JSON Canonicalization

Cryptographic operations like hashing and signing depend on that the target data does not change during serialization, transport, or parsing. By applying the rules defined by JCS (JSON Canonicalization Scheme), data provided in the JSON [RFC8259] format can be exchanged "as is", while still being subject to secure cryptographic operations. JCS achieves this by building on the serialization formats for JSON primitives as defined by ECMAScript [ES6], constraining JSON data to the
I-JSON [RFC7493] subset, and through a platform independent property sorting scheme.

Working document: https://cyberphone.github.io/ietf-json-canon
Published IETF Draft: https://tools.ietf.org/html/draft-rundgren-json-canonicalization-scheme-05

The JSON Canonicalization Scheme concept in a nutshell:

Serialization of primitive JSON data types using methods compatible with ECMAScript's JSON.stringify()
Lexicographic sorting of JSON Object properties in a recursive process
JSON Array data is also subject to canonicalization, but element order remains untouched

Sample Input:

{
  "numbers": [333333333.33333329, 1E30, 4.50, 2e-3, 0.000000000000000000000000001],
  "string": "\u20ac$\u000F\u000aA'\u0042\u0022\u005c\\\"\/",
  "literals": [null, true, false]
}

Expected Output:

{"literals":[null,true,false],"numbers":[333333333.3333333,1e+30,4.5,0.002,1e-27],"string":"€$\u000f\nA'B\"\\\\\"/"}

Note: for platform interoperable canonicalization, the output must be converted to UTF-8 as well, here shown in hexadecimal notation:

7b 22 6c 69 74 65 72 61 6c 73 22 3a 5b 6e 75 6c 6c 2c 74 72 75 65 2c 66 61 6c 73 65 5d 2c 22 6e
75 6d 62 65 72 73 22 3a 5b 33 33 33 33 33 33 33 33 33 2e 33 33 33 33 33 33 33 2c 31 65 2b 33 30
2c 34 2e 35 2c 30 2e 30 30 32 2c 31 65 2d 32 37 5d 2c 22 73 74 72 69 6e 67 22 3a 22 e2 82 ac 24
5c 75 30 30 30 66 5c 6e 41 27 42 5c 22 5c 5c 5c 5c 5c 22 2f 22 7d

rpiazza / json-canonicalization

JSON Canonicalization

Sample Input:

Expected Output:

Combining JCS and JWS (RFC7515)

On-line Browser JCS Test

ECMAScript Proposal: JSON.canonify()

Other Canonicalization Efforts

About

Languages