/**
* \file ecdsa.h
*
* \brief This file contains ECDSA definitions and functions.
*
* The Elliptic Curve Digital Signature Algorithm (ECDSA) is defined in
* <em>Standards for Efficient Cryptography Group (SECG):
* SEC1 Elliptic Curve Cryptography</em>.
* The use of ECDSA for TLS is defined in <em>RFC-4492: Elliptic Curve
* Cryptography (ECC) Cipher Suites for Transport Layer Security (TLS)</em>.
*
*/
/*
* Copyright The Mbed TLS Contributors
* 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.
*/
#ifndef MBEDTLS_ECDSA_H
#define MBEDTLS_ECDSA_H
#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#include "mbedtls/ecp.h"
#include "mbedtls/md.h"
/**
* \addtogroup mbedtls
* \{
* \defgroup mbedtls_ecdsa_module ECDSA
* \{
*/
/**
* \brief Maximum ECDSA signature size for a given curve bit size
*
* \param bits Curve size in bits
* \return Maximum signature size in bytes
*
* \note This macro returns a compile-time constant if its argument
* is one. It may evaluate its argument multiple times.
*/
/*
* Ecdsa-Sig-Value ::= SEQUENCE {
* r INTEGER,
* s INTEGER
* }
*
* For each of r and s, the value (V) may include an extra initial "0" bit.
*/
#define MBEDTLS_ECDSA_MAX_SIG_LEN( bits ) \
( /*T,L of SEQUENCE*/ ( ( bits ) >= 61 * 8 ? 3 : 2 ) + \
/*T,L of r,s*/ 2 * ( ( ( bits ) >= 127 * 8 ? 3 : 2 ) + \
/*V of r,s*/ ( ( bits ) + 8 ) / 8 ) )
/** The maximal size of an ECDSA signature in Bytes. */
#define MBEDTLS_ECDSA_MAX_LEN MBEDTLS_ECDSA_MAX_SIG_LEN( MBEDTLS_ECP_MAX_BITS )
#ifdef __cplusplus
extern "C" {
#endif
/**
* \brief The ECDSA context structure.
*
* \warning Performing multiple operations concurrently on the same
* ECDSA context is not supported; objects of this type
* should not be shared between multiple threads.
*/
typedef mbedtls_ecp_keypair mbedtls_ecdsa_context;
#if defined(MBEDTLS_ECP_RESTARTABLE)
/**
* \brief Internal restart context for ecdsa_verify()
*
* \note Opaque struct, defined in ecdsa.c
*/
typedef struct mbedtls_ecdsa_restart_ver mbedtls_ecdsa_restart_ver_ctx;
/**
* \brief Internal restart context for ecdsa_sign()
*
* \note Opaque struct, defined in ecdsa.c
*/
typedef struct mbedtls_ecdsa_restart_sig mbedtls_ecdsa_restart_sig_ctx;
#if defined(MBEDTLS_ECDSA_DETERMINISTIC)
/**
* \brief Internal restart context for ecdsa_sign_det()
*
* \note Opaque struct, defined in ecdsa.c
*/
typedef struct mbedtls_ecdsa_restart_det mbedtls_ecdsa_restart_det_ctx;
#endif
/**
* \brief General context for resuming ECDSA operations
*/
typedef struct
{
mbedtls_ecp_restart_ctx ecp; /*!< base context for ECP restart and
shared administrative info */
mbedtls_ecdsa_restart_ver_ctx *ver; /*!< ecdsa_verify() sub-context */
mbedtls_ecdsa_restart_sig_ctx *sig; /*!< ecdsa_sign() sub-context */
#if defined(MBEDTLS_ECDSA_DETERMINISTIC)
mbedtls_ecdsa_restart_det_ctx *det; /*!< ecdsa_sign_det() sub-context */
#endif
} mbedtls_ecdsa_restart_ctx;
#else /* MBEDTLS_ECP_RESTARTABLE */
/* Now we can declare functions that take a pointer to that */
typedef void mbedtls_ecdsa_restart_ctx;
#endif /* MBEDTLS_ECP_RESTARTABLE */
/**
* \brief This function checks whether a given group can be used
* for ECDSA.
*
* \param gid The ECP group ID to check.
*
* \return \c 1 if the group can be used, \c 0 otherwise
*/
int mbedtls_ecdsa_can_do( mbedtls_ecp_group_id gid );
/**
* \brief This function computes the ECDSA signature of a
* previously-hashed message.
*
* \note The deterministic version implemented in
* mbedtls_ecdsa_sign_det() is usually preferred.
*
* \note If the bitlength of the message hash is larger than the
* bitlength of the group order, then the hash is truncated
* as defined in <em>Standards for Efficient Cryptography Group
* (SECG): SEC1 Elliptic Curve Cryptography</em>, section
* 4.1.3, step 5.
