RSA Cryptography with raw keys, c# -

i have been given 256 byte modulus ('n'), 256 byte private exponent ('d') , 3 byte {1,0,1} public exponent ('e'). trying sign 32 bytes of data.

i have tried create new rsaparameters.

byte[] n = new byte[256]; //populated in code  byte[] d = new byte[256]; //populated in code byte[] e = new byte[]{1,0,1};  byte[] junkdata = new byte[32]; //populated in code  rsaparameters rsaparam = new rsaparameters(); rsaparam.modulus = n; rsaparam.exponent = e; rsaparam.d = d; 

i create rsacrytoserviceprovider, import parameters it, , try sign data.

var csp = new rsacryptoserviceprovider(2048); csp.importparameters(rsaparam); csp.signdata(junkdata, new sha1cryptoserviceprovider()); 

the problem rsacryptoserviceprovider appears public only, , when try sign receive 'keyset not exist' cryptography exception.

do need p , q elements sign data, or doing wrong? help!

i'm surprised importparameters didn't throw (are using mono?).

rsacryptoserviceprovider (and of rsa implementations in .net framework , .net core) require populated rsaparameters structure private keys.

https://stackoverflow.com/a/42117655/6535399 gives answer in bit more detail.