How can I get a X.509 certificate file to play with OpenSSL commands "x509" command?

If you have no other easy way to get a sample X.509 certificate file, you can create one yourself using these steps:

1. Open "Notepad" with a black text file.

2. Copy and paste the following data into the "Notepad" window. Remember to copy all lines including both "-----BEGIN CERTIFICATE-----" and "-----END CERTIFICATE-----".

-----BEGIN CERTIFICATE-----
MIIHnTCCBoWgAwIBAgIQB3a13cqDpLnKWY9ddx+eRjANBgkqhkiG9w0BAQsFADB1
MQswCQYDVQQGEwJVUzEVMBMGA1UEChMMRGlnaUNlcnQgSW5jMRkwFwYDVQQLExB3
d3cuZGlnaWNlcnQuY29tMTQwMgYDVQQDEytEaWdpQ2VydCBTSEEyIEV4dGVuZGVk
IFZhbGlkYXRpb24gU2VydmVyIENBMB4XDTE2MDMwOTAwMDAwMFoXDTE4MDMxNDEy
MDAwMFowggEhMR0wGwYDVQQPDBRQcml2YXRlIE9yZ2FuaXphdGlvbjETMBEGCysG
AQQBgjc8AgEDEwJVUzEZMBcGCysGAQQBgjc8AgECEwhEZWxhd2FyZTEQMA4GA1UE
BRMHNDMzNzQ0NjESMBAGA1UECRMJU3VpdGUgOTAwMRcwFQYDVQQJEw4xMzU1IE1h
cmtldCBTdDEOMAwGA1UEERMFOTQxMDMxCzAJBgNVBAYTAlVTMRMwEQYDVQQIEwpD
YWxpZm9ybmlhMRYwFAYDVQQHEw1TYW4gRnJhbmNpc2NvMRYwFAYDVQQKEw1Ud2l0
dGVyLCBJbmMuMRkwFwYDVQQLExBUd2l0dGVyIFNlY3VyaXR5MRQwEgYDVQQDEwt0
d2l0dGVyLmNvbTCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBAMIImPpn
AAVVtgthDhrXtYrBzAO+PBf7lPfZ+kyfRmCcaq19OuU0WhKwsguq7JbhWIEvrWCr
R5Np44R1U8H5D7lGq57qqxiYjGhUCFFlQxphlydcXg8V6c0Wq91RW3Yv/NMRmZ3S
pj2HAnXmJJbiBD4UnPp+uHFCNwC1sIriM5WL2j/7Y003YtUcAuowftwNU9XUC7ij
EBNtH4mUC2qURGcpgq3m1bBS/JVXBtbRImaE05IqAseUVt9VP8IT8nwWeDOhU/d3
l1y3lgXVRPS/74MiXXrmj+Ss3zSetg8KU/Aa23E3aZL2FKkcdWVyRSQJOyxq17lp
pdzfbZxr/MaiWzECAwEAAaOCA3kwggN1MB8GA1UdIwQYMBaAFD3TUKXWoK3u80pg
CmXTIdT4+NYPMB0GA1UdDgQWBBSfYnuyiA7uG3ngaSTluj9HpgsC8DAnBgNVHREE
IDAeggt0d2l0dGVyLmNvbYIPd3d3LnR3aXR0ZXIuY29tMA4GA1UdDwEB/wQEAwIF
oDAdBgNVHSUEFjAUBggrBgEFBQcDAQYIKwYBBQUHAwIwdQYDVR0fBG4wbDA0oDKg
MIYuaHR0cDovL2NybDMuZGlnaWNlcnQuY29tL3NoYTItZXYtc2VydmVyLWcxLmNy
bDA0oDKgMIYuaHR0cDovL2NybDQuZGlnaWNlcnQuY29tL3NoYTItZXYtc2VydmVy
LWcxLmNybDBLBgNVHSAERDBCMDcGCWCGSAGG/WwCATAqMCgGCCsGAQUFBwIBFhxo
dHRwczovL3d3dy5kaWdpY2VydC5jb20vQ1BTMAcGBWeBDAEBMIGIBggrBgEFBQcB
AQR8MHowJAYIKwYBBQUHMAGGGGh0dHA6Ly9vY3NwLmRpZ2ljZXJ0LmNvbTBSBggr
BgEFBQcwAoZGaHR0cDovL2NhY2VydHMuZGlnaWNlcnQuY29tL0RpZ2lDZXJ0U0hB
MkV4dGVuZGVkVmFsaWRhdGlvblNlcnZlckNBLmNydDAMBgNVHRMBAf8EAjAAMIIB
fAYKKwYBBAHWeQIEAgSCAWwEggFoAWYAdgCkuQmQtBhYFIe7E6LMZ3AKPDWYBPkb
37jjd80OyA3cEAAAAVNdgFLZAAAEAwBHMEUCICZCA9wZjkyHJRy3UTCYnwI21m/U
XKRXWc7US9arx68qAiEAtK1UZMDl2wRt/o1OxInzFdQCQ+2QTIvLbHe5slXu6boA
dQBo9pj4H2SCvjqM7rkoHUz8cVFdZ5PURNEKZ6y7T0/7xAAAAVNdgFKcAAAEAwBG
MEQCIGF6AFQ8TKA8AqktUZ/45JJuKYHCIFIkqcPWIIDLWIZmAiA5PVUV5BBCM2AK
ce/CeXCyim1y140g/4RxghYW6sNCNwB1AFYUBpov18Ls0/XhvUSyPsdGdrm8mRFc
wO+UmFXWidDdAAABU12AU6YAAAQDAEYwRAIgXUM1kBRW2bTGAqVvy/aDoYTrdKvM
I6x5p0FF2S+jGmkCIFmAWDXHV/YBi4thS8HGZc3iVCh5wwaCGM3kztEaUYmQMA0G
CSqGSIb3DQEBCwUAA4IBAQC7+PUbZaNQAx8YEMg1Uy+cih5Iar3l5ljJ0eih/KsD
Qo9Y8woYppEuwVC3cN0V2q0I8RXSRE105BgrZbYF2fn32CRs21/sbH0/v6VMonNo
OEJBzeL20fjYidN1Sr39q02e7kjJNCPVg8yTlRREpSXlsfwXWFOnACSBwpRzmD43
bRKVH6zjIPiy2wmxXP6ibb3p0ITHnosxLsf3pWXjL/YeWqQq6mUDMRKmeCRR3k1E
03kXQyxV4AD4hccLqP4K6m17dOkpWbKWNN+/wxWy/ApMuP0hNPgoZSLQBaMidNzh
Y63izHj1KcOdLNg8VVCCEPoEX8IlbLMIY/YTfN5XAFjs
-----END CERTIFICATE-----

3. Save the data in "Notepad" to a file called "twitter.crt" into a working folder like "C:\Users\fyicenter\twitter.pem".

By the way, the above certificate is from www.twitter.com.

⇒ OpenSSL "x509 -text" - Print Certificate Info

⇐ OpenSSL "x509" Command Options

⇑ OpenSSL "x509" Command

⇑⇑ OpenSSL Tutorials