DV SSL/TLS Certificate for flor-tsukuba.jp

Certificate is witin its validity period

Issued by Let's Encrypt (E5)

About the flor-tsukuba.jp DV SSL/TLS Certificate

This certificate with serial number 06:2d:01:3f:fc:de:df:90:e5:cd:dd:f6:13:23:94:f6:a1:f0 for flor-tsukuba.jp 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 flor-tsukuba.jp 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): 06:2d:01:3f:fc:de:df:90:e5:cd:dd:f6:13:23:94:f6:a1:f0
Serial Number (int): 537988083573526645871724070919784837325296
Serial Number Length: 139 bits, 18 octets

Subject Key Identifier: f7:6e:9f:64:46:9d:96:02:59:d2:2c:11:d0:8d:c7:90:55:b1:ae:d3
Authority Key Identifier: 9f:2b:5f:cf:3c:21:4f:9d:04:b7:ed:2b:2c:c4:c6:70:8b:d2:d7:0d

Fingerprint (SHA-1): a3:0c:7d:d6:c4:62:24:35:64:31:47:66:80:98:bd:0b:d1:ac:75:ff
Fingerprint (SHA-256): 37:b6:fb:70:9c:fe:51:3c:97:ff:0b:aa:f9:61:f3:15:a3:ac:7c:8a:aa:29:51:31:08:60:b4:47:64:fd:e6:87

Issuing Certificate URL: http://e5.i.lencr.org/

Revocation Information

CRL Distribution Point: http://e5.c.lencr.org/113.crl

Check the revocation status for certificate flor-tsukuba.jp
2
DNS Names
0
Email Addresses
0
IP Addresses

Advanced Certificate Properties

Technical details of the X.509 certificate for flor-tsukuba.jp

Public Key Algorithm
ECDSA
Key Size
256
Signature Algorithm
ECDSA with SHA384
Key Usage
Digital Signature
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 flor-tsukuba.jp in PEM and ASN.1 format.

Certificate (PEM)

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

Public Key (PEM)

-----BEGIN PUBLIC KEY-----
MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEsoyxQ9AKdwwXWjKhbjE8ErMmhNI6
X839AjFtNv7VFuxUsGtvcn/U94EMc34XhNUs1JjDJkv6FaTrUh7TA/LOrQ==
-----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 537988083573526645871724070919784837325296
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.2.840.10045.4.3.3
 . . . . . . . . [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 'E5'
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2025-06-30 19:04:20 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2025-09-28 19:04:19 +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 'flor-tsukuba.jp'
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.2.840.10045.2.1
 . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.2.840.10045.3.1.7
 . . . . . . . . . . . . [c:0|t:3|false] BIT STRING (520 bits)
				0004b28cb143d00a770c175a32a16e313c12b32684d23a5fcdfd02316d36fed516ec54b06b6f727fd4f7810c737e1784d52cd498c3264bfa15a4eb521ed303f2cead
 . . . . . . . . [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 (1 bits)
							0780
 . . . . . . . . . . . . . . . . [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)
							f76e9f64469d960259d22c11d08dc79055b1aed3
 . . . . . . . . . . . . . . . . [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 9f2b5fcf3c214f9d04b7ed2b2cc4c6708bd2d70d
 . . . . . . . . . . . . . . . . [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 (38 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://e5.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 (40 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'flor-tsukuba.jp'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.flor-tsukuba.jp'
 . . . . . . . . . . . . . . . . [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://e5.c.lencr.org/113.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)
							00f10076007d591e12e1782a7b1c61677c5efdf8d0875c14a04e959eb9032fd90e8c2e79b800000197c26f66bc0000040300473045022100998dc6b71a5d9eb579f0e3382b8934a3adb486bcb9c01a3bcbec855a99804b71022071170a3971bfb5c30ab848e13018900e5dfd21a0615619b2b1113f407b82215b007700dddcca3495d7e11605e79532fac79ff83d1c50dfdb003a1412760a2cacbbc82a00000197c26f66e40000040300483046022100b31a6a1f0ef9137c415f0c76bb17e9636633e9305c8cc43f04fc488b17404aca022100a057c3874cc936114fd374f50ae443a20e6a07ede5a3d92a84cdbc2964f07254
 . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.2.840.10045.4.3.3
 . . . . [c:0|t:3|false] BIT STRING (824 bits)
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:2|false] INTEGER 5686886902466859245914507862184533120461084795736530348042759453407829297781564415337092265796254326478198839339227
 . . . . . . . . . . . . [c:0|t:2|false] INTEGER 34134205189328931321170438779249223525339718548491011592103215964272218134757628039511799920406391109916984605176568