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RSAES-OAEP Encrypt String with AES-128 Content Encryption and SHA256

See more Encryption Examples

Encrypts a string using RSAES-OAEP with SHA256 and AES-128 content encryption to produce PKCS7 output (base64 encoded).

Note: This example requires Chilkat v9.5.0.67 or greater.

Zig

const std = @import("std");
const chilkat = @import("chilkat");

pub fn main(init: std.process.Init) !void {
    const alloc = init.arena.allocator();

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    // First build a string to be encrypted
    const sb = try chilkat.StringBuilder.init();
    defer sb.deinit();
    var i: i32 = 1;
    while (i < 25) {
        sb.appendInt(i) catch {};
        sb.append(" the quick brown fox jumped over the lazy dog.\r\n") catch {};
        i = i + 1;
    }

    std.debug.print("{s}\n", .{try sb.getAsString(alloc)});

    // The string to be encrypted looks like this:

    // 1 the quick brown fox jumped over the lazy dog.
    // 2 the quick brown fox jumped over the lazy dog.
    // 3 the quick brown fox jumped over the lazy dog.
    // 4 the quick brown fox jumped over the lazy dog.
    // 5 the quick brown fox jumped over the lazy dog.
    // 6 the quick brown fox jumped over the lazy dog.
    // ...

    // Load a digital certificate.
    // We don't need the private key for encryption.
    // Only the public key is needed (which is included in a certificate).
    const cert = try chilkat.Cert.init();
    defer cert.deinit();
    cert.loadFromFile("qa_data/rsaes-oaep/cert.pem") catch {
        std.debug.print("{s}\n", .{try cert.getLastErrorText(alloc)});
        return;
    };

    const crypt = try chilkat.Crypt2.init();
    defer crypt.deinit();

    // Tell the crypt object to use the certificate.
    crypt.setEncryptCert(cert) catch {};

    // Indicate that we want PKI encryption (i.e. public-key infrastructure)
    // to produce a CMS message (Cryptographic Message Syntax/PKCS7),
    // that is be created with RSAES-OAEP padding, SHA256, and AES-128 for the
    // bulk encryption.
    crypt.setCryptAlgorithm("pki");
    crypt.setPkcs7CryptAlg("aes");
    crypt.setKeyLength(128);
    crypt.setOaepHash("sha256");
    crypt.setOaepPadding(true);

    // Also, don't forget to be specific about the character encoding (byte representation) of the
    // string to be encrypted.
    crypt.setCharset("utf-8");

    // Now indicate that the PKCS7 output is to be returned in the base64 encoding.
    crypt.setEncodingMode("base64");

    const base64_pkcs7 = crypt.encryptStringENC(alloc, try sb.getAsString(alloc)) catch {
        std.debug.print("{s}\n", .{try crypt.getLastErrorText(alloc)});
        return;
    };

    // Show the output
    std.debug.print("{s}\n", .{base64_pkcs7});

    // This base64 can be copy-and-pasted into the form at http://lapo.it/asn1js/
    // to verify that all the chosen algorithms were indeed used.

    std.debug.print("OK.\n", .{});
}