Amazon Cloud Directory Authentication

Amazon Cloud Directory is a highly available multi-tenant directory-based store in AWS. These directories scale automatically to hundreds of millions of objects as needed for applications. This lets operation’s staff focus on developing and deploying applications that drive the business, not managing directory infrastructure.

To learn more, please see this guide.

Configuration

Support is enabled by including the following dependency in the WAR overlay:

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<dependency>
    <groupId>org.apereo.cas</groupId>
    <artifactId>cas-server-support-cloud-directory-authentication</artifactId>
    <version>${cas.version}</version>
</dependency>
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implementation "org.apereo.cas:cas-server-support-cloud-directory-authentication:${project.'cas.version'}"
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dependencyManagement {
    imports {
        mavenBom "org.apereo.cas:cas-server-support-bom:${project.'cas.version'}"
    }
}

dependencies {
    implementation "org.apereo.cas:cas-server-support-cloud-directory-authentication"
}
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dependencies {
    /*
        The following platform references are included automatically and are listed for reference only.

        implementation enforcedPlatform("org.apereo.cas:cas-server-support-bom:${project.'cas.version'}")
        implementation platform(org.springframework.boot.gradle.plugin.SpringBootPlugin.BOM_COORDINATES)
        
    */
    implementation "org.apereo.cas:cas-server-support-cloud-directory-authentication"
}

The following settings and properties are available from the CAS configuration catalog:

cas.authn.cloud-directory.credential-access-keyUse access-key provided by AWS to authenticate.
no default
RequiredSpEL

Use access-key provided by AWS to authenticate.

Type
String
Default
none
Defined by
AmazonCloudDirectoryProperties
Supports
Spring Expression Language
cas.authn.cloud-directory.credential-secret-keyUse secret key provided by AWS to authenticate.
no default
RequiredSpEL

Use secret key provided by AWS to authenticate.

Type
String
Default
none
Defined by
AmazonCloudDirectoryProperties
Supports
Spring Expression Language
cas.authn.cloud-directory.directory-arnDirectory ARN.
no default
Required

Directory ARN.

Type
String
Default
none
Defined by
AmazonCloudDirectoryProperties
cas.authn.cloud-directory.endpointAWS custom endpoint.
no default
Required

AWS custom endpoint.

Type
String
Default
none
Defined by
AmazonCloudDirectoryProperties
cas.authn.cloud-directory.password-attribute-namePassword attribute to choose on the entry to compare.
no default
Required

Password attribute to choose on the entry to compare.

Type
String
Default
none
Defined by
AmazonCloudDirectoryProperties
cas.authn.cloud-directory.password-encoder.encoding-algorithmThe encoding algorithm to use such as MD5 .
no default
Required

The encoding algorithm to use such as MD5. Relevant when the type used is DEFAULT or GLIBC_CRYPT. When used with PasswordEncoderTypes#PBKDF2, it should be one of PBKDF2WithHmacSHA1, PBKDF2WithHmacSHA256 or PBKDF2WithHmacSHA512.

Type
String
Default
none
Defined by
PasswordEncoderProperties
cas.authn.cloud-directory.password-encoder.typeDefine the password encoder type to use.
NONE
Required

Define the password encoder type to use. Type may be specified as blank or NONE to disable password encoding. It may also refer to a fully-qualified class name that implements the Spring Security's PasswordEncoder interface if you wish you define your own encoder.

The following types may be used:
  • NONE: No password encoding (i.e. plain-text) takes place.
  • DEFAULT: Use the DefaultPasswordEncoder of CAS. For message-digest algorithms via character-encoding and encoding-algorithm.
  • BCRYPT: Use the BCryptPasswordEncoder based on the strength provided and an optional secret.
  • SCRYPT: Use the SCryptPasswordEncoder.
  • PBKDF2: Use the Pbkdf2PasswordEncoder based on the strength provided and an optional secret.
  • STANDARD: Use the StandardPasswordEncoder based on the secret provided.
  • SSHA: Use the LdapShaPasswordEncoder supports Ldap SHA and SSHA (salted-SHA). The values are base-64 encoded and have the label {SHA} or {SSHA} prepended to the encoded hash.
  • GLIBC_CRYPT: Use the GlibcCryptPasswordEncoder based on the encoding-algorithm, strength provided and an optional secret.
  • org.example.MyEncoder: An implementation of PasswordEncoder of your own choosing.
  • file:///path/to/script.groovy: Path to a Groovy script charged with handling password encoding operations.
Type
String
Default
NONE
Defined by
PasswordEncoderProperties
cas.authn.cloud-directory.principal-transformation.groovy.locationThe location of the resource.
no default
Required

The location of the resource. Resources can be URLs, or files found either on the classpath or outside somewhere in the file system.

