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THE CERTIFICATE BEHIND THE CONNECTION

TLS certificate checker.

Inspect SSL/TLS certificates for any public domain or subdomain.

Checks HTTPS on port 443, including subject alternative names, validity dates and the presented chain.

SSL certificate

TLSv1.2

mail01.as42579.net · 77.73.147.137:443

Unverified
Certificate verification failed. These are unverified certificate details presented by the server. Peer certificate CN=`lists.sargasso.net' did not match expected CN=`mail01.as42579.net'

Certificate verification failed

Subject
CN=lists.sargasso.net
Issuer
C=US O=Let's Encrypt CN=YR2
Valid from
2026-09-21T21:06:46+00:00
Expires
2026-12-20T21:06:45+00:00
Days remaining
84
Serial (hex)
065BA97F2DFAEAC6F235F88C6BE7A11F4D42
Signature
RSA-SHA256
Public key
RSA 4096

Subject alternative names (SAN)

DNS:lists.sargasso.net

SHA-256 fingerprint

64:C6:C9:36:76:28:8E:B3:C8:8C:0E:D3:02:B2:FC:03:A8:12:35:8E:0C:BB:1D:BF:79:65:6F:EC:48:3F:EE:E7
Certificate extensions & PEM
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
71:4D:57:54:F8:A5:96:93:C6:57:F2:8F:90:7F:0C:2A:6D:54:86:C8
authorityKeyIdentifier
40:15:2D:26:79:ED:32:20:9E:DF:9A:72:1D:D6:32:1F:81:0C:81:0C
authorityInfoAccess
CA Issuers - URI:http://yr2.i.lencr.org/
subjectAltName
DNS:lists.sargasso.net
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr2.c.lencr.org/67.crl
ct_precert_scts
Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 1A:8B:9D:6B:0F:FE:BF:81:B4:79:39:C6:D2:31:0A:86: D6:D1:02:D4:F0:46:E2:18:2C:9D:E3:5F:5E:26:25:EF Timestamp : Sep 21 22:05:17.364 2026 GMT Extensions: 00:00:05:00:43:B5:B0:9F Signature : ecdsa-with-SHA256 30:46:02:21:00:F7:9B:19:C3:2B:A0:FB:08:94:CA:74: 3A:F6:87:2E:27:95:A8:38:5B:03:C4:EC:4F:57:74:3D: 8C:3B:61:9E:C4:02:21:00:8E:AC:B9:7F:19:DC:A9:7E: D3:56:6B:9E:03:FE:E1:9B:AE:A3:DD:DC:63:4E:BE:4C: F6:9E:47:97:98:CE:43:9F Signed Certificate Timestamp: Version : v1 (0x0) Log ID : C2:31:7E:57:45:19:A3:45:EE:7F:38:DE:B2:90:41:EB: C7:C2:21:5A:22:BF:7F:D5:B5:AD:76:9A:D9:0E:52:CD Timestamp : Sep 21 22:05:18.813 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:46:02:21:00:EA:3B:52:C6:68:65:9F:3C:34:47:2F: 21:D4:A6:84:77:1B:46:53:EE:8A:3A:EB:3A:33:CB:E4: C6:16:66:8A:37:02:21:00:96:3E:23:D0:0C:BC:54:2E: 77:D7:DF:89:32:74:CD:54:A7:23:9E:83:D3:DB:E1:45: CA:F6:06:36:1E:FF:D1:90
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: ECDHE-RSA-AES128-GCM-SHA256 · Checked 2026-09-26T22:28:34+00:00

Server-presented chain · 2 additional certificates

Chain certificate 1

Subject
C=US O=Let's Encrypt CN=YR2
Issuer
C=US O=ISRG CN=Root YR
Valid from
2025-09-03T00:00:00+00:00
Expires
2028-09-02T23:59:59+00:00
Days remaining
707
Serial (hex)
4EBD24947E24D394802D84A52FD5B319
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

23:8B:85:A0:09:9C:65:B9:70:47:7D:57:24:F1:A1:D4:75:CE:50:58:CF:FE:4E:FA:87:33:89:9B:DB:86:3C:47
Certificate extensions & PEM
keyUsage
Digital Signature, Certificate Sign, CRL Sign
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:TRUE, pathlen:0
subjectKeyIdentifier
40:15:2D:26:79:ED:32:20:9E:DF:9A:72:1D:D6:32:1F:81:0C:81:0C
authorityKeyIdentifier
DE:E7:5B:60:D0:22:6D:40:28:7D:3F:0D:01:FE:A4:B5:52:B4:51:94
authorityInfoAccess
CA Issuers - URI:http://yr.i.lencr.org/
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr.c.lencr.org/ 
-----BEGIN CERTIFICATE-----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==
-----END CERTIFICATE-----

Chain certificate 2

Subject
C=US O=ISRG CN=Root YR
Issuer
C=US O=Internet Security Research Group CN=ISRG Root X1
Valid from
2026-05-13T00:00:00+00:00
Expires
2032-09-02T23:59:59+00:00
Days remaining
2168
Serial (hex)
F24B6D17F9D9AD7CB1C9FEA78782699F
Signature
RSA-SHA256
Public key
RSA 4096

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

07:26:39:D0:B1:40:D5:BF:FA:E1:6A:D9:C3:F6:CC:60:86:04:06:21:F5:1E:E6:1A:6D:46:A8:91:5C:07:CF:76
Certificate extensions & PEM
keyUsage
Certificate Sign, CRL Sign
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:TRUE
subjectKeyIdentifier
DE:E7:5B:60:D0:22:6D:40:28:7D:3F:0D:01:FE:A4:B5:52:B4:51:94
authorityKeyIdentifier
79:B4:59:E6:7B:B6:E5:E4:01:73:80:08:88:C8:1A:58:F6:E9:9B:6E
authorityInfoAccess
CA Issuers - URI:http://x1.i.lencr.org/
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://x1.c.lencr.org/ 
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

One endpoint on port 443. Server-presented chain; no revocation, OCSP, CT or full TLS security scan.

View certificate JSON

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