Okta Invalid URL Error Occurs When Adding an ACS URL Containing an Underscore
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Overview
Adding an Assertion Consumer Service (ACS) URL containing an underscore in the domain to a custom Security Assertion Markup Language (SAML) integration causes Okta to reject the domain name and generate an error. Okta rejects underscores in domain names because they violate RFC 952 and RFC 1123 hostname specifications. Replacing the underscore with a hyphen satisfies the Okta validation logic and resolves the error. Attempting to save the integration with an underscore in the domain results in the following error:
Is not a valid URL. Valid example http://www.okta.com
Applies To
- Okta Identity Engine (OIE)
- Okta Classic Engine
- Okta Integration Network (OIN)
- Security Assertion Markup Language (SAML)
- Custom SAML Integrations
Cause
According to RFC 952, a domain name is a text string up to 24 characters drawn from the alphabet (A-Z), digits (0-9), minus sign (-), and period (.). No blank or space characters are permitted as part of a name. RFC 1123 expands this to allow the first character to be either a letter or a digit and increases the maximum length. Okta internal URL validation logic rejects underscores in domain names to comply with these specifications.
Solution
What steps resolve the invalid URL error?
Resolve the invalid URL error by replacing the underscore character with a hyphen in the domain name and saving the integration.
- Replace the underscore character with a hyphen in the ACS URL domain name.
- Select Save to apply the changes to the custom SAML integration in Okta.
NOTE: The connected application or platform must allow the interchangeability of underscores to hyphens in the domain name.
