Node incompatibility for "sha256" algorithm

[zenshixd]

Hello,

there seems to be some differences between this library and Node.js, consider following code:

const bCrypto = require('./browser');
const nCrypto = require('crypto');

const key = `-----BEGIN RSA PRIVATE KEY-----
MIIEowIBAAKCAQEAvvjcmEFSc9CYHZ8gN5phm9xBDxEXbM/8K62Rw5TpAENI3RZr
7Ua570EL3GEJBFM5IfWjn4zlEoXdLIM4Rj4mC9TQdxsmRYr9zGL8r9/jDTwwPTTk
ApGTZWJg5og2IrVaKByXnJHQGtHEkgNS0ay3JnL8TEOUr75WujU8YRPoBCnSnFtN
vhGRgrp+4QOROtP5pW85FmQKTkYK1s0bdlJM4YCDyicFPuqo8d2+pn8uXHcmHq7C
2QJwVEOSESpSEKwwVpZ2jQws7QRb5+ELaRdH2QQQ239FZRhVrEMsNf3AOSXcNULl
W+Mp6rbwY9+xM84g5pKgGJ80i3LDqsPvdvMAcwIDAQABAoIBAB8JvHSkfT2kg+yg
jbBrz3xw9kP4H6oIPbBto9i5TYtE5EVGnSDx00tu83oMbVY+HnWGAmNul1aE2jcf
VpiYBj/7BSyuhXBdEDXVSsNc7H6cryxreblvJpkePaiKL95BQldtmjiQvFV3jW67
yoyYeSXvH1FX1IUhtt/Jwjf278kpKIhfTmshlRaSUavjZWYv4kj7qOURUTkXuZrF
yfy3jyid1lRmLzOOGsNs9EMjNMdbThLYOmhrkrMr4dM7jWby850MMTXMJxIcTlAJ
SlhPONvvJfS2D49dKVPBxMMh3DoBGsOcd6lZiy3VSRBrUHXFyI98pH7Y+2NHCjjw
SApfDI0CgYEA+raJ+kkLooZ+Sf+0chVCRlr/6XmEcvJk6VDMV2OP/2AJpWLOZLVY
R2fkC4qtnW4MTBM191l+qarPooWU2ZvAcVmP/A9341kTcawdg1NPB7GDsNEum8yL
9JVc8FU0cF4UU39U7JjoQ1rwcMhFVg8qVogyOZ/qvBY5ddJncEzFGl8CgYEAwv/Q
g40OrTxx2FHMpS7vh8rHU7qrsclhX2AdnNlvtlm/ejAB1lgaJHSUakVZtbCo2X0J
wD8dmpbibtPVYtyq/AXvRG0I9ufxh5na6F0T91ndagF+gEuDdT57OKXaBOJnKU1E
Z3GC5bYcWdtz4VX54opg1VRRWRM21zBf1oZ6+m0CgYAh85RN05SCxunVRY5/IIfg
FTSwvmcEVfT6b5msf+whLjVAM1g15ST2TohgU8BdIGkD6FoXjAQOH/aMUMCuk1wF
PZa1ELcwj4CFlURN43tBVHW7/Sftq06MqalzVmaKjQL9p7GtdKuHa4pCC6zwEY+v
NjRu/0v/epb/cKXXXF4YywKBgQCoSf66idJQ0Amwl2f2ZztyBh9gs4naNeJDXcAw
zbcLuQj3etcbFY36SGKOFKwHkh8nFDKGJ/J0qCNjYo6Wc7tdJgIJG9DQxfw8+xth
znKc1oGwKvnx3znkxbeye/BcpshBbN3MKLq/ZRuysSKhJoIycRqBAfPy3BJIRQdx
LT6VQQKBgBD/advmsuU2ElAbEkVdHqFt3yqP09oa2oBrnqc07hP8ztv/yUxUbm9Z
olkHrmkLrXwnaYVqKaUPhC6JdaXOFu8/Jv3kpbsxuBDXJ9+wOQAMbREQa6232YOn
VbDhsJpqb5CSqNlGEYidSrksQY9qgZM2LjvxGmAysDM/FZk25pZ7
-----END RSA PRIVATE KEY-----
`;

let p = Buffer.from(key, 'utf8');

