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Solidity and web3 sha3

I try to hash a tokenId with a seed in my smart contract. For simplicity and to avoid other errors I leave the seed out for now. I basically just want to hash a number on my contract and hash the same number on my javascript code and receive the same output.
Code looks something like this on Solidity:
function _tokenURI(uint256 tokenId) internal view returns (string memory) {
string memory currentBaseURI = _baseURI();
bytes32 hashedToken = keccak256(abi.encodePacked(tokenId));
return
bytes(currentBaseURI).length > 0
? string(abi.encodePacked(currentBaseURI, hashedToken, baseExtension))
: "";
}
which also leads to an error on client side invalid codepoint at offset. To tackle this I tried to cast bit32 to string using these functions
function _bytes32ToString(bytes32 _bytes32)
private
pure
returns (string memory)
{
uint8 i = 0;
bytes memory bytesArray = new bytes(64);
for (i = 0; i < bytesArray.length; i++) {
uint8 _f = uint8(_bytes32[i / 2] & 0x0f);
uint8 _l = uint8(_bytes32[i / 2] >> 4);
bytesArray[i] = _toByte(_f);
i = i + 1;
bytesArray[i] = _toByte(_l);
}
return string(bytesArray);
}
function _toByte(uint8 _uint8) private pure returns (bytes1) {
if (_uint8 < 10) {
return bytes1(_uint8 + 48);
} else {
return bytes1(_uint8 + 87);
}
}
though I'm not sure if this is equivalent. Code on the frontend looks like:
const hashed = web3.utils.soliditySha3(
{ type: "uint256", value: tokenId}
);
What do I need to change in order to receive the exact same output? And what does
invalid codepoint at offset
mean?

Maybe issue is that tokenId is not uint256 or Web3, Solidity version? I did few tests with Remix IDE and I recieved the same results.
Solidity code:
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
contract Hash {
function getHashValue_1() public view returns(bytes32){
return keccak256(abi.encodePacked(uint256(234)));
}
// bytes32: 0x61c831beab28d67d1bb40b5ae1a11e2757fa842f031a2d0bc94a7867bc5d26c2
function getHashValue_3() public view returns(bytes32){
return keccak256(abi.encodePacked(uint256(10),string('StringSecretValue')));
}
// bytes32: 0x5938b4caf29ac4903ee34628c3dc1eb5c670a6bd392a006d0cb91f1fc5db3819
}
JS code:
(async () => {
try {
console.log('Web3 version is '+ Web3.version);
// Web3 version is 1.3.0
let theValueYouNeed = web3.utils.soliditySha3("234");
theValueYouNeed = web3.utils.soliditySha3({type: 'uint256', value: '234'});
theValueYouNeed = web3.utils.soliditySha3({t: 'uint256', v: '234'});
// above hashed value is 0x61c831beab28d67d1bb40b5ae1a11e2757fa842f031a2d0bc94a7867bc5d26c2
console.log('Hashed value 1 is '+theValueYouNeed);
theValueYouNeed = web3.utils.soliditySha3({t: 'uint256', v: '10'},{t: 'string', v: 'StringSecretValue'});
console.log('Hashed value 2 is '+theValueYouNeed);
// above hashed value is 0x5938b4caf29ac4903ee34628c3dc1eb5c670a6bd392a006d0cb91f1fc5db3819
} catch (e) {
console.log(e.message)
}
})()
I'm not sure but invalid codepoint at offset should mean that a designated value does not fall within the range or set of allowed values... So maybe there is something wrong with tokenId and you could do some tests with hardcoded values?

You get the invalid codepoint error because you mix string and byte data when you call abi.encodePacked(currentBaseURI, hashedToken, baseExtension)).
When Javascript gets the return value from the contract it expects a UTF8 string, but inside your hashedToken you have byte values that are not valid for a UTF8-encoded string.
This kind of error might be "intermittent". It might happen in just some cases. You're lucky to see it during development and not in production.
How to fix it?
You are on the right track converting the hash result to a string.
There is an alternative way to do it in this answer which uses less gas by using only bitwise operations.
To convert the hex value in Javascript you can use web3.utils.hexToNumberString().

