Link Active Directory SAML groups to Vault

Enable an instance of the KV secret engine for AD FS under a custom path:

$ vault secrets enable -path=<ADFS_KV_PLUGIN_PATH> kv-v2

For example:

$ vault secrets enable -path=adfs-kv kv-v2

• Open the Enable a Secrets Engine page:

  1. Open the GUI for your Vault instance.

  2. Login under the namespace for the plugin or select the namespace from the selector at the bottom of the left-hand menu and re-authenticate.

  3. Select Secrets Engines from the left-hand menu.

  4. Click Enable new engine + on the Secrets Engines page.

• Enable the KV plugin:

  1. Select the KV token.
  2. Set a mount path that reflects the plugin purpose. For example: dfs-kv.
  3. Click Enable engine.

Use vault write to create a read-only policy for AD FS clients that use the new KV plugin:

$ vault policy write <RO_ADFS_POLICY_NAME> - << EOF
# Read and list policy for the AD FS KV mount
path "<ADFS_KV_PLUGIN_PATH>/*" {
  capabilities = ["read", "list"]
}
EOF

For example:

$ vault policy write ro-saml-adfs - << EOF
# Read and list policy for the AD FS KV mount
path "adfs-kv/*" {
  capabilities = ["read", "list"]
}
EOF

• Open the Create ACL Policy page:

  1. Open the GUI for your Vault instance.

  2. Login under the namespace for the policy or select the namespace from the selector at the bottom of the left-hand menu and re-authenticate.

  3. Select Policies from the left-hand menu.

  4. Select ACL Policies from the left-hand menu.

  5. Click Create ACL policy + on the ACL Policies page.

• Set the policy details and click Create policy:

  • Name: "ro-saml-adfs"
  • Policy:

    # Read and list policy for the AD FS KV mount
    path "<ADFS_KV_PLUGIN_PATH>/*" {
      capabilities = ["read", "list"]
    }
    

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1. Create an external group in Vault and save the group ID to a file named group_id.txt:

   $ vault write                            \
     -format=json                           \
     identity/group name="SamlVaultReader"  \
     policies="ro-adfs-test"                \
     type="external" | jq -r ".data.id" > group_id.txt
   

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2. Retrieve the mount accessor for the AD FS authentication method and save it to a file named accessor_adfs.txt:

   $ vault auth list -format=json |               \
     jq -r '.["<SAML_PLUGIN_PATH>/"].accessor' >  \
     accessor_adfs.txt
   

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3. Create a group alias:

   $ vault write identity/group-alias         \
     name="<YOUR_EXISTING_AD_GROUP>"          \
     mount_accessor=$(cat accessor_adfs.txt)  \
     canonical_id="$(cat group_id.txt)"
   

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• Open the Create Group page:

  1. Open the GUI for your Vault instance.

  2. Login under the namespace for the group or select the namespace from the selector at the bottom of the left-hand menu and re-authenticate.

  3. Select Access from the left-hand menu.

  4. Select Groups from the left-hand menu.

  5. Click Create group + on the Groups page.

• Follow the prompts to create an external group with the following information:

  • Name: your new Vault group name
  • Type: external
  • Policies: the read-only AD FS policy you created. For example, ro-adfs-test.

• Click Add alias and follow the prompts to map the Vault group name to an existing group in Active Directory:

  • Name: the name of an existing AD group (must match exactly).
  • Auth Backend: <SAML_PLUGIN_PATH>/ (saml)