Improve ECDH documentation
- Rephrase file/function/parameter/enum/define/error descriptions into full and clear sentences. - Make sure to adhere to the Arm writing guidelines. - Fix missing/incorrect Doxygen tags. - Standardize terminology used within the file. GitHub PR: #1317
This commit is contained in:
Rose Zadik
Jaeden Amero
parent
042e97fa75
commit
de2d6221c8
1 changed files with 150 additions and 88 deletions
|
|
@ -1,10 +1,18 @@
|
|||
/**
|
||||
* \file ecdh.h
|
||||
*
|
||||
* \brief Elliptic curve Diffie-Hellman
|
||||
* \brief The Elliptic Curve Diffie-Hellman (ECDH) protocol APIs.
|
||||
*
|
||||
* ECDH is an anonymous key agreement protocol allowing two parties to
|
||||
* establish a shared secret over an insecure channel. Each party must have an
|
||||
* elliptic-curve public–private key pair.
|
||||
*
|
||||
* For more information, see <em>NIST SP 800-56A Rev. 2: Recommendation for
|
||||
* Pair-Wise Key Establishment Schemes Using Discrete Logarithm
|
||||
* Cryptography</em>.
|
||||
*/
|
||||
/*
|
||||
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
|
||||
* Copyright (C) 2006-2018, Arm Limited (or its affiliates), All Rights Reserved
|
||||
* SPDX-License-Identifier: Apache-2.0
|
||||
*
|
||||
* Licensed under the Apache License, Version 2.0 (the "License"); you may
|
||||
|
|
@ -19,8 +27,9 @@
|
|||
* 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)
|
||||
* This file is part of Mbed TLS (https://tls.mbed.org)
|
||||
*/
|
||||
|
||||
#ifndef MBEDTLS_ECDH_H
|
||||
#define MBEDTLS_ECDH_H
|
||||
|
||||
|
|
@ -31,7 +40,9 @@ extern "C" {
|
|||
#endif
|
||||
|
||||
/**
|
||||
* When importing from an EC key, select if it is our key or the peer's key
|
||||
* Defines the source of the imported EC key:
|
||||
* <ul><li>Our key.</li>
|
||||
* <li>The key of the peer.</li></ul>
|
||||
*/
|
||||
typedef enum
|
||||
{
|
||||
|
|
@ -40,56 +51,67 @@ typedef enum
|
|||
} mbedtls_ecdh_side;
|
||||
|
||||
/**
|
||||
* \brief ECDH context structure
|
||||
* \brief The ECDH context structure.
|
||||
*/
|
||||
typedef struct
|
||||
{
|
||||
mbedtls_ecp_group grp; /*!< elliptic curve used */
|
||||
mbedtls_mpi d; /*!< our secret value (private key) */
|
||||
mbedtls_ecp_point Q; /*!< our public value (public key) */
|
||||
mbedtls_ecp_point Qp; /*!< peer's public value (public key) */
|
||||
mbedtls_mpi z; /*!< shared secret */
|
||||
int point_format; /*!< format for point export in TLS messages */
|
||||
mbedtls_ecp_point Vi; /*!< blinding value (for later) */
|
||||
mbedtls_ecp_point Vf; /*!< un-blinding value (for later) */
|
||||
mbedtls_mpi _d; /*!< previous d (for later) */
|
||||
mbedtls_ecp_group grp; /*!< The elliptic curve used. */
|
||||
mbedtls_mpi d; /*!< The private key. */
|
||||
mbedtls_ecp_point Q; /*!< The public key. */
|
||||
mbedtls_ecp_point Qp; /*!< The value of the public key of the peer. */
|
||||
mbedtls_mpi z; /*!< The shared secret. */
|
||||
int point_format; /*!< The format of point export in TLS messages. */
|
||||
mbedtls_ecp_point Vi; /*!< The blinding value. */
|
||||
mbedtls_ecp_point Vf; /*!< The unblinding value. */
|
||||
mbedtls_mpi _d; /*!< The previous \p d. */
|
||||
}
|
||||
mbedtls_ecdh_context;
|
||||
|
||||
/**
|
||||
* \brief Generate a public key.
|
||||
* Raw function that only does the core computation.
|
||||
* \brief This function generates an ECDH keypair on an elliptic
|
||||
* curve.
