
SHA-1 certificate error on Google.com - ademarre
https://twitter.com/AndreDeMarre/status/797965638757060608
======
peterwwillis
Same (for multiple subdomains too).

    
    
      This certificate has been verified for the following usages:
      
      SSL Server Certificate
    
      Issued To
      
      Common Name (CN)	www.google.com
      Organization (O)	Google Inc
      Organizational Unit (OU)	<Not Part Of Certificate>
      Serial Number	2C:B5:67:C4:00:95:F4:FF
      Issued By
      
      Common Name (CN)	Google Internet Authority G2
      Organization (O)	Google Inc
      Organizational Unit (OU)	<Not Part Of Certificate>
      Validity Period
      
      Issued On	11/2/16
      Expires On	1/25/17
      Fingerprints
      
      SHA-256 Fingerprint	DB 4F 9A C6 02 74 B6 91 73 B9 BF 67 B3 64 37 20
      3A 11 6A 4B 87 C2 7A A5 18 D6 71 A5 39 37 54 82
      SHA-1 Fingerprint	DD 3B 8A D7 5A DA C1 7A F7 DC 6C A4 40 08 C3 E0
      14 2A 3E B3
    

Also:

    
    
      psypete@zippy:~$ ncat --ssl -v -4 www.google.com 443
      Ncat: SSL connection to 172.217.4.36:443. Google Inc
      Ncat: SHA-1 fingerprint: DD3B 8AD7 5ADA C17A F7DC 6CA4 4008 C3E0 142A 3EB3
      ^C
      psypete@zippy:~$ ncat --ssl -v -4 www.google.com 443
      Ncat: SSL connection to 172.217.3.4:443. Google Inc
      Ncat: SHA-1 fingerprint: DD3B 8AD7 5ADA C17A F7DC 6CA4 4008 C3E0 142A 3EB3
      ^C
      psypete@zippy:~$ ncat --ssl -v -4 google.com 443
      Ncat: SSL connection to 172.217.1.206:443. Google Inc
      Ncat: SHA-1 fingerprint: 5E7B 8140 CF98 AFE9 2BBA BA06 0D83 1277 1702 DD49
      ^C
      psypete@zippy:~$ ncat --ssl -v -4 google.com 443
      Ncat: SSL connection to 216.58.217.174:443. Google Inc
      Ncat: SHA-1 fingerprint: 5E7B 8140 CF98 AFE9 2BBA BA06 0D83 1277 1702 DD49

------
advisedwang
Can you share the certificate you were served?

~~~
ademarre
Not sure the best way to share it, so I'll paste it here...

\-----BEGIN CERTIFICATE-----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\+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 qUJdPg==
\-----END CERTIFICATE-----

It's a SHA-256 certificate which expires in January, and it was signed by a
SHA-1 intermediate that expires 12/31/16.

~~~
tialaramex
So, the way X.509 works, certificates aren't signed by a particular other
certificate, but by a named Issuer and private key. This particular Issuer,
"Google Internet Authority G2" has both an older SHA-1 certificate (which
expires when you said) and a newer SHA-256 certificate, with the same key that
expires a year later. So, there are two things that might happen here, one is
their fault, one is (maybe) yours

1\. They could be sending the SHA-1 intermediate instead of the correct
SHA-256 intermediate. This would affect everyone connecting to that particular
server. Google has to fix this by correcting the intermediate certificate
delivered during TLS handshake.

2\. Your client (browser) could have cached the SHA-1 certificate from
somewhere and be relying on it (because the name and key match) even though
Google provided a SHA-256 certificate that's better.

If you can still reproduce the error, tools like openssl's s_client mode can
dump all the certificates sent over, and don't have a cache of their own, so
that's useful for diagnosis.

