www.346.me

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 03:02:97:b1:26:a0:09:c7:d1:93:38:87:86:b8:bd:1e:70:e6 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=www.346.me

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 03:02:97:b1:26:a0:09:c7:d1:93:38:87:86:b8:bd:1e:70:e6
Serial Number (int): 262219055776441197700159777699308135936230
Serial Number lenght: 138 bits, 18 octets

SubjectKeyId: 12:19:0b:6b:6b:38:6c:18:4d:4f:60:a4:1b:93:1d:c2:a8:74:48:69
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): c3:84:b7:45:86:e3:3a:85:4c:a9:61:bf:cd:11:b8:ce:56:b0:d2:15
Fingerprint (sha256): 0e:8a:e5:81:5c:6a:9b:ed:06:e3:e3:69:b7:db:15:3e:57:dc:2e:24:d5:39:89:7c:22:db:cb:c2:42:60:4f:0f

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 www.346.me

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for www.346.me

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

www.346.me

Other certificates including the domain name 346.me

(limited to 100 certificates)
346.me
futureflight.co.za
www.346.me
www.346.me
346.me
retire.fund
346.me
346.me
346.me
www.346.me
garafraxis.world
346.me
346.me
346.me
www.346.me
www.346.me

Certificate

The complete raw certificate details for www.346.me in PEM and ASN.1 format.

Certificate (PEM)

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

Public Key (PEM)

-----BEGIN PUBLIC KEY-----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-----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 262219055776441197700159777699308135936230
 . . . . . . . . [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 2019-09-30 17:52:57 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2019-12-29 17:52:57 +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 'www.346.me'
 . . . . . . . . [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 658722494244973393528567617944263230095203695144373163598262963801591850275893312129130735068142233219106434756397151935112657166981351253309248827853999165342826822153797953834553692684951533359464498388900860931992659575226165887195479779721194485521938295444367997554593322361491974537916608996915781899654890996094311269115846519286775772003787029736340032365486804729757685307755768219566098663976340679726877788091669655384349034906266916553023163675879946667559610112350200611771225545863822219249537086183371206399787380429191527218802061065776910476562852859840810336151362479995895301529900826468330510582794096533354269262812894203721710186318027842019537686798223867768939356483391550679992814034990232214462383274601213414672836155156111794133865156527352119236419748817581002702529911242742066791374038039592708207428238373575187624163312199761465457999723109221356356394991965445562074984464365812833802366628760895081533159912235693719171580233586965621986138058051306635331322684011939672686844797702055725579101267511611231334543615354453161231767256670459754629344847089421530295224764003151193206340767037151090614666761497453775196999901383316274118602639727842244220687957770130179022031131111571273509410849819
 . . . . . . . . . . . . . . . . . . . . [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)
							12190b6b6b386c184d4f60a41b931dc2a8744869
 . . . . . . . . . . . . . . . . [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 (14 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.346.me'
 . . . . . . . . . . . . . . . . [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 (244 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (241 bytes)
							00ef007600747eda8331ad331091219cce254f4270c2bffd5e422008c6373579e6107bcc560000016d8384bcb70000040300473045022063ea2df7cd251b0f1fcd1bcd8b30838e7210faa3cf6c206a4f5177a08e332c4d022100d8ae6d731cf72b9832a7dc3e49045f6640470abdb1ad10379608b97a9f2c25c900750063f2dbcde83bcc2ccf0b728427576b33a48d61778fbd75a638b1c768544bd88d0000016d8384bccd00000403004630440220442ceb7b079c1376eb6f6de387ae63d5132fdabb29857e04a4a7668c43a8dad602205d952e289909c73b78dc28ec668ded33f6ac74ebd12b017e34f2d2eb3f9a94a8
 . . . . [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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