/// <summary>
/// Creates an envelope encryption content key.
/// </summary>
/// <param name="keyId">The key id.</param>
/// <param name="contentKey">The content key data.</param>
/// <param name="name">The name.</param>
/// <param name="cert">The cert.</param>
/// <returns>The content key.</returns>
internal static ContentKeyData InitializeEnvelopeContentKey(Guid keyId, byte[] contentKey, string name, X509Certificate2 cert)
{
if (cert == null)
{
throw new ArgumentNullException("cert");
}
if (contentKey == null)
{
throw new ArgumentNullException("contentKey");
}
if (contentKey.Length != EncryptionUtils.KeySizeInBytesForAes128)
{
throw new ArgumentOutOfRangeException("contentKey", "Envelope Encryption content keys are 128-bits (16 bytes) in length.");
}
byte[] encryptedContentKey = EncryptionUtils.EncryptSymmetricKeyData(cert, contentKey);
ContentKeyData contentKeyData = new ContentKeyData
{
Id = EncryptionUtils.GetKeyIdentifierAsString(keyId),
EncryptedContentKey = Convert.ToBase64String(encryptedContentKey),
ContentKeyType = (int)ContentKeyType.EnvelopeEncryption,
ProtectionKeyId = cert.Thumbprint,
ProtectionKeyType = (int)ProtectionKeyType.X509CertificateThumbprint,
Name = name,
Checksum = EncryptionUtils.CalculateChecksum(contentKey, keyId)
};
return(contentKeyData);
}
/// <summary>
/// Creates the common content key.
/// </summary>
/// <param name="keyId">The key id.</param>
/// <param name="contentKey">The content key data.</param>
/// <param name="name">The name.</param>
/// <param name="cert">The cert.</param>
/// <returns>The content key.</returns>
internal static ContentKeyData CreateCommonContentKey(Guid keyId, byte[] contentKey, string name, X509Certificate2 cert)
{
byte[] encryptedContentKey = CommonEncryption.EncryptContentKeyToCertificate(cert, contentKey);
ContentKeyData contentKeyData = new ContentKeyData
{
Id = EncryptionUtils.GetKeyIdentifierAsString(keyId),
EncryptedContentKey = Convert.ToBase64String(encryptedContentKey),
ContentKeyType = (int)ContentKeyType.CommonEncryption,
ProtectionKeyId = cert.Thumbprint,
ProtectionKeyType = (int)ProtectionKeyType.X509CertificateThumbprint,
Name = name,
Checksum = EncryptionUtils.CalculateChecksum(contentKey, keyId)
};
return(contentKeyData);
}
/// <summary>
/// Creates FairPlay Pfx Password.
/// </summary>
/// <param name="keyId">The key id.</param>
/// <param name="contentKey">The content key data.</param>
/// <param name="name">The name.</param>
/// <param name="cert">The cert.</param>
/// <returns>The content key.</returns>
internal static ContentKeyData InitializeFairPlayPfxPassword(Guid keyId, byte[] contentKey, string name, X509Certificate2 cert)
{
RSACryptoServiceProvider rsaPublicKey = cert.PublicKey.Key as RSACryptoServiceProvider;
RSAOAEPKeyExchangeFormatter keyFormatter = new RSAOAEPKeyExchangeFormatter(rsaPublicKey);
byte[] encryptedContentKey = keyFormatter.CreateKeyExchange(contentKey);
ContentKeyData contentKeyData = new ContentKeyData
{
Id = EncryptionUtils.GetKeyIdentifierAsString(keyId),
EncryptedContentKey = Convert.ToBase64String(encryptedContentKey),
ContentKeyType = (int)ContentKeyType.FairPlayPfxPassword,
ProtectionKeyId = cert.Thumbprint,
ProtectionKeyType = (int)ProtectionKeyType.X509CertificateThumbprint,
Name = name,
};
return(contentKeyData);
}
/// <summary>
/// Gets the key identifier as string.
/// </summary>
/// <returns>The key ID.</returns>
public string GetKeyIdentifierAsString()
{
return(EncryptionUtils.GetKeyIdentifierAsString(this.KeyIdentifier));
}