How to convert the object of Uint8Array to string? - javascript

I have same problem as this question. I see the answer but I couldn't understand how I can do it. Is there any other suggestions?
My code is:
var eccrypto = require("eccrypto");
var w,actual;
var publicKey = Buffer.from([4, 86, 82, 58, 244, 11, 140, 41, 132, 245, 184, 162, 163, 98, 49, 119, 168, 235, 252, 50, 6, 91, 147, 191, 190, 61, 65, 63, 101, 164, 132, 213, 188, 106, 26, 203, 171, 215, 240, 151, 7, 193, 10, 151, 103, 107, 1, 135, 117, 225, 5, 41, 55, 57, 18, 205, 98, 178, 82, 135, 170, 111, 188, 98, 57],'hex');
var privateKey= Buffer.from([238, 239, 199, 101, 188, 134, 13, 13, 195, 172, 125, 168, 225, 189, 72, 148, 225, 200, 127, 218, 204, 11, 150, 146, 180, 243, 195, 109, 200, 119, 50, 20],'hex');
eccrypto.encrypt(publicKey, Buffer.from("message")).then(function(encrypted) {
console.log(encrypted)
let encoded =JSON.stringify(encrypted)
w=encoded;
console.log(encoded)
actual = JSON.parse((encoded))
console.log(actual)
});
eccrypto.decrypt(privateKey,actual).then(function(plaintext) {
console.log("Message to part B:", plaintext.toString());
});
When I use actual variable I have this error:
Uncaught (in promise) Error: Bad public key
this the output of encrypted :
this the output of encoded :
and this the output of actual "there is some things changes i think, is not it ?":
thank you advance.


While parsing, you need to send a reviver function, which conditionally parses the object. If you see how encoded looks, you will understand why the reviver function needs to be written this way.


I think you need to remove the "hex" encoding parameter from your Buffer.from.

Related

Unable to convert bytes Uint8Array to string in javascript

I am unable to decrypt this Uint8Array
Uint8Array(32) [
174, 157, 255, 238, 54, 143, 97, 132,
70, 243, 7, 249, 98, 188, 68, 170,
53, 82, 78, 9, 96, 226, 182, 160,
131, 79, 3, 147, 153, 34, 205, 162
]
using this code
const string = new TextDecoder().decode(hash);
console.log(string);
I get this: ����Kc2Jk�&an↕�9���&��h-Lﺠ�Ԋ
I've also tried with many online converters but it says there's some problem with the byte array. This byte array is a response from an API.
Where Am I wrong? How can I convert it properly?