|
||||
*
|
||||
* \param grp ECP group
|
||||
* \param d Destination MPI (secret exponent, aka private key)
|
||||
* \param Q Destination point (public key)
|
||||
* \param f_rng RNG function
|
||||
* \param p_rng RNG parameter
|
||||
* This function performs the first of two core computations
|
||||
* implemented during the ECDH key exchange. The second core
|
||||
* computation is performed by mbedtls_ecdh_compute_shared().
|
||||
*
|
||||
* \return 0 if successful,
|
||||
* or a MBEDTLS_ERR_ECP_XXX or MBEDTLS_MPI_XXX error code
|
||||
* \param grp The ECP group.
|
||||
* \param d The destination MPI (private key).
|
||||
* \param Q The destination point (public key).
|
||||
* \param f_rng The RNG function.
|
||||
* \param p_rng The RNG parameter.
|
||||
*
|
||||
* \return \c 0 on success, or an \c MBEDTLS_ERR_ECP_XXX or
|
||||
* \c MBEDTLS_MPI_XXX error code on failure.
|
||||
*
|
||||
* \see ecp.h
|
||||
*/
|
||||
int mbedtls_ecdh_gen_public( mbedtls_ecp_group *grp, mbedtls_mpi *d, mbedtls_ecp_point *Q,
|
||||
int (*f_rng)(void *, unsigned char *, size_t),
|
||||
void *p_rng );
|
||||
|
||||
/**
|
||||
* \brief Compute shared secret
|
||||
* Raw function that only does the core computation.
|
||||
* \brief This function computes the shared secret.
|
||||
*
|
||||
* \param grp ECP group
|
||||
* \param z Destination MPI (shared secret)
|
||||
* \param Q Public key from other party
|
||||
* \param d Our secret exponent (private key)
|
||||
* \param f_rng RNG function (see notes)
|
||||
* \param p_rng RNG parameter
|
||||
* This function performs the second of two core computations
|
||||
* implemented during the ECDH key exchange. The first core
|
||||
* computation is performed by mbedtls_ecdh_gen_public().
|
||||
*
|
||||
* \return 0 if successful,
|
||||
* or a MBEDTLS_ERR_ECP_XXX or MBEDTLS_MPI_XXX error code
|
||||
* \param grp The ECP group.
|
||||
* \param z The destination MPI (shared secret).
|
||||
* \param Q The public key from another party.
|
||||
* \param d Our secret exponent (private key).
|
||||
* \param f_rng The RNG function.
|
||||
* \param p_rng The RNG parameter.
|
||||
*
|
||||
* \note If f_rng is not NULL, it is used to implement
|
||||
* \return \c 0 on success, or an \c MBEDTLS_ERR_ECP_XXX or
|
||||
* \c MBEDTLS_MPI_XXX error code on failure.
|
||||
*
|
||||
* \see ecp.h
|
||||
*
|
||||
* \note If \p f_rng is not NULL, it is used to implement
|
||||
* countermeasures against potential elaborate timing
|
||||
* attacks, see \c mbedtls_ecp_mul() for details.
|
||||
* attacks. For more information, see mbedtls_ecp_mul().
|
||||
*/
|
||||
int mbedtls_ecdh_compute_shared( mbedtls_ecp_group *grp, mbedtls_mpi *z,
|
||||
const mbedtls_ecp_point *Q, const mbedtls_mpi *d,
|
||||
|
|
@ -97,34 +119,41 @@ int mbedtls_ecdh_compute_shared( mbedtls_ecp_group *grp, mbedtls_mpi *z,
|
|||
void *p_rng );
|
||||
|
||||
/**
|
||||
* \brief Initialize context
|
||||
* \brief This function initializes an ECDH context.
|
||||
*
|
||||
* \param ctx Context to initialize
|
||||
* \param ctx The ECDH context to initialize.
|
||||
*/
|
||||
void mbedtls_ecdh_init( mbedtls_ecdh_context *ctx );
|
||||
|
||||
/**
|
||||
* \brief Free context
|
||||
* \brief This function frees a context.
|
||||
*
|
||||
* \param ctx Context to free
|
||||
* \param ctx The context to free.
|
||||
*/
|
||||
void mbedtls_ecdh_free( mbedtls_ecdh_context *ctx );
|
||||
|
||||
/**
|
||||
* \brief Generate a public key and a TLS ServerKeyExchange payload.
|
||||
* (First function used by a TLS server for ECDHE.)
|
||||
* \brief This function generates a public key and a TLS
|
||||
* ServerKeyExchange payload.
