无法访问github.com

Question

I am having the following error message while pushing the code to github repo,everything worked well yesterday.

git push -u origin master

fatal: unable to access 'https://github.com/resumic/schema/': SSL certificate 
problem: self signed certificate in certificate chain

Answer 1

Well, something or someone else is pretending to be GitHub for you. Open GitHub in a browser and inspect the certificate chain (F12 → Security).

Or use curl:

$ curl -vI https://github.com

*   Trying 192.30.253.113...
* Connected to github.com (192.30.253.113) port 443 (#0)
...
* Server certificate:
*  subject: businessCategory=Private Organization; jurisdictionC=US; jurisdictionST=Delaware; serialNumber=5157550; street=88 Colin P Kelly, Jr Street; postalCode=94107; C=US; ST=California; L=San Francisco; O=GitHub, Inc.; CN=github.com
*  start date: Mar 10 00:00:00 2016 GMT
*  expire date: May 17 12:00:00 2018 GMT
*  subjectAltName: host "github.com" matched cert's "github.com"
*  issuer: C=US; O=DigiCert Inc; OU=www.digicert.com; CN=DigiCert SHA2 Extended Validation Server CA
*  SSL certificate verify ok.

Use curl -kvI if you're getting a cert validation error ( -k for "Handshake anyway, even if the certs don't verify").

or OpenSSL:

$ openssl s_client -connect github.com:443 -servername github.com

CONNECTED(00000003)
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 SHA2 Extended Validation Server CA
verify return:1
depth=0 businessCategory = Private Organization, jurisdictionC = US, jurisdictionST = Delaware, serialNumber = 5157550, street = "88 Colin P Kelly, Jr Street", postalCode = 94107, C = US, ST = California, L = San Francisco, O = "GitHub, Inc.", CN = github.com
verify return:1
---
Certificate chain
 0 s:/businessCategory=Private Organization/jurisdictionC=US/jurisdictionST=Delaware/serialNumber=5157550/street=88 Colin P Kelly, Jr Street/postalCode=94107/C=US/ST=California/L=San Francisco/O=GitHub, Inc./CN=github.com
   i:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 Extended Validation Server CA
 1 s:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 Extended Validation Server CA
   i:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert High Assurance EV Root CA

The chain at the time of writing this is:

Root cert fingerprint:
‎5f b7 ee 06 33 e2 59 db ad 0c 4c 9a e6 d3 8f 1a 61 c7 dc 25

EV leaf cert:
‎7e 2f 3a 4f 8f e8 fa 8a 57 30 ae ca 02 96 96 63 7e 98 6f 3f