affiliate.docsapp.in

Issued by R3

About this certificate

This digital certificate with serial number 04:d7:15:f1:94:b5:9f:a9:f0:f1:ad:68:ec:ce:cf:65:f0:f0 was issued on by Let's Encrypt.

With 8 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=affiliate.docsapp.in

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 04:d7:15:f1:94:b5:9f:a9:f0:f1:ad:68:ec:ce:cf:65:f0:f0
Serial Number (int): 421639020762683478676290887700742433796336
Serial Number lenght: 139 bits, 18 octets

SubjectKeyId: 34:f6:b1:6d:8d:35:a1:86:25:62:fc:cc:c4:fb:41:6e:6e:af:ef:36
AuthorityKeyId: 14:2e:b3:17:b7:58:56:cb:ae:50:09:40:e6:1f:af:9d:8b:14:c2:c6

Fingerprint (sha1): bc:36:9e:88:5c:fc:b3:f3:16:8d:c9:4e:5d:c6:4e:da:56:4e:f7:7e
Fingerprint (sha256): e9:46:87:cd:f4:79:3e:2d:45:c9:c5:e2:58:1a:5f:76:50:cb:63:c4:22:77:37:69:37:b1:45:85:37:45:48:94

Issuing Certificate URL: http://r3.i.lencr.org/

Revocation information

OCSP Server: http://r3.o.lencr.org

Check the revocation status for certificate affiliate.docsapp.in

8

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for affiliate.docsapp.in

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

affiliate.docsapp.in
partners.healthxp.in
partners.jammubasket.com
partners.medibuddy.in
track.docsapp.in
track.healthxp.in
track.jammubasket.com
tracking.medibuddy.in

Other certificates including the domain name docsapp.in

(limited to 100 certificates)
affiliate.docsapp.in
affiliate.docsapp.in
store.docsapp.in
store.docsapp.in
affiliate.docsapp.in
partners.redirectvia.com
*.docsapp.in
affiliate.docsapp.in
affiliate.docsapp.in
affiliate.docsapp.in
affiliate.docsapp.in
affiliate.docsapp.in
store.docsapp.in
store1.docsapp.in
store.docsapp.in
affiliate.docsapp.in
affiliate.docsapp.in
store.docsapp.in
*.docsapp.in
*.docsapp.in
rb.docsapp.in
partners.jammubasket.com
*.docsapp.in
affiliate.docsapp.in
affiliate.docsapp.in
affiliate.docsapp.in
affiliate.docsapp.in
affiliate.docsapp.in
affiliate.docsapp.in
store1.docsapp.in
docsapp.in
affiliate.docsapp.in
affiliate.docsapp.in
*.docsapp.in
affiliate.docsapp.in
affiliate.docsapp.in
www.redirectvia.com
store.docsapp.in
www.redirectvia.com
partners.jammubasket.com
store.docsapp.in
affiliate.docsapp.in
store.docsapp.in
affiliate.docsapp.in
affiliate.docsapp.in
docsapp.in
affiliate.docsapp.in
affiliate.docsapp.in
affiliate.docsapp.in
affiliate.docsapp.in
*.docsapp.in
redirectvia.com
affiliate.docsapp.in
store1.docsapp.in
partners.jammubasket.com
affiliate.docsapp.in
*.docsapp.in
redirectvia.com
affiliate.docsapp.in
redirectvia.com
store.docsapp.in
affiliate.docsapp.in
track.wowfas.com
affiliate.docsapp.in
redirectvia.com
affiliate.docsapp.in
store.docsapp.in
store.docsapp.in
affiliate.docsapp.in
partners.jammubasket.com
affiliate.docsapp.in
affiliate.docsapp.in
store1.docsapp.in
affiliate.docsapp.in
affiliate.docsapp.in
redirectvia.com
*.docsapp.in
affiliate.docsapp.in
track.wowfas.com
affiliate.docsapp.in
docsapp.in
*.docsapp.in

Certificate

The complete raw certificate details for affiliate.docsapp.in in PEM and ASN.1 format.

Certificate (PEM)

