rezn-jcsd

rezn-jcsd is a fast, dependency-free UNIX socket daemon for canonicalizing JSON according to RFC 8785 (JCS).

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Why?

https://discuss.ocaml.org/t/canonical-json-with-yojson-for-signature-verification/16725/16

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Features

• Canonicalizes JSON via UNIX socket or CLI
• Vendored Go implementation (Apache 2.0)
• C++ implementation based on the Go implementation - suitable for FFI
• Suitable for cryptographic signing pipelines
• Minimal, auditable, production-ready

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Usage

Socket mode (default)

Launch the service (creating socket file in /tmp for quick testing)

REZN_JCSD_SOCKET=/tmp/jcsd.sock ./jcsd

Hit it with some JSON

echo '{"op":"canon","source":"{ \"b\":2, \"a\":1 }"}' | socat - UNIX-CONNECT:/tmp/jcsd.sock

Returns:

{"result":"{\"a\":1,\"b\":2}"}

CLI mode

cat input.json | reznjcs-cli > canonical.json

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Environment

• REZN_JCSD_SOCKET: override default socket path (/run/rezn-jcsd/jcs.sock)

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Building

go build -o reznjcs-cli ./cmd/cli
go build -o jcsd ./cmd/jcsd

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C++ implementation

See the corresponding readme

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License

• rezn-jcsd is licensed under MIT

• Canonicalization logic is vendored from Anders Rundgren's json-canonicalization library, originally published under the Apache License 2.0

  • See internal/jcs/README.md