In my C program, I generate a public/private key pair with the function C_GenerateKeyPair and a sensitive (secret) key with C_GenerateKey. The aim is to wrap the secret key with the public key, but when I call the function C_WrapKey, I get the error CKR_KEY_TYPE_INCONSISTENT. The code runs if I use another wrapping secret key with attributes Wrap and Encrypt set.
The template used for the public key is the one proposed in PKCS#11 documentation:
CK_SESSION_HANDLE hSession;
CK_OBJECT_HANDLE hPublicKey, hPrivateKey;
CK_MECHANISM mechanism = {
CKM_RSA_PKCS_KEY_PAIR_GEN, NULL_PTR, 0
};
CK_ULONG modulusBits = 768;
CK_BYTE publicExponent[] = { 3 };
CK_BYTE id[] = {123};
CK_BBOOL true = CK_TRUE;
CK_ATTRIBUTE publicKeyTemplate[] = {
{CKA_ENCRYPT, &true, sizeof(true)},
{CKA_VERIFY, &true, sizeof(true)},
{CKA_WRAP, &true, sizeof(true)},
{CKA_MODULUS_BITS, &modulusBits, sizeof(modulusBits)},
{CKA_PUBLIC_EXPONENT, publicExponent, sizeof(publicExponent)}
};
The Wrap and Encrypt attribute are correctly specified, while for the secret key to be wrapped I add the attribute CKA_EXTRACTABLE.
Thanks in advance for your help.
The error CKR_KEY_TYPE_INCONSISTENT is due to a wrong CK_MECHANISM, used in the function C_WrapKey. If we want to wrap a secret key with a RSA public key, set the following mechanism:
CK_MECHANISM dec_mec = {CKM_RSA_PKCS, NULL_PTR, 0};
Related
I am implementing Apple's App Attestation service.
As part of the process, i receive a EC key and a signature.
Sample key:
-----BEGIN PUBLIC KEY-----
MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEd34IR9wYL76jLyZ148O/hjXo9iaF
z/q/xEMXCwYPy6yxbxYzWDZPegG4FH+snXaXQPYD6QIzZNY/kcMjIGtUTg==
-----END PUBLIC KEY-----
Sample signature:
MEUCIQDXR/22YAi90PUdKrtTHwigrDxWFoiCqPLB/Of1bZPCKQIgNLxFAeUU2x+FSWfhRGX0SOKUIDxPRoigsCHpJxgGXXU=
Sample sha256 hash:
S3i6LAEzew5SDjQbq59/FraEAvGDg9y7fRIfbnhHPf4=
If i put this into a couple of txt files like so:
System.IO.File.WriteAllBytes("/wherever/sig", Convert.FromBase64String(sampleSignature));
System.IO.File.WriteAllBytes("/wherever/hash", Convert.FromBase64String(sampleSha256Hash));
Then i can validate the signature with Openssl like so
openssl dgst -sha256 -verify sampleKey.pem -signature /wherever/sig /wherever/hash
(the above outputs)
Verified OK
I can verify the signature using Bouncy Castle like so:
var bouncyCert = DotNetUtilities.FromX509Certificate(certificate);
var bouncyPk = (ECPublicKeyParameters)bouncyCert.GetPublicKey();
var verifier = SignerUtilities.GetSigner("SHA-256withECDSA");
verifier.Init(false, bouncyPk);
verifier.BlockUpdate(sha256HashByteArray, 0, sha256HashByteArray.Length);
var valid = verifier.VerifySignature(signature); // Happy days, this is true
Since i don't want to share my whole certificate here, the same sample may be achieved as follows:
// these are the values from the sample key shared at the start of the post
// as returned by BC. Note that .Net's Y byte array is completely different.
