c# - How to create digital signature(RSA) of file's checksum? -

c# - How to create digital signature(RSA) of file's checksum? -

welcome! job implement digital signature. i've read creating public , private key i'm stuck silly thing. how encrypt checksum(sha256) using rsa algorithm? mean part: c(m) = m ^ e mod n. should convert checksum(which hex?) int, can compute ^e mod n?

you don't encrypt checksum sign it. if utilize c#, take @ rsacryptoserviceprovider class, in particular in msdn's cryptographic signatures section contains detailed description of process.

however seems reinventing wheel , going low-level. maybe higher-level libraries bouncycastle or free cryptoblackbox bundle of our secureblackbox easier use.

c# rsa digital-signature sha256