| /** |
| * \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 */ |
