cdn.aumio.de

Issued by Amazon

About this certificate

This digital certificate with serial number 09:92:3d:69:23:c4:c9:23:78:19:e3:64:64:a1:95:0c was issued on by Amazon.

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=cdn.aumio.de

Amazon

Organization: Amazon
Organization unit: Server CA 1B
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 09:92:3d:69:23:c4:c9:23:78:19:e3:64:64:a1:95:0c
Serial Number (int): 12722372860423089093895866392458138892
Serial Number lenght: 124 bits, 16 octets

SubjectKeyId: e3:01:31:22:a3:0b:fe:ad:04:ac:72:16:74:3f:57:81:a9:07:5d:6a
AuthorityKeyId: 59:a4:66:06:52:a0:7b:95:92:3c:a3:94:07:27:96:74:5b:f9:3d:d0

Fingerprint (sha1): a1:f5:3a:e8:7a:cb:9a:95:3d:e2:7c:71:cb:d1:fc:23:3e:ab:db:7c
Fingerprint (sha256): 21:1d:e0:fd:3d:5e:00:ed:39:c5:0d:09:fe:dc:3d:95:76:b5:40:58:c5:ee:91:a6:ad:6e:e5:a1:a0:ee:dc:84

Issuing Certificate URL: http://crt.sca1b.amazontrust.com/sca1b.crt

Revocation information

OCSP Server: http://ocsp.sca1b.amazontrust.com
CRL Distribution Point: http://crl.sca1b.amazontrust.com/sca1b.crl

Check the revocation status for certificate cdn.aumio.de

2

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for cdn.aumio.de

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

10 extensions
No unhandled critical extensions

CA Certificate

This is not a CA certificate

Subject Alternative Names

cdn.aumio.de
*.cdn.aumio.de

Other certificates including the domain name aumio.de

(limited to 100 certificates)
gitlab.aumio.de
aumio.de
wp-staging.aumio.de
bitwarden.aumio.de
www.aumio.de
aumio.de
www.aumio.de
aumio.de
aumio.de
aumio.com
www.aumio.de
cdn.aumio.de
aumio.de
link.aumio.de
bitwarden.aumio.de
aumio.de
www.sigastudio.com
aumio.de
www.aumio.de
aumio.de
wp-staging.aumio.de
gitlab.aumio.de
app.aumio.de
preparedhouston.com
aumio.de
bitwarden.aumio.de
aumio.de
aumio.de
aumio.de
aumio.de
www.aumio.de
staging.aumio.de
hostpress.aumio.de
aumio.de
aumio.de
aumio.de
viro.kurowasi.com
aumio.de
aumio.de
gitlab.aumio.de
aumio.de
cdn.aumio.de
aumio.de
aumio.de
aumio.de
sentry.service.aws.aumio.de
gitlab.aumio.de
aumio.de
gitlab.aumio.de

Certificate

The complete raw certificate details for cdn.aumio.de in PEM and ASN.1 format.

Certificate (PEM)

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

Public Key (PEM)

-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAva6u8X4aq+va72VQ1s5i
00AeH5/cICaaEssDZd8j2DxLh8BTh9T/k2ELKVFJbNlToHzcqkBo5YoGXeOnJiMG
d/DHIzD+wrMtrFemqFErQOG1MtMAVAoFZJ867KcG2KjozTuqRMS6dMp6vHngaDTk
ziG3Cm9vCXO1Cphy0bzedfud3/Ju1VxqYDExMm0B+SVeAaHqlAneyWUqQwrmtHdE
Q+vgAYaS1LM9LcC9dHs+HK/YDhPyAgr9oG2z37l9NIUgMSO/fjbtM7jo6Tjg2HFn
xJIkamMeUJeHURhNQ3AYeJ6TomYt0vqj7gy1e3FZTMaMqJCeZmwU5oR/iDKs6w2V
5QIDAQAB
-----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 12722372860423089093895866392458138892
 . . . . . . . . [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 'Amazon'
 . . . . . . . . . . . . [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 'Server CA 1B'
 . . . . . . . . . . . . [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 'Amazon'
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2019-12-09 00:00:00 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2021-01-09 12:00:00 +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 'cdn.aumio.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 (2160 bits)
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:2|false] INTEGER 23945179219974070136616633493322771728923880048915734606816215252997057506306261181957516162884416215330645988273227309646031834474266322590429844203490199305139195957424793329287996745133555883931687203127824294667761454595407631064569974861261626534319101543295422373275872115240967425793724784290761594511383132209320346812168039821072448173689165775355055628679498208163278657934077187884720740367250490842881938881111469960055308640843704491950101857946892241253854830416143756471156556655276356795716760932936358883953338387077904100456832708696687344990094931077050960736172311597628359420420514581860945073637
 . . . . . . . . . . . . . . . . . . . . [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 59a4660652a07b95923ca394072796745bf93dd0
 . . . . . . . . . . . . . . . . [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)
							e3013122a30bfead04ac7216743f5781a9075d6a
 . . . . . . . . . . . . . . . . [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 'cdn.aumio.de'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String '*.cdn.aumio.de'
 . . . . . . . . . . . . . . . . [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 2.5.29.31 (cRLDistributionPoints)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (52 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.sca1b.amazontrust.com/sca1b.crl'
 . . . . . . . . . . . . . . . . [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 (25 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.16.840.1.114412.1.2 (digiCertDVCert)
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [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 1.3.6.1.5.5.7.1.1 (authorityInfoAccess)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (105 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.sca1b.amazontrust.com'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [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.sca1b.amazontrust.com/sca1b.crt'
 . . . . . . . . . . . . . . . . [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 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)
							00f0007500bbd9dfbc1f8a71b593942397aa927b473857950aab52e81a909664368e1ed1850000016eeaf5fbfc000004030046304402202c5f516ee2b87b2b41d340cfdb47ac08795fb41a2c3498776906a126a1c8890902200c58988efae7d54b1d2daa4e46aabc0f76c0d0a297310339e049263dd9f63e1c0077008775bfe7597cf88c43995fbdf36eff568d475636ff4ab560c1b4eaff5ea0830f0000016eeaf5fc920000040300483046022100876d3f7850e793d92b6621414033cde18ab1430f0fb5d3698b71377f31eb37b3022100f7c19ed613dd8e21b71045ac4ff331785cb5b386c15d1cea15ea72d0d6c98641
 . . . . [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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