it-swarm.com.de

Warum tritt beim Besuch von google.net kein Zertifikatfehler auf, obwohl ein an google.com ausgestelltes Zertifikat angezeigt wird?

Die folgende Ausgabe zeigt, dass google.net Ein Zertifikat präsentiert, das an www.google.com Ausgestellt wurde.

$ openssl s_client -connect google.net:443 < /dev/null > out.txt 2>&1; cat out.txt
depth=2 /C=US/O=GeoTrust Inc./CN=GeoTrust Global CA
verify error:num=20:unable to get local issuer certificate
verify return:0
CONNECTED(00000003)
---
Certificate chain
 0 s:/C=US/ST=California/L=Mountain View/O=Google Inc/CN=www.google.com
   i:/C=US/O=Google Inc/CN=Google Internet Authority G2
 1 s:/C=US/O=Google Inc/CN=Google Internet Authority G2
   i:/C=US/O=GeoTrust Inc./CN=GeoTrust Global CA
 2 s:/C=US/O=GeoTrust Inc./CN=GeoTrust Global CA
   i:/C=US/O=Equifax/OU=Equifax Secure Certificate Authority
---
Server certificate
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
subject=/C=US/ST=California/L=Mountain View/O=Google Inc/CN=www.google.com
issuer=/C=US/O=Google Inc/CN=Google Internet Authority G2
---
No client certificate CA names sent
---
SSL handshake has read 3296 bytes and written 456 bytes
---
New, TLSv1/SSLv3, Cipher is AES128-SHA
Server public key is 2048 bit
Secure Renegotiation IS supported
Compression: NONE
Expansion: NONE
SSL-Session:
    Protocol  : TLSv1
    Cipher    : AES128-SHA
    Session-ID: 74F80EC832F6806A3E10956F29A90BF423010BFBD8727BC171F9BFE39D3F89E9
    Session-ID-ctx: 
    Master-Key: 01F60D0A6DC7FF255D1C468EF06E5B7875A99E95C7FA8551F664A514B2EC5535EBB6E76E204743BF7D46F683B36E0988
    Key-Arg   : None
    Start Time: 1499657382
    Timeout   : 300 (sec)
    Verify return code: 0 (ok)
---
DONE

Ich habe das Zertifikat in eine separate Datei kopiert, um es zu analysieren.

$ cat cert.txt
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Dann sehe ich das Zertifikat mit OpenSSL CLI.

$ openssl x509 -in cert.txt -text
Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number:
            01:18:f0:44:a8:f3:18:92
        Signature Algorithm: sha256WithRSAEncryption
        Issuer: C=US, O=Google Inc, CN=Google Internet Authority G2
        Validity
            Not Before: Jun 28 10:07:46 2017 GMT
            Not After : Sep 20 09:27:00 2017 GMT
        Subject: C=US, ST=California, L=Mountain View, O=Google Inc, CN=www.google.com
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
            RSA Public Key: (2048 bit)
                Modulus (2048 bit):
                    00:91:df:f8:10:02:c2:99:53:36:dc:ca:38:bd:fd:
                    90:10:a7:ff:b4:83:92:40:e2:3a:37:95:42:ab:be:
                    9c:99:e3:ea:ae:e0:cd:45:56:fe:21:dd:3b:75:44:
                    f2:05:bb:59:f0:52:8b:b3:5f:11:45:7d:34:67:ae:
                    62:0d:c6:14:ae:25:8f:a9:99:00:c7:c8:ac:43:96:
                    c4:2d:87:54:6b:de:20:74:04:d5:f9:7e:95:ee:f0:
                    56:d6:a2:06:15:38:5b:6d:4a:24:3e:11:2b:a3:56:
                    34:5a:f7:d5:35:f9:49:47:40:4a:d9:39:7d:c8:7c:
                    dc:bd:1d:0a:7c:3a:cc:e3:10:25:bd:3d:c8:81:bc:
                    82:b6:0d:cd:c4:05:33:4b:04:c9:a0:4c:b6:a5:37:
                    f8:1f:51:17:5c:50:40:c6:f2:af:f2:6a:dc:62:42:
                    78:3f:cb:a8:c9:9a:c8:ff:64:e6:e0:f3:3f:eb:f9:
                    f3:b9:2b:c9:f3:dd:f7:60:16:65:28:1a:0e:7e:b3:
                    61:f9:00:a0:6f:4e:68:00:0e:3d:f4:a6:0d:cf:91:
                    77:14:7d:30:64:a3:93:44:6a:0c:0b:4c:c1:17:36:
                    69:fb:9e:7b:3b:6b:a1:e8:00:e9:04:ae:5b:51:35:
                    93:7b:7d:4d:0e:5e:c8:20:7d:16:27:f3:06:14:31:
                    8b:d5
                Exponent: 65537 (0x10001)
        X509v3 extensions:
            X509v3 Extended Key Usage: 
                TLS Web Server Authentication, TLS Web Client Authentication
            X509v3 Subject Alternative Name: 
                DNS:www.google.com
            Authority Information Access: 
                CA Issuers - URI:http://pki.google.com/GIAG2.crt
                OCSP - URI:http://clients1.google.com/ocsp

            X509v3 Subject Key Identifier: 
                88:FF:28:68:F3:5D:98:C9:73:75:B7:82:8D:64:C8:ED:D3:0E:7B:2A
            X509v3 Basic Constraints: critical
                CA:FALSE
            X509v3 Authority Key Identifier: 
                keyid:4A:DD:06:16:1B:BC:F6:68:B5:76:F5:81:B6:BB:62:1A:BA:5A:81:2F

