DV SSL/TLS Certificate for rk.edu.pl

Certificate is witin its validity period

Issued by Let's Encrypt (R10)

About the rk.edu.pl DV SSL/TLS Certificate

This certificate with serial number 06:e4:1c:a6:f2:4a:5c:03:ee:cf:92:62:f0:58:54:61:e2:57 for rk.edu.pl was issued on by Let's Encrypt.

With 2 subject alternative names, this certificate can be used to secure multiple FQDNs. This DV SSL/TLS Certificate is currently within its validity period but we haven't checked the revocation status of this certificate, you can do this simply on revocationcheck.com. We have found some issues with the compliance of this certificate, they are be shown below. We hope this DV SSL/TLS Certificate review for rk.edu.pl provides you with the detailed information you were looking for.


We have identified some issues with this certificate:
  • Subscriber certificates use of Subject Key Identifier is NOT RECOMMENDED (BRs v2: 7.1.2.7.6)
  • Subscriber Certificate: commonName is NOT RECOMMENDED. (BRs: 7.1.2.7.1)

Let's Encrypt

Organization: Let's Encrypt
Country: US

This X.509 certificate will expire on

Certificate Details

Serial Number (hex): 06:e4:1c:a6:f2:4a:5c:03:ee:cf:92:62:f0:58:54:61:e2:57
Serial Number (int): 600296180467930429460413523540857749365335
Serial Number Length: 139 bits, 18 octets

Subject Key Identifier: d2:24:b7:76:5c:4d:0c:b3:96:18:b0:32:ad:0a:de:23:87:f0:13:83
Authority Key Identifier: bb:bc:c3:47:a5:e4:bc:a9:c6:c3:a4:72:0c:10:8d:a2:35:e1:c8:e8

Fingerprint (SHA-1): b8:b7:62:0f:14:db:7d:b9:1b:65:7e:fc:8d:fe:cb:49:95:f2:64:69
Fingerprint (SHA-256): 0b:30:0f:d2:11:86:38:35:4e:8e:c5:e8:04:8f:b9:19:d5:d7:07:62:e9:94:a3:3c:f3:6f:44:48:a7:3d:97:6a

Issuing Certificate URL: http://r10.i.lencr.org/

Revocation Information

CRL Distribution Point: http://r10.c.lencr.org/88.crl

Check the revocation status for certificate rk.edu.pl
2
DNS Names
0
Email Addresses
0
IP Addresses

Advanced Certificate Properties

Technical details of the X.509 certificate for rk.edu.pl

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
10
CA Certificate
This is not a CA certificate

Subject Alternative Names

X.509 Certificate

The complete raw X.509 certificate details for rk.edu.pl in PEM and ASN.1 format.

Certificate (PEM)

-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Public Key (PEM)

-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA4Sz0LgigB0zjPNWkiolq
0a/a3XPX/XDwkQ1ogSbvoMEHTHnl997JWkCa36BtfQf9SEvIXqJUzoskGZpFJcDp
ayZB4vKvgZbWkbyHfVt91xNn2rQiUQOWDY4xQElegKuihqQBvg0sogOe2W0ndlRS
CeFwxkhZpdIWYQ6RqlsUTUnMTl57GZjiCa193w6hkzDhHHava58LuJgJBhWoaGRe
wWsc5EdVuxEt7Z8xC6g545osSSjApc2TLa5zSgWT8V0yV52VmJ4eFvYNHSHqSSqH
gR/wKEjbdswyFsGIS6qeeGOd3wjoUwlcMBc4dhTOmDRWOeIoBAER25Fh2M71cBWo
hwIDAQAB
-----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 600296180467930429460413523540857749365335
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.2.840.113549.1.1.11
 . . . . . . . . . . . . [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
 . . . . . . . . . . . . . . . . . . . . [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
 . . . . . . . . . . . . . . . . . . . . [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
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'R10'
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2025-06-04 20:03:47 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2025-09-02 20:03:46 +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
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'rk.edu.pl'
 . . . . . . . . [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
 . . . . . . . . . . . . . . . . [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 28425786175859419447879529792203161404388078179171375997438235519041759575037114225074637021889726293462859306766601794890886281924637845374522483558382517205439469706455951044669826501151749242130926335203578208698820943188536264327696874485100291630415234423124778354589366268015136181148454634426462298793969781547188808376312044760597819618519181201720190019456778736596861758611894993245630658030440264883292111235919571647534774037772047240969728261029399658590444022324742101036042641382899647257962828926859761386782915870605407529366351735546280107269769676526241783672739769011277625748261674080125299566727
 . . . . . . . . . . . . . . . . . . . . [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
 . . . . . . . . . . . . . . . . . . . . [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
 . . . . . . . . . . . . . . . . . . . . [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
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.3.2
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.19
 . . . . . . . . . . . . . . . . . . . . [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
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (22 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (20 bytes)
							d224b7765c4d0cb39618b032ad0ade2387f01383
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.35
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (24 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:0|false] OtherName bbbcc347a5e4bca9c6c3a4720c108da235e1c8e8
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.1.1
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (39 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.48.2
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:6|false] IA5String 'http://r10.i.lencr.org/'
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.17
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (28 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'rk.edu.pl'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.rk.edu.pl'
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.32
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (12 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
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.31
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (39 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:0|true] OtherName 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:0|true] OtherName 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:6|false] IA5String 'http://r10.c.lencr.org/88.crl'
 . . . . . . . . . . . . . . . . [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)
							00f1007700a442c506496061548f0fd4ea9cfb7a2d26454d87a97f2fdf4559f6274f3a8454000001973cc07fcc00000403004830460221008c3f5a37083e911335167091d5f522c02ee63bae4da59c71703e37d4b5ae8bb1022100f31406f2593413093f32fad534d1b3ed34907acbd5699306f3228951242b833e00760012f14e34bd53724c840619c38f3f7a13f8e7b56287889c6d300584ebe586263a000001973cc08f75000004030047304502207e22cc0c2d0b15a3376101388890aa4503d62dc92a13c2c092932482c6dd0c820221008d2364660249b8ea10d496c975fc3774ecd17d489d599f48e7a39b45cd1804b1
 . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.2.840.113549.1.1.11
 . . . . . . . . [c:0|t:5|false] NULL []
 . . . . [c:0|t:3|false] BIT STRING (2048 bits)
		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