239 lines
		
	
	
		
			8.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
		
		
			
		
	
	
			239 lines
		
	
	
		
			8.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
|  | /**
 | ||
|  |  * \file ecjpake.h | ||
|  |  * | ||
|  |  * \brief Elliptic curve J-PAKE | ||
|  |  * | ||
|  |  *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved | ||
|  |  *  SPDX-License-Identifier: Apache-2.0 | ||
|  |  * | ||
|  |  *  Licensed under the Apache License, Version 2.0 (the "License"); you may | ||
|  |  *  not use this file except in compliance with the License. | ||
|  |  *  You may obtain a copy of the License at | ||
|  |  * | ||
|  |  *  http://www.apache.org/licenses/LICENSE-2.0
 | ||
|  |  * | ||
|  |  *  Unless required by applicable law or agreed to in writing, software | ||
|  |  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT | ||
|  |  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | ||
|  |  *  See the License for the specific language governing permissions and | ||
|  |  *  limitations under the License. | ||
|  |  * | ||
|  |  *  This file is part of mbed TLS (https://tls.mbed.org)
 | ||
|  |  */ | ||
|  | #ifndef MBEDTLS_ECJPAKE_H
 | ||
|  | #define MBEDTLS_ECJPAKE_H
 | ||
|  | 
 | ||
|  | /*
 | ||
|  |  * J-PAKE is a password-authenticated key exchange that allows deriving a | ||
|  |  * strong shared secret from a (potentially low entropy) pre-shared | ||
|  |  * passphrase, with forward secrecy and mutual authentication. | ||
|  |  * https://en.wikipedia.org/wiki/Password_Authenticated_Key_Exchange_by_Juggling
 | ||
|  |  * | ||
|  |  * This file implements the Elliptic Curve variant of J-PAKE, | ||
|  |  * as defined in Chapter 7.4 of the Thread v1.0 Specification, | ||
|  |  * available to members of the Thread Group http://threadgroup.org/
 | ||
|  |  * | ||
|  |  * As the J-PAKE algorithm is inherently symmetric, so is our API. | ||
|  |  * Each party needs to send its first round message, in any order, to the | ||
|  |  * other party, then each sends its second round message, in any order. | ||
|  |  * The payloads are serialized in a way suitable for use in TLS, but could | ||
|  |  * also be use outside TLS. | ||
|  |  */ | ||
|  | 
 | ||
|  | #include "ecp.h"
 | ||
|  | #include "md.h"
 | ||
|  | 
 | ||
|  | #ifdef __cplusplus
 | ||
|  | extern "C" { | ||
|  | #endif
 | ||
|  | 
 | ||
|  | /**
 | ||
|  |  * Roles in the EC J-PAKE exchange | ||
|  |  */ | ||
|  | typedef enum { | ||
|  |     MBEDTLS_ECJPAKE_CLIENT = 0,         /**< Client                         */ | ||
|  |     MBEDTLS_ECJPAKE_SERVER,             /**< Server                         */ | ||
|  | } mbedtls_ecjpake_role; | ||
|  | 
 | ||
|  | /**
 | ||
|  |  * EC J-PAKE context structure. | ||
|  |  * | ||
|  |  * J-PAKE is a symmetric protocol, except for the identifiers used in | ||
|  |  * Zero-Knowledge Proofs, and the serialization of the second message | ||
|  |  * (KeyExchange) as defined by the Thread spec. | ||
|  |  * | ||
|  |  * In order to benefit from this symmetry, we choose a different naming | ||
|  |  * convetion from the Thread v1.0 spec. Correspondance is indicated in the | ||
|  |  * description as a pair C: client name, S: server name | ||
|  |  */ | ||
|  | typedef struct | ||
|  | { | ||
|  |     const mbedtls_md_info_t *md_info;   /**< Hash to use                    */ | ||
|  |     mbedtls_ecp_group grp;              /**< Elliptic curve                 */ | ||
|  |     mbedtls_ecjpake_role role;          /**< Are we client or server?       */ | ||
|  |     int point_format;                   /**< Format for point export        */ | ||
|  | 
 | ||
|  |     mbedtls_ecp_point Xm1;              /**< My public key 1   C: X1, S: X3 */ | ||
