Database corruption on keys/values with backslash

[jeff-hykin]

Minimal Reproduce

NodeJS: v14.17.1

const path = require("path")
const http = require("http")
const Gun = require('gun')

const databasePort = 8765
const databasePath = path.join(__dirname, "data", "database")
const gun = Gun({
    web: http.createServer(Gun.serve(path.dirname(databasePath))).listen(databasePort),
    file: path.basename(databasePath),
})

// add some data (corrupts the database)
gun.get("vulns").get("XT\\").put({hi: "testing"},()=>{
        console.log("first one finished")
        // no issues here ^ 
        gun.get("vulns").get("XT\\").put({hi: "testing"},()=>{
            // this one ^ and any/all queries afterwords fail (data corruption)
            console.log("second one finished")
            process.exit()
        })
    })

Issue Description

Having a \ at the end of a key or a string value seems to corrupt the database.

undefined:1
"\u001bXT\\":{"
            ^

SyntaxError: Unexpected token : in JSON at position 12
    at JSON.parse (<anonymous>)
    at parse (/Users/jeffhykin/repos/vulerabilities_visualized/node_modules/.pnpm/gun@0.2020.1235/node_modules/gun/lib/yson.js:42:55)
    at yson.parseAsync (/Users/jeffhykin/repos/vulerabilities_visualized/node_modules/.pnpm/gun@0.2020.1235/node_modules/gun/lib/yson.js:12:2)
    at p.read (/Users/jeffhykin/repos/vulerabilities_visualized/node_modules/.pnpm/gun@0.2020.1235/node_modules/gun/lib/radisk.js:389:6)
    at /Users/jeffhykin/repos/vulerabilities_visualized/node_modules/.pnpm/gun@0.2020.1235/node_modules/gun/lib/rfs.js:40:4
    at FSReqCallback.readFileAfterClose [as oncomplete] (internal/fs/read_file_context.js:73:3)

The error is thrown from yson.js

Its line #33 if its a string value that ends with \

Its line #42 if the key ends with \

Currently my only fix is to delete the whole database and remove \ from all strings going to the database

[amark]

@jeff-hykin thank you! Very important catch, I'll be checking into the parsing, thank you.

[Promaethius]

I think this is what I was running into. Commenting out yson.js includes fixed the issue

[amark]

@Promaethius thanks for confirming. Thankfully its my fault - tho I'm hoping somebody would be willing to do a screencall with me to help get it fixed? I'm pretty overwhelmed, but this is important.

[Promaethius]

@amark I'd be down to help, still trying to divine the purpose of yson.js

[amark]

@Promaethius sorry only saw this now.

YSON is a yielding JSON parser.

Native JSON parses X size data by blocking the CPU thread.

That trashes performance if the JSON file is 1MB+ size.

YSON instead parses the data in 32KB strides.

Here are some tests: https://github.com/amark/gun/blob/master/test/common.js#L81-L99

Add a new test with your \\ data. Find that it is failing with the crash, try editing YSON until fixed.

If you get stuck anywhere, I'm happy to help or jump on a call. (Twitter DMs notify my phone the fastest)

[Maygician]

Also can be noticed while working with escape sequences. Was evaluating stuff gotten from the form on another device and newline character becomes \n. (That's two characters). escape()/unescape() did solve the problem in my case. (Workaround rather)