PassTLSClientCert

The PassTLSClientCert middleware adds the selected data from the passed client TLS certificate to a header.

Configuration Example

Middleware PassTLSClientCert

apiVersion: traefik.io/v1alpha1
kind: Middleware
metadata:
  name: test-passtlsclientcert
spec:
  passTLSClientCert:
    pem: true
    info:
      notAfter: true
      notBefore: true
      sans: true
      subject:
        country: true
        province: true
        locality: true
        organization: true
        organizationalUnit: true
        commonName: true
        serialNumber: true
        domainComponent: true
      issuer:
        country: true
        province: true
        locality: true
        organization: true
        commonName: true
        serialNumber: true
        domainComponent: true

General Information

PassTLSClientCert can add two headers to the request:

X-Forwarded-Tls-Client-Cert that contains the pem.
X-Forwarded-Tls-Client-Cert-Info that contains all the selected certificate information in an escaped string.

info

X-Forwarded-Tls-Client-Cert-Info header value is a string that has been escaped in order to be a valid URL query.
These options only work accordingly to the MutualTLS configuration.
That is to say, only the certificates that match the clientAuth.clientAuthType policy are passed.

Example of a complete certificate and explaining each of the middleware options

Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number: 1 (0x1)
        Signature Algorithm: sha1WithRSAEncryption
        Issuer: DC=org, DC=cheese, O=Cheese, O=Cheese 2, OU=Simple Signing Section, OU=Simple Signing Section 2, CN=Simple Signing CA, CN=Simple Signing CA 2, C=FR, C=US, L=TOULOUSE, L=LYON, ST=Signing State, ST=Signing State 2/[email protected]/[email protected]
        Validity
            Not Before: Dec  6 11:10:16 2018 GMT
            Not After : Dec  5 11:10:16 2020 GMT
        Subject: DC=org, DC=cheese, O=Cheese, O=Cheese 2, OU=Simple Signing Section, OU=Simple Signing Section 2, CN=*.example.org, CN=*.example.com, C=FR, C=US, L=TOULOUSE, L=LYON, ST=Cheese org state, ST=Cheese com [email protected]/[email protected]
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
                RSA Public-Key: (2048 bit)
                Modulus:
                    00:de:77:fa:8d:03:70:30:39:dd:51:1b:cc:60:db:
                    a9:5a:13:b1:af:fe:2c:c6:38:9b:88:0a:0f:8e:d9:
                    1b:a1:1d:af:0d:66:e4:13:5b:bc:5d:36:92:d7:5e:
                    d0:fa:88:29:d3:78:e1:81:de:98:b2:a9:22:3f:bf:
                    8a:af:12:92:63:d4:a9:c3:f2:e4:7e:d2:dc:a2:c5:
                    39:1c:7a:eb:d7:12:70:63:2e:41:47:e0:f0:08:e8:
                    dc:be:09:01:ec:28:09:af:35:d7:79:9c:50:35:d1:
                    6b:e5:87:7b:34:f6:d2:31:65:1d:18:42:69:6c:04:
                    11:83:fe:44:ae:90:92:2d:0b:75:39:57:62:e6:17:
                    2f:47:2b:c7:53:dd:10:2d:c9:e3:06:13:d2:b9:ba:
                    63:2e:3c:7d:83:6b:d6:89:c9:cc:9d:4d:bf:9f:e8:
                    a3:7b:da:c8:99:2b:ba:66:d6:8e:f8:41:41:a0:c9:
                    d0:5e:c8:11:a4:55:4a:93:83:87:63:04:63:41:9c:
                    fb:68:04:67:c2:71:2f:f2:65:1d:02:5d:15:db:2c:
                    d9:04:69:85:c2:7d:0d:ea:3b:ac:85:f8:d4:8f:0f:
                    c5:70:b2:45:e1:ec:b2:54:0b:e9:f7:82:b4:9b:1b:
                    2d:b9:25:d4:ab:ca:8f:5b:44:3e:15:dd:b8:7f:b7:
                    ee:f9
                Exponent: 65537 (0x10001)
        X509v3 extensions:
            X509v3 Key Usage: critical
                Digital Signature, Key Encipherment
            X509v3 Basic Constraints:
                CA:FALSE
            X509v3 Extended Key Usage:
                TLS Web Server Authentication, TLS Web Client Authentication
            X509v3 Subject Key Identifier:
                94:BA:73:78:A2:87:FB:58:28:28:CF:98:3B:C2:45:70:16:6E:29:2F
            X509v3 Authority Key Identifier:
                keyid:1E:52:A2:E8:54:D5:37:EB:D5:A8:1D:E4:C2:04:1D:37:E2:F7:70:03

            X509v3 Subject Alternative Name:
                DNS:*.example.org, DNS:*.example.net, DNS:*.example.com, IP Address:10.0.1.0, IP Address:10.0.1.2, email:[email protected], email:[email protected]
    Signature Algorithm: sha1WithRSAEncryption
         76:6b:05:b0:0e:34:11:b1:83:99:91:dc:ae:1b:e2:08:15:8b:
         16:b2:9b:27:1c:02:ac:b5:df:1b:d0:d0:75:a4:2b:2c:5c:65:
         ed:99:ab:f7:cd:fe:38:3f:c3:9a:22:31:1b:ac:8c:1c:c2:f9:
         5d:d4:75:7a:2e:72:c7:85:a9:04:af:9f:2a:cc:d3:96:75:f0:
         8e:c7:c6:76:48:ac:45:a4:b9:02:1e:2f:c0:15:c4:07:08:92:
         cb:27:50:67:a1:c8:05:c5:3a:b3:a6:48:be:eb:d5:59:ab:a2:
         1b:95:30:71:13:5b:0a:9a:73:3b:60:cc:10:d0:6a:c7:e5:d7:
         8b:2f:f9:2e:98:f2:ff:81:14:24:09:e3:4b:55:57:09:1a:22:
         74:f1:f6:40:13:31:43:89:71:0a:96:1a:05:82:1f:83:3a:87:
         9b:17:25:ef:5a:55:f2:2d:cd:0d:4d:e4:81:58:b6:e3:8d:09:
         62:9a:0c:bd:e4:e5:5c:f0:95:da:cb:c7:34:2c:34:5f:6d:fc:
         60:7b:12:5b:86:fd:df:21:89:3b:48:08:30:bf:67:ff:8c:e6:
         9b:53:cc:87:36:47:70:40:3b:d9:90:2a:d2:d2:82:c6:9c:f5:
         d1:d8:e0:e6:fd:aa:2f:95:7e:39:ac:fc:4e:d4:ce:65:b3:ec:
         c6:98:8a:31
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Configuration Options

