java - 无法使用私钥签署数据，获取 swift 中 key 不支持的算法

Question

我使用以下代码快速生成了私钥:

 let publicKeyAttr: [NSObject: NSObject] = [
                kSecAttrIsPermanent:true as NSObject,
                kSecAttrApplicationTag:"com.xeoscript.app.RsaFromScrach.public2".data(using: String.Encoding.utf8)! as NSObject] // added this value
        let privateKeyAttr: [NSObject: NSObject] = [
                kSecAttrIsPermanent:true as NSObject,
                kSecAttrApplicationTag:"com.xeoscript.app.RsaFromScrach.private2".data(using: String.Encoding.utf8)! as NSObject] // added this

        var keyPairAttr = [NSObject: NSObject]()
        keyPairAttr[kSecAttrKeyType] = kSecAttrKeyTypeRSA
        keyPairAttr[kSecAttrKeySizeInBits] = 2048 as NSObject
        keyPairAttr[kSecPublicKeyAttrs] = publicKeyAttr as NSObject
        keyPairAttr[kSecPrivateKeyAttrs] = privateKeyAttr as NSObject

        statusCode = SecKeyGeneratePair(keyPairAttr as CFDictionary, &publicKey, &privateKey)

然后我使用SecKeyAlgorithm.rsaEncryptionPKCS1 算法使用私钥对一段数据进行签名。

签名代码如下:

 public func sign(privateKey myPrivateKey: SecKey, value: String, base64EncodingOptions: Data.Base64EncodingOptions = []) throws -> String?
    {
        enum LoginErrors: Error {
            case badUsername
            case badPassword
        }
        guard #available(iOS 10.0, watchOS 3.0, tvOS 10.0, *) else {
               return "Not available"
           }
        let data = value.data(using: .utf8)!

        var error: Unmanaged<CFError>?
        guard let signedData = SecKeyCreateSignature(myPrivateKey,
                                                     SecKeyAlgorithm.rsaEncryptionPKCS1,
                                                     data as CFData,
                                                     &error) as Data? else
        {
            return nil
        }
        return "(signedData.base64EncodedString())"
    }

我收到此异常:

[0] (null)  "NSDescription" : "algid:encrypt:RSA:PKCS1: algorithm not supported by the key <SecKeyRef algorithm id: 1, key type: RSAPrivateKey, version: 4, block size: 2048 bits, addr: 0x280a0e5a0>"  

Answer 1

SecKeyAlgorithm.rsaEncryptionPKCS1 不正确，这是尝试使用 RSA 私钥进行混合加密。

而是传递适当的内容，例如 rsaSignatureDigestPKCS1v15SHA256、rsaSignatureDigestPSSSHA256 或显示的其他选项之一 here .

请注意，rsaSignatureDigestPKCS1v15SHA256 是确定性的。

此外，我建议在 2020 年使用椭圆曲线签名、RSA，无论多么诱人，都是错误的选择。

现在有很多支持 ECC 的华丽库，我不会使用 SecKit。