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

brooklynpubliclibrary.org · 54.198.135.162:443

Verified

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

Subject
CN=bline.bklynlibrary.org
Issuer
C=US O=Let's Encrypt CN=YR1
Valid from
2026-10-05T10:06:35+00:00
Expires
2027-01-03T10:06:34+00:00
Days remaining
77
Serial (hex)
06C7A21E25ABCD8F9481930A63B0090900A2
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

DNS:apps.brooklynpubliclibrary.org, DNS:bline.bklynlibrary.org, DNS:bline.brooklynpubliclibrary.org, DNS:borrow.bklynlibrary.org, DNS:brooklynpubliclibrary.org, DNS:centerforbrooklynhistory.org, DNS:got.bklynlibrary.org, DNS:summerreading.org, DNS:www.brooklynpubliclibrary.org, DNS:www.centerforbrooklynhistory.org, DNS:www.summerreading.org

SHA-256 fingerprint

45:DD:60:E0:21:AD:42:95:68:2F:B7:54:57:3D:40:5E:55:C3:5C:BA:C8:0D:34:1A:DA:8B:99:CD:1A:0D:B0:CF
Certificate extensions & PEM
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
6A:0B:9A:97:33:E7:05:88:1E:36:ED:96:5A:C4:DD:25:AE:03:A5:18
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:apps.brooklynpubliclibrary.org, DNS:bline.bklynlibrary.org, DNS:bline.brooklynpubliclibrary.org, DNS:borrow.bklynlibrary.org, DNS:brooklynpubliclibrary.org, DNS:centerforbrooklynhistory.org, DNS:got.bklynlibrary.org, DNS:summerreading.org, DNS:www.brooklynpubliclibrary.org, DNS:www.centerforbrooklynhistory.org, DNS:www.summerreading.org
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr1.c.lencr.org/35.crl
ct_precert_scts
Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 1C:9F:68:2C:E9:FA:F0:45:69:50:F8:1B:96:8A:87:DD: DB:32:10:D8:4C:E6:C8:B2:E3:82:52:4A:C4:CF:59:9F Timestamp : Oct 5 11:05:06.105 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:44:02:20:0B:F8:9E:2A:4A:F9:E4:62:2E:D1:A4:76: C7:B2:A6:7F:D8:B7:20:DC:AA:7E:8C:86:68:3F:F1:27: 26:28:B2:22:02:20:0C:26:AE:E2:39:BE:EA:33:7D:1B: C0:C0:5C:0C:A2:08:93:22:37:6C:57:C8:1A:7E:62:8A: 78:CE:FC:43:6F:90 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 1A:8B:9D:6B:8D:D7:91:D1:CD:05:49:ED:B6:03:55:D6: 06:B6:4F:AD:30:DB:71:FE:78:8F:0F:C7:C8:FB:C4:B1 Timestamp : Oct 5 11:05:06.580 2026 GMT Extensions: 00:00:05:00:05:81:B1:FC Signature : ecdsa-with-SHA256 30:45:02:21:00:E5:42:3F:B4:E6:55:40:F6:6C:00:31: 67:45:B0:47:46:48:7D:33:BF:00:2F:92:55:C3:75:FE: F3:53:82:DA:EE:02:20:44:23:33:90:BE:85:8C:83:A0: BF:F8:6E:99:09:FA:02:FE:AF:5A:2F:4E:E2:20:FE:92: 2F:32:C6:FC:C8:55:DA
-----BEGIN CERTIFICATE-----
