Android-Java RSA Decrypt

i need to create a public key for RSA algorithm from a binary string. My code is: String pubKey = 'tihq/Gk3OUs5NzP+XTRKXBwSxHtB0TWn0RREcpXEtp316tyD9DzKaIbdKexb/mRr'; byte[] keyByt

Solution 1:

SOLVED. The problem is that i have modulus and exponent and so i must to do this:

String pubKey = "tihq/Gk3OUs5NzP+XTRKXBwSxHtB0TWn0RREcpXEtp316tyD9DzKaIbdKexb/mRr"; //64 caratteri
String exponent = "AQAB";

byte[] keyBytes = Base64.decode(pubKey,Base64.DEFAULT);
byte[] exponentByte = Base64.decode(exponent,Base64.DEFAULT);

KeyFactory keyFactory = KeyFactory.getInstance("RSA");

RSAPublicKeySpec pubKeySpec = new RSAPublicKeySpec(new BigInteger(keyBytes), new BigInteger(exponentByte));
RSAPublicKey publicKey = (RSAPublicKey) keyFactory.generatePublic(pubKeySpec);