从SubjectPublicKeyInfo获取公钥

Question

我正在尝试从SubjectPublicKeyInfo 获取公钥。但是当我尝试时：

PublicKey publicKey = k.generatePublic(keypsec);

byte[] encoded=publicKey.getEncoded();
SubjectPublicKeyInfo subPkInfo2 = new SubjectPublicKeyInfo(rsaEncryption, encoded);     
RSAPublicKeyStructure  pubKey = new RSAPublicKeyStructure((ASN1Sequence)subPkInfo2.getPublicKey());

它抛出这个

java.lang.IllegalArgumentException: illegal object in getInstance: org.bouncycastle.asn1.DERSequence
    at org.bouncycastle.asn1.DERInteger.getInstance(DERInteger.java:37)
    at org.bouncycastle.asn1.x509.RSAPublicKeyStructure.<init>(RSAPublicKeyStructure.java:63)

有任何想法吗？我尝试过 PubliKeyFactory 但它只是调用最后一行。

Answer 1

好吧，我将回答我自己的问题：

byte[] encoded=publicKey.getEncoded();
SubjectPublicKeyInfo subPkInfo2 = new SubjectPublicKeyInfo(rsaEncryption, encoded); 

这是错误的。PublicKey 已经是 ASN1typeSubjectpublicKeyInfo。为了用这个函数创建一个SubjectPublicKeyInfo

SubjectPublicKeyInfo(AlgorithmIdentifier algId, byte[] publicKey)

您需要一个算法标识符和编码形式的密钥本身。publicKey.getEncoded() 是一个编码的密钥+算法标识符。

反正。如果您想将 SATSA 公钥转换为主题公钥信息，您可以执行以下操作：

byte[] publickeyb=SATSApublickey.getEncoded();
    SubjectPublicKeyInfo subPkInfo = new SubjectPublicKeyInfo((ASN1Sequence)ASN1Object.fromByteArray(publickeyb));

如果你想从SubjectPublicKeyInfo 获取你的公钥作为RSAkeyparameters

RSAKeyParameters param=(RSAKeyParameters) PublicKeyFactory.createKey(subPkInfo);