|  |     mbedtls_ecp_point Xm2;              /**< My public key 2   C: X2, S: X4 */ | ||
|  |     mbedtls_ecp_point Xp1;              /**< Peer public key 1 C: X3, S: X1 */ | ||
|  |     mbedtls_ecp_point Xp2;              /**< Peer public key 2 C: X4, S: X2 */ | ||
|  |     mbedtls_ecp_point Xp;               /**< Peer public key   C: Xs, S: Xc */ | ||
|  | 
 | ||
|  |     mbedtls_mpi xm1;                    /**< My private key 1  C: x1, S: x3 */ | ||
|  |     mbedtls_mpi xm2;                    /**< My private key 2  C: x2, S: x4 */ | ||
|  | 
 | ||
|  |     mbedtls_mpi s;                      /**< Pre-shared secret (passphrase) */ | ||
|  | } mbedtls_ecjpake_context; | ||
|  | 
 | ||
|  | /**
 | ||
|  |  * \brief           Initialize a context | ||
|  |  *                  (just makes it ready for setup() or free()). | ||
|  |  * | ||
|  |  * \param ctx       context to initialize | ||
|  |  */ | ||
|  | void mbedtls_ecjpake_init( mbedtls_ecjpake_context *ctx ); | ||
|  | 
 | ||
|  | /**
 | ||
|  |  * \brief           Set up a context for use | ||
|  |  * | ||
|  |  * \note            Currently the only values for hash/curve allowed by the | ||
|  |  *                  standard are MBEDTLS_MD_SHA256/MBEDTLS_ECP_DP_SECP256R1. | ||
|  |  * | ||
|  |  * \param ctx       context to set up | ||
|  |  * \param role      Our role: client or server | ||
|  |  * \param hash      hash function to use (MBEDTLS_MD_XXX) | ||
|  |  * \param curve     elliptic curve identifier (MBEDTLS_ECP_DP_XXX) | ||
|  |  * \param secret    pre-shared secret (passphrase) | ||
|  |  * \param len       length of the shared secret | ||
|  |  * | ||
|  |  * \return          0 if successfull, | ||
|  |  *                  a negative error code otherwise | ||
|  |  */ | ||
|  | int mbedtls_ecjpake_setup( mbedtls_ecjpake_context *ctx, | ||
|  |                            mbedtls_ecjpake_role role, | ||
|  |                            mbedtls_md_type_t hash, | ||
|  |                            mbedtls_ecp_group_id curve, | ||
|  |                            const unsigned char *secret, | ||
|  |                            size_t len ); | ||
|  | 
 | ||
|  | /*
 | ||
|  |  * \brief           Check if a context is ready for use | ||
|  |  * | ||
|  |  * \param ctx       Context to check | ||
|  |  * | ||
|  |  * \return          0 if the context is ready for use, | ||
|  |  *                  MBEDTLS_ERR_ECP_BAD_INPUT_DATA otherwise | ||
|  |  */ | ||
|  | int mbedtls_ecjpake_check( const mbedtls_ecjpake_context *ctx ); | ||
|  | 
 | ||
|  | /**
 | ||
|  |  * \brief           Generate and write the first round message | ||
|  |  *                  (TLS: contents of the Client/ServerHello extension, | ||
|  |  *                  excluding extension type and length bytes) | ||
|  |  * | ||
|  |  * \param ctx       Context to use | ||
|  |  * \param buf       Buffer to write the contents to | ||
|  |  * \param len       Buffer size | ||
|  |  * \param olen      Will be updated with the number of bytes written | ||
|  |  * \param f_rng     RNG function | ||
|  |  * \param p_rng     RNG parameter | ||
|  |  * | ||
|  |  * \return          0 if successfull, | ||
|  |  *                  a negative error code otherwise | ||
|  |  */ | ||
|  | int mbedtls_ecjpake_write_round_one( mbedtls_ecjpake_context *ctx, | ||
|  |                             unsigned char *buf, size_t len, size_t *olen, | ||
|  |                             int (*f_rng)(void *, unsigned char *, size_t), | ||
|  |                             void *p_rng ); | ||
|  | 
 | ||
|  | /**
 | ||
|  |  * \brief           Read and process the first round message | ||
|  |  *                  (TLS: contents of the Client/ServerHello extension, | ||
