Transaction signing corrupts floating point string

[professorhantzen]

Supply rippleAPI.sign with a JSON string for an OfferCreate transaction containing a floating point string as TakerPays. Choose a value with a large number of digits. Sometimes this creates a serialised transaction with the correct value embedded, other times the value becomes corrupted.

This has been verified by taking the serialised output from the sign function, and sending it to the websocket server at wss://s-west.ripple.com:51233 and comparing the output.

Eg, inputting the following JSON into api.sign:

TakerPays: 
   { currency: 'BTC',
     issuer: 'rvYAfWj5gh67oV6fW32ZzP3Aw4Eubs59B',
     value: '0.01153351040117655' }

Results in a serialised transaction that rippled interprets as:

"TakerPays":
{"currency":"BTC",
"issuer":"rvYAfWj5gh67oV6fW32ZzP3Aw4Eubs59B",
"value":"0.01153351040117655"}

vs inputting:

TakerPays: 
   { currency: 'BTC',
     issuer: 'rvYAfWj5gh67oV6fW32ZzP3Aw4Eubs59B',
     value: '0.19999999999999991' }

Which results in:

"TakerPays":
{"currency":"BTC",
"issuer":"rvYAfWj5gh67oV6fW32ZzP3Aw4Eubs59B",
"value":"1841616395.698057"}

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[sublimator]

ripple-binary-codec needs to check the significant digits is no greater than 16 probably. RippleAPI probably doesn't with the simple json schema.

[sublimator]

0.1999 9999 9999 9999 1

17 significant digits.

On 9 Nov 2016 11:46 p.m., "Nicholas Dudfield" ndudfield@gmail.com wrote:

ripple-binary-codec needs to check the significant digits is no greater than 16 probably. RippleAPI probably doesn't with the simple json schema.

[sublimator]

If I get to my pc b4 someone else fixes it I'll fix it.

[professorhantzen]

Thank you! What form of fix is likely? Will ripple-binary-codec return an error if the supplied value exceeds 16 significant digits, or will it round the value?

Also, a temporary workaround for inputs into the current sign function:

var floatingPointString = '0.19999999999999991';
floatingPointString = ''+(floatingPointString*1).toPrecision(16)/1;

The multiply by 1 casts the string to a number, toPrecision reduces it to 16 significant digits, dividing by 1 removes trailing zeroes. Finally, the addition to an empty string converts the number to a string.

[sublimator]

Earth to ripple? @clark800? Who maintains this these days?

[intelliot]

This should be fixed as of ripple-lib 0.17.5 and later.