swaroop: basics of encrypted MP4 playback.

[dcpomatic.git] / src / lib / decrypted_ecinema_kdm.cc

diff --git a/src/lib/decrypted_ecinema_kdm.cc b/src/lib/decrypted_ecinema_kdm.cc
index 2cb4f61d7a3ece135d9894ae2e3ae756358d18fd..a03004e4378eb9c7ef9355e24e66a06e008ff842 100644 (file)
--- a/src/lib/decrypted_ecinema_kdm.cc
+++ b/src/lib/decrypted_ecinema_kdm.cc
@@ -22,21 +22,53 @@
 
 #include "encrypted_ecinema_kdm.h"
 #include "decrypted_ecinema_kdm.h"
+#include "exceptions.h"
 #include <dcp/key.h>
+#include <dcp/util.h>
 #include <dcp/certificate.h>
+#include <openssl/rsa.h>
+#include <openssl/pem.h>
+#include <openssl/err.h>
 
+using std::string;
+using std::runtime_error;
 using dcp::Certificate;
 
-DecryptedECinemaKDM::DecryptedECinemaKDM (dcp::Key content_key)
-       : _content_key (content_key)
+DecryptedECinemaKDM::DecryptedECinemaKDM (string id, dcp::Key content_key)
+       : _id (id)
+       , _content_key (content_key)
 {
 
 }
 
+DecryptedECinemaKDM::DecryptedECinemaKDM (EncryptedECinemaKDM kdm, string private_key)
+       : _id (kdm.id())
+{
+       /* Read the private key */
+
+       BIO* bio = BIO_new_mem_buf (const_cast<char *> (private_key.c_str()), -1);
+       if (!bio) {
+               throw runtime_error ("could not create memory BIO");
+       }
+
+       RSA* rsa = PEM_read_bio_RSAPrivateKey (bio, 0, 0, 0);
+       if (!rsa) {
+               throw FileError ("could not read RSA private key file", private_key);
+       }
+
+       uint8_t value[RSA_size(rsa)];
+       int const len = RSA_private_decrypt (kdm.key().size(), kdm.key().data().get(), value, rsa, RSA_PKCS1_OAEP_PADDING);
+       if (len == -1) {
+               throw KDMError (ERR_error_string(ERR_get_error(), 0), "");
+       }
+
+       _content_key = dcp::Key (value, len);
+}
+
 EncryptedECinemaKDM
 DecryptedECinemaKDM::encrypt (Certificate recipient)
 {
-       return EncryptedECinemaKDM (_content_key, recipient);
+       return EncryptedECinemaKDM (_id, _content_key, recipient);
 }
 
 #endif