tests: Add https-mtls server to force client auth

- test2088 verifies that mutual tls works

This adds a new certificate to generate which has the clientAuth key
usage enabled, and uses it to connect to a https-mtls server.

Closes #16923

tests/data/Makefile.am

@@ -253,7 +253,7 @@ test2056 test2057 test2058 test2059 test2060 test2061 test2062 test2063 \
 test2064 test2065 test2066 test2067 test2068 test2069 test2070 test2071 \
 test2072 test2073 test2074 test2075 test2076 test2077 test2078 test2079 \
 test2080 test2081 test2082 test2083 test2084 test2085 test2086 test2087 \
-\
+test2088 \
 test2100 test2101 \
 \
 test2200 test2201 test2202 test2203 test2204 test2205 \

tests/data/test2088

@@ -0,0 +1,55 @@
+<testcase>
+<info>
+<keywords>
+HTTPS
+HTTP GET
+Client Auth
+</keywords>
+</info>
+
+#
+# Server-side
+<reply>
+<data>
+HTTP/1.1 200 OK
+Date: Tue, 09 Nov 2010 14:49:00 GMT
+Server: test-server/fake
+Content-Length: 7
+
+MooMoo
+</data>
+</reply>
+
+#
+# Client-side
+<client>
+<features>
+SSL
+!Schannel
+!sectransp
+!bearssl
+local-http
+</features>
+<server>
+https-mtls
+</server>
+<name>
+HTTPS GET with client authentication (mtls)
+</name>
+<command>
+--cacert %CERTDIR/certs/test-ca.crt --cert %CERTDIR/certs/test-client-cert.crt --key %CERTDIR/certs/test-client-cert.key https://localhost:%HTTPS-MTLSPORT/%TESTNUMBER
+</command>
+</client>
+
+#
+# Verify data after the test has been "shot"
+<verify>
+<protocol>
+GET /%TESTNUMBER HTTP/1.1
+Host: localhost:%HTTPS-MTLSPORT
+User-Agent: curl/%VERSION
+Accept: */*
+
+</protocol>
+</verify>
+</testcase>