using Microsoft.Win32.SafeHandles;

using System;

using System.Collections.Generic;

using System.Linq;

using System.Runtime.InteropServices;

using System.Text;

namespace PSWindowsUpdate

{

public class NativeMethods

{

/// <summary>

/// The CredRead function reads a credential from the user's credential set.

/// The credential set used is the one associated with the logon session of the current token.

/// The token must not have the user's SID disabled.

/// </summary>

/// <remarks>

/// If the value of the Type member of the CREDENTIAL structure specified by the Credential parameter is

/// CRED_TYPE_DOMAIN_EXTENDED, a namespace must be specified in the target name. This function can return only one

/// credential of the specified type.

/// </remarks>

/// <param name="target">Pointer to a null-terminated string that contains the name of the credential to read.</param>

/// <param name="type">Type of the credential to read. Type must be one of the CRED_TYPE_* defined types.</param>

/// <param name="reservedFlag">Currently reserved and must be zero.</param>

/// <param name="credentialPtr">

/// Pointer to a single allocated block buffer to return the credential.

/// Any pointers contained within the buffer are pointers to locations within this single allocated block.

/// The single returned buffer must be freed by calling CredFree.

/// </param>

/// <returns>The function returns TRUE on success and FALSE on failure.</returns>

[DllImport("Advapi32.dll", EntryPoint = "CredReadW", CharSet = CharSet.Unicode, SetLastError = true)]

internal static extern bool CredRead(

string target,

CredentialType type,

int reservedFlag,

out IntPtr credentialPtr);

/// <summary>

/// The CredWrite function creates a new credential or modifies an existing credential in the user's credential set.

/// The new credential is associated with the logon session of the current token.

/// The token must not have the user's security identifier (SID) disabled.

/// </summary>

/// <remarks>

/// This function creates a credential if a credential with the specified TargetName and Type does not exist. If a

/// credential with the specified TargetName and Type exists, the new specified credential replaces the existing one.

/// When this function writes a CRED_TYPE_CERTIFICATE credential, the Credential-&gt;CredentialBlob member specifies the

/// PIN protecting the private key of the certificate specified by the Credential-&gt;UserName member. The credential

/// manager does not maintain the PIN. Rather, the PIN is passed to the cryptographic service provider (CSP) indicated

/// on the certificate for later use by the CSP and the authentication packages. The CSP defines the lifetime of the

/// PIN. Most CSPs flush the PIN when the smart card removal from the smart card reader.

/// If the value of the Type member of the CREDENTIAL structure specified by the Credential parameter is

/// CRED_TYPE_DOMAIN_EXTENDED, a namespace must be specified in the target name. This function does not support writing

/// to target names that contain wildcards.

/// </remarks>

/// <param name="userCredential">A pointer to the CREDENTIAL structure to be written.</param>

/// <param name="flags">Flags that control the function's operation. The following flag is defined.</param>

/// <returns>If the function succeeds, the function returns TRUE, if the function fails, it returns FALSE. </returns>

[DllImport("Advapi32.dll", EntryPoint = "CredWriteW", CharSet = CharSet.Unicode, SetLastError = true)]

internal static extern bool CredWrite([In] ref CREDENTIAL userCredential, [In] uint flags);

/// <summary>

/// The CredFree function frees a buffer returned by any of the credentials management functions.

/// </summary>

/// <param name="cred">Pointer to the buffer to be freed.</param>

[DllImport("Advapi32.dll", SetLastError = true)]

internal static extern void CredFree([In] IntPtr cred);

/// <summary>

/// The CredDelete function deletes a credential from the user's credential set.

/// The credential set used is the one associated with the logon session of the current token.

/// The token must not have the user's SID disabled.

/// </summary>

/// <param name="target">Pointer to a null-terminated string that contains the name of the credential to delete.</param>

/// <param name="type">

/// Type of the credential to delete. Must be one of the CRED_TYPE_* defined types.

/// For a list of the defined types, see the Type member of the CREDENTIAL structure.

/// If the value of this parameter is CRED_TYPE_DOMAIN_EXTENDED,

/// this function can delete a credential that specifies a user name when there are multiple credentials for the same

/// target. The value of the TargetName parameter must specify the user name as Target|UserName.

