torq studioDevTools
Tools durchsuchen▼

Loading…

Guide

How to use this tool, examples, and related tips.

How to Use the HMAC-SHA1 Generator

Enter your message in the message field.

Enter your secret key.

The HMAC-SHA1 tag is computed instantly and displayed as a 40-character hexadecimal string.

Copy the output for use in your legacy system or verification workflow.

What Is HMAC-SHA1?

HMAC-SHA1 is the HMAC construction applied using SHA-1 as the underlying hash function. It produces a 160-bit (40-character hex) authentication tag. While SHA-1 is deprecated as a standalone hash function for security use due to demonstrated collision attacks, HMAC-SHA1 retains reasonable security for message authentication — an attacker needs to forge a MAC under the HMAC construction, which is a harder problem than finding a SHA-1 collision. HMAC-SHA1 is nonetheless deprecated for new systems and should be replaced with HMAC-SHA256 where possible. It persists in legacy protocols including OAuth 1.0a, some SSH implementations, and older API signing schemes.

When to Use This Tool

OAuth 1.0a signing — OAuth 1.0a uses HMAC-SHA1 as its default signature method. Use this tool to generate or verify OAuth 1.0a request signatures manually.

Legacy API compatibility — Some older APIs and SDKs still use HMAC-SHA1 as their request signing algorithm.

Debugging signature mismatches — Reproduce HMAC-SHA1 values step by step to isolate encoding, key, or algorithm issues in a signing pipeline.

Migration verification — Verify HMAC-SHA1 values from a legacy system before migrating to HMAC-SHA256.

Related Tools

  • HMAC-SHA256 generator
  • HMAC generator
  • SHA-1 hash generator
  • HMAC-SHA512 generator
  • JWT decoder

FAQ

Answers about this tool and how your data is handled.

Is HMAC-SHA1 secure?

HMAC-SHA1 is not recommended for new systems. It is more resistant to attack than raw SHA-1, but it is deprecated in favor of HMAC-SHA256. Use it only when legacy compatibility requires it — such as OAuth 1.0a.

Is HMAC-SHA1 affected by the SHA-1 collision attacks?

The HMAC construction provides some protection against SHA-1's collision weakness because forging an HMAC requires knowledge of the secret key. However, the underlying algorithm is still deprecated, and HMAC-SHA256 is a straightforward upgrade.

Does this tool send my data to a server?

No. HMAC computation runs entirely in your browser. Your message and key never leave your machine.

What is the output length of HMAC-SHA1?

Always 40 hexadecimal characters, representing 160 bits — matching SHA-1's output length.

Where is HMAC-SHA1 still commonly used?

OAuth 1.0a request signing, some Git hosting webhook signatures, legacy AWS API signing (now replaced by AWS Signature Version 4 using HMAC-SHA256), and older SSH protocol implementations.

Verwandte Tools

Zuerst dieselbe Kategorie, dann andere Utilities.