*
* \see ecp.h
*
* \param grp The context for the elliptic curve to use.
* This must be initialized and have group parameters
* set, for example through mbedtls_ecp_group_load().
* \param r The MPI context in which to store the first part
* the signature. This must be initialized.
* \param s The MPI context in which to store the second part
* the signature. This must be initialized.
* \param d The private signing key. This must be initialized.
* \param buf The content to be signed. This is usually the hash of
* the original data to be signed. This must be a readable
* buffer of length \p blen Bytes. It may be \c NULL if
* \p blen is zero.
* \param blen The length of \p buf in Bytes.
* \param f_rng The RNG function. This must not be \c NULL.
* \param p_rng The RNG context to be passed to \p f_rng. This may be
* \c NULL if \p f_rng doesn't need a context parameter.
*
* \return \c 0 on success.
* \return An \c MBEDTLS_ERR_ECP_XXX
* or \c MBEDTLS_MPI_XXX error code on failure.
*/
int mbedtls_ecdsa_sign( mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi *s,
const mbedtls_mpi *d, const unsigned char *buf, size_t blen,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
#if defined(MBEDTLS_ECDSA_DETERMINISTIC)
#if ! defined(MBEDTLS_DEPRECATED_REMOVED)
#if defined(MBEDTLS_DEPRECATED_WARNING)
#define MBEDTLS_DEPRECATED __attribute__((deprecated))
#else
#define MBEDTLS_DEPRECATED
#endif
/**
* \brief This function computes the ECDSA signature of a
* previously-hashed message, deterministic version.
*
* For more information, see <em>RFC-6979: Deterministic
* Usage of the Digital Signature Algorithm (DSA) and Elliptic
* Curve Digital Signature Algorithm (ECDSA)</em>.
*
* \note If the bitlength of the message hash is larger than the
* bitlength of the group order, then the hash is truncated as
* defined in <em>Standards for Efficient Cryptography Group
* (SECG): SEC1 Elliptic Curve Cryptography</em>, section
* 4.1.3, step 5.
*
* \warning Since the output of the internal RNG is always the same for
* the same key and message, this limits the efficiency of
* blinding and leaks information through side channels. For
* secure behavior use mbedtls_ecdsa_sign_det_ext() instead.
*
* (Optimally the blinding is a random value that is different
* on every execution. In this case the blinding is still
* random from the attackers perspective, but is the same on
* each execution. This means that this blinding does not
* prevent attackers from recovering secrets by combining
* several measurement traces, but may prevent some attacks
* that exploit relationships between secret data.)
*
* \see ecp.h
*
* \param grp The context for the elliptic curve to use.
* This must be initialized and have group parameters
* set, for example through mbedtls_ecp_group_load().
* \param r The MPI context in which to store the first part
* the signature. This must be initialized.
* \param s The MPI context in which to store the second part
* the signature. This must be initialized.
* \param d The private signing key. This must be initialized
* and setup, for example through mbedtls_ecp_gen_privkey().
* \param buf The hashed content to be signed. This must be a readable
* buffer of length \p blen Bytes. It may be \c NULL if
* \p blen is zero.
* \param blen The length of \p buf in Bytes.
* \param md_alg The hash algorithm used to hash the original data.
*
* \return \c 0 on success.
* \return An \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_MPI_XXX
* error code on failure.
*/
int mbedtls_ecdsa_sign_det( mbedtls_ecp_group *grp, mbedtls_mpi *r,
mbedtls_mpi *s, const mbedtls_mpi *d,
const unsigned char *buf, size_t blen,
mbedtls_md_type_t md_alg ) MBEDTLS_DEPRECATED;
#undef MBEDTLS_DEPRECATED
#endif /* MBEDTLS_DEPRECATED_REMOVED */
/**
* \brief This function computes the ECDSA signature of a
* previously-hashed message, deterministic version.
*
* For more information, see <em>RFC-6979: Deterministic
* Usage of the Digital Signature Algorithm (DSA) and Elliptic
* Curve Digital Signature Algorithm (ECDSA)</em>.
*
* \note If the bitlength of the message hash is larger than the
* bitlength of the group order, then the hash is truncated as
* defined in <em>Standards for Efficient Cryptography Group
* (SECG): SEC1 Elliptic Curve Cryptography</em>, section
* 4.1.3, step 5.
*
* \see ecp.h
*
* \param grp The context for the elliptic curve to use.
* This must be initialized and have group parameters
* set, for example through mbedtls_ecp_group_load().
* \param r The MPI context in which to store the first part
* the signature. This must be initialized.
* \param s The MPI context in which to store the second part
* the signature. This must be initialized.