In the event the configured resource is a Groovy script, especially if the script is set to reload on changes, you may need to adjust the total number of inotify instances. On Linux, you may need to add the following line to /etc/sysctl.conf: fs.inotify.max_user_instances = 256.

You can check the current value via cat /proc/sys/fs/inotify/max_user_instances.

In situations and scenarios where CAS is able to automatically watch the underlying resource for changes and detect updates and modifications dynamically, you may be able to specify the following setting as either an environment variable or system property with a value of false to disable the resource watcher: org.apereo.cas.util.io.PathWatcherService.

Type
Resource
Default
none
Defined by
GroovyPrincipalTransformationProperties
cas.authn.cloud-directory.regionAWS region used.
no default
Required

AWS region used.

Type
String
Default
none
Defined by
AmazonCloudDirectoryProperties
cas.authn.cloud-directory.schema-arnSchema ARN.
no default
Required

Schema ARN.

Type
String
Default
none
Defined by
AmazonCloudDirectoryProperties
cas.authn.cloud-directory.username-attribute-nameUsername attribute to choose when locating accounts.
no default
Required

Username attribute to choose when locating accounts.

Type
String
Default
none
Defined by
AmazonCloudDirectoryProperties
cas.authn.cloud-directory.client-execution-timeoutClient execution timeout.
PT10S
Duration

Client execution timeout.

Type
String
Default
PT10S
Defined by
AmazonCloudDirectoryProperties
cas.authn.cloud-directory.connection-timeoutConnection timeout.
PT5S
Duration

Connection timeout.

Type
String
Default
PT5S
Defined by
AmazonCloudDirectoryProperties
cas.authn.cloud-directory.facet-nameFacet name.
no default

Facet name.

Type
String
Default
none
Defined by
AmazonCloudDirectoryProperties
cas.authn.cloud-directory.local-addressLocal address.
no default

Local address.

Type
String
Default
none
Defined by
AmazonCloudDirectoryProperties
cas.authn.cloud-directory.max-connectionsMaximum connections setting.
10

Maximum connections setting.

Type
Integer
Default
10
Defined by
AmazonCloudDirectoryProperties
cas.authn.cloud-directory.nameThe name of the authentication handler.
no default

The name of the authentication handler.

Type
String
Default
none
Defined by
AmazonCloudDirectoryProperties
cas.authn.cloud-directory.orderThe order of this authentication handler in the chain.
no default

The order of this authentication handler in the chain.

Type
Integer
Default
none
Defined by
AmazonCloudDirectoryProperties
cas.authn.cloud-directory.password-encoder.character-encodingThe encoding algorithm to use such as 'UTF-8'.
UTF-8

The encoding algorithm to use such as 'UTF-8'. Relevant when the type used is DEFAULT.

Type
String
Default
UTF-8
Defined by
PasswordEncoderProperties
cas.authn.cloud-directory.password-encoder.hash-lengthWhen used by PasswordEncoderTypes#ARGON2 , it indicates the hash strength/length.
16

When used by PasswordEncoderTypes#ARGON2, it indicates the hash strength/length.

Type
Integer
Default
16
Defined by
PasswordEncoderProperties
cas.authn.cloud-directory.password-encoder.iterationsWhen used by PasswordEncoderTypes#PBKDF2 , it indicates the required number of iterations.
310000

When used by PasswordEncoderTypes#PBKDF2, it indicates the required number of iterations.

Type
Integer
Default
310000
Defined by
PasswordEncoderProperties
cas.authn.cloud-directory.password-encoder.secretSecret to use with PasswordEncoderTypes#STANDARD , PasswordEncoderTypes#PBKDF2 , PasswordEncoderTypes#BCRYPT , PasswordEncoderTypes#GLIBC_CRYPT password encoders.
no default

Secret to use with PasswordEncoderTypes#STANDARD, PasswordEncoderTypes#PBKDF2, PasswordEncoderTypes#BCRYPT, PasswordEncoderTypes#GLIBC_CRYPT password encoders. Secret usually is an optional setting.

Type
String
Default
none
Defined by
PasswordEncoderProperties
cas.authn.cloud-directory.password-encoder.strengthStrength or number of iterations to use for password hashing.
16

Strength or number of iterations to use for password hashing. Usually relevant when dealing with PasswordEncoderTypes#BCRYPT, PasswordEncoderTypes#PBKDF2 or PasswordEncoderTypes#GLIBC_CRYPT. When used by PasswordEncoderTypes#ARGON2 or PasswordEncoderTypes#PBKDF2, it indicates the salt strength.