Field	Description	Default	Required
`pem`	Fills the `X-Forwarded-Tls-Client-Cert` header with the certificate information. More information here.	false	No
`info.serialNumber`	Add the `Serial Number` of the certificate. More information about `info` here.	false	No
`info.notAfter`	Add the `Not After` information from the `Validity` part. More information about `info` here.	false	No
`info.notBefore`	Add the `Not Before` information from the `Validity` part. More information about `info` here.	false	No
`info.sans`	Add the `Subject Alternative Name` information from the `Subject Alternative Name` part. More information about `info` here.	false	No
`info.subject`	The `info.subject` selects the specific client certificate subject details you want to add to the `X-Forwarded-Tls-Client-Cert-Info` header. More information about `info` here.	false	No
`info.subject.country`	Add the `country` information into the subject. The data is taken from the subject part with the `C` key. More information about `info` here.	false	No
`info.subject.province`	Add the `province` information into the subject. The data is taken from the subject part with the `ST` key. More information about `info` here.	false	No
`info.subject.locality`	Add the `locality` information into the subject. The data is taken from the subject part with the `L` key. More information about `info` here.	false	No
`info.subject.organization`	Add the `organization` information into the subject. The data is taken from the subject part with the `O` key. More information about `info` here.	false	No
`info.subject.organizationalUnit`	Add the `organizationalUnit` information into the subject. The data is taken from the subject part with the `OU` key. More information about `info` here.	false	No
`info.subject.commonName`	Add the `commonName` information into the subject. The data is taken from the subject part with the `CN` key.	false	No
`info.subject.serialNumber`	Add the `serialNumber` information into the subject. The data is taken from the subject part with the `SN` key.	false	No
`info.subject.domainComponent`	Add the `domainComponent` information into the subject. The data is taken from the subject part with the `DC` key. More information about `info` here.	false	No
`info.issuer`	The `info.issuer` selects the specific client certificate issuer details you want to add to the `X-Forwarded-Tls-Client-Cert-Info` header. More information about `info` here.	false	No
`info.issuer.country`	Add the `country` information into the issuer. The data is taken from the issuer part with the `C` key. More information about `info` here.	false	No
`info.issuer.province`	Add the `province` information into the issuer. The data is taken from the issuer part with the `ST` key. More information about `info` here.	false	No
`info.issuer.locality`	Add the `locality` information into the issuer. The data is taken from the issuer part with the `L` key. More information about `info` here.	false	No
`info.issuer.organization`	Add the `organization` information into the issuer. The data is taken from the issuer part with the `O` key. More information about `info` here.	false	No
`info.issuer.commonName`	Add the `commonName` information into the issuer. The data is taken from the issuer part with the `CN` key. More information about `info` here.	false	No
`info.issuer.serialNumber`	Add the `serialNumber` information into the issuer. The data is taken from the issuer part with the `SN` key. More information about `info` here.	false	No
`info.issuer.domainComponent`	Add the `domainComponent` information into the issuer. The data is taken from the issuer part with the `DC` key. More information about `info` here.	false	No

pem

Data Format

The delimiters and \n will be removed.
If there are more than one certificate, they are separated by a ",".

Header size

The X-Forwarded-Tls-Client-Cert header value could exceed the web server header size limit

The header size limit of web servers is commonly between 4kb and 8kb.
If that turns out to be a problem, and if reconfiguring the server to allow larger headers is not an option, one can alleviate the problem by selecting only the interesting parts of the cert, through the use of the info options described below. (And by setting pem to false).

info

The info option selects the specific client certificate details you want to add to the X-Forwarded-Tls-Client-Cert-Info header.

Data Format

The value of the header is an escaped concatenation of all the selected certificate details. Unless specified otherwise, all the header values examples are shown unescaped, for readability.

If there are more than one certificate, they are separated by a ,.

The following example shows such a concatenation, when all the available fields are selected:

Subject="DC=org,DC=cheese,C=FR,C=US,ST=Cheese org state,ST=Cheese com state,L=TOULOUSE,L=LYON,O=Cheese,O=Cheese 2,CN=*.example.com";Issuer="DC=org,DC=cheese,C=FR,C=US,ST=Signing State,ST=Signing State 2,L=TOULOUSE,L=LYON,O=Cheese,O=Cheese 2,CN=Simple Signing CA 2";NB="1544094616";NA="1607166616";SAN="*.example.org,*.example.net,*.example.com,[email protected],[email protected],10.0.1.0,10.0.1.2"

Configuration Example​

General Information​

Configuration Options​

pem​

Data Format​

Header size​

info​

Data Format​

Configuration Example

General Information

Configuration Options

pem

Data Format

Header size

info

Data Format