AES encryption in JS equivalent of C#

I need to encrypt a string using AES encryption. This encryption was happening in C# earlier, but it needs to be converted into JavaScript (will be run on a browser).
The current code in C# for encryption is as following -
public static string EncryptString(string plainText, string encryptionKey)
{
byte[] clearBytes = Encoding.Unicode.GetBytes(plainText);
using (Aes encryptor = Aes.Create())
{
Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(encryptionKey, new byte[] { 0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 });
encryptor.Key = pdb.GetBytes(32);
encryptor.IV = pdb.GetBytes(16);
using (MemoryStream ms = new MemoryStream())
{
using (CryptoStream cs = new CryptoStream(ms, encryptor.CreateEncryptor(), CryptoStreamMode.Write))
{
cs.Write(clearBytes, 0, clearBytes.Length);
cs.Close();
}
plainText = Convert.ToBase64String(ms.ToArray());
}
}
return plainText;
}
I have tried to use CryptoJS to replicate the same functionality, but it's not giving me the equivalent encrypted base64 string. Here's my CryptoJS code -
function encryptString(encryptString, secretKey) {
var iv = CryptoJS.enc.Hex.parse('Ivan Medvedev');
var key = CryptoJS.PBKDF2(secretKey, iv, { keySize: 256 / 32, iterations: 500 });
var encrypted = CryptoJS.AES.encrypt(encryptString, key,{iv:iv);
return encrypted;
}
The encrypted string has to be sent to a server which will be able to decrypt it. The server is able to decrypt the encrypted string generated from the C# code, but not the encrypted string generated from JS code. I tried to compare the encrypted strings generated by both the code and found that the C# code is generating longer encrypted strings. For example keeping 'Example String' as plainText and 'Example Key' as the key, I get the following result -
C# - eAQO+odxOdGlNRB81SHR2XzJhyWtz6XmQDko9HyDe0w=
JS - 9ex5i2g+8iUCwdwN92SF+A==
The length of JS encrypted string is always shorter than the C# one. Is there something I am doing wrong? I just have to replicated the C# code into the JS code.
Update:
My current code after Zergatul's answer is this -
function encryptString(encryptString, secretKey) {
var keyBytes = CryptoJS.PBKDF2(secretKey, 'Ivan Medvedev', { keySize: 48 / 4, iterations: 1000 });
console.log(keyBytes.toString());
// take first 32 bytes as key (like in C# code)
var key = new CryptoJS.lib.WordArray.init(keyBytes.words, 32);
// skip first 32 bytes and take next 16 bytes as IV
var iv = new CryptoJS.lib.WordArray.init(keyBytes.words.splice(32 / 4), 16);
console.log(key.toString());
console.log(iv.toString());
var encrypted = CryptoJS.AES.encrypt(encryptString, key, { iv: iv });
return encrypted;
}
As illustrated in his/her answer that if the C# code converts the plainText into bytes using ASCII instead of Unicode, both the C# and JS code will produce exact results. But since I am not able to modify the decryption code, I have to convert the code to be equivalent of the original C# code which was using Unicode.
So, I tried to see, what's the difference between both the bytes array between ASCII and Unicode byte conversion in C#. Here's what I found -
ASCII Byte Array: [69,120,97,109,112,108,101,32,83,116, 114, 105, 110, 103]
Unicode Byte Array: [69,0,120,0,97,0,109,0,112,0,108,0,101,0,32,0,83,0,116,0, 114,0, 105,0, 110,0, 103,0]
So some extra bytes are available for each character in C# (So Unicode allocates twice as much bytes to each character than ASCII).
Here's the difference between both Unicode and ASCII conversion respectively -
ASCII
clearBytes: [69,120,97,109,112,108,101,32,83,116,114,105,110,103,]
encryptor.Key: [123,213,18,82,141,249,182,218,247,31,246,83,80,77,195,134,230,92,0,125,232,210,135,115,145,193,140,239,228,225,183,13,]
encryptor.IV: [101,74,46,177,46,233,68,252,83,169,211,13,249,61,118,167,]
Result: eQus9GLPKULh9vhRWOJjog==
Unicode:
clearBytes: [69,0,120,0,97,0,109,0,112,0,108,0,101,0,32,0,83,0,116,0,114,0,105,0,110,0,103,0,]
encryptor.Key: [123,213,18,82,141,249,182,218,247,31,246,83,80,77,195,134,230,92,0,125,232,210,135,115,145,193,140,239,228,225,183,13,]
encryptor.IV: [101,74,46,177,46,233,68,252,83,169,211,13,249,61,118,167,]
Result: eAQO+odxOdGlNRB81SHR2XzJhyWtz6XmQDko9HyDe0w=
So since both the key and iv being generated have exact same byte array in both Unicode and ASCII approach, it should not have generated different output, but somehow it's doing that. I think it's because of clearBytes' length, as it's using its length to write to CryptoStream.
I tried to see what's the output of the generated bytes in the JS code is and found that it uses words which needed to be converted into Strings using toString() method.
keyBytes: 7bd512528df9b6daf71ff653504dc386e65c007de8d2877391c18cefe4e1b70d654a2eb12ee944fc53a9d30df93d76a7
key: 7bd512528df9b6daf71ff653504dc386e65c007de8d2877391c18cefe4e1b70d
iv: 654a2eb12ee944fc53a9d30df93d76a7
Since, I am not able to affect the generated encrypted string's length in the JS code (No access to the write stream directly), thus still stuck here.