Org.BouncyCastle.Math.BigInteger x = new Org.BouncyCastle.Math.BigInteger(Convert.FromBase64String("d34IR9wYL76jLyZ148O/hjXo9iaFz/q/xEMXCwYPy6w="));
Org.BouncyCastle.Math.BigInteger y = new Org.BouncyCastle.Math.BigInteger(Convert.FromBase64String("ALFvFjNYNk96AbgUf6yddpdA9gPpAjNk1j+RwyMga1RO"));
X9ECParameters nistParams = NistNamedCurves.GetByName("P-256");
ECDomainParameters domainParameters = new ECDomainParameters(nistParams.Curve, nistParams.G, nistParams.N, nistParams.H, nistParams.GetSeed());
var G = nistParams.G;
Org.BouncyCastle.Math.EC.ECCurve curve = nistParams.Curve;
Org.BouncyCastle.Math.EC.ECPoint q = curve.CreatePoint(x, y);
ECPublicKeyParameters pubkeyParam = new ECPublicKeyParameters(q, domainParameters);
var verifier = SignerUtilities.GetSigner("SHA-256withECDSA");
verifier.Init(false, pubkeyParam);
verifier.BlockUpdate(sha256HashByteArray, 0, sha256HashByteArray.Length);
var valid = verifier.VerifySignature(signature); // again, happy days.
However, i really want to avoid using bouncy castle.
So i am trying to use ECDsa available in .net core:
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;
var certificate = new X509Certificate2(cert);
var publicKey = certificate.GetECDsaPublicKey();
var valid = publicKey.VerifyHash(sha256HashByteArray, signature); // FALSE :(
if you want to try to run the above here's the sample that creates the keys without the whole certificate:
using System.Security.Cryptography;
var ecParams = new ECParameters();
ecParams.Curve = ECCurve.CreateFromValue("1.2.840.10045.3.1.7");
ecParams.Q.X = Convert.FromBase64String("d34IR9wYL76jLyZ148O/hjXo9iaFz/q/xEMXCwYPy6w=");
// I KNOW that this is different from BC sample - i got each respective values from
// certificates in respective libraries, and it seems the way they format the coordinates
// are different.
ecParams.Q.Y = Convert.FromBase64String("sW8WM1g2T3oBuBR/rJ12l0D2A+kCM2TWP5HDIyBrVE4=");
var ecDsa = ECDsa.Create(ecParams);
var isValid = ecDsa.VerifyHash(nonce, signature); // FALSE :(
I tried using VerifyData() instead and feeding raw data and HashAlgorithmName.SHA256 with no luck.
I found a response here (https://stackoverflow.com/a/49449863/2057955) that seems to suggest that .net expects the signature as r,s concatenation, so i pulled them out of the DER sequence that i get back from my device (see sample signature) however that had no luck at all, i just can't get that 'true' back.
Question: how can i verify this EC signature using .Net Core on LINUX/MacOs (so unable to use ECDsaCng class)?
SignerUtilities.GetSigner() hashes implicitly, i.e. sha256HashByteArray is hashed again. Therefore instead of ECDsa#VerifyHash() (does not hash implicitly) the method ECDsa#VerifyData() (hashes implicitly) must be used.
Also, SignerUtilities.GetSigner() returns a signature in ASN.1 format, and ECDsa#VerifyData() expects a signature in r|s format (as you already figured out).
If both are taken into account, the verification is successful:
byte[] publicKey = Convert.FromBase64String("MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEd34IR9wYL76jLyZ148O/hjXo9iaFz/q/xEMXCwYPy6yxbxYzWDZPegG4FH+snXaXQPYD6QIzZNY/kcMjIGtUTg==");
byte[] sha256HashByteArray = Convert.FromBase64String("S3i6LAEzew5SDjQbq59/FraEAvGDg9y7fRIfbnhHPf4=");
byte[] signatureRS = Convert.FromBase64String("10f9tmAIvdD1HSq7Ux8IoKw8VhaIgqjywfzn9W2Twik0vEUB5RTbH4VJZ+FEZfRI4pQgPE9GiKCwIeknGAZddQ==");
var ecDsa = ECDsa.Create();
