*.ogrencievimapp.com

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 04:4c:ca:7b:5b:9d:c1:27:a2:10:ad:8b:40:46:d0:cd:3f:5e was issued on by Let's Encrypt.

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=*.ogrencievimapp.com

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 04:4c:ca:7b:5b:9d:c1:27:a2:10:ad:8b:40:46:d0:cd:3f:5e
Serial Number (int): 374579748178892336567211963891883216551774
Serial Number lenght: 139 bits, 18 octets

SubjectKeyId: 06:07:3f:49:55:96:05:c7:38:b8:28:f6:3d:a0:56:78:0b:9b:4d:fe
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): 2b:03:db:1c:81:e3:1f:12:43:6b:73:fd:e5:63:25:cd:cf:46:9a:8e
Fingerprint (sha256): 81:26:06:b9:e8:3d:6d:2f:3d:20:b0:62:91:8c:38:f7:3c:25:d1:08:74:d8:49:4b:3f:bd:cd:40:8d:b6:3e:5a

Issuing Certificate URL: http://cert.int-x3.letsencrypt.org/

Revocation information

OCSP Server: http://ocsp.int-x3.letsencrypt.org

Check the revocation status for certificate *.ogrencievimapp.com

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for *.ogrencievimapp.com

Public Key Algorithm

RSA

Key Size

4096

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

*.ogrencievimapp.com

Other certificates including the domain name ogrencievimapp.com

(limited to 100 certificates)

Certificate

The complete raw certificate details for *.ogrencievimapp.com in PEM and ASN.1 format.

Certificate (PEM)

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

Public Key (PEM)

-----BEGIN PUBLIC KEY-----
MIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIICCgKCAgEA11U3EIwWLTBQPWmDEpQx
svKoa00YaxF7SEdCfK3hVDgYNiwjzSyr+31k+5idf8wAqNcXBVqfmR77KRtVg0vK
sBkhJPc5mqmbDeZUZ7e5ICDaYBDDVG/2i5CPybL5JNLfL5E/XF5tudZLnQCv7lYn
aB3L+Xmu4pBK3UeOa9951pjjAvG0B5oxOLZzBu6yTZ92pS/0R4R75r45YzbDoLcN
UoVMgCJtbRe+9wYDd8nL6ZuNcgO86l481hGTpPGvCLucrWzw0Ad1mO5Q/2OPrUMV
vfzzXQ5/jigjCIXT8WZcHFHacgxVWiHX2WcVuKwjmGU3ZfVroN6wVbbK7RZm+Of1
ujWkQ05kesy7l9evPRs6xgD+F319h27e9ISZxxBXJVhTPsDYeoK++QsudQRocyvv
hebGag5LWNvnebaZCKnRUROsJKhQt9crHofLBR5gD3VnuxEHlNbhUQ0zdnDhywtd
SdOeL01ahJMSLYP/aqn27Akinh/Z00TObdu44Rkx9Z2YmcZZZ2JYLh94oAh133S8
8T6RQROZ/uBD+O9HlV2hMzs4WKBZ8fFvxo4H7maGx2B1uD9eVtqk7rmZ71t0KrsC
tjM/OARnDMo8NEvmUMZvDWBD7AZ+iLw2PHTELrkFa71clkQ7l2DF02ZmMffpj6HY
4DGdneUNf+5FkhI5OLeVdV0CAwEAAQ==
-----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 374579748178892336567211963891883216551774
 . . . . . . . . [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 2018-12-27 20:54:52 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2019-03-27 20:54:52 +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:12|false] UTF8String '*.ogrencievimapp.com'
 . . . . . . . . [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 (4208 bits)
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:2|false] INTEGER 878481471741058041668776532803371461444144956263306794429368137781464888681307569134397868974779374229408710724159597500833183359175453864687832441351150070345857634294949970054110736524481230980174973945288352443958734788003978958834786903354288849539790977457471160143816753922277706382805765113839753939312200099531620719352998332292298964301827816287671555724139839748193988434662977168067697666962664037632818202637239770975694450733916557384035518788648002236232658813605545407002023486009005479483043020308564085169973101066121203297024048775587925023439698565885339786857170646278561213995951137576583237729364358850087980743376593513042328003508616408530158091123721099519191649621852016324547838747433899535733117214165474388114858032979816801507674138087185950616081862254587317602669961753333347675535238733994961287698916956656602690492086270595315499622540151519659710327061353894534166512103134762499633670433996517403068101689542502425814788960692390656557125928787012257070521362540618905435687870258120932744210293046326034528299611686938407847607129411451077112973359881499357879980204398133665357742729609637495924464947966613288186511801357299824053184307137963755234716943353537977495869443651961930860664812893
 . . . . . . . . . . . . . . . . . . . . [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)
							06073f49559605c738b828f63da056780b9b4dfe
 . . . . . . . . . . . . . . . . [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 (24 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String '*.ogrencievimapp.com'
 . . . . . . . . . . . . . . . . [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 (69 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 1.3.6.1.4.1.11129.2.4.2
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (245 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (242 bytes)
							00f00076005581d4c2169036014aea0b9b573c53f0c0e43878702508172fa3aa1d0713d30c00000167f1a9bf560000040300473045022076b983ee3d9882fbe1fd8da3fff6995601b9df41d73f04f3a7b1849e3dfcbcfe022100d22f49ca986c269b9f8b41227da980afe24d9e0101b18dd44d9cc553a5385dcd007600293c519654c83965baaa50fc5807d4b76fbf587a2972dca4c30cf4e54547f47800000167f1a9c002000004030047304502210092dfd18d3c2ec198a6c8e853bfc35fc0c7e5bdb1ad1b0cc7a99d952ed916f33a0220258f80ec1f6d6fb1f3925ef79bf6cb1a8033a52818242fcc068781f3eb4551f6
 . . . . [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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