path: root/include/openssl/engine.h

/*
 * Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved.
 * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved
 *
 * Licensed under the OpenSSL license (the "License").  You may not use
 * this file except in compliance with the License.  You can obtain a copy
 * in the file LICENSE in the source distribution or at
 * https://www.openssl.org/source/license.html
 */

#ifndef HEADER_ENGINE_H
# define HEADER_ENGINE_H

# include <openssl/opensslconf.h>

# ifndef OPENSSL_NO_ENGINE
# if OPENSSL_API_COMPAT < 0x10100000L
#  include <openssl/bn.h>
#  include <openssl/rsa.h>
#  include <openssl/dsa.h>
#  include <openssl/dh.h>
#  include <openssl/ec.h>
#  include <openssl/rand.h>
#  include <openssl/ui.h>
#  include <openssl/err.h>
# endif
# include <openssl/ossl_typ.h>
# include <openssl/symhacks.h>
# include <openssl/x509.h>
# include <openssl/engineerr.h>
# ifdef  __cplusplus
extern "C" {
# endif

/*
 * These flags are used to control combinations of algorithm (methods) by
 * bitwise "OR"ing.
 */
# define ENGINE_METHOD_RSA               (unsigned int)0x0001
# define ENGINE_METHOD_DSA               (unsigned int)0x0002
# define ENGINE_METHOD_DH                (unsigned int)0x0004
# define ENGINE_METHOD_RAND              (unsigned int)0x0008
# define ENGINE_METHOD_CIPHERS           (unsigned int)0x0040
# define ENGINE_METHOD_DIGESTS           (unsigned int)0x0080
# define ENGINE_METHOD_PKEY_METHS        (unsigned int)0x0200
# define ENGINE_METHOD_PKEY_ASN1_METHS   (unsigned int)0x0400
# define ENGINE_METHOD_EC                (unsigned int)0x0800
/* Obvious all-or-nothing cases. */
# define ENGINE_METHOD_ALL               (unsigned int)0xFFFF
# define ENGINE_METHOD_NONE              (unsigned int)0x0000

/*
 * This(ese) flag(s) controls behaviour of the ENGINE_TABLE mechanism used
 * internally to control registration of ENGINE implementations, and can be
 * set by ENGINE_set_table_flags(). The "NOINIT" flag prevents attempts to
 * initialise registered ENGINEs if they are not already initialised.
 */
# define ENGINE_TABLE_FLAG_NOINIT        (unsigned int)0x0001

/* ENGINE flags that can be set by ENGINE_set_flags(). */
/* Not used */
/* #define ENGINE_FLAGS_MALLOCED        0x0001 */

/*
 * This flag is for ENGINEs that wish to handle the various 'CMD'-related
 * control commands on their own. Without this flag, ENGINE_ctrl() handles
 * these control commands on behalf of the ENGINE using their "cmd_defns"
 * data.
 */
# define ENGINE_FLAGS_MANUAL_CMD_CTRL    (int)0x0002

/*
 * This flag is for ENGINEs who return new duplicate structures when found
 * via "ENGINE_by_id()". When an ENGINE must store state (eg. if
 * ENGINE_ctrl() commands are called in sequence as part of some stateful
 * process like key-generation setup and execution), it can set this flag -
 * then each attempt to obtain the ENGINE will result in it being copied into
 * a new structure. Normally, ENGINEs don't declare this flag so
 * ENGINE_by_id() just increments the existing ENGINE's structural reference
 * count.
 */
# define ENGINE_FLAGS_BY_ID_COPY         (int)0x0004

/*
 * This flag if for an ENGINE that does not want its methods registered as
 * part of ENGINE_register_all_complete() for example if the methods are not
 * usable as default methods.
 */

# define ENGINE_FLAGS_NO_REGISTER_ALL    (int)0x0008

/*
 * ENGINEs can support their own command types, and these flags are used in
 * ENGINE_CTRL_GET_CMD_FLAGS to indicate to the caller what kind of input
 * each command expects. Currently only numeric and string input is
 * supported. If a control command supports none of the _NUMERIC, _STRING, or
 * _NO_INPUT options, then it is regarded as an "internal" control command -
 * and not for use in config setting situations. As such, they're not
 * available to the ENGINE_ctrl_cmd_string() function, only raw ENGINE_ctrl()
 * access. Changes to this list of 'command types' should be reflected
 * carefully in ENGINE_cmd_is_executable() and ENGINE_ctrl_cmd_string().
 */

