ATTENTION: If your certificate has been issued on or after January 14th, 2019, then you will need another intermediate certificate which can be found here: https://www.interssl.com/de/knowledgebase.php?action=displayarticle&id=1052
COMODO Knowledge Base offers a detailed tutorial including screenshots: https://support.sectigo.com/Com_KnowledgeDetailPage?Id=kA01N000000zFIw
For pro users, the short version below is focusing on the details of the certificate chain:
After validating the COMODO certificate request, COMODO is delivering your PositiveSSL certificate by email. The email includes an attached ZIP file that contains the following files:
EITHER:
<yourdomain>.ca_bundle
<yourdomain>.crt
OR:
COMODORSADomainValidationSecureServerCA.crt
COMODORSAAddTrustCA.crt
AddTrustExternalCARoot.crt
<numbers>.crt
Plesk 12 is only offering two textfields for pasting your certificate. In order to paste your PositiveSSL certificate including the full certificate chain, copy the contents of your "your_domain_com.crt" / "<numbers>.crt" into the field Certificate. The following content has to be pasted into the "CA-Certificate" field:
PositiveSSL CA-Certificate (Intermediate):
-----BEGIN CERTIFICATE----- MIIGCDCCA/CgAwIBAgIQKy5u6tl1NmwUim7bo3yMBzANBgkqhkiG9w0BAQwFADCB hTELMAkGA1UEBhMCR0IxGzAZBgNVBAgTEkdyZWF0ZXIgTWFuY2hlc3RlcjEQMA4G A1UEBxMHU2FsZm9yZDEaMBgGA1UEChMRQ09NT0RPIENBIExpbWl0ZWQxKzApBgNV BAMTIkNPTU9ETyBSU0EgQ2VydGlmaWNhdGlvbiBBdXRob3JpdHkwHhcNMTQwMjEy MDAwMDAwWhcNMjkwMjExMjM1OTU5WjCBkDELMAkGA1UEBhMCR0IxGzAZBgNVBAgT EkdyZWF0ZXIgTWFuY2hlc3RlcjEQMA4GA1UEBxMHU2FsZm9yZDEaMBgGA1UEChMR Q09NT0RPIENBIExpbWl0ZWQxNjA0BgNVBAMTLUNPTU9ETyBSU0EgRG9tYWluIFZh bGlkYXRpb24gU2VjdXJlIFNlcnZlciBDQTCCASIwDQYJKoZIhvcNAQEBBQADggEP ADCCAQoCggEBAI7CAhnhoFmk6zg1jSz9AdDTScBkxwtiBUUWOqigwAwCfx3M28Sh bXcDow+G+eMGnD4LgYqbSRutA776S9uMIO3Vzl5ljj4Nr0zCsLdFXlIvNN5IJGS0 Qa4Al/e+Z96e0HqnU4A7fK31llVvl0cKfIWLIpeNs4TgllfQcBhglo/uLQeTnaG6 ytHNe+nEKpooIZFNb5JPJaXyejXdJtxGpdCsWTWM/06RQ1A/WZMebFEh7lgUq/51 UHg+TLAchhP6a5i84DuUHoVS3AOTJBhuyydRReZw3iVDpA3hSqXttn7IzW3uLh0n c13cRTCAquOyQQuvvUSH2rnlG51/ruWFgqUCAwEAAaOCAWUwggFhMB8GA1UdIwQY MBaAFLuvfgI9+qbxPISOre44mOzZMjLUMB0GA1UdDgQWBBSQr2o6lFoL2JDqElZz 30O0Oija5zAOBgNVHQ8BAf8EBAMCAYYwEgYDVR0TAQH/BAgwBgEB/wIBADAdBgNV HSUEFjAUBggrBgEFBQcDAQYIKwYBBQUHAwIwGwYDVR0gBBQwEjAGBgRVHSAAMAgG BmeBDAECATBMBgNVHR8ERTBDMEGgP6A9hjtodHRwOi8vY3JsLmNvbW9kb2NhLmNv bS9DT01PRE9SU0FDZXJ0aWZpY2F0aW9uQXV0aG9yaXR5LmNybDBxBggrBgEFBQcB AQRlMGMwOwYIKwYBBQUHMAKGL2h0dHA6Ly9jcnQuY29tb2RvY2EuY29tL0NPTU9E T1JTQUFkZFRydXN0Q0EuY3J0MCQGCCsGAQUFBzABhhhodHRwOi8vb2NzcC5jb21v ZG9jYS5jb20wDQYJKoZIhvcNAQEMBQADggIBAE4rdk+SHGI2ibp3wScF9BzWRJ2p