nodejs webcrypto imporKey rsa error "error:0D07207B:asn1 encoding routines:ASN1_get

Ok, so I was building an application and using RSA to decrypt data encrypted from the browser's webcrypto and I was getting a strange error before the web side even started.. I tried searching the error but I didn't find anything helpful.. I'm using nodejs(v16.10.0)

//failing nodejs example
var crypto=require('crypto')
var privateKeyStr=`-----BEGIN PRIVATE KEY-----
REAL_PRIVATE_KEY_HERE
-----END PRIVATE KEY-----`
function str2ab(str) {
    const buf = new ArrayBuffer(str.length);
    const bufView = new Uint8Array(buf);
    for (let i = 0, strLen = str.length; i < strLen; i  ) {
        bufView[i] = str.charCodeAt(i);
    }
    return buf;
}
function ab2str(buf,getOwnPropertyNames) {
    var buff=new Uint8Array(buf)
    return Object.getOwnPropertyNames(buff)
    .map(i=>String.fromCharCode(buff[i])).join('')
}

atob=(text)=>Buffer.from(text,'base64').toString()
btoa=(text)=>Buffer.from(text).toString('base64')

let pemHead1="-----BEGIN PRIVATE KEY-----", pemFoot1="-----END PRIVATE KEY-----"

var prvKeyText=atob(privateKeyStr.substring(pemHead1.length,privateKeyStr.length-pemFoot1.length));

(async()=>{
  prvKey=await crypto.webcrypto.subtle.importKey('pkcs8',str2ab(prvKeyText),{name:"RSA-OAEP",hash:"SHA-256"},true,['decrypt'])
  
  rsa_decrypt=async(secret_text)=>ab2str( await crypto.webcrypto.subtle.decrypt('RSA-OAEP',prvKey,str2ab(atob(secret_text))) )
})()

And this kind of code for webcrypto does work in the browser but it fails in nodejs(v16.10.0)

