CODEWITHSUNDEEP
c#encryptioncryptographyrsabouncycastle
Yusuf ÇAĞRI
Yusuf ÇAĞRI

Reputation: 1

how to encrypt and decrypt with only public key with rsa c#

I want to encrypt and decrypt the RSA using only the public key, but I get an error on the decryption side. Error: "unknown block type" Can you help?

BigInteger rsaPubMod = new BigInteger(Base64.Decode("ALGZqqOFBDh6qULIV0hf5g+Zg5uQqTYWhrw9fzUJwWL8dW7V6kd+9kO8yD+1/f8NVmSDAWGfmVImsPNZp/8x/tF/DycPi5vfRuzHfFcT0mSgD7VW2CfuKM0Gh2WOpgXct6IMC7UsWTkPf8VBSgHobbkr+Ex5pm09mooe2KXTtXN3"));
BigInteger rsaPubExp = new BigInteger(Base64.Decode("AQAB"));
Org.BouncyCastle.Crypto.AsymmetricCipherKeyPair keyPair = new AsymmetricCipherKeyPair(new RsaKeyParameters(false, rsaPubMod, rsaPubExp), new RsaKeyParameters(true, rsaPubMod,rsaPubExp));
RsaKeyParameters pubParameters = new RsaKeyParameters(false, rsaPubMod, rsaPubExp);
IAsymmetricBlockCipher eng = new Pkcs1Encoding(new RsaEngine());
eng.Init(true, pubParameters);
byte[] encdata = Convert.FromBase64String("test");
var encdataResult = eng.ProcessBlock(encdata, 0, encdata.Length);
string result = Convert.ToBase64String(encdataResult);
IAsymmetricBlockCipher deng = new Pkcs1Encoding(new RsaEngine());
deng.Init(false, pubParameters);
byte[] decdata = Convert.FromBase64String(result);
var dencdataResult = deng.ProcessBlock(decdata, 0, decdata.Length);
string result2 = Encoding.UTF8.GetString(dencdataResult);

Upvotes: 0

Views: 1040

Answers (1)

bartonjs
bartonjs

Reputation: 33098

RSA is an asymmetric algorithm. With a public key you can encrypt, or perform signature verification. With a private key you can decrypt, perform signature creation, or create a public key.

Upvotes: 3

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