Knowledge

ERROR_SECRET_TOO_LONG - 1382 (0x566)

The length of a secret exceeds the maximum length allowed.

Updated: Feb 21, 2026

Technical Background

The ERROR_SECRET_TOO_LONG error code indicates that a secret, such as a password or token, has exceeded the maximum allowable length. This error is typically encountered when attempting to set or validate a secret value in certain Windows API functions.

Error Details

  • Error Name: ERROR_SECRET_TOO_LONG
  • Numeric Code: 1382 (0x566)
  • Short Description: The length of a secret exceeds the maximum allowed length.

This error is specific to operations involving secrets and is indicative of an input parameter that has exceeded its defined limit. It can occur in various contexts, such as setting passwords or tokens within security-related functions.

Common Causes

  1. Invalid Parameter Values: The provided secret value exceeds the maximum allowed length for the operation being performed.
  2. Incorrect Object Type: The function expecting a specific type of object (e.g., password) was passed an object that is not compatible with the expected input.
  3. Exceeding Limits: The system has predefined limits on the length of secrets, and these limits have been exceeded by the provided value.

Real-World Context

This error can be encountered in scenarios where security-sensitive data needs to be validated or set. For example, when setting a password for a user account or token for authentication purposes, if the secret is too long, this error will be returned.

Is This Error Critical?

The criticality of this error depends on the context in which it occurs. In most cases, it indicates an input validation issue and does not necessarily imply a severe system failure. However, it should be addressed to ensure data integrity and security.

How to Diagnose

  1. Review Operation Context: Ensure that the operation being performed is appropriate for the context in which it is used.
  2. Validate Parameters: Check the length of the secret value provided as input. Ensure it does not exceed the maximum allowed length defined by the function or system.
  3. Confirm Object Types: Verify that the type of object (e.g., password, token) being passed to the function matches the expected input type.
  4. Verify Input Data: Confirm that all other parameters are valid and within their acceptable ranges.

How to Resolve

  1. Correct Parameter Usage: Ensure that the secret value provided is within the maximum allowed length for the operation.
  2. Adjust Operation Context: If necessary, adjust the context in which the operation is being performed to ensure it aligns with system expectations.
  3. Restore Data: If data corruption or incorrect input is suspected, restore the correct values and retry the operation.
  4. Retry Operation with Valid Inputs: After addressing any issues identified during diagnosis, attempt to perform the operation again using valid inputs.

Developer Notes

When working with secrets in Windows API functions, it is crucial to ensure that all input parameters are within their defined limits. Developers should consult the relevant documentation for specific function definitions and constraints to avoid encountering this error.

Related Errors

  • ERROR_INVALID_PARAMETER: Indicates an invalid parameter value was passed to a function.
  • ERROR_INSUFFICIENT_BUFFER: Occurs when a buffer is too small to hold the data being returned or processed by a function.
  • ERROR_BAD_LENGTH: Indicates that a length specified in a structure does not match the expected value.

FAQ

Q: What causes ERROR_SECRET_TOO_LONG?

A: This error occurs when a secret, such as a password or token, exceeds the maximum allowable length for an operation.

Q: How can I prevent this error?

A: Ensure that all input parameters are within their defined limits and match the expected data types. Consult the relevant documentation for specific constraints.

Summary

The ERROR_SECRET_TOO_LONG error code is a specific parameter depth error indicating that a secret value has exceeded its maximum allowable length. It is important to validate input parameters and ensure they meet the required constraints to avoid this error and maintain system integrity and security.