command above will output certificate(s) in PEM format. The ".crt" file extension is handled by both macOS and Window. You mention ".cer" extension in the question which is conventionally used for the DER encoded files. A binary encoding. Try the ".crt" file first and if it's not accepted, easy to convert from PEM to DER: openssl x509 -inform pem -in mycerts.crt -outform der -out mycerts.cer the simple way I believe is to import it then export it, using the certificate manager in Windows Management Console. If you're working in PowerShell you can use something like the follo...

Answer : I am answering to this to give an idea about the scenario and solution as per the android developer site for others benefit. I have solved this using custom trust manager. The problem was with the server certificate, it misses intermediate certificate authority. However with the first flow certificate path is completed somehow and result was successful certificate path validation. There is a solution for this in android developer site. it suggest to use custom trust manager that trusts this server certificate or it suggest to server to include the intermediate CA in the server chain. custom trust manager. source: https://developer.android.com/training/articles/security-ssl.html#UnknownCa // Load CAs from an InputStream // (could be from a resource or ByteArrayInputStream or ...) CertificateFactory cf = CertificateFactory.getInstance("X.509"); // From https://www.washington.edu/itconnect/security/ca/load-der.crt InputStream caInput = new BufferedInputStream...