HTTP HTTP GET HTTP proxy HTTP proxy Digest auth multi # Server-side # this is returned first since we get no proxy-auth HTTP/1.1 407 Authorization Required to proxy me my dear Proxy-Authenticate: Digest realm="weirdorealm", nonce="12345" Content-Length: 33 And you should ignore this data. # then this is returned when we get proxy-auth HTTP/1.1 200 OK Content-Length: 21 Server: no Nice proxy auth sir! HTTP/1.1 401 OK Content-Length: 21 Server: no Denied access. Leave # Client-side http https-proxy https # tool is what to use instead of 'curl' lib%TESTNUMBER !SSPI crypto proxy digest Debug http_proxy=%HOSTIP:%HTTPPORT https_proxy=https://%HOSTIP:%HTTPSPROXYPORT CURL_ENTROPY=99376 HTTP proxy auth Digest, then change proxy with env var and do it again http://test.remote.example.com/path/%TESTNUMBER https://another.example.com:%HTTPSPORT/ daniel:monkey123 another:bump456 # Verify data after the test has been "shot" GET http://test.remote.example.com/path/%TESTNUMBER HTTP/1.1 Host: test.remote.example.com Accept: */* Proxy-Connection: Keep-Alive GET http://test.remote.example.com/path/%TESTNUMBER HTTP/1.1 Host: test.remote.example.com Proxy-Authorization: Digest username="daniel", realm="weirdorealm", nonce="12345", uri="/path/%TESTNUMBER", response="7a1672891aff03248887b1a6674b8096" Accept: */* Proxy-Connection: Keep-Alive CONNECT another.example.com:%HTTPSPORT HTTP/1.1 Host: another.example.com:%HTTPSPORT Proxy-Connection: Keep-Alive # CONNECT fails 7