|
||||
*
|
||||
* \param ctx ECDH context
|
||||
* \param olen number of chars written
|
||||
* \param buf destination buffer
|
||||
* \param blen length of buffer
|
||||
* \param f_rng RNG function
|
||||
* \param p_rng RNG parameter
|
||||
* This is the first function used by a TLS server for ECDHE
|
||||
* ciphersuites.
|
||||
*
|
||||
* \note This function assumes that ctx->grp has already been
|
||||
* properly set (for example using mbedtls_ecp_group_load).
|
||||
* \param ctx The ECDH context.
|
||||
* \param olen The number of characters written.
|
||||
* \param buf The destination buffer.
|
||||
* \param blen The length of the destination buffer.
|
||||
* \param f_rng The RNG function.
|
||||
* \param p_rng The RNG parameter.
|
||||
*
|
||||
* \return 0 if successful, or an MBEDTLS_ERR_ECP_XXX error code
|
||||
* \note This function assumes that the ECP group (grp) of the
|
||||
* \p ctx context has already been properly set,
|
||||
* for example, using mbedtls_ecp_group_load().
|
||||
*
|
||||
* \return \c 0 on success, or an \c MBEDTLS_ERR_ECP_XXX error code
|
||||
* on failure.
|
||||
*
|
||||
* \see ecp.h
|
||||
*/
|
||||
int mbedtls_ecdh_make_params( mbedtls_ecdh_context *ctx, size_t *olen,
|
||||
unsigned char *buf, size_t blen,
|
||||
|
|
@ -132,45 +161,63 @@ int mbedtls_ecdh_make_params( mbedtls_ecdh_context *ctx, size_t *olen,
|
|||
void *p_rng );
|
||||
|
||||
/**
|
||||
* \brief Parse and procress a TLS ServerKeyExhange payload.
|
||||
* (First function used by a TLS client for ECDHE.)
|
||||
* \brief This function parses and processes a TLS ServerKeyExhange
|
||||
* payload.
|
||||
*
|
||||
* \param ctx ECDH context
|
||||
* \param buf pointer to start of input buffer
|
||||
* \param end one past end of buffer
|
||||
* This is the first function used by a TLS client for ECDHE
|
||||
* ciphersuites.
|
||||
*
|
||||
* \return 0 if successful, or an MBEDTLS_ERR_ECP_XXX error code
|
||||
* \param ctx The ECDH context.
|
||||
* \param buf The pointer to the start of the input buffer.
|
||||
* \param end The address for one Byte past the end of the buffer.
|
||||
*
|
||||
* \return \c 0 on success, or an \c MBEDTLS_ERR_ECP_XXX error code
|
||||
* on failure.
|
||||
*
|
||||
* \see ecp.h
|
||||
*/
|
||||
int mbedtls_ecdh_read_params( mbedtls_ecdh_context *ctx,
|
||||
const unsigned char **buf, const unsigned char *end );
|
||||
|
||||
/**
|
||||
* \brief Setup an ECDH context from an EC key.
|
||||
* (Used by clients and servers in place of the
|
||||
* ServerKeyEchange for static ECDH: import ECDH parameters
|
||||
* from a certificate's EC key information.)
|
||||
* \brief This function sets up an ECDH context from an EC key.
|
||||
*
|
||||
* \param ctx ECDH constext to set
|
||||
* \param key EC key to use
|
||||
* \param side Is it our key (1) or the peer's key (0) ?
|
||||
* It is used by clients and servers in place of the
|
||||
* ServerKeyEchange for static ECDH, and imports ECDH
|
||||
* parameters from the EC key information of a certificate.
|
||||
*
|
||||
* \return 0 if successful, or an MBEDTLS_ERR_ECP_XXX error code
|
||||
* \param ctx The ECDH context to set up.
|
||||
* \param key The EC key to use.
|
||||
* \param side Defines the source of the key:
|
||||
* <ul><li>1: Our key.</li>
|
||||
<li>0: The key of the peer.</li></ul>
|
||||
*
|
||||
* \return \c 0 on success, or an \c MBEDTLS_ERR_ECP_XXX error code
|
||||
* on failure.
|
||||
*
|
||||
* \see ecp.h
|
||||
*/
|
||||
int mbedtls_ecdh_get_params( mbedtls_ecdh_context *ctx, const mbedtls_ecp_keypair *key,
|
||||
mbedtls_ecdh_side side );
|
||||
|
||||
/**
|
||||
* \brief Generate a public key and a TLS ClientKeyExchange payload.