Decompressing bytes in C#

I have a simple program which is decompressing a byte array in C#.
There is the code of "Decompress" func:
private byte[] Decompress(byte[] compressed)
{
using var from = new MemoryStream(compressed);
using var to = new MemoryStream();
using var gZipStream = new GZipStream(from, CompressionMode.Decompress);
gZipStream.CopyTo(to);
return to.ToArray();
}
and I have two byte arrays
var first = new byte[] { 31, 139, 8, 0, 0, 0, 0, 0, 0, 10, 45, 202, 65, 10, 128, 48, 12, 5, 209, 171, 132, 28, 195, 219, 68, 251, 91, 11, 38, 41, 105, 92, 137, 119, 23, 197, 221, 240, 152, 139, 39, 80, 120, 185, 88, 13, 234, 214, 55, 94, 88, 197, 154, 83, 115, 73, 154, 103, 84, 217, 64, 56, 48, 118, 177, 164, 130, 57, 164, 7, 5, 20, 186, 226, 141, 22, 72, 90, 97, 168, 61, 41, 251, 167, 7, 124, 72, 20, 250, 167, 233, 145, 124, 223, 15, 199, 8, 21, 161, 110, 0, 0, 0 };
var second = new byte[] { 31, 139, 8, 0, 0, 0, 0, 0, 0, 10, 1, 80, 0, 175, 255, 34, 127, 33, 66, 194, 252, 100, 6, 77, 155, 56, 146, 208, 225, 255, 219, 203, 33, 122, 153, 14, 246, 130, 28, 163, 183, 127, 145, 96, 71, 208, 206, 123, 9, 122, 133, 204, 255, 86, 191, 73, 197, 91, 247, 121, 156, 180, 101, 176, 125, 158, 123, 114, 192, 252, 70, 193, 148, 180, 183, 200, 146, 79, 121, 135, 152, 90, 247, 107, 168, 157, 128, 84, 121, 4, 122, 92, 145, 45, 223, 177, 179, 189, 149, 80, 0, 0, 0 }
my next step is:
var decompressed = Decompress(first);
var result = Encoding.UTF8.GetString(decompressed);
Output: {"seed":{"mnemonic":"mango goat surface elephant despair remember regret benefit timber leopard member sort"}}
var decompressed = Decompress(second);
var result = Encoding.UTF8.GetString(decompressed);
Output: "!B??d♠M?8??????!z???∟???`G??{ z???V?I?[?y??e?}?{r??F?????Oy??Z?k???Ty♦z\?-?
The structure of these arrays is the same... length (103), first 10 elements and last 3 elements. But first array decompresses with func Decompress fine and the second one is very bad. I don't know why it's happening. Someone explain where is my mistake.
I tried to decompress with python using gzip but I have the same result. There is the code
import gzip
first = [31, 139, 8, 0, 0, 0, 0, 0, 0, 10, 45, 202, 65, 10, 128, 48, 12, 5, 209, 171, 132, 28, 195, 219, 68, 251, 91, 11, 38, 41, 105, 92, 137, 119, 23, 197, 221, 240, 152, 139, 39, 80, 120, 185, 88, 13, 234, 214, 55, 94, 88, 197, 154, 83, 115, 73, 154, 103, 84, 217, 64, 56, 48, 118, 177, 164, 130, 57, 164, 7, 5, 20, 186, 226, 141, 22, 72, 90, 97, 168, 61, 41, 251, 167, 7, 124, 72, 20, 250, 167, 233, 145, 124, 223, 15, 199, 8, 21, 161, 110, 0, 0, 0 ];
second = [31, 139, 8, 0, 0, 0, 0, 0, 0, 10, 1, 80, 0, 175, 255, 34, 127, 33, 66, 194, 252, 100, 6, 77, 155, 56, 146, 208, 225, 255, 219, 203, 33, 122, 153, 14, 246, 130, 28, 163, 183, 127, 145, 96, 71, 208, 206, 123, 9, 122, 133, 204, 255, 86, 191, 73, 197, 91, 247, 121, 156, 180, 101, 176, 125, 158, 123, 114, 192, 252, 70, 193, 148, 180, 183, 200, 146, 79, 121, 135, 152, 90, 247, 107, 168, 157, 128, 84, 121, 4, 122, 92, 145, 45, 223, 177, 179, 189, 149, 80, 0, 0, 0 ];
bytes_of_values = bytes(first)
decompressed_block = gzip.decompress(bytes_of_values)
print(decompressed_block.decode('utf8', 'ignore'))
#Output: {"seed":{"mnemonic":"mango goat surface elephant despair remember regret benefit timber leopard member sort"}}
bytes_of_values = bytes(second)
decompressed_block = gzip.decompress(bytes_of_values)
print(decompressed_block.decode('utf8', 'ignore'))
#Output: "!Bd♠M8!z∟`G{ zVI[ye}{rFȒOyZkTy♦z\-
UPDATE #1
FIRST ARRAY was expanded with this JS function.
const crypto = require('crypto')
module.exports = function (size ) {
return {
expand (data ) {
const buffer = crypto.randomBytes(data.length < size - 4 ? size : data.length + 4)
buffer.writeUInt32BE(data.length, 0)
data.copy(buffer, 4, 0)
return buffer
},
shrink (buffer ) {
const dataLen = buffer.readUInt32BE(0)
return buffer.slice(4, dataLen + 4)
}
}
}
Where size = 2 ** 15 (2^15 = 32768); data = {"seed":{"mnemonic":"mango goat surface elephant despair remember regret benefit timber leopard member sort"}}. In output we have a Buffer with size 32768. After that I take this Buffer and convert to string like "[1, 2, 3 ,4 ,5, etc.]" (remind that size is 32768) and pass this to C#. In C# I use this code:
var shrink = BinaryPrimitives.ReadUInt32BigEndian(data); //data == array with size 32768 (string from JS)
//shrink == 103 (integer)
var segment = new ArraySegment<byte>(data, 4, (int)shrink).ToArray();
// segment == FIRST ARRAY
after following these steps I get the FIRST ARRAY and it decompresses fine. The structure of the first array are identical to SECOND ARRAY. And I understood that SECOND ARRAY uses the same algorithm. But it doesn't unpack.