mj6q1WZmAT7qSeaiNbz69t2Vjpk1mA42GHWx3d1Qcnyu3HeIzg/3kCDKo2cuH1Z/ e+FE6kKVxF0NAVBGFfKBiVlsit2M8RKhjTpCipj4SzR7JzsItG8kO3KdY3RYPBps P0/HEZrIqPW1N+8QRcZs2eBelSaz662jue5/DJpmNXMyYE7l3YphLG5SEXdoltMY dVEVABt0iN3hxzgEQyjpFv3ZBdRdRydg1vs4O2xyopT4Qhrf7W8GjEXCBgCq5Ojc 2bXhc3js9iPc0d1sjhqPpepUfJa3w/5Vjo1JXvxku88+vZbrac2/4EjxYoIQ5QxG V/Iz2tDIY+3GH5QFlkoakdH368+PUq4NCNk+qKBR6cGHdNXJ93SrLlP7u3r7l+L4 HyaPs9Kg4DdbKDsx5Q5XLVq4rXmsXiBmGqW5prU5wfWYQ//u+aen/e7KJD2AFsQX j4rBYKEMrltDR5FL1ZoXX/nUh8HCjLfn4g8wGTeGrODcQgPmlKidrv0PJFGUzpII 0fxQ8ANAe4hZ7Q7drNJ3gjTcBpUC2JD5Leo31Rpg0Gcg19hCC0Wvgmje3WYkN5Ap lBlGGSW4gNfL1IYoakRwJiNiqZ+Gb7+6kHDSVneFeO/qJakXzlByjAA6quPbYzSf +AZxAeKCINT+b72x -----END CERTIFICATE----- -----BEGIN CERTIFICATE----- MIIFdDCCBFygAwIBAgIQJ2buVutJ846r13Ci/ITeIjANBgkqhkiG9w0BAQwFADBv MQswCQYDVQQGEwJTRTEUMBIGA1UEChMLQWRkVHJ1c3QgQUIxJjAkBgNVBAsTHUFk ZFRydXN0IEV4dGVybmFsIFRUUCBOZXR3b3JrMSIwIAYDVQQDExlBZGRUcnVzdCBF eHRlcm5hbCBDQSBSb290MB4XDTAwMDUzMDEwNDgzOFoXDTIwMDUzMDEwNDgzOFow gYUxCzAJBgNVBAYTAkdCMRswGQYDVQQIExJHcmVhdGVyIE1hbmNoZXN0ZXIxEDAO BgNVBAcTB1NhbGZvcmQxGjAYBgNVBAoTEUNPTU9ETyBDQSBMaW1pdGVkMSswKQYD VQQDEyJDT01PRE8gUlNBIENlcnRpZmljYXRpb24gQXV0aG9yaXR5MIICIjANBgkq hkiG9w0BAQEFAAOCAg8AMIICCgKCAgEAkehUktIKVrGsDSTdxc9EZ3SZKzejfSNw AHG8U9/E+ioSj0t/EFa9n3Byt2F/yUsPF6c947AEYe7/EZfH9IY+Cvo+XPmT5jR6 2RRr55yzhaCCenavcZDX7P0N+pxs+t+wgvQUfvm+xKYvT3+Zf7X8Z0NyvQwA1onr ayzT7Y+YHBSrfuXjbvzYqOSSJNpDa2K4Vf3qwbxstovzDo2a5JtsaZn4eEgwRdWt 4Q08RWD8MpZRJ7xnw8outmvqRsfHIKCxH2XeSAi6pE6p8oNGN4Tr6MyBSENnTnIq m1y9TBsoilwie7SrmNnu4FGDwwlGTm0+mfqVF9p8M1dBPI1R7Qu2XK8sYxrfV8g/ vOldxJuvRZnio1oktLqpVj3Pb6r/SVi+8Kj/9Lit6Tf7urj0Czr56ENCHonYhMsT 8dm74YlguIwoVqwUHZwK53Hrzw7dPamWoUi9PPevtQ0iTMARgexWO/bTouJbt7IE IlKVgJNp6I5MZfGRAy1wdALqi2cVKWlSArvX31BqVUa/oKMoYX9w0MOiqiwhqkfO KJwGRXa/ghgntNWutMtQ5mv0TIZxMOmm3xaG4Nj/QN370EKIf6MzOi5cHkERgWPO GHFrK+ymircxXDpqR+DDeVnWIBqv8mqYqnK8V0rSS527EPywTEHl7R09XiidnMy/ s1Hap0flhFMCAwEAAaOB9DCB8TAfBgNVHSMEGDAWgBStvZh6NLQm9/rEJlTvA73g JMtUGjAdBgNVHQ4EFgQUu69+Aj36pvE8hI6t7jiY7NkyMtQwDgYDVR0PAQH/BAQD AgGGMA8GA1UdEwEB/wQFMAMBAf8wEQYDVR0gBAowCDAGBgRVHSAAMEQGA1UdHwQ9 MDswOaA3oDWGM2h0dHA6Ly9jcmwudXNlcnRydXN0LmNvbS9BZGRUcnVzdEV4dGVy bmFsQ0FSb290LmNybDA1BggrBgEFBQcBAQQpMCcwJQYIKwYBBQUHMAGGGWh0dHA6 Ly9vY3NwLnVzZXJ0cnVzdC5jb20wDQYJKoZIhvcNAQEMBQADggEBAGS/g/FfmoXQ zbihKVcN6Fr30ek+8nYEbvFScLsePP9NDXRqzIGCJdPDoCpdTPW6i6FtxFQJdcfj Jw5dhHk3QBN39bSsHNA7qxcS1u80GH4r6XnTq1dFDK8o+tDb5VCViLvfhVdpfZLY Uspzgb8c8+a4bmYRBbMelC1/kZWSWfFMzqORcUx8Rww7Cxn2obFshj5cqsQugsv5 B5a6SE2Q8pTIqXOi6wZ7I53eovNNVZ96YUWYGGjHXkBrI/V5eu+MtWuLt29G9Hvx PUsE2JOAWVrgQSQdso8VYFhH2+9uRv0V9dlfmrPb2LjkQLPNlzmuhbsdjrzch5vR pu/xO28QOG8= -----END CERTIFICATE-----
