About Derive HKDF key
A simple Hashed Message Authenticaton Code (HMAC)-based key derivation function (HKDF), defined in RFC5869.
Input: binary bytes (text input uses UTF-8; a file retains its original bytes). Output: text.
Format reference: Derive HKDF key background and specification
Example
Use “Try example” to load this public sample and its settings, then run it.
Settings used in this example
| Parameter | Example value | Input and choices |
|---|---|---|
| Salt | {"option":"Hex","string":"000102030405060708090a0b0c"} | Key/text encoding: Hex, Decimal, Base64, UTF8, Latin1 |
| Info | {"option":"Hex","string":"f0f1f2f3f4f5f6f7f8f9"} | Key/text encoding: Hex, Decimal, Base64, UTF8, Latin1 |
| Hashing function | SHA256 | Text20 Available choices
|
| Extract mode | "with salt" | with salt, no salt, skip |
| L (number of output octets) | 42 | Minimum: 0 |
Result
3cb25f25faacd57a90434f64d0362f2a2d2d0a90cf1a5a4c5db02d56ecc4c5bf34007208d5b887185865
Parameters
| Parameter | Default value | Input and choices |
|---|---|---|
| Salt | {"option":"Hex","string":""} | Key/text encoding: Hex, Decimal, Base64, UTF8, Latin1 |
| Info | {"option":"Hex","string":""} | Key/text encoding: Hex, Decimal, Base64, UTF8, Latin1 |
| Hashing function | SHA256 | Text20 Available choices
|
| Extract mode | "with salt" | with salt, no salt, skip |
| L (number of output octets) | 16 | Minimum: 0 |
Before interpreting the result
Use the exact key encoding, mode, padding and IV expected by the source system. Historical ciphers are useful for learning and analysis. Encoding alone provides no confidentiality.
How to use this page
- Paste your input or open a local file.
- Adjust tool options if needed, then choose Run tool.
- Copy the result or download the original output bytes.
Inputs and results are not added to the public catalogue or saved in the URL. Processing happens in your browser; HTTP Request and DNS over HTTPS send the requests you explicitly run. Files up to 128 MiB can be opened; decompression and image tools may have smaller processing limits. Large results have a shortened preview. Text and HTML downloads use UTF-8; binary downloads preserve output bytes. Pasted text follows browser newline handling; open a file when exact input bytes matter.