zlib inflate without DICTID and ADLER32 checksum nodejs

i am trying to inflate a buffer with the zlib module in NodeJs. I had the problem that i always got the "unexpected end of file" error so i used my original data and let nodejs deflate it to compare the byte values.
(1) So this is the value that i have:
120, 156, 106, 46, 97, 96, 96, 96, 73, 97, 96, 76, 1, 49, 152, 82, 24, 216, 226, 75, 138, 18, 147, 83, 115, 128, 60, 198, 92, 32, 161, 17, 173, 148, 158, 88, 146, 90, 158, 88, 169, 91, 80, 148, 162, 155, 155, 152, 153, 167, 91, 104, 96, 94, 172, 164, 83, 173, 148, 155, 153, 92, 148, 95, 172, 100, 101, 160, 103, 80, 27, 155, 149, 194, 32, 148, 145, 154, 88, 84, 146, 148, 154, 88, 18, 159, 153, 87, 146, 90, 84, 150, 152, 147, 196, 192, 176, 80, 41, 133, 129, 41, 191, 32, 145, 11, 104, 75, 113, 10, 3, 115, 94, 102, 14, 144, 85, 2, 97, 1, 0, 0, 0, 255, 255
(2) And this is what zlib.deflateSync gave me:
120, 156, 1, 125, 0, 130, 255, 120, 156, 106, 46, 97, 96, 96, 96, 73, 97, 96, 76, 1, 49, 152, 82, 24, 216, 226, 75, 138, 18, 147, 83, 115, 128, 60, 198, 92, 32, 161, 17, 173, 148, 158, 88, 146, 90, 158, 88, 169, 91, 80, 148, 162, 155, 155, 152, 153, 167, 91, 104, 96, 94, 172, 164, 83, 173, 148, 155, 153, 92, 148, 95, 172, 100, 101, 160, 103, 80, 27, 155, 149, 194, 32, 148, 145, 154, 88, 84, 146, 148, 154, 88, 18, 159, 153, 87, 146, 90, 84, 150, 152, 147, 196, 192, 176, 80, 41, 133, 129, 41, 191, 32, 145, 11, 104, 75, 113, 10, 3, 115, 94, 102, 14, 144, 85, 2, 97, 1, 0, 0, 0, 255, 255, 164, 112, 54, 45, (bold = same)
So as far as i can tell from the RFC the first two bytes are the compression method and flags and therefor both have it. The other bold part is the compressed data. So far so good.
The first part that doesn't match is the DICTID part. But according to the RFC it is only four bytes long so what are the other three bytes (255, 120, 156)? The last part that is not bold is the ADLER32 checksum of the compressed data.
Question: Is zlib (nodejs) somehow able to inflate data without the DICTID and ADLER32 checksum?
Current Code Snippet:
const data = /* Array from (1) */;
const buffer = Buffer.from(data);
const out = zlib.inflateSync(buffer);
Output: Error: unexpected end of file
Background: What i am ultimately trying to do is the following but in javascript instead of python.
Note: The command line program zlib-flate is somehow able to inflate the bytes from (1) so i am assuming i do something wrong.