MIIGHzCCBQegAwIBAgISBseiHiWrzY+UgZMKY7AJCQCiMA0GCSqGSIb3DQEBCwUA
MDMxCzAJBgNVBAYTAlVTMRYwFAYDVQQKEw1MZXQncyBFbmNyeXB0MQwwCgYDVQQD
EwNZUjEwHhcNMjYxMDA1MTAwNjM1WhcNMjcwMTAzMTAwNjM0WjAhMR8wHQYDVQQD
ExZibGluZS5ia2x5bmxpYnJhcnkub3JnMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8A
MIIBCgKCAQEAoFcgKjAYxoXe1lpa/oYNSk7tvHtzoNitEVbhOKolHvEi5VNbIFcd
ku0/dinh9VMTSt9Lg8PG9Y+VllwTNHsdp379arzP9DKs+dgNS9wEcQ7hWMFSNjgb
SgUdrRh11xYwU80pSGPFZJfWOcZ3vqdVJyopPzyCm3y3605gvYUfKacyvbuGQo12
J7O5wGbA6QXb82Q3BMGYHwDAUoNvPymITp8aRYAhF9HIwQq6I1DSmvPAhQZjtr9i
x3poNAq9TE7QnCPuUQzuYDOcpfj+BlDsFMJIWAaaqR9MfxzHiVcsQ+Fg1RJZPcfD
PHpuok6SxZ7Qu2Sb7DhZBbg2oC74l+90uwIDAQABo4IDPTCCAzkwDgYDVR0PAQH/
BAQDAgWgMBMGA1UdJQQMMAoGCCsGAQUFBwMBMAwGA1UdEwEB/wQCMAAwHQYDVR0O
BBYEFGoLmpcz5wWIHjbtllrE3SWuA6UYMB8GA1UdIwQYMBaAFB8vNb5GFILNQLGu
eSxVePr31Gj7MDMGCCsGAQUFBwEBBCcwJTAjBggrBgEFBQcwAoYXaHR0cDovL3ly
MS5pLmxlbmNyLm9yZy8wggE5BgNVHREEggEwMIIBLIIeYXBwcy5icm9va2x5bnB1
YmxpY2xpYnJhcnkub3JnghZibGluZS5ia2x5bmxpYnJhcnkub3Jngh9ibGluZS5i
cm9va2x5bnB1YmxpY2xpYnJhcnkub3Jnghdib3Jyb3cuYmtseW5saWJyYXJ5Lm9y
Z4IZYnJvb2tseW5wdWJsaWNsaWJyYXJ5Lm9yZ4IcY2VudGVyZm9yYnJvb2tseW5o
aXN0b3J5Lm9yZ4IUZ290LmJrbHlubGlicmFyeS5vcmeCEXN1bW1lcnJlYWRpbmcu
b3Jngh13d3cuYnJvb2tseW5wdWJsaWNsaWJyYXJ5Lm9yZ4Igd3d3LmNlbnRlcmZv
cmJyb29rbHluaGlzdG9yeS5vcmeCFXd3dy5zdW1tZXJyZWFkaW5nLm9yZzATBgNV
HSAEDDAKMAgGBmeBDAECATAuBgNVHR8EJzAlMCOgIaAfhh1odHRwOi8veXIxLmMu
bGVuY3Iub3JnLzM1LmNybDCCAQsGCisGAQQB1nkCBAIEgfwEgfkA9wB1AByfaCzp
+vBFaVD4G5aKh93bMhDYTObIsuOCUkrEz1mfAAABoQu9HzkAAAQDAEYwRAIgC/ie
Kkr55GIu0aR2x7Kmf9i3INyqfoyGaD/xJyYosiICIAwmruI5vuozfRvAwFwMogiT
IjdsV8gafmKKeM78Q2+QAH4AGouda43XkdHNBUnttgNV1ga2T60w23H+eI8Px8j7
xLEAAAGhC70hFAAIAAAFAAWBsfwEAwBHMEUCIQDlQj+05lVA9mwAMWdFsEdGSH0z
vwAvklXDdf7zU4La7gIgRCMzkL6FjIOgv/humQn6Av6vWi9O4iD+ki8yxvzIVdow
DQYJKoZIhvcNAQELBQADggEBABl2jlyXv4IuyJeOK2mg+g71Lgjc9WjVc6Kl9mjC
qt8vxxTVl7LJOVcOXQ+MkL/RSIYplvOqxuissDSGPFKxq+irnlBbQg/n7acPSPxI
R/vtoYeLGA2BBnnvj+FwZdZD368KgI0L2qmqDAgBc8cfdzA6rqdv2z1hh/B+ZHeV
S7xKa6qo+vf79jW7/XK46lc9AkKjosQajaJ7L9TFPZjlbBak/CgL1FkaujHvs7qC
YGTW1eZK+ZoO6ZigPr/yV/9q7vekvSNw9ylIkhFC1nUAg45WIa17kqY1zrgIytmj
4pgVxY6z/wf+MSwOnDCwJ3GUY+FkIXYk9urP9ycJjBvdHus=
-----END CERTIFICATE-----

Cipher: TLS_AES_256_GCM_SHA384 · Checked 2026-10-17T10:44:49+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
686
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
2147
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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