|
||||
* (Second function used by a TLS client for ECDH(E).)
|
||||
* \brief This function generates a public key and a TLS
|
||||
* ClientKeyExchange payload.
|
||||
*
|
||||
* \param ctx ECDH context
|
||||
* \param olen number of bytes actually written
|
||||
* \param buf destination buffer
|
||||
* \param blen size of destination buffer
|
||||
* \param f_rng RNG function
|
||||
* \param p_rng RNG parameter
|
||||
* This is the second function used by a TLS client for ECDH(E)
|
||||
* ciphersuites.
|
||||
*
|
||||
* \return 0 if successful, or an MBEDTLS_ERR_ECP_XXX error code
|
||||
* \param ctx The ECDH context.
|
||||
* \param olen The number of Bytes written.
|
||||
* \param buf The destination buffer.
|
||||
* \param blen The size of the destination buffer.
|
||||
* \param f_rng The RNG function.
|
||||
* \param p_rng The RNG parameter.
|
||||
*
|
||||
* \return \c 0 on success, or an \c MBEDTLS_ERR_ECP_XXX error code
|
||||
* on failure.
|
||||
*
|
||||
* \see ecp.h
|
||||
*/
|
||||
int mbedtls_ecdh_make_public( mbedtls_ecdh_context *ctx, size_t *olen,
|
||||
unsigned char *buf, size_t blen,
|
||||
|
|
@ -178,30 +225,45 @@ int mbedtls_ecdh_make_public( mbedtls_ecdh_context *ctx, size_t *olen,
|
|||
void *p_rng );
|
||||
|
||||
/**
|
||||
* \brief Parse and process a TLS ClientKeyExchange payload.
|
||||
* (Second function used by a TLS server for ECDH(E).)
|
||||
* \brief This function parses and processes a TLS ClientKeyExchange
|
||||
* payload.
|
||||
*
|
||||
* \param ctx ECDH context
|
||||
* \param buf start of input buffer
|
||||
* \param blen length of input buffer
|
||||
* This is the second function used by a TLS server for ECDH(E)
|
||||
* ciphersuites.
|
||||
*
|
||||
* \return 0 if successful, or an MBEDTLS_ERR_ECP_XXX error code
|
||||
* \param ctx The ECDH context.
|
||||
* \param buf The start of the input buffer.
|
||||
* \param blen The length of the input buffer.
|
||||
*
|
||||
* \return \c 0 on success, or an \c MBEDTLS_ERR_ECP_XXX error code
|
||||
* on failure.
|
||||
*
|
||||
* \see ecp.h
|
||||
*/
|
||||
int mbedtls_ecdh_read_public( mbedtls_ecdh_context *ctx,
|
||||
const unsigned char *buf, size_t blen );
|
||||
|
||||
/**
|
||||
* \brief Derive and export the shared secret.
|
||||
* (Last function used by both TLS client en servers.)
|
||||
* \brief This function derives and exports the shared secret.
|
||||
*
|
||||
* \param ctx ECDH context
|
||||
* \param olen number of bytes written
|
||||
* \param buf destination buffer
|
||||
* \param blen buffer length
|
||||
* \param f_rng RNG function, see notes for \c mbedtls_ecdh_compute_shared()
|
||||
* \param p_rng RNG parameter
|
||||
* This is the last function used by both TLS client
|
||||
* and servers.
|
||||
*
|
||||
* \return 0 if successful, or an MBEDTLS_ERR_ECP_XXX error code
|
||||
* \param ctx The ECDH context.
|
||||
* \param olen The number of Bytes written.
|
||||
* \param buf The destination buffer.
|
||||
* \param blen The length of the destination buffer.
|
||||
* \param f_rng The RNG function.
|
||||
* \param p_rng The RNG parameter.
|
||||
*
|
||||
* \return \c 0 on success, or an \c MBEDTLS_ERR_ECP_XXX error code
|
||||
* on failure.
|
||||
*
|
||||
* \see ecp.h
|
||||
*
|
||||
* \note If \p f_rng is not NULL, it is used to implement
|
||||
* countermeasures against potential elaborate timing
|
||||
* attacks. For more information, see mbedtls_ecp_mul().
|
||||
*/
|
||||
int mbedtls_ecdh_calc_secret( mbedtls_ecdh_context *ctx, size_t *olen,
|
||||
unsigned char *buf, size_t blen,
|
||||
|
|
|
|||
Loading…
Reference in a new issue