/*
 * Copyright (C) the libgit2 contributors. All rights reserved.
 *
 * This file is part of libgit2, distributed under the GNU GPL v2 with
 * a Linking Exception. For full terms see the included COPYING file.
 */
/**
 * License: GPL-2.0(Linking Exception)
 */
module libgit2.credential;


private static import libgit2.sys.credential;
private import libgit2.common: GIT_EXTERN;

/*
 * @file git2/credential.h
 * @brief Git authentication & credential management
 * @defgroup git_credential Authentication & credential management
 * @ingroup Git
 * @{
 */
extern (C):
nothrow @nogc:
public:

/**
 * Supported credential types
 *
 * This represents the various types of authentication methods supported by
 * the library.
 */
enum git_credential_t
{
	/**
	 * A vanilla user/password request
	 * @see git_credential_userpass_plaintext_new
	 */
	GIT_CREDENTIAL_USERPASS_PLAINTEXT = 1u << 0,

	/**
	 * An SSH key-based authentication request
	 * @see git_credential_ssh_key_new
	 */
	GIT_CREDENTIAL_SSH_KEY = 1u << 1,

	/**
	 * An SSH key-based authentication request, with a custom signature
	 * @see git_credential_ssh_custom_new
	 */
	GIT_CREDENTIAL_SSH_CUSTOM = 1u << 2,

	/**
	 * An NTLM/Negotiate-based authentication request.
	 * @see git_credential_default
	 */
	GIT_CREDENTIAL_DEFAULT = 1u << 3,

	/**
	 * An SSH interactive authentication request
	 * @see git_credential_ssh_interactive_new
	 */
	GIT_CREDENTIAL_SSH_INTERACTIVE = 1u << 4,

	/**
	 * Username-only authentication request
	 *
	 * Used as a pre-authentication step if the underlying transport
	 * (eg. SSH, with no username in its URL) does not know which username
	 * to use.
	 *
	 * @see git_credential_username_new
	 */
	GIT_CREDENTIAL_USERNAME = 1u << 5,

	/**
	 * An SSH key-based authentication request
	 *
	 * Allows credentials to be read from memory instead of files.
	 * Note that because of differences in crypto backend support, it might
	 * not be functional.
	 *
	 * @see git_credential_ssh_key_memory_new
	 */
	GIT_CREDENTIAL_SSH_MEMORY = 1u << 6,
}

//Declaration name in C language
enum
{
	GIT_CREDENTIAL_USERPASS_PLAINTEXT = .git_credential_t.GIT_CREDENTIAL_USERPASS_PLAINTEXT,
	GIT_CREDENTIAL_SSH_KEY = .git_credential_t.GIT_CREDENTIAL_SSH_KEY,
	GIT_CREDENTIAL_SSH_CUSTOM = .git_credential_t.GIT_CREDENTIAL_SSH_CUSTOM,
	GIT_CREDENTIAL_DEFAULT = .git_credential_t.GIT_CREDENTIAL_DEFAULT,
	GIT_CREDENTIAL_SSH_INTERACTIVE = .git_credential_t.GIT_CREDENTIAL_SSH_INTERACTIVE,
	GIT_CREDENTIAL_USERNAME = .git_credential_t.GIT_CREDENTIAL_USERNAME,
	GIT_CREDENTIAL_SSH_MEMORY = .git_credential_t.GIT_CREDENTIAL_SSH_MEMORY,
}

/**
 * The base structure for all credential types
 */
alias git_credential = libgit2.sys.credential.git_credential;

alias git_credential_userpass_plaintext = libgit2.sys.credential.git_credential_userpass_plaintext;

/**
 * Username-only credential information
 */
alias git_credential_username = libgit2.sys.credential.git_credential_username;

/**
 * A key for NTLM/Kerberos "default" credentials
 */
alias git_credential_default = .git_credential;

/**
 * A ssh key from disk
 */
alias git_credential_ssh_key = libgit2.sys.credential.git_credential_ssh_key;

/**
 * Keyboard-interactive based ssh authentication
 */
alias git_credential_ssh_interactive = libgit2.sys.credential.git_credential_ssh_interactive;

/**
 * A key with a custom signature function
 */
alias git_credential_ssh_custom = libgit2.sys.credential.git_credential_ssh_custom;

/**
 * Credential acquisition callback.
 *
 * This callback is usually involved any time another system might need
 * authentication. As such, you are expected to provide a valid
 * git_credential object back, depending on allowed_types (a
 * git_credential_t bitmask).
 *
 * Note that most authentication details are your responsibility - this
 * callback will be called until the authentication succeeds, or you report
 * an error. As such, it's easy to get in a loop if you fail to stop providing
 * the same incorrect credentials.
 *
 * Returns: 0 for success, < 0 to indicate an error, > 0 to indicate no credential was acquired
 */
/*
 * Params:
 *      out_ = The newly created credential object.
 *      url = The resource for which we are demanding a credential.
 *      username_from_url = The username that was embedded in a "user\@host" remote url, or null if not included.
 *      allowed_types = A bitmask stating which credential types are OK to return.
 *      payload = The payload provided when specifying this callback.
 */
alias git_credential_acquire_cb = int function(.git_credential** out_, const (char)* url, const (char)* username_from_url, uint allowed_types, void* payload);

/**
 * Free a credential.
 *
 * This is only necessary if you own the object; that is, if you are a
 * transport.
 *
 * Params:
 *      cred = the object to free
 */
@GIT_EXTERN
void git_credential_free(.git_credential* cred);

/**
 * Check whether a credential object contains username information.
 *
 * Params:
 *      cred = object to check
 *
 * Returns: 1 if the credential object has non-null username, 0 otherwise
 */
@GIT_EXTERN
int git_credential_has_username(.git_credential* cred);