-----BEGIN CERTIFICATE-----
MIIE2DCCA8CgAwIBAgISBNcV8ZS1n6nw8a1o7M7PZfDwMA0GCSqGSIb3DQEBCwUA
MDIxCzAJBgNVBAYTAlVTMRYwFAYDVQQKEw1MZXQncyBFbmNyeXB0MQswCQYDVQQD
EwJSMzAeFw0yMTA3MjIwODM4MzdaFw0yMTEwMjAwODM4MzVaMB8xHTAbBgNVBAMT
FGFmZmlsaWF0ZS5kb2NzYXBwLmluMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIB
CgKCAQEA0Zn6UHxK8Zd8SYf+i0mv9wgtaBvkeNXGRr/SfQT7j2RuJqLm1XpvHPpf
S0AjfIXcR/31V4so0+e3vdZibvP5leJxCDXcEH5LaPV64MhtNdeWXwNh5bn8f8AB
8ZK+UuDKQM/CXn51x3jnpK39sF9rVdJIhmALs3IguHeExGCaqPFrcgajrjJqGGbJ
8bpdNbugIlUVTaI6ZCfJ2FmBaLbEksjfiuie678acHe0IIA/Jy75CidrFcH8WH+g
6P2OthxYgFMcZHzBH7Nka08kjS7w+WbgVIQFXrJDtF5W12IEmt4ZVXNZSzTcQ9U+
WNtPJVbG7Bj7xPqVMg0I9kRS11rl/wIDAQABo4IB+TCCAfUwDgYDVR0PAQH/BAQD
AgWgMB0GA1UdJQQWMBQGCCsGAQUFBwMBBggrBgEFBQcDAjAMBgNVHRMBAf8EAjAA
MB0GA1UdDgQWBBQ09rFtjTWhhiVi/MzE+0Fubq/vNjAfBgNVHSMEGDAWgBQULrMX
t1hWy65QCUDmH6+dixTCxjBVBggrBgEFBQcBAQRJMEcwIQYIKwYBBQUHMAGGFWh0
dHA6Ly9yMy5vLmxlbmNyLm9yZzAiBggrBgEFBQcwAoYWaHR0cDovL3IzLmkubGVu
Y3Iub3JnLzCBuwYDVR0RBIGzMIGwghRhZmZpbGlhdGUuZG9jc2FwcC5pboIUcGFy
dG5lcnMuaGVhbHRoeHAuaW6CGHBhcnRuZXJzLmphbW11YmFza2V0LmNvbYIVcGFy
dG5lcnMubWVkaWJ1ZGR5LmlughB0cmFjay5kb2NzYXBwLmlughF0cmFjay5oZWFs
dGh4cC5pboIVdHJhY2suamFtbXViYXNrZXQuY29tghV0cmFja2luZy5tZWRpYnVk
ZHkuaW4wTAYDVR0gBEUwQzAIBgZngQwBAgEwNwYLKwYBBAGC3xMBAQEwKDAmBggr
BgEFBQcCARYaaHR0cDovL2Nwcy5sZXRzZW5jcnlwdC5vcmcwEwYKKwYBBAHWeQIE
AwEB/wQCBQAwDQYJKoZIhvcNAQELBQADggEBAJr0H2/OQEbsmVF036yXMp31LRyj
KD0iV/+RwTROgCLY1txDrOszNb07Qj2zGMlChfBej5KJtwvs37ABLp9JRJPezMG8
QL5XgU3g0/0VT0PUmHedL55kVzc7K4d9XV7XqWLBYXbBKLAp1g8MW9I0Amf1LMOt
hSac33zYb5JFeaQoKH/38gpF8w+vRZ6rxpN3PAaJ9BEcSHUXqwxOexT0md80dymQ
VhQXnZ/Mp93oIns/IkkMUCaVWdnPGTV9cPhUdbqehiByRtdtFcLvDjpTIp/syL6c
0sHEBB/+Y20BOBmIPzSWlSVAEF5x1iLC4h1ZU4ohOnjtGzTUWzbmfyS7d/o=
-----END CERTIFICATE-----

Public Key (PEM)

-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA0Zn6UHxK8Zd8SYf+i0mv
9wgtaBvkeNXGRr/SfQT7j2RuJqLm1XpvHPpfS0AjfIXcR/31V4so0+e3vdZibvP5
leJxCDXcEH5LaPV64MhtNdeWXwNh5bn8f8AB8ZK+UuDKQM/CXn51x3jnpK39sF9r
VdJIhmALs3IguHeExGCaqPFrcgajrjJqGGbJ8bpdNbugIlUVTaI6ZCfJ2FmBaLbE
ksjfiuie678acHe0IIA/Jy75CidrFcH8WH+g6P2OthxYgFMcZHzBH7Nka08kjS7w
+WbgVIQFXrJDtF5W12IEmt4ZVXNZSzTcQ9U+WNtPJVbG7Bj7xPqVMg0I9kRS11rl
/wIDAQAB
-----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 421639020762683478676290887700742433796336
 . . . . . . . . [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 'R3'
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2021-07-22 08:38:37 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2021-10-20 08:38:35 +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 'affiliate.docsapp.in'
 . . . . . . . . [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 26459735016379770747551094434163025249881493587165341382115479431658605288729180830251785410793052778519089072323673912531674710826233793865222024600323588079454432650723179736876814844697500361335483574965241882456055844201508401912148448037693529791838931873555713432741189786507111729166903372694828973628535380064125922426101933395655643526998181146960438164971347312275317949204433740364228016560717686097898163300988613081277901668465210976703400111406627821847140857835386225323779724594497140670412602244456834952736891327419083814193637624655260196965819275443284647576334661499817265213640756839918285284863
 . . . . . . . . . . . . . . . . . . . . [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)
							34f6b16d8d35a1862562fcccc4fb416e6eafef36
 . . . . . . . . . . . . . . . . [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 142eb317b75856cbae500940e61faf9d8b14c2c6
 . . . . . . . . . . . . . . . . [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 (73 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://r3.o.lencr.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://r3.i.lencr.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 (179 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'affiliate.docsapp.in'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'partners.healthxp.in'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'partners.jammubasket.com'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'partners.medibuddy.in'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'track.docsapp.in'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'track.healthxp.in'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'track.jammubasket.com'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'tracking.medibuddy.in'
 . . . . . . . . . . . . . . . . [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 1.3.6.1.4.1.11129.2.4.3 (CT Precertificate Poison)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:1|false] BOOLEAN true
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (2 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:5|false] NULL 
 . . . . [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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