public static extern bool CredWrite(ref NativeMethods.CREDENTIAL credential,
uint flags);
/// <summary>
/// Persist the provided credentials in the Windows credentials manager for this user.
/// The credentials are stored until the user logs off.
/// </summary>
/// <param name="uri">Uri to serve as the key in the credentials manager</param>
/// <param name="username">Username to store</param>
/// <param name="password">Password to store</param>
/// <param name="credentialsType">The type of credentials (e.g., Windows, AcsServiceIdentity)</param>
/// <returns>ERROR_SUCCESS (0) if successful. Otherwise, a Win32 error code returned by CredWrite.</returns>
public static int StoreCredentials(String targetName, String userName, SecureString password, String comment, Dictionary <String, String> attributes)
{
NativeMethods.CREDENTIAL toPersist = new NativeMethods.CREDENTIAL();
NativeMethods.CREDENTIAL_ATTRIBUTE[] toPersistAttributes = new NativeMethods.CREDENTIAL_ATTRIBUTE[attributes.Count];
toPersist.CredentialBlob = IntPtr.Zero;
try
{
toPersist.Flags = 0;
toPersist.Type = (int)NativeMethods.CRED_TYPE_GENERIC;
toPersist.TargetName = targetName;
toPersist.Comment = comment;
toPersist.CredentialBlob = Marshal.SecureStringToCoTaskMemUnicode(password);
toPersist.CredentialBlobSize = password.Length * sizeof(char);
toPersist.Persist = NativeMethods.CRED_PERSIST_LOCAL_MACHINE;
if (attributes.Count > 0)
{
int attributeIndex = 0;
int totalSize = 0;
// Convert the managed dictionary into an array of managed CREDENTIAL_ATTRIBUTE and keep track of
// how much memory we're using
foreach (KeyValuePair <String, String> attributePair in attributes)
{
NativeMethods.CREDENTIAL_ATTRIBUTE toPersistAttribute = new NativeMethods.CREDENTIAL_ATTRIBUTE();
toPersistAttribute.Keyword = attributePair.Key;
toPersistAttribute.Flags = 0;
toPersistAttribute.ValueSize = attributePair.Value.Length * sizeof(char);
toPersistAttribute.Value = Marshal.StringToCoTaskMemUni(attributePair.Value);
totalSize += Marshal.SizeOf(toPersistAttribute);
toPersistAttributes[attributeIndex++] = toPersistAttribute;
}
// Block off the space for the entire array and assign the toPersist.Attributes the pointer to the head
// of the list
IntPtr pAttribute = Marshal.AllocCoTaskMem(totalSize);
toPersist.AttributeCount = attributes.Count;
toPersist.Attributes = pAttribute;
// Start copying the attributes into the memory block we allocated
for (attributeIndex = 0; attributeIndex < toPersistAttributes.Length; attributeIndex++)
{
Marshal.StructureToPtr(toPersistAttributes[attributeIndex], pAttribute, false);
pAttribute = new IntPtr(pAttribute.ToInt64() + Marshal.SizeOf(toPersistAttributes[attributeIndex]));
}
}
else
{
toPersist.AttributeCount = 0;
toPersist.Attributes = IntPtr.Zero;
}
toPersist.TargetAlias = null;
toPersist.UserName = userName;
bool retVal = NativeMethods.CredWrite(ref toPersist, 0);
if (!retVal)
{
return(Marshal.GetLastWin32Error());
}
return(NativeMethods.ERROR_SUCCESS);
}
finally
{
if (IntPtr.Zero != toPersist.CredentialBlob)
{
Marshal.ZeroFreeCoTaskMemUnicode(toPersist.CredentialBlob);
toPersist.CredentialBlob = IntPtr.Zero;
}
if (IntPtr.Zero != toPersist.Attributes)
{
Marshal.FreeCoTaskMem(toPersist.Attributes);
toPersist.Attributes = IntPtr.Zero;
}
for (int attributeIndex = 0; attributeIndex < toPersistAttributes.Length; attributeIndex++)
{
NativeMethods.CREDENTIAL_ATTRIBUTE toPersistAttribute = toPersistAttributes[attributeIndex];
if (IntPtr.Zero != toPersistAttribute.Value)
{
Marshal.ZeroFreeCoTaskMemUnicode(toPersistAttribute.Value);
toPersistAttribute.Value = IntPtr.Zero;
}
}
}
}
