openssl-public-decrypt for Rust

[yardevx]

Hello guys, is there in Rust such functionality like PHP has https://www.php.net/manual/en/function.openssl-public-decrypt.php ? I looked at rust-openssl but can't find such functionality.

[Skepfyr]

PHP uses EVP_PKEY_verify_recover to implement that method, openssl (or in fact openssl-sys) doesn't implement anything exposing that (PRs welcome!). However, why do you want this? Decrypting with a public key is a verify weird operation to want, the OpenSSL docs say this:

Normally an application is only interested in whether a signature verification operation is successful in those cases the EVP_[PKEY_]verify() function should be used.

EVP_PKEY_verify is exposed by PkeyCtxRef::verify.

[xdevor]

this openssl_public_decrypt rust implementation works to me

use openssl::rsa::{Padding, Rsa};

pub struct CryptHelper;

impl CryptHelper {
    pub fn openssl_public_decrypt(public_key_pem: &str, encrypted_data: &[u8]) -> Result<Vec<u8>, openssl::error::ErrorStack> {
        let rsa = Rsa::public_key_from_pem(public_key_pem.as_bytes())?;

        // Create a buffer to hold the decrypted data
        let mut decrypted_data = vec![0; rsa.size() as usize];

        // Perform the decryption
        let decrypted_len = rsa.public_decrypt(encrypted_data, &mut decrypted_data, Padding::PKCS1)?;

        // Truncate the buffer to the actual length of decrypted data
        decrypted_data.truncate(decrypted_len);

        Ok(decrypted_data)
    }
}