Type
Integer
Default
16
Defined by
PasswordEncoderProperties
cas.authn.cloud-directory.principal-transformation.blocking-patternA regular expression that will be used against the username to match for blocking/forbidden values.
no default
SpEL

A regular expression that will be used against the username to match for blocking/forbidden values. If a match is found, an exception will be thrown and principal transformation will fail.

Type
String
Default
none
Defined by
PrincipalTransformationProperties
Supports
Spring Expression Language
cas.authn.cloud-directory.principal-transformation.case-conversionIndicate whether the principal identifier should be transformed into upper-case, lower-case, etc.
NONE
Indicate whether the principal identifier should be transformed into upper-case, lower-case, etc. Available values are as follows:
  • NONE: No conversion.
  • LOWERCASE: Lowercase conversion.
  • UPPERCASE: Uppercase conversion.
Type
PrincipalTransformationProperties.CaseConversion
Default
NONE
Defined by
PrincipalTransformationProperties
cas.authn.cloud-directory.principal-transformation.patternA regular expression that will be used against the provided username for username extractions.
no default
SpEL

A regular expression that will be used against the provided username for username extractions. On a successful match, the first matched group in the pattern will be used as the extracted username.

Type
String
Default
none
Defined by
PrincipalTransformationProperties
Supports
Spring Expression Language
cas.authn.cloud-directory.principal-transformation.prefixPrefix to add to the principal id prior to authentication.
no default
SpEL

Prefix to add to the principal id prior to authentication.

Type
String
Default
none
Defined by
PrincipalTransformationProperties
Supports
Spring Expression Language
cas.authn.cloud-directory.principal-transformation.suffixSuffix to add to the principal id prior to authentication.
no default
SpEL

Suffix to add to the principal id prior to authentication.

Type
String
Default
none
Defined by
PrincipalTransformationProperties
Supports
Spring Expression Language
cas.authn.cloud-directory.profile-nameProfile name to use.
no default

Profile name to use.

Type
String
Default
none
Defined by
AmazonCloudDirectoryProperties
cas.authn.cloud-directory.profile-pathProfile path.
no default

Profile path.

Type
String
Default
none
Defined by
AmazonCloudDirectoryProperties
cas.authn.cloud-directory.proxy-hostOptionally specifies the proxy host to connect through.
no default

Optionally specifies the proxy host to connect through.

Type
String
Default
none
Defined by
AmazonCloudDirectoryProperties
cas.authn.cloud-directory.proxy-passwordOptionally specifies the proxy password to connect through.
no default

Optionally specifies the proxy password to connect through.

Type
String
Default
none
Defined by
AmazonCloudDirectoryProperties
cas.authn.cloud-directory.proxy-usernameOptionally specifies the proxy username to connect through.
no default

Optionally specifies the proxy username to connect through.

Type
String
Default
none
Defined by
AmazonCloudDirectoryProperties
cas.authn.cloud-directory.retry-modeOutline the requested retry mode.
STANDARD

Outline the requested retry mode. Accepted values are STANDARD, LEGACY.

Type
String
Default
STANDARD
Defined by
AmazonCloudDirectoryProperties
cas.authn.cloud-directory.socket-timeoutSocket timeout.
PT5S
Duration

Socket timeout.

Type
String
Default
PT5S
Defined by
AmazonCloudDirectoryProperties
cas.authn.cloud-directory.use-reaperFlag that indicates whether to use reaper.
false

Flag that indicates whether to use reaper.

Type
Boolean
Default
false
Defined by
AmazonCloudDirectoryProperties
cas.authn.cloud-directory.username-index-pathUsername index path.
no default

Username index path.

Type
String
Default
none
Defined by
AmazonCloudDirectoryProperties

Required settings may be needed to activate or affect the feature; review them even when they have a default. Optional settings only need to be set to change a default or to turn on the behavior they control. Third party settings belong to libraries such as Spring Boot that CAS builds on; their own documentation may have more detail.

Groovy scripting

CAS takes advantage of Apache Groovy in forms of either embedded or external scripts that allow one to, by default, dynamically build constructs, attributes, access strategies and a lot more. To activate the functionality described here, you may need to prepare CAS to support and integrate with Apache Groovy.

Please review this guide to configure your build.