let txt = "eyJhbGciOiJSUzI1NiIsInVybCI6Imh0dHBzOi8vYWNtZS1zdGFnaW5nLXYwMi5hcGkubGV0c2VuY3J5cHQub3JnL2FjbWUvbmV3LWFjY3QiLCJub25jZSI6InBuTDIzaDBpR0pPYm9PcWJpdmozOGtPdmdsZTJrbVZWaF9DTXcyeExZSWc4VkMzTzdTRSIsImp3ayI6eyJlIjoiQVFBQiIsImt0eSI6IlJTQSIsIm4iOiJ1VjlEUzB4bnNfOWtYbXZlQUp2VmwxV0M3emduTFlvdnNqcDY5UldQYTJ2UFVCUm1iS1lRWlZOZXQwOTdSaWxjUXNtaEhNMTVpdDA2QUdrQ2ZiNHNZcU1aWVd0QXh0a0N3U2pKUEN1OWN4WmdoU0dYWFFEM3dncm8wYl9vbmN2d1V1cjhaeG10U09pRmJQVElOZWUwUVlMWEg3ak12cVhKN3VzMTcxSU5jNDBhOXU1WDJoa3hGMVFBeWdOYmx2RVJxWHo2V2otNjR3TEhIMnBZNk9QaVFST2Rub0VlQ29DNEhXMjNqNlNDckZXTlNOei1DcUxTZWtYM0Z3TGZUMk55Z3l5N1pEeWFPZHhobFRPa0NxdUlJVGFHMF81Qjl1a1ZHRW9yQ0E5RmhYb20yRk50b1J3c0I3eUFtdkpDQ3B4Q1lUTmFuZ3VWYmVmU3luYS14VWR1ZHcifX0.eyJ0ZXJtc09mU2VydmljZUFncmVlZCI6dHJ1ZSwiY29udGFjdCI6WyJtYWlsdG86ZW1haWxAZXhhbXBsZS5jb20iXX0";

let nData = nCrypto.createSign('sha256WithRSAEncryption').update(txt).sign(p);
console.log('node', nData);
let bData = bCrypto.createSign('sha256WithRSAEncryption').update(txt).sign(p);
console.log('browserify-sign', bData);
console.log('isEqual', nData.toString('hex') === bData.toString('hex'));

nData = nCrypto.createSign('sha256').update(txt).sign(p);
console.log('node', nData);
bData = bCrypto.createSign('sha256').update(txt).sign(p);
console.log('browserify-sign', bData);
console.log('isEqual', nData.toString('hex') === bData.toString('hex'));

For sha256WithRSAEncryption both Node.js and browserify-sign are correctly signing the text using provided private key, but for sha256 only Node.js is able to sign a text, while browserify-sign` throws an error:

Error: wrong private key type
    at sign (/home/ubuntu/Projects/browserify-sign/browser/sign.js:24:63)
    at Sign.signMethod [as sign] (/home/ubuntu/Projects/browserify-sign/browser/index.js:43:13)
    at Object.<anonymous> (/home/ubuntu/Projects/browserify-sign/test-bsign.js:45:50)
    at Module._compile (node:internal/modules/cjs/loader:1256:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1310:10)
    at Module.load (node:internal/modules/cjs/loader:1119:32)
    at Module._load (node:internal/modules/cjs/loader:960:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:81:12)
    at node:internal/main/run_main_module:23:47

From my initial investigation, its because sha256 algorithm expects only ECDSA key, but we are providing RSA key instead.

Is it expected? Since browserify-sign wants to duplicate node behaviour, I think its a bug.

[ljharb]

Is there an older version of node where they were in agreement?

If no, it's definitely a bug, and if so, it's a bit trickier to bring it into compliance.

[zenshixd]

I tested LTS versions from Node 4 up to Node 18 - and discrepancy seems to be present in all of those versions.

[ljharb]

This package goes back farther than that :-) it’d be good to compare in node 0.10 as well.

[zenshixd]

Node 0.10.48 - still same issue:

D:\Projects\browserify-sign git:[main]> nvm use 0.10.48
Now using node v0.10.48 (64-bit)

D:\Projects\browserify-sign git:[main]> node test.js
node <SlowBuffer 7f c4 32 92 34 e0 9f 9f 84 b7 d2 fe 38 63 6e 95 ba ee ae 6a 8e be d1 9d 35 69 f4 2e fc 3c 84 a4 c7 81 92 7f 23 51 fa 59 40 a0 a4 8c f4 f5 ed 02 f4 ef b0 ...>
browserify-sign <Buffer 7f c4 32 92 34 e0 9f 9f 84 b7 d2 fe 38 63 6e 95 ba ee ae 6a 8e be d1 9d 35 69 f4 2e fc 3c 84 a4 c7 81 92 7f 23 51 fa 59 40 a0 a4 8c f4 f5 ed 02 f4 ef b0 ...>
isEqual true
node <SlowBuffer 7f c4 32 92 34 e0 9f 9f 84 b7 d2 fe 38 63 6e 95 ba ee ae 6a 8e be d1 9d 35 69 f4 2e fc 3c 84 a4 c7 81 92 7f 23 51 fa 59 40 a0 a4 8c f4 f5 ed 02 f4 ef b0 ...>

D:\Projects\browserify-sign\browser\sign.js:24
  if (signType !== 'rsa' && signType !== 'ecdsa/rsa') { throw new Error('wrong
                                                              ^
Error: wrong private key type
    at sign (D:\Projects\browserify-sign\browser\sign.js:24:63)
    at Sign.signMethod [as sign] (D:\Projects\browserify-sign\browser\index.js:43:13)
    at Object.<anonymous> (D:\Projects\browserify-sign\test.js:44:50)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Function.Module.runMain (module.js:497:10)
    at startup (node.js:119:16)
    at node.js:945:3

[ljharb]

Awesome, thanks for confirming :-) let's fix it then!