Android: InvalidKeySpecException:编码密钥规范未被识别

Question

当我试图用字符串实现RSA公钥时。我在下面提到了例外。我正在尝试验证Android中生成的密钥(string，使用Swift)。如何将字符串转换为私钥/公钥？

static PublicKey getRSAPublicKeyFromString (String publicKeyPEM){
    try {
        KeyFactory keyFactory = KeyFactory.getInstance("RSA", "SC");
        byte[] publicKeyBytes = Base64.decode(publicKeyPEM.getBytes("UTF-8"), Base64.DEFAULT);
        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(publicKeyBytes);
        return keyFactory.generatePublic(x509KeySpec);
    }catch (Exception e){
        e.printStackTrace ();
    }

    return null;
}

异常

java.security.spec.InvalidKeySpecException: encoded key spec not recognised
at org.spongycastle.jcajce.provider.asymmetric.util.BaseKeyFactorySpi.engineGeneratePublic(BaseKeyFactorySpi.java:52)
at org.spongycastle.jcajce.provider.asymmetric.rsa.KeyFactorySpi.engineGeneratePublic(KeyFactorySpi.java:130)
at java.security.KeyFactory.generatePublic(KeyFactory.java:172)

ios中的公钥：

MIGJAoGBAOibWF15OhLJQAWpQN++UFqyG+2uLEG8PPvCajwwh6FWi6jLiZ9VN+l3JpiJTQwF/yxlSJCZCoYnljKeRBnNxpzBnuTJsyuZ4hI8ehLzDvh9nYzX/TlcZYVshJzyIVRZAbuFOCLNIltjB+Qmw8YGlxzeDSFaB6eEC1OP49hDakURAgMBAAE=

Answer 1

不幸的是，您拥有的是一个base64编码的PKCS#1 RSAPublicKey，这是Java不产生或消耗的东西。Java生成并使用了一个稍微通用和稍微复杂的X.509 SubjectPublicKeyInfo。

使用邦西城堡库，下面是一些生成RSAPublicKey的示例代码：

import org.bouncycastle.asn1.ASN1InputStream;
import org.bouncycastle.asn1.ASN1Primitive;

import java.security.KeyFactory;
import java.security.PublicKey;
import java.security.spec.RSAPublicKeySpec;
import java.util.Base64;

public class Main {

    public static void main(String[] args) throws Exception {
        String pubkey64 = "MIGJAoGBAOibWF15OhLJQAWpQN++UFqyG+2uLEG8PPvCajwwh6FWi6jLiZ9VN+l3JpiJTQwF/yxlSJCZCoYnljKeRBnNxpzBnuTJsyuZ4hI8ehLzDvh9nYzX/TlcZYVshJzyIVRZAbuFOCLNIltjB+Qmw8YGlxzeDSFaB6eEC1OP49hDakURAgMBAAE=";
        PublicKey rsaPub = readRSAPublicKey(pubkey64);
        System.out.println(rsaPub);
    }

    private static PublicKey readRSAPublicKey(String pubkey64) throws Exception {
        byte [] derRsaPubBytes = Base64.getDecoder().decode(pubkey64);
        ASN1Primitive asn1Prime = new ASN1InputStream(derRsaPubBytes).readObject();
        org.bouncycastle.asn1.pkcs.RSAPublicKey rsaPub = org.bouncycastle.asn1.pkcs.RSAPublicKey.getInstance(asn1Prime);
        KeyFactory kf = KeyFactory.getInstance("RSA");
        return kf.generatePublic(new RSAPublicKeySpec(rsaPub.getModulus(), rsaPub.getPublicExponent()));
    }
}