smimeasym ~master

smimeasym S/MIME asymmetrical encryption

So the problem to solve is that I needed a function that encrypts an array of ubytes with multiple public keys. The resulting, encrypted, array of bytes, when saved to a file, should be decrypted-able by any private key matching any of the used public key. This should be possible with the openssl cli.

Usage

Key pair suitable

openssl req -x509 -newkey rsa:4096 -days 3650 -nodes -subj "/C=US/ST=*/L=*/O=*/OU=*/CN=Frank/" -keyout frank.key -out frank.pub

There are two main functions

ubyte[] smimeEncryption(ubyte[] buf, string[] publicKeyFilenames);

ubyte[] smimeDecryption(ubyte[] buf, string privateKeyFilename);

X509* loadCert(string filename);
X509* loadCertFromString(string theCert);
void freeCert(X509* certToFree);

ubyte[] smimeEncryptionWithCerts(ubyte[] buf, X509*[] certs);
EVP_PKEY* loadKeyFromString(string data, string password = "");
ubyte[] smimeDecryptionWithKey(ubyte[] buf, EVP_PKEY* key);

The opencli should be able to decrypt created files from the data from smimeEncryption with the following shell command

openssl smime -decrypt -in secrets.txt.enc -inform PEM -inkey bob.key

Tests

The password for the private key frankwithpass.key is foobar.