# age-seed-keygen

An age identity generator with a BIP39 recovery phrase. Every key comes with 24 words you can write down — lose the file, say the words, get it back.

## The idea

age X25519 identity keys are 32 random bytes. BIP39 is a standard for encoding random bytes as human-readable words (the same standard hardware wallets use). This tool generates 256 bits of entropy, turns it into both an age identity and a 24-word mnemonic, and gives you both. Recovery is the reverse — give back the 24 words, get back the exact same identity.

If you already use `ssh-seed-keygen`, you can back up both an SSH key and an age identity from a single mnemonic — or keep them separate. Either way, one piece of paper is all you need.

## Getting started

```bash
bash setup.sh
```

Creates a virtualenv and installs the three dependencies.

## Generating an identity

```bash
.venv/bin/python keygen.py generate
```

Writes the identity file to `~/.config/age/key.txt` by default, then prints your 24 words. Write them down somewhere offline.

```bash
# different output path
.venv/bin/python keygen.py generate -o ~/my-age-key.txt
```

## Recovering an identity

```bash
# pass the words directly
.venv/bin/python keygen.py recover word1 word2 ... word24

# or run it and paste when prompted
.venv/bin/python keygen.py recover
```

Same `-o` flag applies if you want the recovered file somewhere other than the default path.

## Using the identity

The output file is a standard age identity file — it works directly with the `age` CLI:

```bash
# encrypt a file
age -r age1<your-public-key> secret.txt > secret.txt.age

# decrypt using the identity file
age --decrypt -i ~/.config/age/key.txt secret.txt.age > secret.txt
```

## Protecting the identity file

The identity file is written with mode `0600`. If you want to encrypt it at rest, use age itself:

```bash
age --passphrase -o key.txt.age ~/.config/age/key.txt
rm ~/.config/age/key.txt
```

Decrypt before use:

```bash
age --decrypt key.txt.age > ~/.config/age/key.txt
```

## One thing to keep in mind

The mnemonic encodes the private key directly. Anyone with those 24 words has your identity. Treat them at least as carefully as the key file itself.