# You can test whether your desired certificate is trusted by OpenSSL
# with the following command

openssl verify file.crt

# You will get an error for self-signed certificates or certificates,
# signed by an issuer not known by OpenSSL, e.g.
# error 20 at 0 depth lookup:unable to get local issuer certificate

# You can add your certificate to the OpenSSL trustbase as administrator (user root)

# First check the OpenSSL installation base:
openssl version -d

# You will see something like
# OPENSSLDIR: "/etc/ssl"

# Change to the OpenSSL certs directory
cd /etc/ssl/certs

# Copy your certificate file in this directory
cp /path-to/file.crt file.pem
chmod 644 file.pem

# Now get the subject hash of your certificate data
openssl x509 -noout -hash -in file.pem

# You will see a hash value, like e.g.
# a35307e4

# Create a hash specific symbolic link for your certificate file
ln -s file.pem a35307e4.0


# Now you can verify your certificate
openssl verify file.crt

# The result should look similar to the following line
# file.crt: OK