39 lines
851 B
JavaScript
39 lines
851 B
JavaScript
function randomString(n,s){
|
|
//
|
|
// review..
|
|
try{
|
|
n = n || 16
|
|
let b = new Uint8Array(n+1) // +1 for extra random value for initial start position
|
|
crypto.getRandomValues(b)
|
|
|
|
s = s || 'ABCDEFGHIJKLMNOPQRSTUWXYZabcdefghijklmnopqrstuvwxyz01234567890' //-_'
|
|
|
|
let aa = []
|
|
let ii = 0
|
|
let len = s.length
|
|
// note: this might be biased? or might be bad to add seq random numbers?
|
|
for(let i = 0;i< b.length;i++){ // first value (index 0) to start in a random location.
|
|
let v = b[i]
|
|
ii += v
|
|
if(i > 0){
|
|
let iii = ii%len
|
|
let vv = s[iii]
|
|
if(!vv)
|
|
conole.log('out of range?',iii)
|
|
aa.push(vv)
|
|
}
|
|
}//for
|
|
|
|
let r = aa.join('')
|
|
|
|
return r
|
|
}
|
|
catch(e){
|
|
//
|
|
console.log('crypto not supported?')
|
|
return Math.random().toString(36).substring(7) // till crypto bug fix?
|
|
}
|
|
}
|
|
|
|
export default randomString
|