Altcha Server

Altcha server for generating challenges and validating solutions.

Usage

Run the server

From the binary:

$ ALTCHA_HMAC_KEY="HMAC_KEY" bin/altcha run

From the Docker image:

$ docker run -e ALTCHA_HMAC_KEY="HMAC_KEY" -p 3333:3333 ghcr.io/scottbass3/altcha-server:latest

From source:

$ ALTCHA_HMAC_KEY="HMAC_KEY" go run ./cmd/altcha run

Once the server is running, visit http://localhost:3333/request to request a challenge. Post the solution to http://localhost:3333/verify.

Altcha documentation: https://altcha.org/fr/docs/get-started/

Other commands

Generate a challenge:

$ ALTCHA_HMAC_KEY="HMAC_KEY" bin/altcha generate

Solve a challenge:

$ ALTCHA_HMAC_KEY="HMAC_KEY" bin/altcha solve [CHALLENGE] [SALT]

Verify a solution:

$ ALTCHA_HMAC_KEY="HMAC_KEY" bin/altcha verify [CHALLENGE] [SALT] [SIGNATURE] [SOLUTION]

Environment variables

Name	Description	Default	Required
ALTCHA_BASE_URL	Base URL prefix for endpoints		No
ALTCHA_PORT	Server listen port	3333	No
ALTCHA_HMAC_KEY	HMAC key used to sign challenges		Yes
ALTCHA_MAX_NUMBER	Max iterations for solving a challenge (difficulty)	1000000	No
ALTCHA_ALGORITHM	Hash algorithm (SHA-1, SHA-256, SHA-512)	SHA-256	No
ALTCHA_SALT	Force a fixed salt for challenges		No
ALTCHA_EXPIRE	Challenge expiration (seconds)	600	No
ALTCHA_CHECK_EXPIRE	Whether to check challenge expiration	1	No

Build the binary

$ make build

Build the Docker image

$ make build-image

Publish the Docker image

$ make release-image