it-sicherheit.news
Issued by Let's Encrypt Authority X3
About this certificate
This digital certificate with serial number 03:b5:2e:61:c4:ce:11:d9:c3:57:03:d4:ee:53:34:13:c5:8e was issued on by Let's Encrypt.
With 2 subject alternative names this certificate can be used to secure multiple fqdn's. This certificate has already expired and will cause a warning or error message in the browser it's still listed on this site to allow you to look back on previously issued certificates. If we have found any compliance issues with this certificate they will be shown below. I hope this certificate review is providing you the detailed information in a simple form you where looking for.
We have idenified some issues with this certificate:
- Subscriber Certificate: commonName is deprecated. (BRs: 7.1.4.2.2)
Certificate Subject
CN=it-sicherheit.news
Let's Encrypt
Organization:
Let's Encrypt
Country:
US
This certificate has expire since
Certificate Details
Serial Number (hex): 03:b5:2e:61:c4:ce:11:d9:c3:57:03:d4:ee:53:34:13:c5:8eSerial Number (int): 322989618340250794133378327915807248729486
Serial Number lenght: 138 bits, 18 octets
SubjectKeyId: 1e:e6:ec:5f:6a:1e:b0:ee:f5:4a:98:35:a1:d6:ae:cb:8c:db:1d:ba
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1
Fingerprint (sha1): a6:33:c8:05:39:14:fe:17:94:b3:a0:8b:49:26:20:1d:f2:f8:d7:70
Fingerprint (sha256): c3:2d:4d:71:67:9f:d1:3e:b0:03:55:4c:4a:6f:2d:2b:a6:70:9f:c3:2e:ee:7e:6a:fe:62:df:17:d3:95:03:8d
Issuing Certificate URL: http://cert.int-x3.letsencrypt.org/
Revocation information
OCSP Server: http://ocsp.int-x3.letsencrypt.orgCheck the revocation status for certificate it-sicherheit.news
2
DNS Names
0
Email Addresses
0
IP Addresses
Advanced Certificate Properties
Tehnical certificate details for it-sicherheit.news
Public Key Algorithm
RSA
Key Size
2048
Signature Algorithm
SHA256 with RSA
Key Usage
Digital Signature
Key Encipherment
Extended Key Usages
Server Authentication
Client Authentication
Extensions
9 extensions
No
unhandled critical extensions
CA Certificate
This is not a CA certificate
Subject Alternative Names
it-sicherheit.news
www.it-sicherheit.news
www.it-sicherheit.news
Other certificates including the domain name it-sicherheit.news
(limited to 100 certificates)
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
www.it-sicherheit.news
it-sicherheit.news
www.it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
www.it-sicherheit.news
it-sicherheit.news
www.it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
it-sicherheit.news
Certificate
The complete raw certificate details for it-sicherheit.news in PEM and ASN.1 format.
Certificate (PEM)
-----BEGIN CERTIFICATE----- MIIGKDCCBRCgAwIBAgISA7UuYcTOEdnDVwPU7lM0E8WOMA0GCSqGSIb3DQEBCwUA MEoxCzAJBgNVBAYTAlVTMRYwFAYDVQQKEw1MZXQncyBFbmNyeXB0MSMwIQYDVQQD ExpMZXQncyBFbmNyeXB0IEF1dGhvcml0eSBYMzAeFw0xODA0MDcwMTEwMTNaFw0x ODA3MDYwMTEwMTNaMB0xGzAZBgNVBAMTEml0LXNpY2hlcmhlaXQubmV3czCCASIw DQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBAPPKkBTJ1AgmvsNUMJhsS6ihvdG3 Ez8TP0uUaF1yOu19vwMCGECMQG85v0bSIevcjyby3IXCUxS1isj0ymKU/DULTXKI hAGE7Gy1lJmokorammmkzRCgW+cCjW3yJsmhPp6cafDyF34Hd6EDFfqRNfkwROzO W9ItfpWEnNuPzBFgAE9PlnYR8KZZXrZSXQuZrI5jWEGNtLv51mBUd/+2QNfdWL1u KqA18PWpiPgMgkl2ObvyyQlwnif17CcMjpXRguQ+lsQdzWsHu/RM2cMTSPS7BNMw BtmOv4Wkcy1ZxyU9dYPK6on8k8Lbfg/z78EKoYPSv93IA2mIZYttMAG7R/ECAwEA AaOCAzMwggMvMA4GA1UdDwEB/wQEAwIFoDAdBgNVHSUEFjAUBggrBgEFBQcDAQYI KwYBBQUHAwIwDAYDVR0TAQH/BAIwADAdBgNVHQ4EFgQUHubsX2oesO71Spg1odau y4zbHbowHwYDVR0jBBgwFoAUqEpqYwR93brm0Tm3pkVl7/Oo7KEwbwYIKwYBBQUH AQEEYzBhMC4GCCsGAQUFBzABhiJodHRwOi8vb2NzcC5pbnQteDMubGV0c2VuY3J5 cHQub3JnMC8GCCsGAQUFBzAChiNodHRwOi8vY2VydC5pbnQteDMubGV0c2VuY3J5 cHQub3JnLzA1BgNVHREELjAsghJpdC1zaWNoZXJoZWl0Lm5ld3OCFnd3dy5pdC1z aWNoZXJoZWl0Lm5ld3Mwgf4GA1UdIASB9jCB8zAIBgZngQwBAgEwgeYGCysGAQQB gt8TAQEBMIHWMCYGCCsGAQUFBwIBFhpodHRwOi8vY3BzLmxldHNlbmNyeXB0Lm9y