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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

mail.bit-net.kr · 211.174.100.4:443

Verified

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

Subject
CN=mail.bit-net.kr
Issuer
C=US O=Let's Encrypt CN=YR2
Valid from
2026-10-31T20:13:15+00:00
Expires
2027-01-29T20:13:14+00:00
Days remaining
78
Serial (hex)
0574133AE28ACF6F7D2B42D20721EEEB5984
Signature
RSA-SHA256
Public key
RSA 4096

Subject alternative names (SAN)

DNS:mail.bit-net.kr

SHA-256 fingerprint

23:C2:B3:25:57:50:A7:30:F0:3A:A7:37:8D:6B:9B:41:6F:95:17:DC:96:78:22:C7:45:AB:90:2E:63:27:31:B3
Certificate extensions & PEM
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
CE:9C:B3:BA:A8:E4:E3:46:D6:4D:47:AC:1C:2A:EE:32:1B:24:A5:E9
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.bit-net.kr
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr2.c.lencr.org/5.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 31 21:11:45.932 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:44:02:21:00:8D:3D:E6:B5:28:D3:06:AA:DA:59:84: F2:50:8E:8B:D3:5B:ED:FB:23:CB:5D:96:EC:AA:B9:4A: 2C:0E:CC:44:2A:02:1F:5D:6F:11:BD:9E:FE:11:8A:9B: 30:E0:C9:62:80:6A:9F:61:3E:EB:04:98:D8:8C:02:B8: 7C:0F:CE:DC:91:C7 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : A2:81:00:18:73:4E:17:6E:1D:47:E0:95:40:F3:81:BA: 54:66:97:CD:63:A8:43:50:71:6E:B8:09:4E:DA:F1:0D Timestamp : Oct 31 21:11:46.751 2026 GMT Extensions: 00:00:05:00:33:DC:07:F5 Signature : ecdsa-with-SHA256 30:45:02:21:00:93:97:C0:92:6A:C0:1C:20:C6:89:17: 34:33:04:A0:CF:0B:F6:95:84:1C:C5:35:D1:E2:58:3A: 21:D3:97:C6:9D:02:20:37:00:62:50:18:B3:8E:CC:C7: EB:10:A3:67:4A:55:B7:80:17:39:4F:56:E4:5A:C6:32: 67:72:B8:3F:57:D1:6A
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: TLS_AES_256_GCM_SHA384 · Checked 2026-11-12T14:57:27+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
660
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-----
MIIE2jCCAsKgAwIBAgIQTr0klH4k05SALYSlL9WzGTANBgkqhkiG9w0BAQsFADAu
MQswCQYDVQQGEwJVUzENMAsGA1UEChMESVNSRzEQMA4GA1UEAxMHUm9vdCBZUjAe
Fw0yNTA5MDMwMDAwMDBaFw0yODA5MDIyMzU5NTlaMDMxCzAJBgNVBAYTAlVTMRYw
FAYDVQQKEw1MZXQncyBFbmNyeXB0MQwwCgYDVQQDEwNZUjIwggEiMA0GCSqGSIb3
DQEBAQUAA4IBDwAwggEKAoIBAQDZ0LxwBppqh84luqMerV/eeL/fXQ7mLQQv1Lnp
WKZbyvGpx6wh6AfnslAnF6ewTkcHA+gSOoBvm3Dfm06AuGiF+KRut4fAcowqnAQQ
CW98+QPP/eOv/wug7Iyk4NkOxf2I6g2f55T6nJoOTLFcukeRq80JGQEYan+dPFr9
OGUgQK2hGKgNkW87pappsOAuUJcroYhRt5uUis4qaZireiseu32gzDJNBAiKtsvd
6HX4v25bpkRNcS/B/Gtc9kVbUpD+2PLPxdei3Tim55k4tfAEXwD2qyiPTxrTNq6l
N+AMr5g2c1dNqkOTwjxeV6L5lpP1rGiYvLnRaPlOqyZRPW+5AgMBAAGjge4wgesw
DgYDVR0PAQH/BAQDAgGGMBMGA1UdJQQMMAoGCCsGAQUFBwMBMBIGA1UdEwEB/wQI
MAYBAf8CAQAwHQYDVR0OBBYEFEAVLSZ57TIgnt+ach3WMh+BDIEMMB8GA1UdIwQY
MBaAFN7nW2DQIm1AKH0/DQH+pLVStFGUMDIGCCsGAQUFBwEBBCYwJDAiBggrBgEF
BQcwAoYWaHR0cDovL3lyLmkubGVuY3Iub3JnLzATBgNVHSAEDDAKMAgGBmeBDAEC
ATAnBgNVHR8EIDAeMBygGqAYhhZodHRwOi8veXIuYy5sZW5jci5vcmcvMA0GCSqG
SIb3DQEBCwUAA4ICAQB0ZUQWZ9/Yn9COEpo+JfecMnB0h0vwDm/M66IqXqw3LoaL
mx9lZvRTeDIS67PUeI3yCA2W6PKRD0/FE/G57lOmS+Xy5AaaL00ICGOqjNcCaMWW
8o8nevHOd4i4lqgtznE/28QwlcdJyF8yBiWHpnyjhEpmNWJURgOCOg2xpwRMBCsj
MScqYPtOhBeuYQvSwAEeTML2Ukh6uGuX4E14q65Ja8cdjF5bAldnP1eE4FBaAwsZ
G2fOqqrKV03Y85Nw2btedP1AtliQuJZs/Jo/gXxXdc7LrH3McgnpnbTiAncX7yES
hP6kzQejllqMCIt52HOjxDGWafS7Xw+DKwqmH+Eqy8dcbOuag/1AYlQoKNVK3F5q
Hh6tEDiMqQcLIibGKteE6iHo4A/bIScbzrhXUYuism42ZYzmc48FMVIH3qy4L84E
TdAH2gtxw0PAhvRVXp8HP7wfngpzsN/8xOTpeRSbM4+Qbc56G6+Bifmv6sk1ieQb
NA3wJdl4DDUuQSV8hBgx6zoI1ZSGORprDFux7c6rhc77QZMSRrEgomBeklervEve
86ylWmZ3WWHV6RLMi8xNvjd71r4EPIGgY7BZU/VPBkq+uA7Gb6mbJnFgV43uh3xy
LRFgxIAphIukwTGSMZZR+AI+Qnp0BYTWovHXozOf3H8r6hozEoT02JHn0AeTfA==
-----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
2121
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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