/**
 * Return the username associated with a credential object.
 *
 * Params:
 *      cred = object to check
 *
 * Returns: the credential username, or null if not applicable
 */
@GIT_EXTERN
const (char)* git_credential_get_username(.git_credential* cred);

/**
 * Create a new plain-text username and password credential object.
 * The supplied credential parameter will be internally duplicated.
 *
 * Params:
 *      out_ = The newly created credential object.
 *      username = The username of the credential.
 *      password = The password of the credential.
 *
 * Returns: 0 for success or an error code for failure
 */
@GIT_EXTERN
int git_credential_userpass_plaintext_new(.git_credential** out_, const (char)* username, const (char)* password);

/**
 * Create a "default" credential usable for Negotiate mechanisms like NTLM
 * or Kerberos authentication.
 *
 * Params:
 *      out_ = The newly created credential object.
 *
 * Returns: 0 for success or an error code for failure
 */
@GIT_EXTERN
int git_credential_default_new(.git_credential** out_);

/**
 * Create a credential to specify a username.
 *
 * This is used with ssh authentication to query for the username if
 * none is specified in the url.
 *
 * Params:
 *      out_ = The newly created credential object.
 *      username = The username to authenticate with
 *
 * Returns: 0 for success or an error code for failure
 */
@GIT_EXTERN
int git_credential_username_new(.git_credential** out_, const (char)* username);

/**
 * Create a new passphrase-protected ssh key credential object.
 * The supplied credential parameter will be internally duplicated.
 *
 * Params:
 *      out_ = The newly created credential object.
 *      username = username to use to authenticate
 *      publickey = The path to the public key of the credential.
 *      privatekey = The path to the private key of the credential.
 *      passphrase = The passphrase of the credential.
 *
 * Returns: 0 for success or an error code for failure
 */
@GIT_EXTERN
int git_credential_ssh_key_new(.git_credential** out_, const (char)* username, const (char)* publickey, const (char)* privatekey, const (char)* passphrase);

/**
 * Create a new ssh key credential object reading the keys from memory.
 *
 * Params:
 *      out_ = The newly created credential object.
 *      username = username to use to authenticate.
 *      publickey = The public key of the credential.
 *      privatekey = The private key of the credential.
 *      passphrase = The passphrase of the credential.
 *
 * Returns: 0 for success or an error code for failure
 */
@GIT_EXTERN
int git_credential_ssh_key_memory_new(.git_credential** out_, const (char)* username, const (char)* publickey, const (char)* privatekey, const (char)* passphrase);

/*
 * If the user hasn't included libssh2.h before git2.h, we need to
 * define a few types for the callback signatures.
 */
version (LIBSSH2_VERSION) {
} else {
	struct _LIBSSH2_SESSION;
	struct _LIBSSH2_USERAUTH_KBDINT_PROMPT;
	struct _LIBSSH2_USERAUTH_KBDINT_RESPONSE;
	alias LIBSSH2_SESSION = _LIBSSH2_SESSION;
	alias LIBSSH2_USERAUTH_KBDINT_PROMPT = _LIBSSH2_USERAUTH_KBDINT_PROMPT;
	alias LIBSSH2_USERAUTH_KBDINT_RESPONSE = _LIBSSH2_USERAUTH_KBDINT_RESPONSE;
}

alias git_credential_ssh_interactive_cb = void function(const (char)* name, int name_len, const (char)* instruction, int instruction_len, int num_prompts, const (.LIBSSH2_USERAUTH_KBDINT_PROMPT)* prompts, .LIBSSH2_USERAUTH_KBDINT_RESPONSE* responses, void** abstract_);

/**
 * Create a new ssh keyboard-interactive based credential object.
 * The supplied credential parameter will be internally duplicated.
 *
 * Params:
 *      out_ = The newly created credential object.
 *      username = Username to use to authenticate.
 *      prompt_callback = The callback method used for prompts.
 *      payload = Additional data to pass to the callback.
 *
 * Returns: 0 for success or an error code for failure.
 */
@GIT_EXTERN
int git_credential_ssh_interactive_new(.git_credential** out_, const (char)* username, .git_credential_ssh_interactive_cb prompt_callback, void* payload);

/**
 * Create a new ssh key credential object used for querying an ssh-agent.
 * The supplied credential parameter will be internally duplicated.
 *
 * Params:
 *      out_ = The newly created credential object.
 *      username = username to use to authenticate
 *
 * Returns: 0 for success or an error code for failure
 */
@GIT_EXTERN
int git_credential_ssh_key_from_agent(.git_credential** out_, const (char)* username);

alias git_credential_sign_cb = int function(.LIBSSH2_SESSION* session, ubyte** sig, size_t* sig_len, const (ubyte)* data, size_t data_len, void** abstract_);

/**
 * Create an ssh key credential with a custom signing function.
 *
 * This lets you use your own function to sign the challenge.
 *
 * This function and its credential type is provided for completeness
 * and wraps `libssh2_userauth_publickey()`, which is undocumented.
 *
 * The supplied credential parameter will be internally duplicated.
 *
 * Params:
 *      out_ = The newly created credential object.
 *      username = username to use to authenticate
 *      publickey = The bytes of the public key.
 *      publickey_len = The length of the public key in bytes.
 *      sign_callback = The callback method to sign the data during the challenge.
 *      payload = Additional data to pass to the callback.
 *
 * Returns: 0 for success or an error code for failure
 */
@GIT_EXTERN
int git_credential_ssh_custom_new(.git_credential** out_, const (char)* username, const (char)* publickey, size_t publickey_len, .git_credential_sign_cb sign_callback, void* payload);

/* @} */