ecDsa.ImportSubjectPublicKeyInfo(publicKey, out _);
var isValid = ecDsa.VerifyData(sha256HashByteArray, signatureRS, HashAlgorithmName.SHA256);
Console.WriteLine(isValid); // True
Regarding the signature formats:
The posted signature in ASN.1 format
MEUCIQDXR/22YAi90PUdKrtTHwigrDxWFoiCqPLB/Of1bZPCKQIgNLxFAeUU2x+FSWfhRGX0SOKUIDxPRoigsCHpJxgGXXU=
is hex encoded
3045022100d747fdb66008bdd0f51d2abb531f08a0ac3c56168882a8f2c1fce7f56d93c229022034bc4501e514db1f854967e14465f448e294203c4f4688a0b021e92718065d75
From this, the signature in r|s format can be derived as (s. here)
d747fdb66008bdd0f51d2abb531f08a0ac3c56168882a8f2c1fce7f56d93c22934bc4501e514db1f854967e14465f448e294203c4f4688a0b021e92718065d75
or Base64 encoded:
10f9tmAIvdD1HSq7Ux8IoKw8VhaIgqjywfzn9W2Twik0vEUB5RTbH4VJZ+FEZfRI4pQgPE9GiKCwIeknGAZddQ==
I'm using "node-forge" to generate a publicKey to use with my AES symmetric key but I don't know how to use the data provided by my backend to create this publicKey. Currently, I receive from an authentication api the following:
e: "10001"
n:"c7c5dd235568711a943ebbdacac890ca2cf12c1ab539f77726e8874d2ab4220cf06369358b5eff0425fb17d4f696f741cf04c5ea874415e7f67d118a2e763e641e8675b8f42e9277b3f70f14e4de23fe16f51abdc427490f47e4b28ae3e5eb3563ba797fe90f9b70ba878646b1b297c52ba735827682b67309d38b423e31b50b"
maxdigits: "131"
Where "e" is my exponent, "n" is my module and "maxdigits" is the length my BigIntegers are supposed to have.
But when I try something like this:
const keys = forge.pki.rsa.generateKeyPair({ e: res.e, n: res.n });
My backend returns an error. What am I doing wrong?
forge.pki.rsa.generateKeyPair is the wrong method in this context. forge.pki.rsa.generateKeyPair creates a new key pair with random modulus. The first parameter specifies the modulus/key size in bits, the second the exponent ([1] and [2]):
// var forge = require('node-forge'); // in nodejs-context
var pki = forge.pki;
var rsa = forge.pki.rsa;
var keypair = rsa.generateKeyPair({bits: 2048, e: 0x10001});
var pubKeyPEM = pki.publicKeyToPem(keypair.publicKey);
var privKeyPEM = pki.privateKeyToPem(keypair.privateKey);
console.log(pubKeyPEM);
console.log(privKeyPEM);
The forge.pki.rsa.setPublicKey-method is used to generate a public key via modulus and exponent, where the modulus is the first parameter and the exponent is the second parameter ([2]), both of type forge.jsbn.BigInteger ([3]):
var BigInteger = forge.jsbn.BigInteger;
var n = new BigInteger('c7c5dd235568711a943ebbdacac890ca2cf12c1ab539f77726e8874d2ab4220cf06369358b5eff0425fb17d4f696f741cf04c5ea874415e7f67d118a2e763e641e8675b8f42e9277b3f70f14e4de23fe16f51abdc427490f47e4b28ae3e5eb3563ba797fe90f9b70ba878646b1b297c52ba735827682b67309d38b423e31b50b', 16);
var e = new BigInteger('10001', 16);
var pubKey = rsa.setPublicKey(n, e);
var pubKeyPEM = pki.publicKeyToPem(pubKey)
console.log(pubKeyPEM); // Check with e.g. https://lapo.it/asn1js/
I am using this library, node-jwks-rsa, to fetch JWT keys from my auth0 jwks.json file in order to verify that the id_token my application retrieves after authentication is actually coming from my auth provider.
Under the hood it uses this method to build a public key PEM
export function certToPEM(cert) {
cert = cert.match(/.{1,64}/g).join('\n');
cert = `-----BEGIN CERTIFICATE-----\n${cert}\n-----END CERTIFICATE-----\n`;
return cert;
}
(Using the x50c as argument from the .jwks file).
which I then use in combination with jsonwebtoken to verify that the JWT(id_token) is valid.
