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.stl.ru · 85.95.151.18:443

Unverified
Certificate verification failed. These are unverified certificate details presented by the server. Peer certificate subjectAltName did not match expected name `mail.stl.ru'

Certificate verification failed

Subject
CN=mail.ptkom.ru
Issuer
C=US O=Let's Encrypt CN=YR2
Valid from
2026-09-24T04:13:05+00:00
Expires
2026-12-23T04:13:04+00:00
Days remaining
72
Serial (hex)
06CD3AF7A000D4D8C097054971DBD2B1B56E
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

DNS:mail.ptkom.ru

SHA-256 fingerprint

5A:A5:2E:4E:20:63:70:5A:72:CA:85:2D:A5:71:9C:A6:15:DD:F0:EA:1D:04:52:0A:CC:A7:75:67:9E:B6:54:E5
Certificate extensions & PEM
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
BF:AB:5A:0E:EC:C8:32:ED:50:2C:C7:9E:02:5D:E8:BE:FB:83:3C:1F
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:mail.ptkom.ru
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr2.c.lencr.org/111.crl
ct_precert_scts
Signed Certificate Timestamp: Version : v1 (0x0) Log ID : CB:38:F7:15:89:7C:84:A1:44:5F:5B:C1:DD:FB:C9:6E: F2:9A:59:CD:47:0A:69:05:85:B0:CB:14:C3:14:58:E7 Timestamp : Sep 24 05:11:35.677 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:21:00:CF:32:70:71:C1:01:DB:33:B0:95:FC: 49:C5:8F:41:DF:F5:7C:24:45:B2:3C:EA:4B:0A:5F:EA: B9:29:3F:03:3B:02:20:21:CB:6C:FA:A8:4D:C2:74:D3: 56:5D:F4:1F:B9:57:96:6A:35:78:B3:19:2B:1F:0F:9A: 8B:DC:C2:F9:BF:8B:94 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 46:AF:86:3D:3B:3E:E5:9F:A5:77:DE:A8:24:5D:36:B0: D9:ED:22:A2:23:F4:61:77:41:22:94:52:EE:95:50:5F Timestamp : Sep 24 05:11:35.935 2026 GMT Extensions: 00:00:05:00:34:B8:B1:3D Signature : ecdsa-with-SHA256 30:44:02:20:3A:AD:B4:7D:7F:97:70:AA:53:35:83:B4: D4:BA:DA:CA:CE:A4:24:A1:42:09:9A:00:75:8E:B7:3C: 28:C5:7F:A9:02:20:7E:1F:FA:EC:9C:42:30:6A:96:4F: 41:35:7A:F5:6F:FC:2C:4D:8E:0F:B9:12:7D:53:9F:4E: 15:37:9A:80:66:65
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: TLS_AES_128_GCM_SHA256 · Checked 2026-10-11T17:07:30+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
692
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
2153
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-----
