Just go to the DigiCert Chain Checker at http://www.digicert.com/help/ and enter www.facebook.com or try login.facebook.com, secure.facebook.com, or just "facebook.com". Digicert and Symantec (Verisign/Geotrust/Equifax) issue certificates to Facebook. What you get depends on which browser you use and which server you hit.
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Daniel Kahn Gillmor Sent: Thursday, December 08, 2011 2:09 PM To: Erwann Abalea; EFF Observatory Subject: Re: [SSL Observatory] Number of CAs Bonsoir Erwann-- On Thu, 8 Dec 2011 21:26:45 +0100, Erwann Abalea <[email protected]> wrote: > Strange. Asking with OpenSSL shows a path up to VeriSign (a 2048 bits key). > Using Firefox or Safari shows a path up to DigiCert (a 2048 bits key). > I'm in France. Try looking at the top DigiCert certificate in the chain in firefox or safari -- is it self-signed, or is it issued by Entrust.net? 0 dkg@pip:/tmp/cdtemp.ma5ZAf$ echo | openssl s_client -CAfile Entrust.net_Secure_Server_CA.crt -connect facebook.com:443 CONNECTED(00000003) depth=3 C = US, O = Entrust.net, OU = www.entrust.net/CPS incorp. by ref. (limits liab.), OU = (c) 1999 Entrust.net Limited, CN = Entrust.net Secure Server Certification Authority verify return:1 depth=2 C = US, O = DigiCert Inc, OU = www.digicert.com, CN = DigiCert High Assurance EV Root CA verify return:1 depth=1 C = US, O = DigiCert Inc, OU = www.digicert.com, CN = DigiCert High Assurance CA-3 verify return:1 depth=0 C = US, ST = California, L = Palo Alto, O = "Facebook, Inc.", CN = www.facebook.com verify return:1 --- Certificate chain 0 s:/C=US/ST=California/L=Palo Alto/O=Facebook, Inc./CN=www.facebook.com i:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert High Assurance CA-3 1 s:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert High Assurance CA-3 i:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert High Assurance EV Root CA 2 s:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert High Assurance EV Root CA i:/C=US/O=Entrust.net/OU=www.entrust.net/CPS incorp. by ref. (limits liab.)/OU=(c) 1999 Entrust.net Limited/CN=Entrust.net Secure Server Certification Authority --- Server certificate -----BEGIN CERTIFICATE----- MIIGMjCCBRqgAwIBAgIQDG/IWVf6H1/JZyyf5lzb5jANBgkqhkiG9w0BAQUFADBm MQswCQYDVQQGEwJVUzEVMBMGA1UEChMMRGlnaUNlcnQgSW5jMRkwFwYDVQQLExB3 d3cuZGlnaWNlcnQuY29tMSUwIwYDVQQDExxEaWdpQ2VydCBIaWdoIEFzc3VyYW5j ZSBDQS0zMB4XDTEwMTExNTAwMDAwMFoXDTEzMTIwMjIzNTk1OVowajELMAkGA1UE BhMCVVMxEzARBgNVBAgTCkNhbGlmb3JuaWExEjAQBgNVBAcTCVBhbG8gQWx0bzEX MBUGA1UEChMORmFjZWJvb2ssIEluYy4xGTAXBgNVBAMTEHd3dy5mYWNlYm9vay5j b20wgZ8wDQYJKoZIhvcNAQEBBQADgY0AMIGJAoGBAMHffWNBvcTk+mUzE3jVYjeW p2HzsZa/I466h6ftB/neLeuox7ytd6ZejQMDNuNN99Dxq2byty4zFr4mD11BFn// twCe+g6ZFWxSGtcKxq375AciP9sEpLZppe3Wh7aIxYP16Maz/8AOH52jhXDtonYU e3A+77BCCzjWggAj3WN1AgMBAAGjggNaMIIDVjAfBgNVHSMEGDAWgBRQ6nOJ2yn7 EI+e5QEg1N55mUiD9zAdBgNVHQ4EFgQUqldKM7bs1W6BE6Y2XvR7Q1jzj0QwKQYD VR0RBCIwIIIQd3d3LmZhY2Vib29rLmNvbYIMZmFjZWJvb2suY29tMHsGCCsGAQUF BwEBBG8wbTAkBggrBgEFBQcwAYYYaHR0cDovL29jc3AuZGlnaWNlcnQuY29tMEUG