|  |  *                  excluding extension type and length bytes) | ||
|  |  * | ||
|  |  * \param ctx       Context to use | ||
|  |  * \param buf       Pointer to extension contents | ||
|  |  * \param len       Extension length | ||
|  |  * | ||
|  |  * \return          0 if successfull, | ||
|  |  *                  a negative error code otherwise | ||
|  |  */ | ||
|  | int mbedtls_ecjpake_read_round_one( mbedtls_ecjpake_context *ctx, | ||
|  |                                     const unsigned char *buf, | ||
|  |                                     size_t len ); | ||
|  | 
 | ||
|  | /**
 | ||
|  |  * \brief           Generate and write the second round message | ||
|  |  *                  (TLS: contents of the Client/ServerKeyExchange) | ||
|  |  * | ||
|  |  * \param ctx       Context to use | ||
|  |  * \param buf       Buffer to write the contents to | ||
|  |  * \param len       Buffer size | ||
|  |  * \param olen      Will be updated with the number of bytes written | ||
|  |  * \param f_rng     RNG function | ||
|  |  * \param p_rng     RNG parameter | ||
|  |  * | ||
|  |  * \return          0 if successfull, | ||
|  |  *                  a negative error code otherwise | ||
|  |  */ | ||
|  | int mbedtls_ecjpake_write_round_two( mbedtls_ecjpake_context *ctx, | ||
|  |                             unsigned char *buf, size_t len, size_t *olen, | ||
|  |                             int (*f_rng)(void *, unsigned char *, size_t), | ||
|  |                             void *p_rng ); | ||
|  | 
 | ||
|  | /**
 | ||
|  |  * \brief           Read and process the second round message | ||
|  |  *                  (TLS: contents of the Client/ServerKeyExchange) | ||
|  |  * | ||
|  |  * \param ctx       Context to use | ||
|  |  * \param buf       Pointer to the message | ||
|  |  * \param len       Message length | ||
|  |  * | ||
|  |  * \return          0 if successfull, | ||
|  |  *                  a negative error code otherwise | ||
|  |  */ | ||
|  | int mbedtls_ecjpake_read_round_two( mbedtls_ecjpake_context *ctx, | ||
|  |                                     const unsigned char *buf, | ||
|  |                                     size_t len ); | ||
|  | 
 | ||
|  | /**
 | ||
|  |  * \brief           Derive the shared secret | ||
|  |  *                  (TLS: Pre-Master Secret) | ||
|  |  * | ||
|  |  * \param ctx       Context to use | ||
|  |  * \param buf       Buffer to write the contents to | ||
|  |  * \param len       Buffer size | ||
|  |  * \param olen      Will be updated with the number of bytes written | ||
|  |  * \param f_rng     RNG function | ||
|  |  * \param p_rng     RNG parameter | ||
|  |  * | ||
|  |  * \return          0 if successfull, | ||
|  |  *                  a negative error code otherwise | ||
|  |  */ | ||
|  | int mbedtls_ecjpake_derive_secret( mbedtls_ecjpake_context *ctx, | ||
|  |                             unsigned char *buf, size_t len, size_t *olen, | ||
|  |                             int (*f_rng)(void *, unsigned char *, size_t), | ||
|  |                             void *p_rng ); | ||
|  | 
 | ||
|  | /**
 | ||
|  |  * \brief           Free a context's content | ||
|  |  * | ||
|  |  * \param ctx       context to free | ||
|  |  */ | ||
|  | void mbedtls_ecjpake_free( mbedtls_ecjpake_context *ctx ); | ||
|  | 
 | ||
|  | #if defined(MBEDTLS_SELF_TEST)
 | ||
|  | /**
 | ||
|  |  * \brief          Checkup routine | ||
|  |  * | ||
|  |  * \return         0 if successful, or 1 if a test failed | ||
|  |  */ | ||
|  | int mbedtls_ecjpake_self_test( int verbose ); | ||
|  | #endif
 | ||
|  | 
 | ||
|  | #ifdef __cplusplus
 | ||
|  | } | ||
|  | #endif
 | ||
|  | 
 | ||
|  | #endif /* ecjpake.h */
 |