Password encoding

If you need to design your own password encoding scheme where the type is specified as a fully qualified Java class name, the structure of the class would be similar to the following:

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package org.example.cas;

import org.springframework.security.crypto.codec.*;
import org.springframework.security.crypto.password.*;

public class MyEncoder extends AbstractPasswordEncoder {
    @Override
    protected byte[] encode(CharSequence rawPassword, byte[] salt) {
        return ...
    }
}

If you need to design your own password encoding scheme where the type is specified as a path to a Groovy script, the structure of the script would be similar to the following:

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import java.util.*

byte[] run(final Object... args) {
    def (rawPassword,generatedSalt,logger,applicationContext) = args
    logger.debug("Encoding password...")
    return ...
}

Boolean matches(final Object... args) {
    def (rawPassword,encodedPassword,logger,applicationContext) = args
    logger.debug("Does match or not ?");
    return ...

To prepare CAS to support and integrate with Apache Groovy, please review this guide.

Principal transformation

Authentication handlers that generally deal with username-password credentials can be configured to transform the user id prior to executing the authentication sequence. Each authentication strategy in CAS provides settings to properly transform the principal. Refer to the relevant settings for the authentication strategy at hand to learn more.

Authentication handlers as part of principal transformation may also be provided a path to a Groovy script to transform the provided username. The outline of the script may take on the following form:

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String run(final Object... args) {
    def (providedUsername,logger) = args
    return providedUsername.concat("SomethingElse")
}

To prepare CAS to support and integrate with Apache Groovy, please review this guide.

Notes on configuration

Configuration Metadata

The collection of configuration properties listed in this section are automatically generated from the CAS source and components that contain the actual field definitions, types, descriptions, modules, etc. This metadata may not always be 100% accurate, or could be lacking details and sufficient explanations.

Be Selective

This section is meant as a guide only. Do NOT copy/paste the entire collection of settings into your CAS configuration; rather pick only the properties that you need. Do NOT enable settings unless you are certain of their purpose and do NOT copy settings into your configuration only to keep them as reference. All these ideas lead to upgrade headaches, maintenance nightmares and premature aging.

YAGNI

Note that for nearly ALL use cases, declaring and configuring properties listed here is sufficient. You should NOT have to explicitly massage a CAS XML/Java/etc configuration file to design an authentication handler, create attribute release policies, etc. CAS at runtime will auto-configure all required changes for you. If you are unsure about the meaning of a given CAS setting, do NOT turn it on without hesitation. Review the codebase or better yet, ask questions to clarify the intended behavior.

Naming Convention

Property names can be specified in very relaxed terms. For instance cas.someProperty, cas.some-property, cas.some_property are all valid names. While all forms are accepted by CAS, there are certain components (in CAS and other frameworks used) whose activation at runtime is conditional on a property value, where this property is required to have been specified in CAS configuration using kebab case. This is both true for properties that are owned by CAS as well as those that might be presented to the system via an external library or framework such as Spring Boot, etc.

:information_source: Note

When possible, properties should be stored in lower-case kebab format, such as cas.property-name=value. The only possible exception to this rule is when naming actuator endpoints; The name of the actuator endpoints (i.e. ssoSessions) MUST remain in camelCase mode.

Settings and properties that are controlled by the CAS platform directly always begin with the prefix cas. All other settings are controlled and provided to CAS via other underlying frameworks and may have their own schemas and syntax. BE CAREFUL with the distinction. Unrecognized properties are rejected by CAS and/or frameworks upon which CAS depends. This means if you somehow misspell a property definition or fail to adhere to the dot-notation syntax and such, your setting is entirely refused by CAS and likely the feature it controls will never be activated in the way you intend.

Validation

Configuration properties are automatically validated on CAS startup to report issues with configuration binding, especially if defined CAS settings cannot be recognized or validated by the configuration schema. Additional validation processes are also handled via Configuration Metadata and property migrations applied automatically on startup by Spring Boot and family.

Indexed Settings

CAS settings able to accept multiple values are typically documented with an index, such as cas.some.setting[0]=value. The index [0] is meant to be incremented by the adopter to allow for distinct multiple configuration blocks.

AWS credentials are fetched from the following sources automatically, where relevant and made possible via CAS configuration:

  1. EC2 instance metadata linked to the IAM role.
  2. External properties file that contains accessKey and secretKey as property keys.
  3. AWS profile path and profile name.
  4. System properties that include aws.accessKeyId, aws.secretKey and aws.sessionToken
  5. Environment variables that include AWS_ACCESS_KEY_ID, AWS_SECRET_KEY and AWS_SESSION_TOKEN.
  6. Properties file on the classpath as awscredentials.properties that contains accessKey and secretKey as property keys.
  7. Static credentials for access key and secret provided directly by the configuration at hand (logging, etc).

Troubleshooting

To enable additional logging, configure the log4j configuration file to add the following levels:

```xml …

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