* \param d The private signing key. This must be initialized
* and setup, for example through mbedtls_ecp_gen_privkey().
* \param buf The hashed content to be signed. This must be a readable
* buffer of length \p blen Bytes. It may be \c NULL if
* \p blen is zero.
* \param blen The length of \p buf in Bytes.
* \param md_alg The hash algorithm used to hash the original data.
* \param f_rng_blind The RNG function used for blinding. This must not be
* \c NULL.
* \param p_rng_blind The RNG context to be passed to \p f_rng. This may be
* \c NULL if \p f_rng doesn't need a context parameter.
*
* \return \c 0 on success.
* \return An \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_MPI_XXX
* error code on failure.
*/
int mbedtls_ecdsa_sign_det_ext( mbedtls_ecp_group *grp, mbedtls_mpi *r,
mbedtls_mpi *s, const mbedtls_mpi *d,
const unsigned char *buf, size_t blen,
mbedtls_md_type_t md_alg,
int (*f_rng_blind)(void *, unsigned char *, size_t),
void *p_rng_blind );
#endif /* MBEDTLS_ECDSA_DETERMINISTIC */
/**
* \brief This function verifies the ECDSA signature of a
* previously-hashed message.
*
* \note If the bitlength of the message hash is larger than the
* bitlength of the group order, then the hash is truncated as
* defined in <em>Standards for Efficient Cryptography Group
* (SECG): SEC1 Elliptic Curve Cryptography</em>, section
* 4.1.4, step 3.
*
* \see ecp.h
*
* \param grp The ECP group to use.
* This must be initialized and have group parameters
* set, for example through mbedtls_ecp_group_load().
* \param buf The hashed content that was signed. This must be a readable
* buffer of length \p blen Bytes. It may be \c NULL if
* \p blen is zero.
* \param blen The length of \p buf in Bytes.
* \param Q The public key to use for verification. This must be
* initialized and setup.
* \param r The first integer of the signature.
* This must be initialized.
* \param s The second integer of the signature.
* This must be initialized.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if the signature
* is invalid.
* \return An \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_MPI_XXX
* error code on failure for any other reason.
*/
int mbedtls_ecdsa_verify( mbedtls_ecp_group *grp,
const unsigned char *buf, size_t blen,
const mbedtls_ecp_point *Q, const mbedtls_mpi *r,
const mbedtls_mpi *s);
/**
* \brief This function computes the ECDSA signature and writes it
* to a buffer, serialized as defined in <em>RFC-4492:
* Elliptic Curve Cryptography (ECC) Cipher Suites for
* Transport Layer Security (TLS)</em>.
*
* \warning It is not thread-safe to use the same context in
* multiple threads.
*
* \note The deterministic version is used if
* MBEDTLS_ECDSA_DETERMINISTIC is defined. For more
* information, see <em>RFC-6979: Deterministic Usage
* of the Digital Signature Algorithm (DSA) and Elliptic
* Curve Digital Signature Algorithm (ECDSA)</em>.
*
* \note If the bitlength of the message hash is larger than the
* bitlength of the group order, then the hash is truncated as
* defined in <em>Standards for Efficient Cryptography Group
* (SECG): SEC1 Elliptic Curve Cryptography</em>, section
* 4.1.3, step 5.
*
* \see ecp.h
*
* \param ctx The ECDSA context to use. This must be initialized
* and have a group and private key bound to it, for example
* via mbedtls_ecdsa_genkey() or mbedtls_ecdsa_from_keypair().
* \param md_alg The message digest that was used to hash the message.
* \param hash The message hash to be signed. This must be a readable
* buffer of length \p blen Bytes.
* \param hlen The length of the hash \p hash in Bytes.
* \param sig The buffer to which to write the signature. This must be a
* writable buffer of length at least twice as large as the
* size of the curve used, plus 9. For example, 73 Bytes if
* a 256-bit curve is used. A buffer length of
* #MBEDTLS_ECDSA_MAX_LEN is always safe.
* \param slen The address at which to store the actual length of
* the signature written. Must not be \c NULL.
* \param f_rng The RNG function. This must not be \c NULL if
* MBEDTLS_ECDSA_DETERMINISTIC is unset. Otherwise,
* it is used only for blinding and may be set to \c NULL, but
* doing so is DEPRECATED.
* \param p_rng The RNG context to be passed to \p f_rng. This may be
* \c NULL if \p f_rng is \c NULL or doesn't use a context.
*
* \return \c 0 on success.
* \return An \c MBEDTLS_ERR_ECP_XXX, \c MBEDTLS_ERR_MPI_XXX or
* \c MBEDTLS_ERR_ASN1_XXX error code on failure.