Here is the example how to reproduce the same ciphertext between C# and CryptoJS:
static void Main(string[] args)
{
byte[] plainText = Encoding.Unicode.GetBytes("Example String"); // this is UTF-16 LE
string cipherText;
using (Aes encryptor = Aes.Create())
{
var pdb = new Rfc2898DeriveBytes("Example Key", Encoding.ASCII.GetBytes("Ivan Medvedev"));
encryptor.Key = pdb.GetBytes(32);
encryptor.IV = pdb.GetBytes(16);
using (MemoryStream ms = new MemoryStream())
{
using (CryptoStream cs = new CryptoStream(ms, encryptor.CreateEncryptor(), CryptoStreamMode.Write))
{
cs.Write(plainText, 0, plainText.Length);
cs.Close();
}
cipherText = Convert.ToBase64String(ms.ToArray());
}
}
Console.WriteLine(cipherText);
}
And JS:
var keyBytes = CryptoJS.PBKDF2('Example Key', 'Ivan Medvedev', { keySize: 48 / 4, iterations: 1000 });
// take first 32 bytes as key (like in C# code)
var key = new CryptoJS.lib.WordArray.init(keyBytes.words, 32);
// skip first 32 bytes and take next 16 bytes as IV
var iv = new CryptoJS.lib.WordArray.init(keyBytes.words.splice(32 / 4), 16);
// use the same encoding as in C# code, to convert string into bytes
var data = CryptoJS.enc.Utf16LE.parse("Example String");
var encrypted = CryptoJS.AES.encrypt(data, key, { iv: iv });
console.log(encrypted.toString());
Both codes return: eAQO+odxOdGlNRB81SHR2XzJhyWtz6XmQDko9HyDe0w=

