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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

rtkmail.risp.ru · 90.189.193.67:443

Verified

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

Subject
CN=rtkmail.risp.ru
Issuer
C=US O=Let's Encrypt CN=YR1
Valid from
2026-08-29T22:02:22+00:00
Expires
2026-11-27T22:02:21+00:00
Days remaining
54
Serial (hex)
0594369A6654CF5E7B44D8E55732195DAD08
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

DNS:mail.gorny.ru, DNS:online.nsk.su, DNS:relay.gorny.ru, DNS:rtkmail-local.risp.ru, DNS:rtkmail.risp.ru

SHA-256 fingerprint

5C:65:5C:92:04:39:C7:3C:46:0A:A8:4D:50:50:67:5D:BC:BB:1A:B7:2A:DC:22:33:10:45:17:F5:30:FC:00:90
Certificate extensions & PEM
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
89:AB:68:24:1E:38:8B:1C:40:77:8C:EF:3C:FB:88:4C:5C:A3:6E:10
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.gorny.ru, DNS:online.nsk.su, DNS:relay.gorny.ru, DNS:rtkmail-local.risp.ru, DNS:rtkmail.risp.ru
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr1.c.lencr.org/9.crl
ct_precert_scts
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 : Aug 29 23:00:52.679 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:20:0A:B3:89:ED:B8:81:E3:66:72:D2:E0:0E: A9:83:69:7B:04:7B:BE:D6:D0:C7:DA:6F:90:5C:FD:4F: 13:69:FA:24:02:21:00:FA:72:4E:9C:26:05:7D:5B:73: 2B:41:76:E1:FB:33:39:CC:2F:BF:3D:BF:0C:B9:B8:C7: BF:B2:54:86:DD:7A:14 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 : Aug 29 23:00:53.364 2026 GMT Extensions: 00:00:05:00:3A:28:5F:6F Signature : ecdsa-with-SHA256 30:46:02:21:00:B2:61:6F:B5:1B:E2:23:C6:2B:51:A7: 9B:29:96:F3:CC:54:82:9B:6D:BC:48:2D:13:91:CC:0D: 4C:3B:4E:DB:A1:02:21:00:A9:E7:8E:CB:BD:05:7A:53: A8:25:AA:06:5C:0D:8C:50:BB:15:24:7A:99:0C:C9:67: 3B:2F:3E:41:07:4D:19:F4
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: TLS_AES_256_GCM_SHA384 · Checked 2026-10-04T09:46:51+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
699
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
2160
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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