How to create SecKey from pem file in Swift-CodePudding

I'm trying to create a SecKey using SecKeyCreateWithData. I'm loading the private key from a .pem file, and I create the key pair like this.

openssl genrsa -des3 -out WM_IO_my_rsa_key_pair 2048

Here is the code, but I get a SecKeyCreate init(RSAPublicKey) failed: -50 error.

import UIKit
import Security

func createKey(pem: String) -> SecKey? {
    let attributes: [NSObject : NSObject] = [
       kSecAttrKeyType: kSecAttrKeyTypeRSA,
       kSecAttrKeyClass: kSecAttrKeyClassPrivate,
       kSecAttrKeySizeInBits: NSNumber(value: 2048)
    ]

    let privateKey = pem
        .replacingOccurrences(of: "-----BEGIN PRIVATE KEY-----", with: "")
        .replacingOccurrences(of: "-----END PRIVATE KEY-----", with: "")
        .split(separator: "\n").joined()

    guard let privateKeyData = Data(base64Encoded: privateKey, options: .ignoreUnknownCharacters) else {
        return nil
    }

    var error: Unmanaged<CFError>?
    return SecKeyCreateWithData(privateKeyData as CFData, attributes as CFDictionary, &error)
}

let privateKey = """
-----BEGIN PRIVATE KEY-----
MIIEvgIBADANBgkqhkiG9w0BAQEFAASCBKgwggSkAgEAAoIBAQCpySPOXAAsi1jN
vxDrNfinFOUZlLk38P8BF2ukJWU7OOAXol6TG8fFrn8O UVW4jjPTZjLT9G6385N
iervmwopS5CtHS2p0ptLm1ExigZAuS/LTaIkw3yugr4b 5roEwL9nFW0Qfd4o/ds
3lKPtdwtO0rfqTfuZ6CqcQP0sTJcky7nk3mIyz6jZOZE2QLL/oF/oUKsi5Wt5uJp
uluZ gt087Ftm1oGKR8lZt5bucbD7WZnmlckNyUh7O973mqqDZ6zTwrgNuxIBmtr
afNetsgZv6/We56IWenKayWW1xA9icPhmViJtzPU3Gu8HW/FMovyRZAMFD1Yzf L
eiSGC5x9AgMBAAECggEAGOrN HEEDYV9yOQrhXlsPokQfkqXTCBwLCbVw0dBrglQ
yecoXgqLrPVI7Fek13VnxPSsYdoa 4Pw8Ow2sGdefGT8nItVskCYTeZDajPJayJC
Y2HHVAHkgG/rmou4VirEG5gf885ilS/rFe0izLhx0amL XsKHFDVAW6ImBaRP4iU
82fkZtLlh4DLi6w/oNu3ePZkMeTl4aAkJH8gRy2Mzsyl0DNi5 mH0du12BVSca58
iAXEhufIweTvDqb3lx0CR5 0 dbk/MeIvoklDCkPAlK9IOXr9m0UYjWXNYTADLi8
PmQf8k7pf74ma/2bFuT8LakIA6z3HEwLO7iKm4VVOQKBgQDYVG7AJWJL3DDMCpz3
csP fKccr72Q3VKCZ5uq0jC/Wp4jfNip/b76Rt3xb8nqzgIDntu B6Vzz6HPB5d4
j8510lNZrRzIQj0unxOx7pJHIGHhGv2dJ00IqVa5aNL8aCNhxXhgR3vIojyoo8R9
nc4WAQu4ID xOCsqtvNBm6T1jwKBgQDI67Obqjqt1IDWV5/7dJundWEtfGBdHYBd
iuVxoyqOKAeasaWXuUxJgpzy/ukIAuI5WtzR8nP/US8MIUkRj7eXDi3E2tgpkUwZ
IT9StEdXM8UznpyXfQX9oMmlHC8MZRwLJkldcbGMjsfXsVcAMbe HBmXs izsxqe
icsEPPe/MwKBgQDU2O5HPAElJrcUa3TZux/AayF5hih8OmcOS6bMQhcYj658uD/t
se6QDd4dyaHf12X/7fPDW36dHjPUoWGVi9jV8GV2HG/vUc0k6/vS3CsstF3ZwFa8
o4iV9xePQeYl1sjJUCQKhwrx8z6/prKT7gpxeAHx3jkMw3klg/CAIwYBXQKBgFIc
OT Rlv95S9nM352k7wPFrZwoKz2Ck/YmkFQbiYWlCE6I8RKLcIjOLxQDZvqWKxuj
bYEDY7Jg3ChJ5hGeOTorWjsL8LE0JvRSKQ3EjS8vAhVxaa9jMbKQJjgqx3N6Uraf
w/XDQ/scUsFsQRDcQKoZ07 yj5P4yxUlXOlzfRAPAoGBALri0o6PhjRRPwKzE3gO
ClUJ1KTEhA55GOPs5ZDPxDckYigSC R8nLLxeueFiFkIDrar85tiO9J4P0j7tovB
Ivu6 QWQso3U3RC2Deb3uWagKHOt9m DB8LdKsLpY/aPUXzPKKXJ4BWVIYExm418
FUzB7PCpc0Cdjg6A7Ca2cP0U
-----END PRIVATE KEY-----
"""

createKey(pem: privateKey)

CodePudding user response：

The pem key is base64 encoded, so you need to decode it first:

guard let privateKeyData = Data(base64Encoded: privateKey, options: .ignoreUnknownCharacters) else {
   ...