/// </param>

/// <param name="flags">Reserved and must be zero.</param>

/// <returns>The function returns TRUE on success and FALSE on failure.</returns>

[DllImport("Advapi32.dll", EntryPoint = "CredDeleteW", CharSet = CharSet.Unicode)]

internal static extern bool CredDelete(StringBuilder target, CredentialType type, int flags);

/// <summary>

/// Enumerate credentials in the credential store

/// signature: BOOL CredEnumerate (

/// _In_ LPCTSTR Filter,

/// _In_ DWORD Flags,

/// _Out_ DWORD *Count,

/// _Out_ PCREDENTIAL **Credentials

/// );

/// <param name="filter">[in]

/// Pointer to a null-terminated string that contains the filter for the returned credentials.Only credentials with a TargetName matching the filter will be returned.The filter specifies a name prefix followed by an asterisk.For instance, the filter "FRED*" will return all credentials with a TargetName beginning with the string "FRED".

/// If NULL is specified, all credentials will be returned.</param>

/// <param name="flag">[in]

/// The value of this parameter can be zero or more of the following values combined with a bitwise-OR operation.

/// Value Meaning

/// CRED_ENUMERATE_ALL_CREDENTIALS 0x1

/// This function enumerates all of the credentials in the user's credential set. The target name of each credential is returned in the "namespace:attribute=target" format. If this flag is set and the Filter parameter is not NULL, the function fails and returns ERROR_INVALID_FLAGS.

/// Windows Server 2003 and Windows XP: This flag is not supported.

/// </param>

/// <param name="count">[out] Count of the credentials returned in the Credentials array.</param>

/// <param name="pCredentials"> [out]

/// Pointer to an array of pointers to credentials.The returned credential is a single allocated block. Any pointers contained within the buffer are pointers to locations within this single allocated block.The single returned buffer must be freed by calling CredFree.

/// Return value

/// </param>

/// <returns>

/// The function returns TRUE on success and FALSE on failure. The GetLastError function can be called to get a more specific status code.The following status codes can be returned.

/// Return code/value Description

/// ERROR_NOT_FOUND

/// 1168 (0x490)

/// No credential exists matching the specified Filter.

/// ERROR_NO_SUCH_LOGON_SESSION

/// 1312 (0x520)

/// The logon session does not exist or there is no credential set associated with this logon session. Network logon sessions do not have an associated credential set.

/// ERROR_INVALID_FLAGS

/// 1004 (0x3EC)

/// A flag that is not valid was specified for the Flags parameter, or CRED_ENUMERATE_ALL_CREDENTIALS is specified for the Flags parameter and the Filter parameter is not NULL.

/// </returns>

/// </summary>

[DllImport("Advapi32.dll", CharSet = CharSet.Unicode, SetLastError = true)]

internal static extern bool CredEnumerate(

string filter,

int flag,

out int count,

out IntPtr pCredentials);

internal static IEnumerable<CREDENTIAL> CredEnumerate()

{

int count;

IntPtr pCredentials;

if (!CredEnumerate(null, 0, out count, out pCredentials))

{

throw new Exception("Failed to enumerate credentials");

}

var source = new IntPtr[count];

for (var index = 0; index < count; ++index)

{

source[index] = Marshal.ReadIntPtr(pCredentials, index * Marshal.SizeOf(typeof(IntPtr)));

}

return source.Select(ptr => (CREDENTIAL)Marshal.PtrToStructure(ptr, typeof(CREDENTIAL)));

}

/// <summary>

/// The CREDENTIAL structure contains an individual credential.

///

/// See CREDENTIAL structure <see href="/?originalUrl=https%3A%2F%2Fgithub.com%2F%26quot%3Bhttp%3A%2F%2Fmsdn.microsoft.com%2Fen-us%2Flibrary%2Fwindows%2Fdesktop%2Faa374788(v%3Dvs.85).aspx%26quot%3B%26gt%3Bdocumentation.%26lt%3B%2Fsee%26gt%3B%253C%2Fdiv">