iot.reddsystem.com

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 03:fc:37:37:4e:37:d1:3b:a1:5b:cd:2c:1b:7b:23:96:eb:87 was issued on by Let's Encrypt.

With 6 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=iot.reddsystem.com

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 03:fc:37:37:4e:37:d1:3b:a1:5b:cd:2c:1b:7b:23:96:eb:87
Serial Number (int): 347161408961902874999956669838645297343367
Serial Number lenght: 138 bits, 18 octets

SubjectKeyId: cd:20:86:97:80:44:25:32:92:b2:08:9a:ba:d9:09:28:65:8c:3a:e9
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): bd:ff:b8:29:a9:6b:fe:bf:fe:a7:7c:62:ad:6f:cb:a9:34:db:a1:04
Fingerprint (sha256): 3b:be:29:7c:bd:b5:3a:06:47:cd:a8:f9:ce:61:d5:d5:e6:f9:22:93:b5:28:22:d0:78:94:f6:32:ff:9d:b9:23

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 iot.reddsystem.com

6

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for iot.reddsystem.com

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

iot.reddsystem.com
libeliumredd.iot.ubidots.com
libeliumredd.reddsystem.com
redd.api.ubidots.com
redd.iot.ubidots.com
redd.ubidots.com

Other certificates including the domain name reddsystem.com

(limited to 100 certificates)
iot.reddsystem.com
iot.reddsystem.com
iot.reddsystem.com
emilia.reddsystem.com
iot.reddsystem.com
redd.iot.ubidots.com
iot.reddsystem.com
iot.reddsystem.com
iot.reddsystem.com
iot.reddsystem.com
iot.reddsystem.com
reddsystem.com
www.reddsystem.com
iot.reddsystem.com
iot.reddsystem.com
iot.reddsystem.com
iot.reddsystem.com
iot.reddsystem.com
iot.reddsystem.com
iot.reddsystem.com
iot.reddsystem.com
emilia.reddsystem.com
iot.reddsystem.com
iot.reddsystem.com
iot.reddsystem.com
iot.reddsystem.com
iot.reddsystem.com
iot.reddsystem.com
iot.reddsystem.com
reddsystem.com

Certificate

The complete raw certificate details for iot.reddsystem.com in PEM and ASN.1 format.

Certificate (PEM)

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

Public Key (PEM)

-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAsPbJNTHALAfxK/rpaVOm
oNyA4EXzWP0WyVouJCTJDmZdKxUKE8V4eN5t32bSeXooRE1iPpnkXsqAjRIq3yyz
GBICdY8CWu+EZcp1YVakIrMp9Bk+/VY64E3SEGFmrHwnuOt75dAINr1FsKKn+pFb
TxEu1R26liPr+FZ4XMo8qyl9qAwDFKi+YuolFq+L7WLCevQf3U61jTFU9/eXwb0h
ZDSGDXEI/0ZzF9NZd1EFyq/WHUTmfAOhSUDHKngj5cYpTUqf4jLi/Rd0r0z4ofSa
D/iqOmQGqNcRNlsm/exMYQvpDTRl8eKNqxKwBY81Dua/dAjFhzAtSz7SzwM+zRHL
CwIDAQAB
-----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 347161408961902874999956669838645297343367
 . . . . . . . . [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 2018-12-23 23:09:00 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2019-03-23 23:09:00 +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 'iot.reddsystem.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 (2160 bits)
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:2|false] INTEGER 22339636370436636690187308493728466141203365556041767252473012390293709705530369289953799982573895488319682678312821634365214284976987171406570610743700770595933301638516045684954639699729592978723177879424454069224648010566535485623805033236262437374777113980989262787279244804559621473593948809012200544205183373301163172261251323448567836112912810861538320570652370614810336958422698559016129776040865601797385740924618350438285384930104952844332326930866972190409481161262830946428393153731303894693953387235450548303754677927432658819888607164751510510751863601693035198039295494191531578444293063320417768426251
 . . . . . . . . . . . . . . . . . . . . [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)
							cd2086978044253292b2089abad90928658c3ae9
 . . . . . . . . . . . . . . . . [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 (144 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'iot.reddsystem.com'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'libeliumredd.iot.ubidots.com'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'libeliumredd.reddsystem.com'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'redd.api.ubidots.com'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'redd.iot.ubidots.com'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'redd.ubidots.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 (244 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (241 bytes)
							00ef007500e2694bae26e8e94009e8861bb63b83d43ee7fe7488fba48f2893019dddf1dbfe00000167dd8b1a3e000004030046304402204a2adc758e0d5be374bb05473e1ad6f6e8f6b0b59e97623cd861796566047358022047078cb08d8ff77e8a0ddb3875487552a8f556c512163cda4ab330e38ad9415400760063f2dbcde83bcc2ccf0b728427576b33a48d61778fbd75a638b1c768544bd88d00000167dd8b1a3e0000040300473045022100fca507ce27774fe1b0cb2b5aecfecba4e07b4232d4976852ca50c6fc32cbe94d02207583ea188835b477b67332ead8a2b19972b600deee40816cff69e4f034a6ddcb
 . . . . [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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