public SecretCollection FindSecrets(IEnumerable <EncryptionKey> keys)
{
if (keys == null)
{
throw new ArgumentNullException(nameof(keys));
}
// Get a copy of the collection so we can remove keys as we use them.
EncryptionKeyCollection unusedKeys = new EncryptionKeyCollection("");
unusedKeys.AddRange(keys);
// Accumulate decrypted secrets here.
SecretCollection secrets = new SecretCollection();
XmlNodeList nodeList = GetXecretsSession(XecretsDocument).SelectNodes("XecretsSession");
foreach (XmlNode node in nodeList)
{
SecretCollection decryptedSessionSecrets = AttemptDecryptXecretsSessionElement(unusedKeys, (XmlElement)node);
secrets.AddRange(decryptedSessionSecrets);
}
secrets.OriginalCount = secrets.Count;
return(secrets);
}
private SecretCollection AttemptDecryptXecretsSessionElement(EncryptionKeyCollection keyCollection, XmlElement xecretsSessionElement)
{
foreach (EncryptionKey key in keyCollection)
{
DateTime lastUpdateUtc = DateTime.Parse(xecretsSessionElement.Attributes["LastUpdateUtc"].Value, CultureInfo.InvariantCulture, DateTimeStyles.AssumeUniversal | DateTimeStyles.AdjustToUniversal);
if (lastUpdateUtc > LastUpdateUtc)
{
LastUpdateUtc = lastUpdateUtc;
}
XmlDocument decryptedXml = DecryptEncryptedData(new InternalEncryptionKey(key), xecretsSessionElement);
if (decryptedXml == null)
{
continue;
}
SecretCollection decryptedSecrets = GetSessionSecrets(decryptedXml.SelectNodes("Secrets/Secret"), key);
// Set the last updated for each and every secret - we don't actually store this per secret, only per
// session, but that's not a fact we expose externally.
foreach (Secret secret in decryptedSecrets)
{
InternalSecret internalSecret = secret as InternalSecret;
internalSecret.LastUpdateUtc = lastUpdateUtc;
}
keyCollection.Remove(key);
return(decryptedSecrets);
}
return(new SecretCollection());
}
public FormatConfidence DetermineFormatConfidence(EncryptionKeyCollection keyCollection)
{
if (_data == null)
{
throw new InvalidOperationException("No data read to check format for");
}
// Here try to extract from the data using the keys. If this fails (exception) it's not our format.
// Even if we get zero secrets, it might not be our format, it could be a later format.
try
{
// Since it's a lazy load, the property reference here must be inside the try
if (XecretsDocument == null)
{
return(FormatConfidence.DefinitelyNot);
}
// Get what we can using the keyCollection
IList <Secret> secrets = FindSecrets(keyCollection);
if (secrets.Count > 0)
{
// If we got any secrest, we're definitely on the right track
return(FormatConfidence.Definitely);
}
// If we just got zero, we're probably the right one.
return(FormatConfidence.Probably);
}
catch (FormatException)
{
// Something went wrong...
return(FormatConfidence.DefinitelyNot);
}
}