How is this method of verification different from generating a private key(RSA) from the modulus and exponent of the jwks.json file and using it for verification instead? (as example see this library)
Additionally here is function as demonstration that generates a PEM from a mod and exponent (taken from http://stackoverflow.com/questions/18835132/xml-to-pem-in-node-js)
export function rsaPublicKeyToPEM(modulusB64, exponentB64) {
const modulus = new Buffer(modulusB64, 'base64');
const exponent = new Buffer(exponentB64, 'base64');
const modulusHex = prepadSigned(modulus.toString('hex'));
const exponentHex = prepadSigned(exponent.toString('hex'));
const modlen = modulusHex.length / 2;
const explen = exponentHex.length / 2;
const encodedModlen = encodeLengthHex(modlen);
const encodedExplen = encodeLengthHex(explen);
const encodedPubkey = '30' +
encodeLengthHex(modlen + explen + encodedModlen.length / 2 + encodedExplen.length / 2 + 2) +
'02' + encodedModlen + modulusHex +
'02' + encodedExplen + exponentHex;
const der = new Buffer(encodedPubkey, 'hex')
.toString('base64');
let pem = `-----BEGIN RSA PUBLIC KEY-----\n`;
pem += `${der.match(/.{1,64}/g).join('\n')}`;
pem += `\n-----END RSA PUBLIC KEY-----\n`;
return pem;
};
The aforementioned jsonwebtoken library can verify a JWT using either -- but why? If both of these verification methods can validate a JWT signature why do they both exist? What are the tradeoffs between them? Is one more secure than the other? Which should I use to verify most fully?
Using a RSA assymetric key pair, the JWT is signed with the private key and verified with the public. You can not verify a digital signature with the private key
Modulus and exponent are the components of the public key and you can use it to build the public key in PEM format, which is a base64 representation of the public key (modulus and exponent) encoded in DER binary format. You can use PEM, DER or modulus and exponent because the contain the same information
But anybody can't build the private key with modulus and exponent. He would need the private RSA elements, which must be kept secret so that no one can sign for you.
I want create multisig address on blockcypher api. pubkeys array is required.
$pubkeys = array(
"02c716d071a76cbf0d29c29cacfec76e0ef8116b37389fb7a3e76d6d32cf59f4d3",
"033ef4d5165637d99b673bcdbb7ead359cee6afd7aaf78d3da9d2392ee4102c8ea",
"022b8934cc41e76cb4286b9f3ed57e2d27798395b04dd23711981a77dc216df8ca"
);
But I don't know, how can I create these keys.
For generate public keys you can use bitcore-lib.
For example if you want use HD keys:
const HdPrivate = require('bitcore-lib').HDPrivateKey;
const HdPublic = require('bitcore-lib').HDPublicKey;
const root = new HdPrivate();
function newPublic(root, depth){
//return the public key at depth
return root.derive(depth).publicKey.toString();
}
const publicKey = newPublic(root, 'm/1');
Of course for you must save and keep secret root.
So I'm trying to create a private/public key from 64 characters that I already know using bitcoinjs with the code below:
key = Bitcoin.ECKey.makeRandom();
// Print your private key (in WIF format)
document.write(key.toWIF());
// => Kxr9tQED9H44gCmp6HAdmemAzU3n84H3dGkuWTKvE23JgHMW8gct
// Print your public key (toString defaults to a Bitcoin address)
document.write(key.pub.getAddress().toString());
// => 14bZ7YWde4KdRb5YN7GYkToz3EHVCvRxkF
If I try to set "key" to my 64 characters instead of "Bitcoin.ECKey.makeRandom();" it fails. Is there a method or library that I overlooked that would allow me to use the known 64 characters in order to generate the private key in wif format and the public address?
Thanks in advance to anyone that may be able to offer some help.
You should use fromWIF method to pass your own data.
from source code of eckey.js
// Static constructors
ECKey.fromWIF = function(string) {
var payload = base58check.decode(string)
var compressed = false
// Ignore the version byte
payload = payload.slice(1)
if (payload.length === 33) {
assert.strictEqual(payload[32], 0x01, 'Invalid compression flag')
// Truncate the compression flag
payload = payload.slice(0, -1)
compressed = true
}
To create WIF from your key please follow https://en.bitcoin.it/wiki/Wallet_import_format
Here is interactive tool http://gobittest.appspot.com/PrivateKey
The solution to generate private and public key:
//public-key
var address = eckey.getBitcoinAddress().toString();
var privateKeyBytesCompressed = privateKeyBytes.slice(0);
privateKeyBytesCompressed.push(0x01);
var privateKeyWIFCompressed = new Bitcoin.Address(privateKeyBytesCompressed);
privateKeyWIFCompressed.version = 0x80;
//private-key
privateKeyWIFCompressed = privateKeyWIFCompressed.toString();
Take a look at moneyart.info for beautifully designed paperwallets.