TL;DR the final code looks like this -
function encryptString(encryptString, secretKey) {
encryptString = addExtraByteToChars(encryptString);
var keyBytes = CryptoJS.PBKDF2(secretKey, 'Ivan Medvedev', { keySize: 48 / 4, iterations: 1000 });
console.log(keyBytes.toString());
var key = new CryptoJS.lib.WordArray.init(keyBytes.words, 32);
var iv = new CryptoJS.lib.WordArray.init(keyBytes.words.splice(32 / 4), 16);
var encrypted = CryptoJS.AES.encrypt(encryptString, key, { iv: iv, });
return encrypted;
}
function addExtraByteToChars(str) {
let strResult = '';
for (var i = 0; i < str.length; ++i) {
strResult += str.charAt(i) + String.fromCharCode(0);
}
return strResult;
}
Explanation:
The C# code in the Zergatul's answer (Thanks to him/her) was using ASCII to convert the plainText into bytes, while my C# code was using Unicode. Unicode was assigning extra byte to each character in the resultant byte array, which was not affecting the generation of both key and iv bytes, but affecting the result since the length of the encryptedString was dependent on the length of the bytes generated from plainText.
As seen in the following bytes generated for each of them using "Example String" and "Example Key" as the plainText and secretKey respectively -
ASCII
clearBytes: [69,120,97,109,112,108,101,32,83,116,114,105,110,103,]
encryptor.Key: [123,213,18,82,141,249,182,218,247,31,246,83,80,77,195,134,230,92,0,125,232,210,135,115,145,193,140,239,228,225,183,13,]
encryptor.IV: [101,74,46,177,46,233,68,252,83,169,211,13,249,61,118,167,]
Result: eQus9GLPKULh9vhRWOJjog==
Unicode:
clearBytes: [69,0,120,0,97,0,109,0,112,0,108,0,101,0,32,0,83,0,116,0,114,0,105,0,110,0,103,0,]
encryptor.Key: [123,213,18,82,141,249,182,218,247,31,246,83,80,77,195,134,230,92,0,125,232,210,135,115,145,193,140,239,228,225,183,13,]
encryptor.IV: [101,74,46,177,46,233,68,252,83,169,211,13,249,61,118,167,]
Result: eAQO+odxOdGlNRB81SHR2XzJhyWtz6XmQDko9HyDe0w=
The JS result was similar too, which confirmed that it's using ASCII byte conversion -
keyBytes: 7bd512528df9b6daf71ff653504dc386e65c007de8d2877391c18cefe4e1b70d654a2eb12ee944fc53a9d30df93d76a7
key: 7bd512528df9b6daf71ff653504dc386e65c007de8d2877391c18cefe4e1b70d
iv: 654a2eb12ee944fc53a9d30df93d76a7
Thus I just need to increase the length of the plainText to make it use Unicode equivalent byte generation (Sorry, not familiar with the term). Since Unicode was assigning 2 space for each character in the byteArray, keeping the second space as 0, I basically created gap in the plainText's characters and filled that gap with character whose ASCII value was 0 using the addExtraByteToChars() function. And it made all the difference.
It's a workaround for sure, but started working for my scenario. I suppose this may or may not prove useful to others, thus sharing the findings. If anyone can suggest better implementation of the addExtraByteToChars() function (probably some term for this conversion instead of ASCII to Unicode or a better, efficient, and not hacky way to do that), please suggest it.

java encryption aes value and javascript encryption value does not match

I have java code which produce aes encryption code for me now I am trying to use it on javascript using crypto-js but both codes provides different keys I dont know why and how to get the same key here is my code
public static String encrypt(String text, byte[] iv, byte[] key)throws Exception{
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
SecretKeySpec keySpec = new SecretKeySpec(key, "AES");
System.out.println("KEY SPECCCC: "+keySpec);
IvParameterSpec ivSpec = new IvParameterSpec(iv);
cipher.init(Cipher.ENCRYPT_MODE,keySpec,ivSpec);
byte [] results = cipher.doFinal(text.getBytes("UTF-8"));
BASE64Encoder encoder = new BASE64Encoder();
return encoder.encode(results);
}
JavaScript code
require(["crypto-js/core", "crypto-js/aes"], function (CryptoJS, AES) {
ciphertext = CryptoJS.AES.encrypt(JSON.stringify(jsondata),
arr.toString(),arr.toString());
});
string to utf-8
var utf8 = unescape(encodeURIComponent(key));
var arr = [];
for (var i = 0; i < utf8.length; i++) {
arr.push(utf8.charCodeAt(i));
}