//working web example(yes this is not a private key I'm using)
var privateKeyStr=`-----BEGIN PRIVATE KEY-----
MIIJQgIBADANBgkqhkiG9w0BAQEFAASCCSwwggkoAgEAAoICAQDUXCf0zdHCtVGY
kGAP0cSHZcdt5R A0wiYNYmGa4Q4TmyZxI8w2HjrbREwH51c/rJ7KxEwPmx288zX
yESmswSDENS/mb 5Kvo oHZCLFHzL z VoCBLDUGCMDMEs1nyEDjsXlLXkuceR6Y
n/YSjy/jSA8ens/Q883PseXPetJBtKxmixVS9DKGuLgYuz22XwaKEOB5SD5WIa0f
Rj8WkS5NU 7GBoAFPtCTNcq1D3qKhb4ifoQIeUfKz8ITrNSQ8hUYrkNSOirJj9tk
K4pb/QHu/pKqL7eoFlNiwbP0FhoWdmSPTbU4xYpSAyjT/qT dGOXEIZxI623tDO3
ZNVDPcF9Sm6rGqrsWbUfkBK413ZX6I98g2aktsHsHaNNLrRU6l p0T0l89 bNDt7
r/vgWV0FWbzyXHbZBhDhLj6eWL8lLAPQlYtgkpsZNZkZRT3wdzeRAAm7WVKeODW9
e5wg5WJpJ EkbBZBaLqtXi4P84eNieg2q4nhyiC  XyokfNtKreideKnRqp9R84h
O19iu 2MEeiy1mJvqqIwa0bhsSHzr6aO4HBgWDn5ierdLQo2EuFNDblGlao98h26
3BJO5bBurVAczbdYJvT8rLCUEwYsDwAnXMeXs3ezv4hualp3VeExgyiYoPZUIPZS
eh8zbk6Gnaz8mmSkRPyKl4gbDzS5 QIDAQABAoICAA2OtJ5UZYfgu4zZ6sgXxExA
mzLQ5en7jxjokhca1h4iI5zNh7a mzmshORloE5HlG14mmhSE qkNfewuXFLDIax
lGOHFU5lCATniaU/3xt/e8nhC MzR09TT7u3l5WAm2Pt KhvJLSgputnivY0XgJM
n2p9CRd1 TXBTcKpPLMlLbx NKZPIMqpEFfD3HTALFK0MSCNFC27iKnueiierC4T
pbLOx22OTRKY5JAapOAjGbhqC1PfKk4wZVuMNSXrzpz8wx ExyaHIKKMhRDKXk07
w3FKCpeYlUpAw5RZtOCqPlFHzMILGoGR4hFmuHHmTFVgoLSoanbH8mVK8rKQRsHz
KdQ8tLquQpnXf P Vx4hAP9cyjpfJWwQDtv3jq /bJiyrM50wJhYekimLEGfSQ0n
8k5vza1Q27/Rz1lG4A3YGew4ywbpsluY3QfT5tUVN ixtiNC15pbIE4LfUd0MN17
8MeQqHwiRVGBZzvGBebssuVw96kUOhZBGZ7DqjpaJU5WDBhXInkFTQNyPrwp d2K
FhwpAwWgPC7b8AIZPSj14aBr60ZDPv CM2Uug9Yc26ZRP emQVEGl6S1dEPDX/hV
Oe2tkjYtkqzwm1XwB5t0Dsvo60i4A5 NBYXzb8g hSqB9Cbr4uhkVGV1DZdk67bj
 5OX  wlMLyt04QtIwmBAoIBAQDzkUhryv4Ue/uCz5tXuY/qyUV1tOJFaGYBdVnQ
FIv6mOIHexMlAiSQnd0h CxTu8kx3 rqL3P6p97ErxYQ2YjmhczR0E4CBemLzxzV
CPLAJnKG I5fjSS QIDezSdn5hOZs0fhsGkfQmZ3x0WaYQDwiny5Hzfe4Ddoi4Ta
/Fms1h6rlB7gHY842GqskYgp6LjNoYEwAVMEVag3RwE2KIq034L6OywD  LhWOVi
itcWLUlyUzsrBxqgIfSkUFXK6GU8uqOwaZ2GIfn5/smRwaXj1WyJjG1zZT6wZ/Bl
Ku tSImKPYrvctp61Ob7IhwdliNOvvXR7xXTeftZeZVenLrlAoIBAQDfMxTx3/fg
jk4E1b8jCN4CuPoA3tflXrY70TEkNpaiqWdnhkmI7U3yQv70gYNYrbCXf6L5H w7
UH5mrLZmpyhBGeVAGweB0gw5K1nfZtuxYIsKBpefh/iTP5EPokBgGN3TysVyaPph
2uvvKsG0lN6sWDYKFtY5YDG2JoBkq9Ek0NfGu0v/GOmqvGXWn/CNu v9FGUZdUOb
6LuXbxwe/yY5Re02Qcwo2JjJrWqz60OIlnNmJ1XuP9EXsakGv/DOMYnbJylb9txq
cHh2eJxJneLyP8eRsIp6DhQaExgmHqmJbYTIipJXVi5QqtsCeSXYm0ZygtsASjqs
cFWSPGlCgg2FAoIBAQCuCDHR63IOWuRD/GkHjmwZm4SI7Rz78PNpuVraBcRa42Al
bjgoqlZMCrAVdIjfr367pz3n5M4e3FGdAWln0rcx14qYpBkI8waDwhHc2g7xYsdU
T0cTWPtXASnTiIzOfSOmH aNiQojrsMedID0JLmSJbGmaHr4Qgb1KTNdcQ/2Iew6
NpS1GAnc2S2nbjj3kPRy4SI4lcmmgDm4fYCNHPy27jlc6Giz1Aexcl48Qe4bR3KC
QJw3S1Un8/skaM5UNCcZ9FW/WEeYrrA5g2atQctxdm6d/Xu7By16yFmJP9uPWhQE
daLPIqafO35rFF04eq1xt5pXTViwCSmiLfCfcKdNAoIBACFhGUvG6 IYRhCxCqGp
rNIJadIBgZYa4PP3J/s7crGm1gEEczDYFGUbodddGxCDATrW6r JB6IjOpQOVkTp
0LpTrhY1NJ00lYFjO1COqGJRhtmb/Mbt5b3XrtEAudHlRh9rXrXqfy9tNwWQhmGE
NfzeQE6n9aek/Co6fc8QZvmzheGBly7yQde3zx8W0jnQFc3GZAw3nkHNv2g5RKJa
FBRSodQQaQDey5K1rZR0pafioCVx0ocL4jBB8H5C7DdZ7zzoEWZgd7wvT8Sf6veT
diI2aZkfJsZ0Hot7uYvR4BbeWxJGrvYCvHBx7Mjk50UKi7GKYkgb0cSCFDoHcNJy
cqUCggEAGJ 31rAPfxH7FXneYlMY9r2KlzAEWFSVFulDJpQNWEhqCQ1XvgqnVoCv
ymjZ8MqwpfAiu4Tiu9/mWY7qKLSxAJscu3qRpDDAU9qLQV67zHp/7/b5X7 j7Hjb
kg2 8sn/ZfIJLHhLueBniNU41xc2IEe/o52bd17juhj5BYFjiv7on83xcCKiGVxm
Em3IXian5uXHg58lb95XNs8rbpjbcNFC7CGtPFfd/sKH16ciButT6C14lXrEL3vH
i8L9n lbKM3UZDFmLO113GSCP adCmXiqSs6DgTiL71KrbNgtbNp4UvskxCq5xRf
PotgmE7pY/5T04uDwhpWK5TOFnCnXg==
-----END PRIVATE KEY-----`
function str2ab(str) {
    const buf = new ArrayBuffer(str.length);
    const bufView = new Uint8Array(buf);
    for (let i = 0, strLen = str.length; i < strLen; i  ) {
        bufView[i] = str.charCodeAt(i);
    }
    return buf;
}
function ab2str(buf,getOwnPropertyNames) {
    var buff=new Uint8Array(buf)
    return Object.getOwnPropertyNames(buff)
    .map(i=>String.fromCharCode(buff[i])).join('')
}

let pemHead1="-----BEGIN PRIVATE KEY-----", pemFoot1="-----END PRIVATE KEY-----"

var prvKeyText=atob(privateKeyStr.substring(pemHead1.length,privateKeyStr.length-pemFoot1.length));

(async()=>{
  prvKey=await crypto.subtle.importKey('pkcs8',str2ab(prvKeyText),{name:"RSA-OAEP",hash:"SHA-256"},true,['decrypt'])
  
  console.log("it works normally")
  console.log(prvKey) //so clearly I don't understand webcrypto in nodejs v16.10.0
  
  rsa_decrypt=async(secret_text)=>ab2str( await crypto.subtle.decrypt('RSA-OAEP',prvKey,str2ab(atob(secret_text))) )
})()
//if an error happened you would see it.. but in your browser it works normal

CodePudding user response：

This is due to your atob() and btoa() methods defined for NodeJS.

Buffer.from() and Buffer#toString() apply UTF-8 by default if no other encoding is specified. However, UTF-8 generally corrupts arbitrary binary data. Instead of UTF-8 use binary as encoding:

atob = (text) => Buffer.from(text, 'base64').toString('binary')
btoa = (text) => Buffer.from(text, 'binary').toString('base64')

With this fix the import works and the error message is no longer displayed.