            X509v3 Certificate Policies: 
                Policy: 1.3.6.1.4.1.11129.2.5.1
                Policy: 2.23.140.1.2.2

            X509v3 CRL Distribution Points: 
                URI:http://pki.google.com/GIAG2.crl

    Signature Algorithm: sha256WithRSAEncryption
        34:40:58:25:d5:4c:19:d6:f2:46:78:23:a1:9a:ff:53:eb:69:
        b7:b9:b8:3a:e6:ec:b9:d6:21:88:3a:37:1b:e0:e0:e9:18:e8:
        1e:c8:58:5e:b8:01:65:2a:f3:42:3b:fd:c8:6f:2a:74:b6:49:
        d1:75:a8:ee:6f:98:9d:cb:6c:bd:e5:d2:84:5b:72:0d:95:ba:
        f7:6b:52:a1:6f:38:1b:c2:a4:d0:4d:d1:57:8a:d9:27:62:3c:
        11:2e:10:6a:fa:34:a2:4e:80:72:20:5a:c0:25:87:ff:c2:74:
        38:f6:54:94:25:f4:9e:4c:b7:e6:96:89:7c:69:e4:03:b7:cf:
        ba:7d:59:ea:92:bd:8d:4f:6a:ed:5f:e2:59:31:8f:c5:f2:ee:
        37:e8:6c:ff:35:66:fa:13:da:eb:14:c1:c7:0a:e2:11:51:de:
        ed:a6:3f:90:75:1c:45:3a:62:cb:f3:ae:b8:d0:75:93:d1:ef:
        ca:98:26:2a:88:82:7d:d0:88:50:b7:13:0b:1f:80:2f:83:21:
        c1:fe:b7:15:59:aa:34:d9:77:30:22:1a:24:c7:8b:62:4d:35:
        d1:86:b1:dc:22:72:1e:34:6e:dc:ac:5b:ae:f3:c4:30:f6:a2:
        f1:60:ee:54:83:8f:bd:93:80:57:46:ed:38:c3:39:36:9a:96:
        f8:48:25:20
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

google.net Wird an keiner Stelle im Zertifikat erwähnt.

Wenn ich jedoch https://google.net/ besuche, wird der Client nahtlos an https://www.google.com/ weitergeleitet.

$ curl -I https://google.net/
HTTP/1.1 302 Found
Location: https://www.google.com/
Cache-Control: private
Content-Type: text/html; charset=UTF-8
P3P: CP="This is not a P3P policy! See https://www.google.com/support/accounts/answer/151657?hl=en for more info."
Date: Mon, 10 Jul 2017 03:34:48 GMT
Server: gws
Content-Length: 220
X-XSS-Protection: 1; mode=block
X-Frame-Options: SAMEORIGIN
Set-Cookie: NID=107=c9VFilfj0RLlIxvNfoJm1nETnE1IiUlg5TNL3GEs8oS_KWVWGEEcLIvQTSvtHjbwLSeqRVDpIYrqox24sE2ju7HbrSOqdu-3fNF7xzqHxV4I4YYeNiXjytTkYeKQ9inI; expires=Tue, 09-Jan-2018 03:34:48 GMT; path=/; domain=.google.net; HttpOnly
Alt-Svc: quic=":443"; ma=2592000; v="39,38,37,36,35"

Ich sehe das gleiche Verhalten auch mit dem Browser.

Ich hatte erwartet, dass Curl diesen Fehler zurückgibt.

curl: (60) SSL certificate problem: Invalid certificate chain

Ich hatte erwartet, dass Firefox diesen Fehler zurückgibt.

Error code: SSL_ERROR_BAD_CERT_DOMAIN

Ich hatte erwartet, dass Chrome diesen Fehler zurückgibt).

NET::ERR_CERT_COMMON_NAME_INVALID

Alle drei Clients stellen jedoch eine Verbindung zu https://google.net/ her und werden zu https://www.google.com/ umgeleitet. Warum gibt es keinen Fehler, obwohl der allgemeine Name im Feld Betreff des Zertifikats google.com lautet, die Domain, mit der ich eine Verbindung herstelle, jedoch google.net ist?

69
Lone Learner

SNI-Loch

Sie sind in ein "SNI-Loch" gefallen. Google legt ein anderes Zertifikat vor, wenn im TLS-Handshake-Teil des Clients kein "Server Name Indication" angegeben ist. OpenSSL setzt dies nicht automatisch. Sie müssen es manuell tun. Aber alle modernen Web-Clients, einschließlich CURL , sollten dies automatisch tun. Daher der Unterschied.

Verwenden von SNI mit OpenSSL

Standard: Ohne SNI:

$ echo '' | openssl s_client -connect google.net:443 2>/dev/null | openssl x509 -noout -text | grep -Ei 'DNS:|CN='
        Issuer: C=US, O=Google Inc, CN=Google Internet Authority G2
        Subject: C=US, ST=California, L=Mountain View, O=Google Inc, CN=www.google.com
                DNS:www.google.com

Manuelles Hinzufügen von SNI über -servername Parameter:

$ echo '' | openssl s_client -connect google.net:443 -servername google.net 2>/dev/null | openssl x509 -noout -text | grep -Ei 'DNS:|CN='
        Issuer: C=US, O=Google Inc, CN=Google Internet Authority G2
        Subject: C=US, ST=California, L=Mountain View, O=Google Inc, CN=*.google.net
                DNS:*.google.net, DNS:google.net

Verschiedene Zertifikate werden zurückgegeben.

97
StackzOfZtuff