$ openssl s_client -connect github.com:443 CONNECTED(00000003) depth=0 businessCategory = Private Organization, 1.3.6.1.4.1.311.60.2.1.3 = US, 1.3.6.1.4.1.311.60.2.1.2 = Delaware, serialNumber = 5157550, street = 548 4th Street, postalCode = 94107, C = US, ST = California, L = San Francisco, O = "GitHub, Inc.", CN = github.com verify error:num=20:unable to get local issuer certificate verify return:1 depth=0 businessCategory = Private Organization, 1.3.6.1.4.1.311.60.2.1.3 = US, 1.3.6.1.4.1.311.60.2.1.2 = Delaware, serialNumber = 5157550, street = 548 4th Street, postalCode = 94107, C = US, ST = California, L = San Francisco, O = "GitHub, Inc.", CN = github.com verify error:num=27:certificate not trusted verify return:1 depth=0 businessCategory = Private Organization, 1.3.6.1.4.1.311.60.2.1.3 = US, 1.3.6.1.4.1.311.60.2.1.2 = Delaware, serialNumber = 5157550, street = 548 4th Street, postalCode = 94107, C = US, ST = California, L = San Francisco, O = "GitHub, Inc.", CN = github.com verify error:num=21:unable to verify the first certificate verify return:1 --- Certificate chain 0 s:/businessCategory=Private Organization/1.3.6.1.4.1.311.60.2.1.3=US/1.3.6.1.4.1.311.60.2.1.2=Delaware/serialNumber=5157550/street=548 4th Street/postalCode=94107/C=US/ST=California/L=San Francisco/O=GitHub, Inc./CN=github.com i:/C=RU/ST=Moscow/O= /OU= /CN= /emailAddress= --- Server certificate -----BEGIN CERTIFICATE----- MIIDNDCCAp2gAwIBAgIUJU621YW5qXzUyvb/p3cQe3DNZzAwDQYJKoZIhvcNAQEF BQAwVDELMAkGA1UEBhMCUlUxDzANBgNVBAgMBk1vc2NvdzEKMAgGA1UECgwBIDEK MAgGA1UECwwBIDEKMAgGA1UEAwwBIDEQMA4GCSqGSIb3DQEJARYBIDAeFw0xNDA0 MDgwMDAwMDBaFw0xNjA0MTIxMjAwMDBaMIHwMR0wGwYDVQQPDBRQcml2YXRlIE9y Z2FuaXphdGlvbjETMBEGCysGAQQBgjc8AgEDEwJVUzEZMBcGCysGAQQBgjc8AgEC EwhEZWxhd2FyZTEQMA4GA1UEBRMHNTE1NzU1MDEXMBUGA1UECRMONTQ4IDR0aCBT dHJlZXQxDjAMBgNVBBETBTk0MTA3MQswCQYDVQQGEwJVUzETMBEGA1UECBMKQ2Fs aWZvcm5pYTEWMBQGA1UEBxMNU2FuIEZyYW5jaXNjbzEVMBMGA1UEChMMR2l0SHVi LCBJbmMuMRMwEQYDVQQDEwpnaXRodWIuY29tMIGfMA0GCSqGSIb3DQEBAQUAA4GN ADCBiQKBgQC+BKiYAgmwo/I7Yq7gGtGLCm9n+UVqD8/H9mFgb0tBT92ienkFzGMr F0gUAT2QOqa3o38XLJeePMitF8VKPnb5k79hBM9xn9Czs8XAB2rjVgfQtgFqNXlH Pvws0UrBSCDqQJG+Hn3mLI38msNPiMD6e1NJ2cTUDro3vhGLan31bQIDAQABo2Yw ZDAlBgNVHREEHjAcggpnaXRodWIuY29tgg53d3cuZ2l0aHViLmNvbTAOBgNVHQ8B Af8EBAMCBaAwHQYDVR0lBBYwFAYIKwYBBQUHAwEGCCsGAQUFBwMCMAwGA1UdEwEB /wQCMAAwDQYJKoZIhvcNAQEFBQADgYEAOlHwD649dHm6H+u1339e5tRQUtdlViE5 wV7Brxbi6mU/S1y7r8yQELKw7J4vjt8INyDXcdwBedDSWVSOyMYwRjYsttdyUKvo pwu+9c4mWIh2YdQpRSSExpjmTfN27en0DLKNihEVEJyffXEB7CQS/d5IgfDtIkI3 7kpMkZqEr7Y= -----END CERTIFICATE----- subject=/businessCategory=Private Organization/1.3.6.1.4.1.311.60.2.1.3=US/1.3.6.1.4.1.311.60.2.1.2=Delaware/serialNumber=5157550/street=548 4th Street/postalCode=94107/C=US/ST=California/L=San Francisco/O=GitHub, Inc./CN=github.com issuer=/C=RU/ST=Moscow/O= /OU= /CN= /emailAddress= --- No client certificate CA names sent --- SSL handshake has read 1137 bytes and written 495 bytes --- New, TLSv1/SSLv3, Cipher is AES256-GCM-SHA384 Server public key is 1024 bit Secure Renegotiation IS supported Compression: NONE Expansion: NONE SSL-Session: Protocol : TLSv1.2 Cipher : AES256-GCM-SHA384 Session-ID: 2A0C61BE8531786FD8304BF48F4BC7F8EB7A6E2C6E360CB911F4953286B5278E Session-ID-ctx: Master-Key: 8B4BB4A72FD34091C59411CD113200B1F0B452A6FE54662C428EEF81EBB065C00FA2F337109074F8946D906D735C66C1 Key-Arg : None PSK identity: None PSK identity hint: None SRP username: None TLS session ticket lifetime hint: 300 (seconds) TLS session ticket: 0000 - 97 b9 50 db e4 60 80 b8-30 b8 f4 07 a8 6b 3a 1e ..P..`..0....k:. 0010 - af f6 ee 8f 64 e1 74 52-e7 fb 35 49 69 ff 00 02 ....d.tR..5Ii... 0020 - e8 5f b0 19 66 3c 31 6d-55 a5 a7 75 27 b4 ff e8 ._..f<1mU..u'... 0030 - 1f ca 27 20 25 6a 82 94-a8 01 26 d5 2c 97 f4 09 ..' %j....&.,... 0040 - 9d 76 d1 48 59 e6 76 b6-ba 03 dd d8 a5 e6 d2 6b .v.HY.v........k 0050 - 4c 5c 17 06 c4 b5 80 c7-ff 09 18 1b 5b d7 35 75 L\..........[.5u 0060 - 66 7b 19 11 f6 41 df b9-bd bf 1d 99 6d 91 47 23 f{...A......m.G# 0070 - 32 81 97 cf 7a f7 aa 68-80 41 38 94 51 fc d2 01 2...z..h.A8.Q... 0080 - d6 e6 a9 22 b0 b2 29 db-b0 0b 1d f9 e5 3e 89 18 ..."..)......>.. 0090 - 32 94 c3 93 17 d0 6f 5c-ed ed 70 b9 df 81 77 d7 2.....o\..p...w. Start Time: 1417766770 Timeout : 300 (sec) Verify return code: 21 (unable to verify the first certificate) ---