DNS
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.primenet.cz · 5.39.200.40:443

Verified

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

Subject
CN=mail.primenet.cz
Issuer
C=US O=Let's Encrypt CN=YR1
Valid from
2026-09-23T20:07:28+00:00
Expires
2026-12-22T20:07:27+00:00
Days remaining
45
Serial (hex)
06553E3DE212D846D32F614C538CCA77A705
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

DNS:mail.primenet.cz

SHA-256 fingerprint

11:95:D6:E3:D6:08:E4:6E:DE:F4:73:0E:E5:2F:0E:AA:BE:D4:6C:7A:70:7F:97:80:D6:AF:AA:8D:E9:71:E2:77
Certificate extensions & PEM
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
85:B3:E7:13:06:ED:F9:81:66:95:18:92:1E:A8:DF:20:24:08:3A:0B
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.primenet.cz
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr1.c.lencr.org/6.crl
ct_precert_scts
Signed Certificate Timestamp: Version : v1 (0x0) Log ID : C8:A3:C4:7F:C7:B3:AD:B9:35:6B:01:3F:6A:7A:12:6D: E3:3A:4E:43:A5:C6:46:F9:97:AD:39:75:99:1D:CF:9A Timestamp : Sep 23 21:05:58.294 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:46:02:21:00:CF:31:63:91:FF:1C:33:4B:E4:0D:D3: 1B:15:35:A1:B8:A9:A8:DA:7E:F1:50:F2:38:D1:ED:48: 5C:74:4C:C4:DA:02:21:00:EE:11:ED:F2:79:A7:4B:33: AE:10:35:A9:B3:D6:1D:7E:47:32:25:F7:19:05:81:77: CA:85:60:50:25:9B:0D:85 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 26:E3:64:6E:58:69:21:23:BC:34:3F:47:24:35:9B:37: 92:CD:24:5A:88:D8:15:D3:93:33:FD:99:18:AB:47:23 Timestamp : Sep 23 21:05:55.806 2026 GMT Extensions: 00:00:05:00:45:A2:9B:1A Signature : ecdsa-with-SHA256 30:45:02:21:00:9B:24:46:61:78:3F:DF:24:8D:5E:CD: 28:F5:4F:E5:27:CF:EE:03:14:06:EE:ED:88:DD:6B:F8: 57:DA:65:47:5A:02:20:34:27:A5:80:C4:1B:13:34:A6: 5B:88:6B:00:1A:41:6A:48:19:3A:5C:3B:24:2E:4C:8F: 98:0F:CF:54:03:72:DB
-----BEGIN CERTIFICATE-----
MIIE+jCCA+KgAwIBAgISBlU+PeIS2EbTL2FMU4zKd6cFMA0GCSqGSIb3DQEBCwUA
MDMxCzAJBgNVBAYTAlVTMRYwFAYDVQQKEw1MZXQncyBFbmNyeXB0MQwwCgYDVQQD
EwNZUjEwHhcNMjYwOTIzMjAwNzI4WhcNMjYxMjIyMjAwNzI3WjAbMRkwFwYDVQQD
ExBtYWlsLnByaW1lbmV0LmN6MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKC
AQEA5o0RZV2rgI7I9TDosNb7S+6D6qXx64X1+DTd4vJy18WjDGrnr7y5uT9P84/f
yQHcl1xINC1HaV9izPzySCeZVL2lYqCuUEkfifu8StHEL8U5lOEBQnLtVdd5zcUn
3TuwGV6KiyNmMW6MKeJyCQ0Jl6II7KAc1V8qngf1cv9bKzSg+nB8jNFwkmV20uXg
bIZWiMtnkMAZi1RUGfOh9ToBJfulBiFe+2mOOzEYERUVeH7nfrZEpPC5hUoTfviB
1YqGygP/sq8Gc0DmAFC7ZYNWBgyB+wZbIfdJ+iukJmScMxipma5LuPgaUGi1rLbS
pwArxrDplfeqasko76gHQxirnwIDAQABo4ICHjCCAhowDgYDVR0PAQH/BAQDAgWg
MBMGA1UdJQQMMAoGCCsGAQUFBwMBMAwGA1UdEwEB/wQCMAAwHQYDVR0OBBYEFIWz
5xMG7fmBZpUYkh6o3yAkCDoLMB8GA1UdIwQYMBaAFB8vNb5GFILNQLGueSxVePr3
1Gj7MDMGCCsGAQUFBwEBBCcwJTAjBggrBgEFBQcwAoYXaHR0cDovL3lyMS5pLmxl
bmNyLm9yZy8wGwYDVR0RBBQwEoIQbWFpbC5wcmltZW5ldC5jejATBgNVHSAEDDAK
MAgGBmeBDAECATAtBgNVHR8EJjAkMCKgIKAehhxodHRwOi8veXIxLmMubGVuY3Iu
b3JnLzYuY3JsMIIBDQYKKwYBBAHWeQIEAgSB/gSB+wD5AHcAyKPEf8ezrbk1awE/
anoSbeM6TkOlxkb5l605dZkdz5oAAAGg0BbsFgAABAMASDBGAiEAzzFjkf8cM0vk
DdMbFTWhuKmo2n7xUPI40e1IXHRMxNoCIQDuEe3yeadLM64QNamz1h1+RzIl9xkF
gXfKhWBQJZsNhQB+ACbjZG5YaSEjvDQ/RyQ1mzeSzSRaiNgV05Mz/ZkYq0cjAAAB
oNAW4l4ACAAABQBFopsaBAMARzBFAiEAmyRGYXg/3ySNXs0o9U/lJ8/uAxQG7u2I
3Wv4V9plR1oCIDQnpYDEGxM0pluIawAaQWpIGTpcOyQuTI+YD89UA3LbMA0GCSqG
SIb3DQEBCwUAA4IBAQBxVHUaf8hMYTV+rEg1vaTVOtVQxAgXga4/gtcSbw4rG7eL
uts9KUX4m4RJosV5npzy68zgal4PLYoNCTZ5w+RBEvES+rsCxm6JgLGjraVfyn4Z
+Gdj1HCz5H0pTxejsX3gk52XzS75G/OLb33yhPNSVPTrHuwKtpnOiN2YRsKXBeMN
muKm0VwbYSTlVZknmxLQpoCXOW/VWBnzMQ4LmS7t2t7j9bqYixGLSi1/6vvWb9B0
Axsi0J2MANaNcVnIsjn+ijXV483mydDi3D8yMDLGnOU6bjb8xfWUOwUI/RNBn1EM
/6MR2vJvfTmbEpMQVndx8gqAkyo1aZ8sQUhQrJhG
-----END CERTIFICATE-----

Cipher: TLS_AES_256_GCM_SHA384 · Checked 2026-11-07T02:19:21+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
665
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
2126
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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