c++ - Encrypt data with RSA public key in Java and decrypt in Crypto++ -

i'm trying encrypt data rsa public key in java , decrypt in crypto++. results in error:

"rsa/eme-pkcs1-v1_5: ciphertext length of 24 doesn't match required length of 128 key"

what doing wrong?

java:

string cipher = encryption.encryptstrrsa(txt, pubkeyk);  public static string encryptstrrsa(string str, publickey pubkey)     throws nosuchalgorithmexception, nosuchpaddingexception, invalidkeyexception,     illegalblocksizeexception, badpaddingexception, nosuchproviderexception {      cipher cipher = cipher.getinstance("rsa/none/pkcs1padding", "bc");     cipher.init(cipher.encrypt_mode, pubkey);      byte[] encryptedaeskey = cipher.dofinal(str.getbytes());     string cipherstr = new string(encryptedaeskey);      system.out.println(cipherstr);     return cipherstr; }  public static publickey strtopublickey(string key64) throws generalsecurityexception {     byte[] data = base64.getdecoder().decode(key64);     x509encodedkeyspec spec = new x509encodedkeyspec(data);     keyfactory fact = keyfactory.getinstance("rsa");     return fact.generatepublic(spec); }  public static string publickeytostr(publickey publ) throws generalsecurityexception {     keyfactory fact = keyfactory.getinstance("rsa");     x509encodedkeyspec spec = fact.getkeyspec(publ, x509encodedkeyspec.class);     return base64.getencoder().encode(spec.getencoded()).tostring(); } 

crypto++:

using namespace cryptopp;  rsaes_pkcs1v15_decryptor priv(privstring); stringsource( cipher, ciphersize, true, new  base64decoder( new pk_decryptorfilter(randpool, priv, new stringsink(sdata)))); 

it dangerous use string instances keeping binary data -- should use byte[] instead.

additionally, in java code there no base64 wrapping of resulting ciphertext, in c++ code being unwrapped base64.

modified code return byte[] , encode result using base64:

public static byte[] encryptrsa(string str, publickey pubkey) throws nosuchalgorithmexception, nosuchpaddingexception, invalidkeyexception, illegalblocksizeexception, badpaddingexception, nosuchproviderexception {     cipher cipher = cipher.getinstance("rsa/ecb/pkcs1padding", "bc");     cipher.init(cipher.encrypt_mode, pubkey);     return cipher.dofinal(str.getbytes()); }  string cipher = base64.getencoder().encodetostring(encryption.encryptrsa("0123456789abcdef", pubkeyk)); 

then can decrypt in crypto++ same way did.

good luck!