ZzCBqwYIKwYBBQUHAgIwgZ4MgZtUaGlzIENlcnRpZmljYXRlIG1heSBvbmx5IGJl IHJlbGllZCB1cG9uIGJ5IFJlbHlpbmcgUGFydGllcyBhbmQgb25seSBpbiBhY2Nv cmRhbmNlIHdpdGggdGhlIENlcnRpZmljYXRlIFBvbGljeSBmb3VuZCBhdCBodHRw czovL2xldHNlbmNyeXB0Lm9yZy9yZXBvc2l0b3J5LzCCAQUGCisGAQQB1nkCBAIE gfYEgfMA8QB3ANt0r+7LKeyx/so+cW0s5bmquzb3hHGDx12dTze2H79kAAABYp3e SHEAAAQDAEgwRgIhANrlWBbycmn6jfz7Ma5KfPBOb/5NiQtVb18Bevv7gtKaAiEA v6GKz5t7V+nOI3ZE93fHVdOI5izy6oPMzrpBXWOTOZoAdgApPFGWVMg5ZbqqUPxY B9S3b79Yeily3KTDDPTlRUf0eAAAAWKd3khwAAAEAwBHMEUCIFePJC388injJK8/ ZZHOiNoSXtL73ZCjk1/hzv8hgL68AiEA8I2Mn8a0dG/g+okc3CQV2Yu9okwfZcfF Qz1hh4csXO0wDQYJKoZIhvcNAQELBQADggEBAItOsOehWN9eH+hHcfQpd3F+5GXm TRJEadJXsXRiUDWXZQIThvUqqxyVnZg38uMDp7U2t9fi9cep8SIWaAUOTbeRxlMH /NsUAHCHL/QPMIP+XtzygfUdAulHaqSfRXxnGoL8oxQ9fpAtfMgHBu1DZOCdTLQL 9Oy5VvDD65oBeYkFKkpmYBPUDQUUe+eibF0/E28gNTXBwhQF1CqbEy3x1xXa5Dfh EfZ4C9Ww3TB/DwwlP3ReEmyhvXuPILNxkVkAy/Dwz1RIeY6hqcC/sYKhydK8pvZJ Uz59ewmNIe04rQkaRRChXPzNUExkWyxVxRMeEiT6ui/VJiUPV9L4QhEJL3s= -----END CERTIFICATE-----
Public Key (PEM)
-----BEGIN PUBLIC KEY----- MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA88qQFMnUCCa+w1QwmGxL qKG90bcTPxM/S5RoXXI67X2/AwIYQIxAbzm/RtIh69yPJvLchcJTFLWKyPTKYpT8 NQtNcoiEAYTsbLWUmaiSitqaaaTNEKBb5wKNbfImyaE+npxp8PIXfgd3oQMV+pE1 +TBE7M5b0i1+lYSc24/MEWAAT0+WdhHwplletlJdC5msjmNYQY20u/nWYFR3/7ZA 191YvW4qoDXw9amI+AyCSXY5u/LJCXCeJ/XsJwyOldGC5D6WxB3Nawe79EzZwxNI 9LsE0zAG2Y6/haRzLVnHJT11g8rqifyTwtt+D/PvwQqhg9K/3cgDaYhli20wAbtH 8QIDAQAB -----END PUBLIC KEY-----
ASN.1 decoded
[c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . [c:2|t:0|true] OtherName . . . . . . . . . . . . [c:0|t:2|false] INTEGER 2 . . . . . . . . [c:0|t:2|false] INTEGER 322989618340250794133378327915807248729486 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.2.840.113549.1.1.11 (sha256WithRSAEncryption) . . . . . . . . . . . . [c:0|t:5|false] NULL . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . [c:0|t:17|true] SET, SET OF . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.4.6 (countryName) . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'US' . . . . . . . . . . . . [c:0|t:17|true] SET, SET OF . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.4.10 (organizationName) . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'Let's Encrypt' . . . . . . . . . . . . [c:0|t:17|true] SET, SET OF . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.4.3 (commonName) . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'Let's Encrypt Authority X3' . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2018-04-07 01:10:13 +0000 UTC . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2018-07-06 01:10:13 +0000 UTC . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . [c:0|t:17|true] SET, SET OF . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.4.3 (commonName) . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'it-sicherheit.news' . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.2.840.113549.1.1.1 (rsaEncryption) . . . . . . . . . . . . . . . . [c:0|t:5|false] NULL . . . . . . . . . . . . [c:0|t:3|false] BIT STRING (2160 bits) . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . [c:0|t:2|false] INTEGER 30775795554772537853378083408121022679908651569512554781077474201474375462533080790648146134051274186268541636068518790498022451012400268660224237416183440826572082940313521831109615049438520897157010165306061003183857786863839767709426358307892783448303287989891858278606481278710423433218812551878267339622864043699388367606685761994180464765065355619245228414953426583330691055246510909613266935694357715265382529142434982440199808792075041213747549208016305229826255183908506021371335825565497479576435318712159677904417748353605920644991078791154521315868342789309202702371346317703447871154412324491612800108529 . . . . . . . . . . . . . . . . . . . . [c:0|t:2|false] INTEGER 65537 . . . . . . . . [c:2|t:3|true] ORAddress . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.15 (keyUsage) . . . . . . . . . . . . . . . . . . . . [c:0|t:1|false] BOOLEAN true . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (4 bytes) . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:3|false] BIT STRING (3 bits) 05a0 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.37 (extKeyUsage) . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (22 bytes) . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.3.1 (serverAuth) . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.3.2 (clientAuth) . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.19 (basicConstraints) . . . . . . . . . . . . . . . . . . . . [c:0|t:1|false] BOOLEAN true . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (2 bytes) . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.14 (subjectKeyIdentifier) . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (22 bytes) . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (20 bytes) 1ee6ec5f6a1eb0eef54a9835a1d6aecb8cdb1dba . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.35 (authorityKeyIdentifier) . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (24 bytes) . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:0|false] OtherName a84a6a63047dddbae6d139b7a64565eff3a8eca1 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.1.1 (authorityInfoAccess) . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (99 bytes) . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.48.1 (ocsp) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:6|false] IA5String 'http://ocsp.int-x3.letsencrypt.org' . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.48.2 (caIssuers) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:6|false] IA5String 'http://cert.int-x3.letsencrypt.org/' . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.17 (subjectAltName) . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (46 bytes) . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'it-sicherheit.news' . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.it-sicherheit.news' . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.32 (certificatePolicies) . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (246 bytes) . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.23.140.1.2.1 (Domain Validation Certificates Policy) . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.4.1.44947.1.1.1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.2.1 (cps) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:22|false] IA5String 'http://cps.letsencrypt.org' . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.2.2 (unotice) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:12|false] UTF8String 'This Certificate may only be relied upon by Relying Parties and only in accordance with the Certificate Policy found at https://letsencrypt.org/repository/' . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.4.1.11129.2.4.2 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (246 bytes) . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (243 bytes) 00f1007700db74afeecb29ecb1feca3e716d2ce5b9aabb36f7847183c75d9d4f37b61fbf64000001629dde48710000040300483046022100dae55816f27269fa8dfcfb31ae4a7cf04e6ffe4d890b556f5f017afbfb82d29a022100bfa18acf9b7b57e9ce237644f777c755d388e62cf2ea83ccceba415d6393399a007600293c519654c83965baaa50fc5807d4b76fbf587a2972dca4c30cf4e54547f478000001629dde487000000403004730450220578f242dfcf229e324af3f6591ce88da125ed2fbdd90a3935fe1ceff2180bebc022100f08d8c9fc6b4746fe0fa891cdc2415d98bbda24c1f65c7c5433d6187872c5ced . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.2.840.113549.1.1.11 (sha256WithRSAEncryption) . . . . . . . . [c:0|t:5|false] NULL . . . . [c:0|t:3|false] BIT STRING (2048 bits) 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