在转换格式的SubjectPublicKeyInfo公钥来RSAPublicKey格式的Java(C

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:

使用充气城堡的SubjectPublicKeyInfo ，就像这样：

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

Answer 2:

Without BouncyCastle:

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

Answer 3:

下面的代码片段工作对我来说，不得不虽然使用BouncyCastle的。

byte[] keyBytes = key.getEncoded(); // X.509 for public key
SubjectPublicKeyInfo subPkInfo = new SubjectPublicKeyInfo((ASN1Sequence)ASN1Object.fromByteArray(keyBytes));
byte[] rsaformat = subPkInfo.getPublicKey().getDEREncoded();

文章来源: Converting A public key in SubjectPublicKeyInfo format to RSAPublicKey format java