First of all even tough your code works fine you wont be able to decrypt it back properly because while you are creating your AES cipher in Java you are using CBC Cipher and You are implementing a Padding algorithm which is PKCS5Padding.
So your java code does the followings;
When it gets the input it first divide it into the 16 bits blocks then if your input doesnt divide into the 16 overall then the reminders will be padded for filling the block with the same number of reminder.You can see what i mean by the following picture.
So it will do the encryption with the padded ciphers in the java side but in the Javascript Part You neither declare what type of Mode Aes will use nor declaring the what type of Padding it suppose to do. So you should add those values into the your code.You can make search following code parts.
mode:CryptoJS.mode.CBC,
padding: CryptoJS.pad.Pkcs7
About the different keys it is occuring because you are sending a Byte[] in to the your Encrypt method then use this unknown Byte[] while you are creating your Key.You didnt mention why your encryption method will be used in your program but you should create that "Byte[] key" same way in the both method.For instance you can refer following code as a example of generating that but it is not secure way of generating keys I just added it for showing you what I mean by you should generate both keys in the same way.
//DONT USE THIS IMPLEMENTATION SINCE IT IS NOT SAFE!
byte[] key = (username + password).getBytes("UTF-8");

Java code generates an encrypted string and for JavaScript to also generate same encrypted string, Following code works!
(function (CryptoJS) {
var C_lib = CryptoJS.lib;
// Converts ByteArray to stadnard WordArray.
// Example: CryptoJS.MD5(CryptoJS.lib.ByteArray ([ Bytes ])).toString(CryptoJS.enc.Base64);
C_lib.ByteArray = function (arr) {
var word = [];
for (var i = 0; i < arr.length; i += 4) {
word.push (arr[i + 0] << 24 | arr[i + 1] << 16 | arr[i + 2] << 8 | arr[i + 3] << 0);
}
return C_lib.WordArray.create (word, arr.length);
};
})(CryptoJS);
var IVstring = CryptoJS.lib.ByteArray(your IV bytearray).toString(CryptoJS.enc.Base64);
var keystring = CryptoJS.lib.ByteArray(your KEY bytearray).toString(CryptoJS.enc.Base64);
var text = 'texttobeencrypted';
var key = CryptoJS.enc.Base64.parse(keystring);
var iv = CryptoJS.enc.Base64.parse(IVstring);
var encrypted = CryptoJS.AES.encrypt(text, key, {iv: iv});
console.log(encrypted.toString());
Edited: Removed dangerous third party resource reference.
aes encryption javascript cryptojs java

Trouble decrypting openSSL AES CTR encrypted text

I have trouble decrypting an message encrypted in php with the openssl_encrypt method. I am using the new WebCrypto API (so I use crypto.subtle).
Encrypting in php:
$ALGO = "aes-256-ctr";
$key = "ae6865183f6f50deb68c3e8eafbede0b33f9e02961770ea5064f209f3bf156b4";
function encrypt ($data, $key) {
global $ALGO;
$iv = openssl_random_pseudo_bytes(openssl_cipher_iv_length($ALGO), $strong);
if (!$strong) {
exit("can't generate strong IV");
}
return bin2hex($iv).openssl_encrypt($data, $ALGO, $key, 0, $iv);
}
$enc = encrypt("Lorem ipsum dolor", $key);
exit($enc);
example output:
8d8c3a57d2dbb3287aca61be0bce59fbeAQ4ILKouAQ5eizPtlUTeHU=
(I can decrypt that in php and get the cleartext back)
In JS I decrypt like this:
function Ui8FromStr (StrStart) {
const Ui8Result = new Uint8Array(StrStart.length);
for (let i = 0; i < StrStart.length; i++) {
Ui8Result[i] = StrStart.charCodeAt(i);
}
return Ui8Result;
}
function StrFromUi8 (Ui8Start) {
let StrResult = "";
Ui8Start.forEach((charcode) => {
StrResult += String.fromCharCode(charcode);
});
return StrResult;
}
function Ui8FromHex (hex) {
for (var bytes = new Uint8Array(Math.ceil(hex.length / 2)), c = 0; c < hex.length; c += 2)
bytes[c/2] = parseInt(hex.substr(c, 2), 16);
return bytes;
}
const ALGO = 'AES-CTR'
function decrypt (CompCipher, HexKey) {
return new Promise (function (resolve, reject) {
// remove IV from cipher
let HexIv = CompCipher.substr(0, 32);
let B64cipher = CompCipher.substr(32);
let Ui8Cipher = Ui8FromStr(atob(B64cipher));
let Ui8Iv = Ui8FromHex (HexIv);
let Ui8Key = Ui8FromHex (HexKey);
crypto.subtle.importKey("raw", Ui8Key, {name: ALGO}, false, ["encrypt", "decrypt"]). then (function (cryptokey){
return crypto.subtle.decrypt({ name: ALGO, counter: Ui8Iv, length: 128}, cryptokey, Ui8Cipher).then(function(result){
let Ui8Result = new Uint8Array(result);
let StrResult = StrFromUi8(Ui8Result);
resolve(StrResult);
}).catch (function (err){
reject(err)
});
})
})
}
when I now run decrypt("8d8c3a57d2dbb3287aca61be0bce59fbeAQ4ILKouAQ5eizPtlUTeHU=", "ae6865183f6f50deb68c3e8eafbede0b33f9e02961770ea5064f209f3bf156b4").then(console.log) I get gibberish: SÌõÅ°blfçSÑ-
The problem I have is, that I am not sure what is meant with counter. I tried the IV but failed.
This Github tutorial suggests*1, that it is the IV - or at least part of it, as I've seen people talk about that the counter is part of the IV (something like 4 bytes, that means that the IV is made from 12 bytes IV and 4 bytes Counter)
If that is indeed true, my question then becomes: Where do I give the script the other 12 bytes of IV when counter is only 4 bytes of it.
Can anyone maybe give me a working example of encryption in php
*1 It says that the same counter has to be used for en- and decryption. This leads me to believe, that it is at least something similar to the IV

