MISP Certificate VerificationΒΆ

The MISP DXL service supports validating the authenticity of the certificate associated with the MISP server that is being connected to.

Enabling and disabling of this capability is controlled via the verifyCertificate property in the server configuration file (see Service Configuration File. While this validation can be disabled, it is highly recommended that it be enabled for production environments.

The remainder of this page walks through the steps necessary to obtain the information required to perform this validation successfully.

Two types of certificate validation take place when connecting to the MISP server:

  1. The host as defined in the service configuration file for the MISP server must match the hostname in the MISP server's certificate.
  2. The MISP server's certificate must be signed by a Certificate Authority (CA) that can be found in the CA bundle (specified via the verifyCertBundle property) associated with the MISP server in the service configuration file.

To determine the hostname in the MISP server's certificate and the certificate of the signing CA you can execute the following command via openssl.

openssl s_client -showcerts -connect <misp-host>:<misp-port>

For example:

openssl s_client -showcerts -connect misptestsystem:443

The output of the command should appear similar to the following:

CONNECTED(00000003)
depth=1 O = MyCorp, OU = MyTest, CN = MyCA
verify error:num=19:self signed certificate in certificate chain
---
Certificate chain
 0 s:/O=MyCorp/OU=MyTeam/CN=misptestsystem
   i:/O=MyCorp/OU=MyTeam/CN=MyCA
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
 1 s:/O=MyCorp/OU=MyTeam/CN=MyCA
   i:/O=MyCorp/OU=MyTeam/CN=MyCA
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

...

In the output above, the two important portions for validating the MISP server's certificate have been highlighted in bold.

  1. The first portion includes the common name (CN) associated with the MISP server's certificate.

    In this particular example the CN is as follows: CN=misptestsystem

    Based on this, for hostname validation to succeed the host value for the MISP server as defined in the service configuration file must have a value of misptestsystem.

  2. The second portion highlighted is the certificate of the CA that was used to sign the MISP server's certificate.

    For certificate validation to succeed, this certificate text must be copied (including the BEGIN and END lines) into a new file. Next, the verifyCertBundle value for the MISP server as defined in the service configuration file must have a path to this newly created file.

    For example:

    -----BEGIN CERTIFICATE-----
MIIDTTCCAjWgAwIBAgIIffd6gTDU39wwDQYJKoZIhvcNAQEFBQAwPDEPMA0GA1UE
CgwGTWNBZmVlMQ4wDAYDVQQLDAVPcmlvbjEZMBcGA1UEAwwQT3Jpb25fQ0FfRFhM
LUVQTzAeFw03MDAxMDEwMDAwMDBaFw00NjA5MDUyMzM3MjRaMDwxDzANBgNVBAoM
Bk1jQWZlZTEOMAwGA1UECwwFT3Jpb24xGTAXBgNVBAMMEE9yaW9uX0NBX0RYTC1F
UE8wggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQDRMqxPEBBkYrcmWg5T
X2r3Z+bidvGGcPzA2vACvdY4DCGkLTtc085EOQoULRNdGSI6yP9W9YH8nquTreHW
O80Aj29kr9Il3+JXad04LzBbjW5MhMCf4fnGiJ5E9ud2BE/xc6RTco/8bIoR27BC
VoTnyHcU0gHz7+PZWaQrPhRKEaNbG3RddY7zKjq56s32rBti2LBbjGg7qVSMLewy
MuBl9owzWwYC8bJnbqHH3h4LdtsG/Zb1ohsR2PaY2gb+Bn2DjWlBVFiFozRKKSLU
ipXlBxiYRRrkfOhEneWiptdLo65cXLd09hRc8h7dEPlYl9jZHGpOBvX1aGjre8w8
LlrXAgMBAAGjUzBRMA8GA1UdEwEB/wQFMAMBAf8wHQYDVR0OBBYEFKitli7CNwfa
mTztGieYRrWLs57FMB8GA1UdIwQYMBaAFKitli7CNwfamTztGieYRrWLs57FMA0G
CSqGSIb3DQEBBQUAA4IBAQAyHKcG55dOvJJPRf9Xt+Uj3nwd1gyehbOhKJYfDqeZ
l5EYGuNpX3HFl3BLjNxqxoj/aw1ICJX4AQQpFRsnB2CjQA53/1+0Cmvq4lw7qL/A
5sbshJKy+4291THE16ynqAF2cySlxhdSpvDMB3Z0v9iGqt5yYvhMc5yHhCpipj0r
iYY/K8QhEtruGy4lHxjwKOf5Ky1nX1pAZmRK4IDQTdn4iT3Cl9Jgr+ERFou7PHXN
0k8wmi1b2oPp5OCJoeB4xzsrbdG2aCgTDTflzL9RiEeflhwlWim2X2oCyZKVW4a4
/Tzcdk4tZlgZazxEDTJ8wI+12JNGBXMN5fuaF5Yuykf1
-----END CERTIFICATE-----