CCsGAQUFBzAChjlodHRwOi8vY2FjZXJ0cy5kaWdpY2VydC5jb20vRGlnaUNlcnRI aWdoQXNzdXJhbmNlQ0EtMy5jcnQwDgYDVR0PAQH/BAQDAgWgMAwGA1UdEwEB/wQC MAAwZQYDVR0fBF4wXDAsoCqgKIYmaHR0cDovL2NybDMuZGlnaWNlcnQuY29tL2Nh My0yMDEwaS5jcmwwLKAqoCiGJmh0dHA6Ly9jcmw0LmRpZ2ljZXJ0LmNvbS9jYTMt MjAxMGkuY3JsMIIBxgYDVR0gBIIBvTCCAbkwggG1BgtghkgBhv1sAQMAATCCAaQw OgYIKwYBBQUHAgEWLmh0dHA6Ly93d3cuZGlnaWNlcnQuY29tL3NzbC1jcHMtcmVw b3NpdG9yeS5odG0wggFkBggrBgEFBQcCAjCCAVYeggFSAEEAbgB5ACAAdQBzAGUA IABvAGYAIAB0AGgAaQBzACAAQwBlAHIAdABpAGYAaQBjAGEAdABlACAAYwBvAG4A cwB0AGkAdAB1AHQAZQBzACAAYQBjAGMAZQBwAHQAYQBuAGMAZQAgAG8AZgAgAHQA aABlACAARABpAGcAaQBDAGUAcgB0ACAAQwBQAC8AQwBQAFMAIABhAG4AZAAgAHQA aABlACAAUgBlAGwAeQBpAG4AZwAgAFAAYQByAHQAeQAgAEEAZwByAGUAZQBtAGUA bgB0ACAAdwBoAGkAYwBoACAAbABpAG0AaQB0ACAAbABpAGEAYgBpAGwAaQB0AHkA IABhAG4AZAAgAGEAcgBlACAAaQBuAGMAbwByAHAAbwByAGEAdABlAGQAIABoAGUA cgBlAGkAbgAgAGIAeQAgAHIAZQBmAGUAcgBlAG4AYwBlAC4wHQYDVR0lBBYwFAYI KwYBBQUHAwEGCCsGAQUFBwMCMA0GCSqGSIb3DQEBBQUAA4IBAQAlM16QP60C/t6S 0p4S9+8Wao26ZqBarmZ2vEoSE+OS1vcPlLwBlSDo8P2sZt4kGK/uor9fo+xectYg GtLGjwcNev+lj30HfO6ZgQBqjYCnjcAAFsUd2AY39+wD6KK0QFyVdQwUAdF1p1aY 8DggH3cVeau14wQKd8nDtZlXdk8ObncaYTdvmrpTUT9RPpXAtMQgl+kmE0DDGeRB 2Sb3OUvyoaTDtQXFvuJlhcspgGHW14e6yCX+hXG70mZjUkkLHWqAYkM8J/w8Khwu gqeCEJjrS1oyfLGPXDkAxC9xtb3+v2DdAEOj8xCWg/hvleSrYh1SBXmU1zHyHHVE yieOb6nD -----END CERTIFICATE----- subject=/C=US/ST=California/L=Palo Alto/O=Facebook, Inc./CN=www.facebook.com issuer=/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert High Assurance CA-3 --- No client certificate CA names sent --- SSL handshake has read 4489 bytes and written 347 bytes --- New, TLSv1/SSLv3, Cipher is RC4-SHA Server public key is 1024 bit Secure Renegotiation IS NOT supported Compression: NONE Expansion: NONE SSL-Session: Protocol : SSLv3 Cipher : RC4-SHA Session-ID: 29B561B5096EA1D63BCE883F853D9758CA7154B5D53168E431F34E055284C503 Session-ID-ctx: Master-Key: 37362E291FF0F4960841D265696159D83517A06215ACC6129EBD29CFC7E5A460782FC98CFFCA 83446DFCF99D4688C321 Key-Arg : None PSK identity: None PSK identity hint: None Start Time: 1323378110 Timeout : 7200 (sec) Verify return code: 0 (ok) --- DONE 0 dkg@pip:/tmp/cdtemp.ma5ZAf$ > A root can't revoke itself. Trust has to come off-band, and is removed > off-band. This is news to me. What are all these CRL Distribution point extensions doing in CA certificates then? How should an application used by a relying party be notified if a Root CA is compromised? What should an application used by a relying party do if it fetches the CRL listed at the distribution point and finds a valid CRL containing the root certificate's serial number? Is there some reference that you could point me to that suggests that X.509's revocation infrastructure is insufficient for revoking root certificates? What sorts of threat does this limitation mitigate? I understand that establishing root trust does need to come out-of-band at some point. I don't understand why you shouldn't believe a trusted party if it tells you that its key is no longer reliable. Regards, --dkg
smime.p7s
Description: S/MIME cryptographic signature