You are handling the key incorrectly in PHP.
In the PHP code you are passing the hex encoded key directly to the openssl_encrypt function, without decoding it. This means the key you are trying to use is twice as long as expected (i.e. 64 bytes). OpenSSL doesn’t check the key length, however—it just truncates it, taking the first 32 bytes and using them as the encryption key.
The Javascript code handles the key correctly, hex decoding it before passing the decoded array to the decryption function.
The overall result is you are using a different key in each case, and so the decryption doesn’t work.
You need to add a call to hex2bin on the key in your PHP code, to convert it from the hex encoding to the actual 32 raw bytes.

Crypto - Is SJCL (javascript) encryption compatible with OpenSSL?

I am trying to decrypt some information that has been encrypted with the SJCL (Stanford Javascript Crypto Library). An example page is at http://bitwiseshiftleft.github.io/sjcl/demo/.
If I encrypt some data, I have been unable to decrypt it using OpenSSL (version 1.0.1f). I have seen another question on stackoverflow asking about this - but that question and its answers didn't really help.
For instance, encrypting with a password of 'password', and a random salt of '6515636B 82C5AC56' with 10000 iterations of a 256 bit key size gives a Key of 'D8CCAA75 3E2983F0 3657AB3C 8A68A85A 9E9F1CAC 43DAB645 489CDE58 0A9EBDAE', which is exactly what I get with OpenSSL. So far, so good.
When I use SJCL with this key and an IV of '9F62544C 9D3FCAB2 DD0833DF 21CA80CF' to encrypt, say, the message 'mymessage', then I get the ciphertext:
{"iv":"n2JUTJ0/yrLdCDPfIcqAzw==",
"v":1,
"iter":10000,
"ks":256,
"ts":64,
"mode":"ccm",
"adata":"",
"cipher":"aes",
"salt":"ZRVja4LFrFY=",
"ct":"FCuQWGYz3onE/lRt/7vCl5A="}
However, no matter how I modify or rewrite my OpenSSL C++ code, I cannot decrypt this data.
I've googled and found a few code samples, but nothing that has actually worked.
I'm aware that I need to use the CCM cipher mode in OpenSSL - but this mode is poorly documented.
Can anyone post some OpenSSL code to successfully decrypt this data?