MIIF9DCCA9ygAwIBAgIRAPJLbRf52a18scn+p4eCaZ8wDQYJKoZIhvcNAQELBQAw
TzELMAkGA1UEBhMCVVMxKTAnBgNVBAoTIEludGVybmV0IFNlY3VyaXR5IFJlc2Vh
cmNoIEdyb3VwMRUwEwYDVQQDEwxJU1JHIFJvb3QgWDEwHhcNMjYwNTEzMDAwMDAw
WhcNMzIwOTAyMjM1OTU5WjAuMQswCQYDVQQGEwJVUzENMAsGA1UEChMESVNSRzEQ
MA4GA1UEAxMHUm9vdCBZUjCCAiIwDQYJKoZIhvcNAQEBBQADggIPADCCAgoCggIB
ANvGJnN78CTJdWL3+eGfsLN5TrNBJs+VH9hRXqRbwxu9sGNiB0BD1fcOxbSUQCJI
M1xE13Db+5Cw1w0s0EBYsvuIP/6joF0w8cuImbgR1OGgYbSQ4OpzI+DG8SGuTlcE
873OCS+kh3srlo6vl43M5OJg4Aeo1sfHp6kTJDoIiFBNJAY+OKfX/FUvYKuhjT+n
o49lmqmupSBI5PkBQiqrEGtWU5uxU/cQWHGu8jSjFBznZqvbNPLMXMLFxCb3WTfr
JBXXjqvWG+v4bjzxjjeAtOlU7qarRDvNOyAuQYLln904M+faKx8hnLCpJ15ZqaEg
cNlY+9MMWcC5yvL2A2j3l9+2buggZX+dOE91zYmIdawTvSZuVvlbRrAlLxIB6pwM
BjneXCjYQ8+3BCCjssbSNpZU3hTcBDdhfAlEDlYr6pEatnMdmDT5BqnKC92bd0Eh
M1fbLHioLccLCuievT8ZkPhZrq7Mii7gNXAcUEAR8+lzYal+9zTg7C5DALyVOeG/
CqfRAMn1KSHCR0NSA6P8tn/mGRlnCct5rtVCLnVySVpU6H1qGg3DgTOuskf8eahT
MiYbI5ezPJmO5ertalskQ1utp74+eDy92PI4ftHKTbq9IWhH4YZKh3WnJEIt+oQv
lYZbY8tpEroKrFB6PFGzrJIDRyts4HqvuH52RFj2zv/BAgMBAAGjgeswgegwDgYD
VR0PAQH/BAQDAgEGMBMGA1UdJQQMMAoGCCsGAQUFBwMBMA8GA1UdEwEB/wQFMAMB
Af8wHQYDVR0OBBYEFN7nW2DQIm1AKH0/DQH+pLVStFGUMB8GA1UdIwQYMBaAFHm0
WeZ7tuXkAXOACIjIGlj26ZtuMDIGCCsGAQUFBwEBBCYwJDAiBggrBgEFBQcwAoYW
aHR0cDovL3gxLmkubGVuY3Iub3JnLzATBgNVHSAEDDAKMAgGBmeBDAECATAnBgNV
HR8EIDAeMBygGqAYhhZodHRwOi8veDEuYy5sZW5jci5vcmcvMA0GCSqGSIb3DQEB
CwUAA4ICAQA8spSI95KKfn2W6GMmDpHBJSPaLbsS3W93cijJCRCYAc1fsJgL1FIL
7C0C9ecPOdcwB2fi0Dk2p94j9iTJCxmt5CFSKLRWwnXT2MMSXexVxqoVB79BdWPx
VXETkVme/qYSAuKVHh5Ps+5BixgmwS1JkjSAc+MfrUbNssVEEnH0aEiAh+rotXAV
JSP/Ye7LJPEwD9DWG72vVWbhAcuOf5OLjz57Ctk7MgQHynZ7+PlHJtajroCaIbtC
r6tcZZaAwUQm+jQyeWdV+2hv9deOYFmKeQyjjcSrN5Nadrw+L9DZJLbA1HqeNvLh
BgqpP0fvJq2N6EtD574N6eMI7uMsJTnji2UDz9el5XLSv9fqJMuDQtYVb2oTNoKp
oUqhxPVC0aq4eG5MESaIdn8b5ZGSSeAJLMHXljEdlNza+ncfkviXk1POLnnFdvx8
/gk6M374WbLWFXw8N141B/Rl/tINGfl1TxOIiqtiMYkL02RSGb1kq34BL9NPP27z
RGMuHGnzS3hFIrRTfKxrzUZ9RzQWzEG3K6fJ3r2nqSltkeytis9DIBoFY9VmVyjL
M71DMi+y1+TRSJVClEMwvA4yL++7q9XZx5r5wBRWB4kQTKH5qyoZnDw7iiuh1lID
yDFx8r7i9vIJU5HS3moZLkYWAOilMaV9N56A9Bgb6dNcHkvg3NoaYA==
-----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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