/* accepts a 'long' input value (3rd parameter to ENGINE_ctrl) */
# define ENGINE_CMD_FLAG_NUMERIC         (unsigned int)0x0001
/*
 * accepts string input (cast from 'void*' to 'const char *', 4th parameter
 * to ENGINE_ctrl)
 */
# define ENGINE_CMD_FLAG_STRING          (unsigned int)0x0002
/*
 * Indicates that the control command takes *no* input. Ie. the control
 * command is unparameterised.
 */
# define ENGINE_CMD_FLAG_NO_INPUT        (unsigned int)0x0004
/*
 * Indicates that the control command is internal. This control command won't
 * be shown in any output, and is only usable through the ENGINE_ctrl_cmd()
 * function.
 */
# define ENGINE_CMD_FLAG_INTERNAL        (unsigned int)0x0008

/*
 * NB: These 3 control commands are deprecated and should not be used.
 * ENGINEs relying on these commands should compile conditional support for
 * compatibility (eg. if these symbols are defined) but should also migrate
 * the same functionality to their own ENGINE-specific control functions that
 * can be "discovered" by calling applications. The fact these control
 * commands wouldn't be "executable" (ie. usable by text-based config)
 * doesn't change the fact that application code can find and use them
 * without requiring per-ENGINE hacking.
 */

/*
 * These flags are used to tell the ctrl function what should be done. All
 * command numbers are shared between all engines, even if some don't make
 * sense to some engines.  In such a case, they do nothing but return the
 * error ENGINE_R_CTRL_COMMAND_NOT_IMPLEMENTED.
 */
# define ENGINE_CTRL_SET_LOGSTREAM               1
# define ENGINE_CTRL_SET_PASSWORD_CALLBACK       2
# define ENGINE_CTRL_HUP                         3/* Close and reinitialise
                                                   * any handles/connections
                                                   * etc. */
# define ENGINE_CTRL_SET_USER_INTERFACE          4/* Alternative to callback */
# define ENGINE_CTRL_SET_CALLBACK_DATA           5/* User-specific data, used
                                                   * when calling the password
                                                   * callback and the user
                                                   * interface */
# define ENGINE_CTRL_LOAD_CONFIGURATION          6/* Load a configuration,
                                                   * given a string that
                                                   * represents a file name
                                                   * or so */
# define ENGINE_CTRL_LOAD_SECTION                7/* Load data from a given
                                                   * section in the already
                                                   * loaded configuration */

/*
 * These control commands allow an application to deal with an arbitrary
 * engine in a dynamic way. Warn: Negative return values indicate errors FOR
 * THESE COMMANDS because zero is used to indicate 'end-of-list'. Other
 * commands, including ENGINE-specific command types, return zero for an
 * error. An ENGINE can choose to implement these ctrl functions, and can
 * internally manage things however it chooses - it does so by setting the
 * ENGINE_FLAGS_MANUAL_CMD_CTRL flag (using ENGINE_set_flags()). Otherwise
 * the ENGINE_ctrl() code handles this on the ENGINE's behalf using the
 * cmd_defns data (set using ENGINE_set_cmd_defns()). This means an ENGINE's
 * ctrl() handler need only implement its own commands - the above "meta"
 * commands will be taken care of.
 */

/*
 * Returns non-zero if the supplied ENGINE has a ctrl() handler. If "not",
 * then all the remaining control commands will return failure, so it is
 * worth checking this first if the caller is trying to "discover" the
 * engine's capabilities and doesn't want errors generated unnecessarily.
 */
# define ENGINE_CTRL_HAS_CTRL_FUNCTION           10
/*
 * Returns a positive command number for the first command supported by the
 * engine. Returns zero if no ctrl commands are supported.
 */
# define ENGINE_CTRL_GET_FIRST_CMD_TYPE          11
/*
 * The 'long' argument specifies a command implemented by the engine, and the
 * return value is the next command supported, or zero if there are no more.
 */
# define ENGINE_CTRL_GET_NEXT_CMD_TYPE           12
/*
 * The 'void*' argument is a command name (cast from 'const char *'), and the
 * return value is the command that corresponds to it.
 */
# define ENGINE_CTRL_GET_CMD_FROM_NAME           13
/*
 * The next two allow a command to be converted into its corresponding string
 * form. In each case, the 'long' argument supplies the command. In the
 * NAME_LEN case, the return value is the length of the command name (not
 * counting a trailing EOL). In the NAME case, the 'void*' argument must be a
 * string buffer large enough, and it will be populated with the name of the
 * command (WITH a trailing EOL).
 */
# define ENGINE_CTRL_GET_NAME_LEN_FROM_CMD       14
# define ENGINE_CTRL_GET_NAME_FROM_CMD           15
/* The next two are similar but give a "short description" of a command. */
# define ENGINE_CTRL_GET_DESC_LEN_FROM_CMD       16
# define ENGINE_CTRL_GET_DESC_FROM_CMD           17
/*
 * With this command, the return value is the OR'd combination of
 * ENGINE_CMD_FLAG_*** values that indicate what kind of input a given
 * engine-specific ctrl command expects.
 */
# define ENGINE_CTRL_GET_CMD_FLAGS               18