You can copy-paste the example at http://wiki.openssl.org/index.php/EVP_Authenticated_Encryption_and_Decryption with a few changes.
First, you need to Base64 decode SJCL's data. But you knew that.
Second, you need to split the message into ct and tag. In this case, ct is the first 9 bytes, and tag is the 8 bytes starting at ct[9].
Third, you need to set the tag length to ts/8 = 8, and you need to set the IV length correctly. If you set the IV too long in SJCL, it will truncate it to 15 - LOL (length of length), where LOL is between 2 and 4 (because SJCL enforces <2^32 bytes length), and is the number of bytes required to describe the length of the message. This is 2 unless the message is at least 65536 bytes long, in which case it is 3, unless the message is at least 2^24 bytes long, in which case it is 4. Keep in mind that if you're decrypting, the ciphertext you are passed includes the tag but LOL must be computed from the message length, which does not include the tag.
With those changes, it should work:
#include <openssl/evp.h>
void handleErrors() {
abort();
}
int decryptccm(unsigned char *ciphertext, int ciphertext_len, unsigned char *aad,
int aad_len, unsigned char *tag, unsigned char *key, unsigned char *iv,
unsigned char *plaintext)
{
EVP_CIPHER_CTX *ctx;
int len;
int plaintext_len;
int ret;
/* Create and initialise the context */
if(!(ctx = EVP_CIPHER_CTX_new())) handleErrors();
/* Initialise the decryption operation. */
if(1 != EVP_DecryptInit_ex(ctx, EVP_aes_256_ccm(), NULL, NULL, NULL))
handleErrors();
int lol = 2;
if (ciphertext_len >= 1<<16) lol++;
if (ciphertext_len >= 1<<24) lol++;
if(1 != EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_CCM_SET_IVLEN, 15-lol, NULL))
handleErrors();
/* Set expected tag value. */
if(1 != EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_CCM_SET_TAG, 8, tag))
handleErrors();
/* Initialise key and IV */
if(1 != EVP_DecryptInit_ex(ctx, NULL, NULL, key, iv)) handleErrors();
/* Provide the total ciphertext length
*/
if(1 != EVP_DecryptUpdate(ctx, NULL, &len, NULL, ciphertext_len))
handleErrors();
/* Provide any AAD data. This can be called zero or more times as
* required
*/
if(1 != EVP_DecryptUpdate(ctx, NULL, &len, aad, aad_len))
handleErrors();
/* Provide the message to be decrypted, and obtain the plaintext output.
* EVP_DecryptUpdate can be called multiple times if necessary
*/
ret = EVP_DecryptUpdate(ctx, plaintext, &len, ciphertext, ciphertext_len);
plaintext_len = len;
/* Clean up */
EVP_CIPHER_CTX_free(ctx);
if(ret > 0)
{
/* Success */
return plaintext_len;
}
else
{
/* Verify failed */
return -1;
}
}
int main(int argc, char **argv) {
// base64-decoded from your example
unsigned char iv[] = { 0x9F,0x62,0x54,0x4C,0x9D,0x3F,0xCA,0xB2,0xDD,0x08,0x33,0xDF,0x21,0xCA,0x80,0xCF };
unsigned char ct[] = { 0x14,0x2B,0x90,0x58,0x66,0x33,0xDE,0x89,0xC4,0xFE,0x54,0x6D,0xFF,0xBB,0xC2,0x97,0x90 };
unsigned char ky[] = { 0xD8,0xCC,0xAA,0x75 ,0x3E,0x29,0x83,0xF0 ,0x36,0x57,0xAB,0x3C ,0x8A,0x68,0xA8,0x5A ,0x9E,0x9F,0x1C,0xAC ,0x43,0xDA,0xB6,0x45 ,0x48,0x9C,0xDE,0x58 ,0x0A,0x9E,0xBD,0xAE };
const unsigned char *message = (const unsigned char *)"mymessage";
unsigned char plaintext[1000];
int ret = decryptccm(ct, 9, "", 0, &ct[9], ky, iv, plaintext);
plaintext[9] = 0;
printf("%d,%s\n",ret,plaintext);
return 0;
}
This program returns "9,mymessage" on my machine.