www.erfolgsmailing.de

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 03:46:a8:48:78:a0:b0:57:a9:27:52:5a:ca:79:4d:fd:35:78 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.erfolgsmailing.de

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 03:46:a8:48:78:a0:b0:57:a9:27:52:5a:ca:79:4d:fd:35:78
Serial Number (int): 285380310075032346534107915805081586185592
Serial Number lenght: 138 bits, 18 octets

SubjectKeyId: 8d:3c:2a:b9:ac:ba:b9:3e:c0:27:09:65:83:6c:2b:c5:39:34:1e:2e
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): 77:25:da:9a:98:13:fd:2b:7a:05:3b:8c:37:19:6e:37:e8:cb:0c:a2
Fingerprint (sha256): f7:91:50:c9:fb:ea:25:ef:1c:90:2c:1c:bc:42:cb:93:13:02:0e:bf:7c:02:ed:a1:44:ef:42:52:85:8e:f0:fa

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.erfolgsmailing.de

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for www.erfolgsmailing.de

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.erfolgsmailing.de

Other certificates including the domain name erfolgsmailing.de

(limited to 100 certificates)

Certificate

The complete raw certificate details for www.erfolgsmailing.de 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 285380310075032346534107915805081586185592
 . . . . . . . . [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 2019-12-16 19:08:16 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2020-03-15 19:08:16 +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.erfolgsmailing.de'
 . . . . . . . . [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 544682091801790095242008458736206018719671033108198825526653691571582192425521098094682067112002331400012722431742698475486650767004133301733850419903637531837488848583833674275865384614314508235944483265328813903085897070110757765745145727729112357270727184452192251226095700853543501090834441107911644419263167747076196423960710692542968104823329491063839168082264641756748643397656091619714282151822538951625753835234674598831400255266600947436348381166777820442412063946918687279716056867653560060623329931322897097240797934038855060449805552891715072475516376287802202741142116626955336546344323608004786347666195047445098629714535228285914009012838893716544066636426461189112166094075461175713878236163412677847317259324715367944286667911559233449081695643591001816267919171696092334659774370475685123625591417221120183879540136554014463401176079350946302752841068359391666660034761241353848760911737362773532546235900409954135503504317762415931486856121720155516167721606767806091884557736484574516065768048210590313954978811038053986719586596893272202946768668379839262494867143127435950860399247842189497840089882745162301432707015489072958888242824258623650247839787785323958169342154151726781344360345162297251905767982461
 . . . . . . . . . . . . . . . . . . . . [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)
							8d3c2ab9acbab93ec0270965836c2bc539341e2e
 . . . . . . . . . . . . . . . . [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 (25 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.erfolgsmailing.de'
 . . . . . . . . . . . . . . . . [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)
							00f0007600f095a459f200d18240102d2f93888ead4bfe1d47e399e1d034a6b0a8aa8eb2730000016f10535f560000040300473045022100983f8342ad6018a80b1e19846e20c1d7567e17179ddc1b7c4a8cd99c4892c38702201e77a84e6f4fe8546a12425abd8da005c8786f1a49536a89c44a045f200a510f00760007b75c1be57d68fff1b0c61d2315c7bae6577c5794b76aeebc613a1a69d3a21c0000016f10535f550000040300473045022100a05c55c9a79d5b7ea2a411c6bc2f0dbd2ebdfe29f0834bae17c5c22d81211a4f02204016f5b3b9238fe61b94fe0378b8423181901e58a499d558837b539138ae5dd8
 . . . . [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)
		0068e466b9ce1926fc6ae3f170d61c7db8e1e4ff721d88460c18cdbbafc48bc844ece5134a82dab58273f0657f5b4f2032e97ab604f831759046972089a016de8b67f6a0e827daedfb6dadeea90cb194eb43a8640813e1a9704b277f3ce89a73933560c11a535b2c47428d4b92d4b9207089fcc97808b67f02db28c819233d1973c6887dd98814e481b6828d981100e1d0496cd313f10e31a43e826e87abbb1cdf7cc5068329c011fa7483efe411e96aae7d8507425200ed636ec920bc42c1799995e492d8fc9af4a2a312c522fcd07c07159acd848a25c0f4e04eb3357036c72d9bb6c10e260a078f97eb50003a7864f9f25f3965e85e54e0c96308f9e085a41b