After hours of trail and error i finally figured it out what the problem was.
To be able to inflate the bytes from (1) you have to set the finishFlush option:
const result = zlib.inflateSync(buffer, {finishFlush: zlib.constants.Z_SYNC_FLUSH});

How to convert the object of Uint8Array to string and convert back string to same object?

I am using eccrypto.js library for public key encryption.
Here I want to encrypt the message of A using public key of B and then let B to decrypt using private key of B.
In the library this is done by:
// Encrypting the message for B.
eccrypto.encrypt(publicKeyB, Buffer.from("msg to b")).then(function(encrypted) {
// B decrypting the message.
eccrypto.decrypt(privateKeyB, encrypted).then(function(plaintext) {
console.log("Message to part B:", plaintext.toString());
});
});
if I console log the encrypted value I got the object as:
{iv: Uint8Array(16), ephemPublicKey: Uint8Array(65), ciphertext: Uint8Array(48), mac: Uint8Array(32)}
ciphertext: Uint8Array(48) [13, 240, 10, 109, 88, 109, 108, 153, 213, 115, 40, 237, 66, 232, 251, 120, 27, 67, 119, 231, 17, 143, 78, 69, 43, 76, 214, 74, 132, 127, 220, 131, 44, 144, 221, 133, 48, 124, 239, 158, 226, 22, 119, 200, 170, 101, 241, 82]
ephemPublicKey: Uint8Array(65) [4, 84, 253, 207, 251, 2, 157, 203, 14, 233, 166, 216, 107, 1, 23, 90, 229, 209, 150, 58, 95, 253, 214, 183, 148, 167, 224, 15, 224, 244, 176, 165, 84, 121, 70, 4, 175, 186, 189, 104, 211, 207, 255, 195, 20, 128, 200, 237, 7, 9, 173, 234, 14, 208, 208, 68, 46, 76, 38, 26, 107, 41, 10, 188, 108]
iv: Uint8Array(16) [230, 246, 79, 17, 203, 191, 117, 7, 57, 149, 198, 68, 193, 220, 159, 56]
mac: Uint8Array(32) [202, 77, 212, 211, 27, 186, 174, 106, 211, 145, 100, 81, 100, 68, 61, 172, 175, 188, 213, 49, 63, 92, 172, 83, 30, 22, 47, 93, 60, 215, 33, 116]
Note: I have to store this in json format so i have converted it into json data.
Now if I convert this object to json and recover the json data the recovered object is not same.
Json object:
{
"iv":{"type":"Buffer","data":[226,253,245,0,227,222,47,37,65,177,171,68,201,142,242,35]},
"ephemPublicKey":{"type":"Buffer","data":[4,9,137,99,138,202,169,89,90,209,92,130,156,105,170,132,192,250,88,232,15,250,33,107,38,13,129,178,21,237,77,136,215,39,215,123,140,226,102,98,39,110,192,209,79,214,138,83,174,192,100,183,157,44,56,128,38,52,170,244,42,213,199,57,232]},
"ciphertext":{"type":"Buffer","data":[135,147,187,164,109,39,204,244,195,161,65,24,178,160,132,146,200,35,113,120,164,140,20,223,225,104,23,111,13,155,193,26,35,73,236,77,209,246,85,16,77,30,250,122,206,242,111,63]},
"mac":{"type":"Buffer","data":[79,195,220,150,230,150,13,187,9,131,12,81,151,107,29,216,138,143,85,52,153,71,179,167,243,141,107,88,97,206,110,107]}}
The recovered object (JSON.parse(encrypted)) is:
{iv: {…}, ephemPublicKey: {…}, ciphertext: {…}, mac: {…}}
ciphertext:
data: (48) [135, 147, 187, 164, 109, 39, 204, 244, 195, 161, 65, 24, 178, 160, 132, 146, 200, 35, 113, 120, 164, 140, 20, 223, 225, 104, 23, 111, 13, 155, 193, 26, 35, 73, 236, 77, 209, 246, 85, 16, 77, 30, 250, 122, 206, 242, 111, 63]
type: "Buffer"
__proto__: Object
ephemPublicKey:
data: (65) [4, 9, 137, 99, 138, 202, 169, 89, 90, 209, 92, 130, 156, 105, 170, 132, 192, 250, 88, 232, 15, 250, 33, 107, 38, 13, 129, 178, 21, 237, 77, 136, 215, 39, 215, 123, 140, 226, 102, 98, 39, 110, 192, 209, 79, 214, 138, 83, 174, 192, 100, 183, 157, 44, 56, 128, 38, 52, 170, 244, 42, 213, 199, 57, 232]
type: "Buffer"
__proto__: Object
iv:
data: (16) [226, 253, 245, 0, 227, 222, 47, 37, 65, 177, 171, 68, 201, 142, 242, 35]
type: "Buffer"
__proto__: Object
mac:
data: (32) [79, 195, 220, 150, 230, 150, 13, 187, 9, 131, 12, 81, 151, 107, 29, 216, 138, 143, 85, 52, 153, 71, 179, 167, 243, 141, 107, 88, 97, 206, 110, 107]
type: "Buffer"
__proto__: Object
__proto__: Object
if i used the recovered object to decrypt I am getting the error as bad public key.
My code is:
let PublicKey = Buffer.from("0418c7ced07c0c17f42b132747c70fddb6b31ea0ad349c2e9f800f48f0a73c2ea028d41b239077a48136ce546f9d2811bf1ec311c56e6a41f33906a1fc2472e451", 'hex')
eccrypto.encrypt(PublicKey, Buffer.from('Message to encrypt').then(function (encrypted) {
console.log(encrypted)
let encoded = JSON.stringify(encrypted)
console.log(encoded)
var actual = JSON.parse((encoded))
console.log(actual)
let pk = Buffer.from("9a2d66404b69023c2c45da81ca4b696a8234b7ae53ea6b7ffc0d6bdd0e0e3279", 'hex')
eccrypto.decrypt(pk, actual).then(function (plaintext) {
console.log("Message to part B:", plaintext.toString());
});
});
I am getting error as bad public key.
If i used the encrypted variable instead of acutal in the eccrypto.decrypt(pk,encrypted)...
then i get the decrypted value.

