corptel.com

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 03:ec:30:45:61:3e:11:b1:90:8a:ff:00:50:42:ad:a4:6d:f2 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=corptel.com

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 03:ec:30:45:61:3e:11:b1:90:8a:ff:00:50:42:ad:a4:6d:f2
Serial Number (int): 341707659573214485719952110903978612780530
Serial Number lenght: 138 bits, 18 octets

SubjectKeyId: 27:7b:1e:2c:95:26:74:df:f9:cc:e3:b5:02:82:93:7f:6f:b6:c2:57
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): d5:98:96:9f:f0:11:27:af:37:0c:f5:82:80:27:42:34:43:22:33:30
Fingerprint (sha256): 0a:d1:a0:7b:93:85:a1:30:62:b6:b7:77:41:ba:12:2f:11:2f:63:5a:2a:17:82:45:66:18:8b:6f:02:1e:75:0f

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 corptel.com

2

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for corptel.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

corptel.com
www.corptel.com

Other certificates including the domain name corptel.com

(limited to 100 certificates)

Certificate

The complete raw certificate details for corptel.com 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 341707659573214485719952110903978612780530
 . . . . . . . . [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 2019-09-01 19:41:36 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2019-11-30 19:41:36 +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 'corptel.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 782639070889100590258814882976702976840076782318475419967751741061503459137155660858740285389882920350215108108460510269779164341641482502831193000088931042679616327585171172774312164377932839054808744877480728361123401547093034922846051382233796704352160114254795459822753801957408507379539747237628188726330706170390391661589064424186401203039568489707945152168755721275347007784224421371971765295111996984623036092256871644079228317556569881648382395575295965687691575206198235221284613879073733614514009886837125267693836722416540520948629548879805783021670668546136083437780336025489823355668508683147265997183178506848887828535514152806030999363903622944295955619650869927954370413996436256555790292402613175002273525514134896607165878366052461773917854448742446122212873801361633843849946437320076873258124923830548546513071376442157304683088886106352931642238196122518136425617148761015350208773311998610274205040289203240459465779124099236943349980311863304708792238829040106461099364146592025620133003012316845347352903067350917211045337763194845296295749768818164661765493631653447891470481484612408816759979175772369649498694854973087423181861594583469175051599396956804568074972000093689840536465074919624864512152899277
 . . . . . . . . . . . . . . . . . . . . [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)
							277b1e2c952674dff9cce3b50282937f6fb6c257
 . . . . . . . . . . . . . . . . [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 (32 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'corptel.com'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.corptel.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 (243 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (240 bytes)
							00ee007500e2694bae26e8e94009e8861bb63b83d43ee7fe7488fba48f2893019dddf1dbfe0000016cee8fc8430000040300463044022061d83bb7eadc3a1e8cab1045a539d881024963ddf227d43c0c219c95d093f765022072b5825eb34869e1537e0b7bbe886fc7d446dbbd47433195727ed06e75cfefce007500293c519654c83965baaa50fc5807d4b76fbf587a2972dca4c30cf4e54547f4780000016cee8fc86c000004030046304402202768e6b38c16df987058fe05e453addf1d66570469164373f9fe0f3e95fcbcb302206de69141f16bfe69bf1be74409d1852a1dd99f8264d5560c9dcc425104722e6a
 . . . . [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)
		007c57626e7b5de9b779cf448d23e87e9192ebe018fd0bc0ed6eeecfa7a24b1c171f25597f2ee9b50958c9559b6774c90a404dd9a8717a8e20b0c1f7f89494ad267638f5813aa9d9114b1cea5e837c2901489f575696d7f7c8d0be5b8b63175943ebd4101026fa50b795973d03f7d00098a62bbf4f1bd9975c7a5eaca4f7878e27dc45ce96e5296ef089209a1a1c1dfecfd0b10ceda887e0b2f50a9ae0d8651e387e9e73ee0187c79654179ef471ac7a3b0711ac7c6f9cad519dabcfb7d476618a4b59e735b77851c650067405d629bcd63de4babdc40f4881e11d5d923a6ac35cfb36b6b3304d70096a5cf85045e7a827de7f2bd10be7f0657f5ed54ec264b5fd