client-self-signed.pem represents the same RDN as client.pem, but using itself as a CA:

openssl req -nodes -new -subj '/CN=client/OU=KernelUser/O=MongoDB/L=New York City/ST=New York/C=US' -out css.csr -keyout css.rsa
openssl rsa -in css.rsa -out css.key
openssl x509 -in css.csr -out jstests/libs/client-self-signed.pem -req -signkey client-self-signed.key -days 3650
cat css.key >> jstests/libs/client-self-signed.pem
rm css.{csr,rsa,key}

---------------------------
client-multivalue-rdn.pem represents the same RDN as client.pem, but grouping some elements together:

openssl req -new -nodes -subj '/CN=client+OU=KernelUser+O=MongoDB/L=New York City+ST=New York+C=US' -multivalue-rdn \
            -keyout client-multivalue-rdn.key -out client-multivalue-rdn.csr
openssl rsa -in client-multivalue-rdn.key -out client-multivalue-rdn.rsa
openssl x509 -in client-multivalue-rdn.csr -out client-multivalue-rdn.pem -req -CA ca.pem -days 3650 -CAcreateserial
cat client-multivalue-rdn.rsa >> client-multivalue-rdn.pem
rm ca.srl client-multivalue-rdn.key client-multivalue-rdn.rsa client-multivalue-rdn.csr

---------------------------

The other ceriticates in this directory come from x509gen.
How to generate a certificate with a custom extension:

1. Generate a normal certificate signing request without an extension
2. Make a copy of the system openssl.cnf and append this text to the file
    On Redhat/Fedora, openssl.cnf is in /etc/pki/tls

See jstests\libs\mongodbauthorizationgrant.cnf for how to generate the text with the
'openssl asn1parse' command.

[MongoDBAuthorizationGrant]
1.3.6.1.4.1.34601.2.1.1 = DER:312B300F0C066261636B75700C0561646D696E30180C0F72656164416E7944617461626173650C0561646D696E

3. Sign the certificate and add the custom extension
4. Make a new pem with the certificate and key

Example Commands
----------------
openssl req -config openssl.cnf -newkey rsa:2048 -nodes -keyout roles.key -out roles.csr

Example with subject name:
openssl req -config openssl.cnf -newkey rsa:2048 -nodes -keyout roles.key -out roles.csr -subj "/C=US/ST=New York/L=New York City/O=MongoDB/OU=KernelUser/CN=client/emailAddress=example@mongodb.com"

openssl x509 -req -sha256 -in roles.csr -days 3650 -out roles.pem -extfile openssl.cnf -extensions MongoDBAuthorizationGrant -CA jstests/libs/ca.pem -CAcreateserial

openssl rsa -in roles.key -out roles2.key

cat roles.pem roles2.key > roles_final.pem


Example Commands for UTF-8
--------------------------
openssl req -new -utf8 -nameopt multiline,utf8  -config .\jstests\libs\client_utf8.cnf -newkey rsa:2048 -nodes -keyout roles.key -out roles.csr