mx02.pqm.net

Issued by COMODO RSA Domain Validation Secure Server CA

About this certificate

This digital certificate with serial number bf:49:55:ca:39:ad:fc:49:8e:dd:3b:47:59:2e:f0:c5 was issued on by COMODO CA Limited.

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=mx02.pqm.net,OU=Domain Control Validated+OU=PositiveSSL

COMODO CA Limited

Organization: COMODO CA Limited
State / Province: Greater Manchester
Locality: Salford
Country: GB

This certificate has expire since

Certificate Details

Serial Number (hex): bf:49:55:ca:39:ad:fc:49:8e:dd:3b:47:59:2e:f0:c5
Serial Number (int): 254263324892348093534762553954607755461
Serial Number lenght: 128 bits, 16 octets

SubjectKeyId: 3e:3c:49:a9:da:98:5f:23:63:28:d7:62:18:4c:d9:a6:d8:98:ab:de
AuthorityKeyId: 90:af:6a:3a:94:5a:0b:d8:90:ea:12:56:73:df:43:b4:3a:28:da:e7

Fingerprint (sha1): 41:62:03:6d:5e:ee:d8:a0:1e:5c:a4:ff:a2:62:d1:3d:a8:ed:98:0c
Fingerprint (sha256): 21:7e:5f:fc:cc:4e:61:2a:ea:44:55:00:b8:82:57:d4:31:25:43:b6:83:b5:58:ca:f2:c7:46:b8:02:c4:d0:fd

Issuing Certificate URL: http://crt.comodoca.com/COMODORSADomainValidationSecureServerCA.crt

Revocation information

OCSP Server: http://ocsp.comodoca.com
CRL Distribution Point: http://crl.comodoca.com/COMODORSADomainValidationSecureServerCA.crl

Check the revocation status for certificate mx02.pqm.net

2

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for mx02.pqm.net

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

9 extensions
No unhandled critical extensions

CA Certificate

This is not a CA certificate

Subject Alternative Names

mx02.pqm.net
www.mx02.pqm.net

Other certificates including the domain name pqm.net

(limited to 100 certificates)

Certificate

The complete raw certificate details for mx02.pqm.net in PEM and ASN.1 format.

Certificate (PEM)

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

Public Key (PEM)

-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAsUO98acU0APvnWZZHtS8
XI0rD99b/SieHXONaOBWoEapEb7sdcnL5pF4LMCmjfLbfzft/iF3aPXuUMNamO9e
Nq2qEs5Bshv4Tf+2aNUVdotzVFDppPbpMCuS8f+dUknlHcdK1SyKo3V/LWdy8hMq
elkm5+kVz38Iswg9CRcoNX1bsfWcyzm89jlkCMSkvc4QBxL7K4fr0GO33TUnAtvd
XfZKHxZ4zajH7+GVqypAao8N2OK8G2F9SABwpTzJOwVMmvwEGKZgA2sWtiJEzmRa
1bs5OdvA7bGR6EX7vCoAzP0J4P4gtbzYcOwXyscjWXntveg2J6z4TUVG4eMhfy4N
ZQIDAQAB
-----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 254263324892348093534762553954607755461
 . . . . . . . . [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 'GB'
 . . . . . . . . . . . . [c:0|t:17|true] SET, SET OF 
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.4.8 (stateOrProvinceName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'Greater Manchester'
 . . . . . . . . . . . . [c:0|t:17|true] SET, SET OF 
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.4.7 (localityName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'Salford'
 . . . . . . . . . . . . [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 'COMODO CA Limited'
 . . . . . . . . . . . . [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 'COMODO RSA Domain Validation Secure Server CA'
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2017-10-10 00:00:00 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2021-01-07 23:59:59 +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 2.5.4.11 (organizationalUnitName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'Domain Control Validated'
 . . . . . . . . . . . . [c:0|t:17|true] SET, SET OF 
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.4.11 (organizationalUnitName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'PositiveSSL'
 . . . . . . . . . . . . [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 'mx02.pqm.net'
 . . . . . . . . [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 (2160 bits)
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:2|false] INTEGER 22377584788711995911258375513673301874088852899437653533919334035287188224934953959012884871268181307391193910903241712638324476232390190216345819731882115878748764313252688792818296402656135837971387811146842424552133148960766987638090869102710523830919456971299257019238589868159304817323539722308554112461271690331677109939693098040990094862859035407536116775463345339273203129935420269818093177383628751173696711471377646358993477590176503234349953378488824747838703634534892747877069644856137689757166237869565486057029380038055731599986746159755467125661930387644762364513233605263862127298624225654500196486501
 . . . . . . . . . . . . . . . . . . . . [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 2.5.29.35 (authorityKeyIdentifier)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (24 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:0|false] OtherName 90af6a3a945a0bd890ea125673df43b43a28dae7
 . . . . . . . . . . . . . . . . [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)
							3e3c49a9da985f236328d762184cd9a6d898abde
 . . . . . . . . . . . . . . . . [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 2.5.29.19 (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 2.5.29.37 (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 2.5.29.32 (certificatePolicies)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (72 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.4.1.6449.1.2.2.7
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [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 'https://secure.comodo.com/CPS'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [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 2.5.29.31 (cRLDistributionPoints)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (77 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://crl.comodoca.com/COMODORSADomainValidationSecureServerCA.crl'
 . . . . . . . . . . . . . . . . [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 (121 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 (caIssuers)
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:6|false] IA5String 'http://crt.comodoca.com/COMODORSADomainValidationSecureServerCA.crt'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [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.comodoca.com'
 . . . . . . . . . . . . . . . . [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 (34 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'mx02.pqm.net'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.mx02.pqm.net'
 . . . . [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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