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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

fuw.edu.pl · 193.0.80.4:443

Verified
The certificate expires within 30 days.

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

Subject
CN=www.fuw.edu.pl
Issuer
C=US O=Let's Encrypt CN=YR1
Valid from
2026-07-25T18:53:11+00:00
Expires
2026-10-23T18:53:10+00:00
Days remaining
20
Serial (hex)
05811EE5EB7CC7684031E4929EA9B18BE2AE
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

DNS:fuw.edu.pl, DNS:www.fuw.edu.pl

SHA-256 fingerprint

3A:3C:28:8E:CA:A0:9E:56:E1:C5:2A:18:1E:10:58:9C:7F:9C:CD:A0:0C:9D:03:16:82:11:34:B7:32:9F:C3:43
Certificate extensions & PEM
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
75:22:F0:38:39:BB:87:A1:F8:19:67:A1:F7:71:07:70:37:83:C3:9F
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:fuw.edu.pl, DNS:www.fuw.edu.pl
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr1.c.lencr.org/47.crl
ct_precert_scts
Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 6C:FE:50:19:43:A8:5E:A9:16:BC:52:D1:33:E4:DC:C9: 1E:F1:41:1C:7D:25:84:20:D1:73:80:9E:18:18:EB:3A Timestamp : Jul 25 19:51:41.363 2026 GMT Extensions: 00:00:05:00:17:73:E4:23 Signature : ecdsa-with-SHA256 30:45:02:21:00:9C:A1:2E:11:C8:9B:84:C9:46:9A:4A: BC:FD:0B:37:58:00:2B:6F:C7:9E:A1:3D:6A:FF:94:FC: 66:8F:DD:1A:D9:02:20:08:05:26:53:62:1A:E2:31:EE: 4F:27:6B:60:E7:65:4E:D9:DD:E9:78:71:35:37:7D:FC: 8B:B9:CD:BF:04:AD:0D Signed Certificate Timestamp: Version : v1 (0x0) Log ID : D8:09:55:3B:94:4F:7A:FF:C8:16:19:6F:94:4F:85:AB: B0:F8:FC:5E:87:55:26:0F:15:D1:2E:72:BB:45:4B:14 Timestamp : Jul 25 19:51:41.398 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:46:02:21:00:DA:EC:F8:3C:E2:68:8F:A1:44:D7:17: FE:4C:4D:8F:64:74:DD:64:CB:E7:BA:F9:9C:33:37:3D: 87:11:C7:EB:6B:02:21:00:D5:8F:1F:30:B9:24:64:D7: 1B:30:E7:2E:4D:B0:59:89:F5:C5:20:59:28:03:93:4F: DE:36:0A:2D:93:42:B5:9C
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: ECDHE-RSA-AES256-GCM-SHA384 · Checked 2026-10-03T05:46:07+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
700
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
2161
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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