pigma.org

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 04:e9:2e:b2:88:5a:a8:c6:5a:e3:47:4f:e7:5a:73:3b:4e:d4 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=pigma.org

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 04:e9:2e:b2:88:5a:a8:c6:5a:e3:47:4f:e7:5a:73:3b:4e:d4
Serial Number (int): 427797006701857047904012105746295281110740
Serial Number lenght: 139 bits, 18 octets

SubjectKeyId: a2:0d:39:92:4b:9d:76:3d:a1:04:0b:84:ef:49:04:5f:38:99:01:a0
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): d2:c5:d7:34:03:cc:71:24:f3:1b:bf:8c:32:eb:79:a4:4a:77:3b:72
Fingerprint (sha256): 65:f2:5a:5b:57:5d:dd:50:4f:c7:50:4b:b8:ca:20:55:0a:7a:f4:2f:67:e0:a2:66:8b:27:23:51:94:7b:ba:5c

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 pigma.org

2

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for pigma.org

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

pigma.org
www.pigma.org

Other certificates including the domain name pigma.org

(limited to 100 certificates)

Certificate

The complete raw certificate details for pigma.org 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 427797006701857047904012105746295281110740
 . . . . . . . . [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 2019-03-25 11:02:21 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2019-06-23 11:02:21 +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 'pigma.org'
 . . . . . . . . [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 868686175803936167494410664025480753554176024856378206046185229195457738956059913183317035010002120533263237948070753112701001151288926239747753907864507028722638284462847234237172062272670558015098375038000440552594364191797516221035232694553959997883202627672643135333835996783984393218989678498198081378768537838378936388384584531830727894968813696953325293810110330128237270352910541818927934506132852880998074387026240251690452124358884323449963278447824865113822508213274475066843867573199660280375877301099831899458291781519901207450150851139740825230312633705680652011149419226345821878265949464340336652543241409627903261808840247138190405552952645629719086994008520299347205411249606606765852337828230721330088953252353887982539752621962233576712241855739782441450688656955107993485144701168714609844191945392446712502426439311181441268490530940778843103480420042400974864910450864060955018891111474557442324985861321731256052626363920401262368410698519613622804236979797537328828326109479769301424960043434857368698422051963732238575777228731545811656919138124690783310650709210589884047941488829318115673681931027443662112149452006805255310379166966180815607804116315333894896135367798296080720430829667068110910599280843
 . . . . . . . . . . . . . . . . . . . . [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)
							a20d39924b9d763da1040b84ef49045f389901a0
 . . . . . . . . . . . . . . . . [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 (28 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'pigma.org'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.pigma.org'
 . . . . . . . . . . . . . . . . [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)
							00f0007600747eda8331ad331091219cce254f4270c2bffd5e422008c6373579e6107bcc5600000169b4bae86f000004030047304502210092a4069941876022e6659703b816a1542a474f5a54964b0c0f724e43735ac4f4022064928e474e0683f113b720d02905ab12369c26def074d8e6b7bbacbb8d3a78c600760063f2dbcde83bcc2ccf0b728427576b33a48d61778fbd75a638b1c768544bd88d00000169b4baea4a0000040300473045022100e06ee541f4b55aa3f50bf630e74ace3034e82795b359a0bef961e5ec075d639f0220359ed85da72a4e043ca93add7a4c950549fc8f8475ed178afd4bb9c2ad14d413
 . . . . [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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