/*
 * ENGINE implementations should start the numbering of their own control
 * commands from this value. (ie. ENGINE_CMD_BASE, ENGINE_CMD_BASE + 1, etc).
 */
# define ENGINE_CMD_BASE                         200

/*
 * NB: These 2 nCipher "chil" control commands are deprecated, and their
 * functionality is now available through ENGINE-specific control commands
 * (exposed through the above-mentioned 'CMD'-handling). Code using these 2
 * commands should be migrated to the more general command handling before
 * these are removed.
 */

/* Flags specific to the nCipher "chil" engine */
# define ENGINE_CTRL_CHIL_SET_FORKCHECK          100
        /*
         * Depending on the value of the (long)i argument, this sets or
         * unsets the SimpleForkCheck flag in the CHIL API to enable or
         * disable checking and workarounds for applications that fork().
         */
# define ENGINE_CTRL_CHIL_NO_LOCKING             101
        /*
         * This prevents the initialisation function from providing mutex
         * callbacks to the nCipher library.
         */

/*
 * If an ENGINE supports its own specific control commands and wishes the
 * framework to handle the above 'ENGINE_CMD_***'-manipulation commands on
 * its behalf, it should supply a null-terminated array of ENGINE_CMD_DEFN
 * entries to ENGINE_set_cmd_defns(). It should also implement a ctrl()
 * handler that supports the stated commands (ie. the "cmd_num" entries as
 * described by the array). NB: The array must be ordered in increasing order
 * of cmd_num. "null-terminated" means that the last ENGINE_CMD_DEFN element
 * has cmd_num set to zero and/or cmd_name set to NULL.
 */
typedef struct ENGINE_CMD_DEFN_st {
    unsigned int cmd_num;       /* The command number */
    const char *cmd_name;       /* The command name itself */
    const char *cmd_desc;       /* A short description of the command */
    unsigned int cmd_flags;     /* The input the command expects */
} ENGINE_CMD_DEFN;

/* Generic function pointer */
typedef int (*ENGINE_GEN_FUNC_PTR) (void);
/* Generic function pointer taking no arguments */
typedef int (*ENGINE_GEN_INT_FUNC_PTR) (ENGINE *);
/* Specific control function pointer */
typedef int (*ENGINE_CTRL_FUNC_PTR) (ENGINE *, int, long, void *,
                                     void (*f) (void));
/* Generic load_key function pointer */
typedef EVP_PKEY *(*ENGINE_LOAD_KEY_PTR)(ENGINE *, const char *,
                                         UI_METHOD *ui_method,
                                         void *callback_data);
typedef int (*ENGINE_SSL_CLIENT_CERT_PTR) (ENGINE *, SSL *ssl,
                                           STACK_OF(X509_NAME) *ca_dn,
                                           X509 **pcert, EVP_PKEY **pkey,
                                           STACK_OF(X509) **pother,
                                           UI_METHOD *ui_method,
                                           void *callback_data);
/*-
 * These callback types are for an ENGINE's handler for cipher and digest logic.
 * These handlers have these prototypes;
 *   int foo(ENGINE *e, const EVP_CIPHER **cipher, const int **nids, int nid);
 *   int foo(ENGINE *e, const EVP_MD **digest, const int **nids, int nid);
 * Looking at how to implement these handlers in the case of cipher support, if
 * the framework wants the EVP_CIPHER for 'nid', it will call;
 *   foo(e, &p_evp_cipher, NULL, nid);    (return zero for failure)
 * If the framework wants a list of supported 'nid's, it will call;
 *   foo(e, NULL, &p_nids, 0); (returns number of 'nids' or -1 for error)
 */
/*
 * Returns to a pointer to the array of supported cipher 'nid's. If the
 * second parameter is non-NULL it is set to the size of the returned array.
 */
typedef int (*ENGINE_CIPHERS_PTR) (ENGINE *, const EVP_CIPHER **,
                                   const int **, int);
typedef int (*ENGINE_DIGESTS_PTR) (ENGINE *, const EVP_MD **, const int **,
                                   int);
typedef int (*ENGINE_PKEY_METHS_PTR) (ENGINE *, EVP_PKEY_METHOD **,
                                      const int **, int);
typedef int (*ENGINE_PKEY_ASN1_METHS_PTR) (ENGINE *, EVP_PKEY_ASN1_METHOD **,
                                           const int **, int);
/*
 * STRUCTURE functions ... all of these functions deal with pointers to
 * ENGINE structures where the pointers have a "structural reference". This
 * means that their reference is to allowed access to the structure but it
 * does not imply that the structure is functional. To simply increment or
 * decrement the structural reference count, use ENGINE_by_id and
 * ENGINE_free. NB: This is not required when iterating using ENGINE_get_next
 * as it will automatically decrement the structural reference count of the
 * "current" ENGINE and increment the structural reference count of the
 * ENGINE it returns (unless it is NULL).
 */

/* Get the first/last "ENGINE" type available. */
ENGINE