You can add a second argument to JSON.parse to allow you to inject code to help interpret the JSON as it's deserialized. It's called a reviver in the documentation.
You will get each key, value pair in the object.
Here is some sample code:
JSON.parse('{"p": 5}', (key, value) =>
typeof value === 'number'
? value * 2 // return value * 2 for numbers
: value // return everything else unchanged
);
Here is mode info on MDN:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse
In your example, I think you want to identify the values as type buffer and then replace them with UInt8Array

or create a new object like this:
const newWorkingObject = {
ciphertext: Buffer.from([...recoveredObject.ciphertext.data]),
ephemPublicKey: Buffer.from([...recoveredObject.ephemPublicKey.data]),
iv: Buffer.from([...recoveredObject.iv.data]),
mac: Buffer.from([...recoveredObject.mac.data]),
}

How to convert Hex to Unit8Array in node?

I can convert Unit8Array to hex by using below code
var bkh = {
publicKey: new Uint8Array([91, 221, 234, 40, 144, 246, 91, 187, 154, 76,
60, 178, 204, 81, 35, 195, 254, 114, 246, 88, 90, 170, 68, 97, 199,
170, 72, 36, 107, 66, 206, 9]
),
secretKey: new Uint8Array([64, 68, 196, 103, 210, 179, 166, 40, 187,
150, 167, 233, 144, 206, 64, 26, 77, 133, 70, 238, 232, 227, 133,
83, 149, 202, 213, 41, 152, 243, 237, 41]
)
}
let hex = Buffer.from(bkh.publicKey).toString('hex');
console.log('master key',hex)
How can I convert this hex value back to Unit8Array in node

var hex = '5bddea2890f65bbb9a4c3cb2cc5123c3fe72f6585aaa4461c7aa48246b42ce09'
new Uint8Array(Buffer.from(hex, 'hex'))
// or
Uint8Array.from(Buffer.from(hex, 'hex'))

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