Objective-C

openssl smime -encrypt -des3 -in <file> <pem file>

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OpenSSL SMIME encrypt file using PEM containing a certificate. Objective-C

#import <CkoPem.h>
#import <CkoCert.h>
#import <CkoCrypt2.h>
#import <CkoBinData.h>
#import <CkoStringBuilder.h>

BOOL success = NO;

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

// Load the cert from a PEM file.

CkoPem *pem = [[CkoPem alloc] init];
// Our particular PEM was not encrypted, so we pass an empty password.
// Also, a private key is not needed for encryption.  The PEM used to test this example
// happens to have a private key, but it's not actually used.
success = [pem LoadPemFile: @"qa_data/openssl/rsaCertAndKey.pem" password: @""];
if (success == NO) {
    NSLog(@"%@",pem.LastErrorText);
    return;
}

if ([pem.NumCerts intValue] == 0) {
    NSLog(@"%@",@"PEM does not contain any certificates.");
    return;
}

CkoCert *cert = [pem GetCert: [NSNumber numberWithInt: 0]];
if (pem.LastMethodSuccess == NO) {
    NSLog(@"%@",pem.LastErrorText);
    return;
}

// -------------------------------------------------------------------------------------
// Duplicate this OpenSSL command:   openssl smime -encrypt -des3 -in <file> <pem file>
// -------------------------------------------------------------------------------------
CkoCrypt2 *crypt = [[CkoCrypt2 alloc] init];
success = [crypt SetEncryptCert: cert];
if (success == NO) {
    NSLog(@"%@",crypt.LastErrorText);

    return;
}

crypt.CryptAlgorithm = @"PKI";
crypt.Pkcs7CryptAlg = @"3des";
crypt.KeyLength = [NSNumber numberWithInt:168];

// Load the file to be encrypted.
CkoBinData *bd = [[CkoBinData alloc] init];
success = [bd LoadFile: @"qa_data/openssl/hello.txt"];
if (success == NO) {
    NSLog(@"%@",@"Failed to load the input file.");
    return;
}

// Encrypt.
success = [crypt EncryptBd: bd];
if (success == NO) {
    NSLog(@"%@",crypt.LastErrorText);
    return;
}

// The openssl smime -encrypt command produces encrypte MIME such as this:

// MIME-Version: 1.0
// Content-Disposition: attachment; filename="smime.p7m"
// Content-Type: application/x-pkcs7-mime; smime-type=enveloped-data; name="smime.p7m"
// Content-Transfer-Encoding: base64
// 
// MIICzwYJKoZIhvcNAQcDoIICwDCCArwCAQAxggF8MIIBeAIBADBgMEoxCzAJBgNVBAYTAlVTMRYw
// FAYDVQQKEw1MZXQncyBFbmNyeXB0MSMwIQYDVQQDExpMZXQncyBFbmNyeXB0IEF1dGhvcml0eSBY
// MwISA9Nqgb1dH/XTDNeKzN1nR85iMA0GCSqGSIb3DQEBAQUABIIBAIQqPexjxWovgxwKV/r3HL/U
// EP9Yozvz5hBeX5VvRZjKSi4FRw5wapElPK+4FB82hiAR9Mi3c16PvPSVkJv3l78Mv5uaaOs/OmUz
// mIHFB6Z+l2E52BDmUVWJZTQ09vdWy6+NIRlg2R9Z1NkmZ4BZCJk6mHB/Yx03IaOxK8LnwieDMthM
// SvxbhJnIOISN7k7ofs+/0vTXUpdQ+tlmwyVySMGQ6VMk+z4sqZJ2stacqCPtt/aiSwJ9p0OKmihf
// 3KDJceXJtavIQeA97yz1LqPvle35mmd5sBhV9qQYdTV/KJ+YM5uEZ9BHYbvMJbADFHwKzhcEY3qA
// 7T9acmEsb7NycOIwggE1BgkqhkiG9w0BBwEwFAYIKoZIhvcNAwcECERX/ZoHweSkgIIBEMmCMx49
// zjVAnGqRaBbvzQT1hg0uQSxIJjxMxC+HSuM+eY9oSOsbrw4uIijHKH9NdOpeDsdRzg2z5EBM7AlP
// Ht9DyPW5C2deV6RPX4F8gyExz+JUXrd+3Yb3AKTdpDkTWDmNCeO0r/YSqp518+mfU5hG8e336u51
// HAM44FeknA8oThWsD/wUB1e8vzsatK4UXW/KSu/166V7z+VT86kd+IHa7t60U9Yp0ZXgcM5Pb5Ni
// 69Qc5MKPzom2801H5UR/WjCgsxOIjOj49sKisjRy79skrJzxY5ZG05T0dKn6KC3TjRpIEEeOyhCd
// Nm2Y7dcW8GLMepdhWay5vePmQxmvmhbAtBprIem14NcrYeG6D5wP

// We have the body in bd
// Construct the header and base64 body...
CkoStringBuilder *sbEncryptedMime = [[CkoStringBuilder alloc] init];

[sbEncryptedMime AppendLine: @"MIME-Version: 1.0" crlf: YES];
[sbEncryptedMime AppendLine: @"Content-Disposition: attachment; filename=\"smime.p7m\"" crlf: YES];
[sbEncryptedMime AppendLine: @"Content-Type: application/x-pkcs7-mime; smime-type=enveloped-data; name=\"smime.p7m\"" crlf: YES];
[sbEncryptedMime AppendLine: @"Content-Transfer-Encoding: base64" crlf: YES];
[sbEncryptedMime AppendLine: @"" crlf: YES];
[sbEncryptedMime AppendLine: [bd GetEncoded: @"base64_mime"] crlf: YES];

// Show the result.
NSLog(@"%@",[sbEncryptedMime GetAsString]);

// or save to a file..
success = [sbEncryptedMime WriteFile: @"qa_output/encryptedMime.txt" charset: @"utf-8" emitBom: NO];