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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

TLSv1.3

mail.lisek.pl · 37.131.166.15:443

Verified

Certificate chain, hostname and dates verified using this server’s CA store.

Subject
CN=mail.lisek.pl
Issuer
C=US O=Let's Encrypt CN=YR1
Valid from
2026-10-16T23:12:12+00:00
Expires
2027-01-14T23:12:11+00:00
Days remaining
71
Serial (hex)
059DFB64A621C39035E0795C8B0EE8C350C0
Signature
RSA-SHA256
Public key
RSA 4096

Subject alternative names (SAN)

DNS:mail.lisek.pl, DNS:poczta.lisek.pl

SHA-256 fingerprint

37:6F:C5:3C:E4:7A:CB:34:E4:13:1A:EB:2E:2E:50:12:56:F0:92:02:6B:45:3A:D0:58:BE:51:10:98:35:97:F7
Certificate extensions & PEM
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
F3:49:84:81:5C:BE:D7:ED:40:34:5E:B0:BA:25:33:60:3C:7F:D7:1F
authorityKeyIdentifier
1F:2F:35:BE:46:14:82:CD:40:B1:AE:79:2C:55:78:FA:F7:D4:68:FB
authorityInfoAccess
CA Issuers - URI:http://yr1.i.lencr.org/
subjectAltName
DNS:mail.lisek.pl, DNS:poczta.lisek.pl
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr1.c.lencr.org/65.crl
ct_precert_scts
Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 60:4C:9A:AF:7A:7F:77:5F:01:D4:06:FC:92:0D:C8:99: EB:0B:1C:7D:F8:C9:52:1B:FA:FA:17:77:3B:97:8B:C9 Timestamp : Oct 17 00:10:42.630 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:21:00:C3:DB:57:3C:8D:2C:24:77:60:B5:D6: CE:8B:94:72:05:FA:61:25:B8:A9:86:B2:65:9D:39:3B: 7D:1E:43:F6:5F:02:20:76:91:A5:AE:5B:4C:66:A9:25: FD:9D:AC:36:CC:64:19:88:24:E3:81:20:47:D9:D5:01: 76:3B:70:1A:71:02:DA Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 44:E8:22:FC:2B:AB:0E:92:EE:D0:E9:FA:D6:96:64:60: 27:76:D0:17:60:E0:89:05:09:C9:23:A1:B0:3F:C3:7F Timestamp : Oct 17 00:10:39.384 2026 GMT Extensions: 00:00:05:00:0B:8D:33:E8 Signature : ecdsa-with-SHA256 30:46:02:21:00:CE:74:1C:94:0D:9E:24:F1:BC:A0:A5: C2:6C:3E:25:B7:3D:B7:C4:C2:AE:7A:79:0C:E0:11:90: 5A:42:13:80:89:02:21:00:94:00:07:46:30:E2:48:F8: BB:95:F8:22:BC:07:E2:92:B7:16:67:D4:42:0B:1B:D7: 17:D5:19:96:42:8B:D3:01
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: TLS_AES_128_GCM_SHA256 · Checked 2026-11-04T22:19:06+00:00

Server-presented chain · 2 additional certificates

Chain certificate 1

Subject
C=US O=Let's Encrypt CN=YR1
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
668
Serial (hex)
A20253F15F2691C05DC1CE13B9BCCA4E
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

13:94:96:34:D9:9C:D6:FD:6A:A8:0B:C0:34:FE:FA:CC:EB:19:69:FE:EF:98:65:86:71:3E:CD:BB:05:75:8D:3F
Certificate extensions & PEM
keyUsage
Digital Signature, Certificate Sign, CRL Sign
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:TRUE, pathlen:0
subjectKeyIdentifier
1F:2F:35:BE:46:14:82:CD:40:B1:AE:79:2C:55:78:FA:F7:D4:68:FB
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
2129
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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