Changes for several issues related to SFTP and LDAP (#1252)

- Adds info the docs about recent changes to LDAP and SFTP
authentication
- Adds new config/envvar parameter
- Adds new sftp option for server
- Adds new example for forcing ldap or sa auth to SFTP
- Adds new example for using certificate authority for auth to SFTP

Closes #1240
Closes #1229
Closes #1226
Closes #1208

source/reference/minio-mc-admin/mc-admin-group.rst

@@ -224,6 +224,8 @@ Syntax
       already exist. Use :mc-cmd:`mc admin group ls` to review the existing
       groups on a deployment.
 
+      A group name cannot contain the characters ``=`` (equal sign) or ``,`` (comma).
+
    .. mc-cmd:: MEMBERS
 
       The name of the user to add to the group.

source/reference/minio-mc/mc-idp-ldap-accesskey-create.rst

@@ -77,6 +77,7 @@ Parameters
    :optional:
 
    An access key to use for the account.
+   The access key cannot contain the characters ``=`` (equal sign) or ``,`` (comma).
 
    Requires :mc-cmd:`~mc idp ldap accesskey create --secret-key`
 

source/reference/minio-server/minio-server.rst

@@ -192,6 +192,11 @@ The command accepts the following arguments:
         - Path to the user's private key file.
         - Absolute path or relative path from current location to the key file to use.
  
+      * - ``trusted-user-ca-key``
+        - Specifies a file containing public key of a certificate authority that is trusted to sign user certificates for authentication.
+          The file must contain a `user principals list <https://man.openbsd.org/ssh-keygen#CERTIFICATES>`__, and the list must include the user(s) that can authenticate with the key. 
+        - Absolute path or relative path from current location to the user's trusted certificate authority public key file.
+
       * - ``pub-key-algos``
         - Comma-separated list of the public key algorithms to support.
         - 
@@ -253,6 +258,9 @@ The command accepts the following arguments:
              hmac-sha1
              hmac-sha1-96
 
+      * - ``disable-password-auth``
+        - Disable password authentication.
+        - ``true``
 
    For example:
 

source/reference/minio-server/settings/iam/ldap.rst

@@ -198,6 +198,28 @@ User DN Search Filter
    :start-after: start-minio-ad-ldap-user-dn-search-filter
    :end-before: end-minio-ad-ldap-user-dn-search-filter
          
+User DN Attributes
+~~~~~~~~~~~~~~~~~~
+
+*Optional*
+
+.. tab-set::
+
+   .. tab-item:: Environment Variable
+      :sync: envvar
+
+      .. envvar:: MINIO_IDENTITY_LDAP_USER_DN_ATTRIBUTES
+
+   .. tab-item:: Configuration Setting
+      :sync: config
+
+      .. mc-conf:: identity_ldap user_dn_attributes
+         :delimiter: " "
+
+.. include:: /includes/common-minio-external-auth.rst
+   :start-after: start-minio-ad-ldap-user-dn-attributes
+   :end-before: end-minio-ad-ldap-user-dn-attributes
+
 Enabled
 ~~~~~~~