将SubjectPublicKeyInfo格式的公钥转换为RSAPublicKey格式java

Question

该PublicKey.getEncoded(),返回包含的SubjectPublicKeyInfo(X.509)格式的公钥的字节数组,我如何将其转换为RSA公共密钥编码？

Answer 1

使用Bouncy Castle SubjectPublicKeyInfo,就像这样:

byte[] encoded = publicKey.getEncoded();
SubjectPublicKeyInfo subjectPublicKeyInfo = new SubjectPublicKeyInfo(
    ASN1Sequence.getInstance(encoded));
byte[] otherEncoded = subjectPublicKeyInfo.parsePublicKey().getEncoded();

Answer 2

没有 BouncyCastle：

PublicKey publicKey = KeyFactory.getInstance("RSA").generatePublic(new X509EncodedKeySpec(publicKeyBinary));