rsac is software that performs encryption and digital signature using RSA public key cipher.
It supports keys of 512-bit, 1,024-bit and 2,048-bit long.
It does not support keys of 4,096-bit long.
As the encryption method, it supports PKCS#1 v.1.5 and RSA-KEM.
The digital signature uses PKCS#1 v.1.5 as a method.
The storage format is PKCS#7 SignedData.
You can use X.509 Public Key Certificate, PKCS#12 for encryption and creation (sign) and verification of digital signatures.
It can be used by any application that conforms to the standard specification.
It has a simple structure, but you can also create an X.509 public key certificate and PKCS#12.
rsac does not support DSS, DSA, ECDSA, and Elliptic Curve Cryptography etc. at all.
In addition, as auxiliary ones, random number split cipher, block cipher (AES-256-CBC), hash function, HMAC etc. are also implemented.