*/
int mbedtls_ecdsa_write_signature( mbedtls_ecdsa_context *ctx,
mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hlen,
unsigned char *sig, size_t *slen,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng );
/**
* \brief This function computes the ECDSA signature and writes it
* to a buffer, in a restartable way.
*
* \see \c mbedtls_ecdsa_write_signature()
*
* \note This function is like \c mbedtls_ecdsa_write_signature()
* but it can return early and restart according to the limit
* set with \c mbedtls_ecp_set_max_ops() to reduce blocking.
*
* \param ctx The ECDSA context to use. This must be initialized
* and have a group and private key bound to it, for example
* via mbedtls_ecdsa_genkey() or mbedtls_ecdsa_from_keypair().
* \param md_alg The message digest that was used to hash the message.
* \param hash The message hash to be signed. This must be a readable
* buffer of length \p blen Bytes.
* \param hlen The length of the hash \p hash in Bytes.
* \param sig The buffer to which to write the signature. This must be a
* writable buffer of length at least twice as large as the
* size of the curve used, plus 9. For example, 73 Bytes if
* a 256-bit curve is used. A buffer length of
* #MBEDTLS_ECDSA_MAX_LEN is always safe.
* \param slen The address at which to store the actual length of
* the signature written. Must not be \c NULL.
* \param f_rng The RNG function. This must not be \c NULL if
* MBEDTLS_ECDSA_DETERMINISTIC is unset. Otherwise,
* it is unused and may be set to \c NULL.
* \param p_rng The RNG context to be passed to \p f_rng. This may be
* \c NULL if \p f_rng is \c NULL or doesn't use a context.
* \param rs_ctx The restart context to use. This may be \c NULL to disable
* restarting. If it is not \c NULL, it must point to an
* initialized restart context.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of
* operations was reached: see \c mbedtls_ecp_set_max_ops().
* \return Another \c MBEDTLS_ERR_ECP_XXX, \c MBEDTLS_ERR_MPI_XXX or
* \c MBEDTLS_ERR_ASN1_XXX error code on failure.
*/
int mbedtls_ecdsa_write_signature_restartable( mbedtls_ecdsa_context *ctx,
mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hlen,
unsigned char *sig, size_t *slen,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng,
mbedtls_ecdsa_restart_ctx *rs_ctx );
#if defined(MBEDTLS_ECDSA_DETERMINISTIC)
#if ! defined(MBEDTLS_DEPRECATED_REMOVED)
#if defined(MBEDTLS_DEPRECATED_WARNING)
#define MBEDTLS_DEPRECATED __attribute__((deprecated))
#else
#define MBEDTLS_DEPRECATED
#endif
/**
* \brief This function computes an ECDSA signature and writes
* it to a buffer, serialized as defined in <em>RFC-4492:
* Elliptic Curve Cryptography (ECC) Cipher Suites for
* Transport Layer Security (TLS)</em>.
*
* The deterministic version is defined in <em>RFC-6979:
* Deterministic Usage of the Digital Signature Algorithm (DSA)
* and Elliptic Curve Digital Signature Algorithm (ECDSA)</em>.
*
* \warning It is not thread-safe to use the same context in
* multiple threads.
*
* \note If the bitlength of the message hash is larger than the
* bitlength of the group order, then the hash is truncated as
* defined in <em>Standards for Efficient Cryptography Group
* (SECG): SEC1 Elliptic Curve Cryptography</em>, section
* 4.1.3, step 5.
*
* \see ecp.h
*
* \deprecated Superseded by mbedtls_ecdsa_write_signature() in
* Mbed TLS version 2.0 and later.
*
* \param ctx The ECDSA context to use. This must be initialized
* and have a group and private key bound to it, for example
* via mbedtls_ecdsa_genkey() or mbedtls_ecdsa_from_keypair().
* \param hash The message hash to be signed. This must be a readable
* buffer of length \p blen Bytes.
* \param hlen The length of the hash \p hash in Bytes.
* \param sig The buffer to which to write the signature. This must be a
* writable buffer of length at least twice as large as the
* size of the curve used, plus 9. For example, 73 Bytes if
* a 256-bit curve is used. A buffer length of
* #MBEDTLS_ECDSA_MAX_LEN is always safe.
* \param slen The address at which to store the actual length of
* the signature written. Must not be \c NULL.
* \param md_alg The message digest that was used to hash the message.
*
* \return \c 0 on success.
* \return An \c MBEDTLS_ERR_ECP_XXX, \c MBEDTLS_ERR_MPI_XXX or
* \c MBEDTLS_ERR_ASN1_XXX error code on failure.
*/
int mbedtls_ecdsa_write_signature_det( mbedtls_ecdsa_context *ctx,
const unsigned char *hash, size_t hlen,
unsigned char *sig, size_t *slen,
mbedtls_md_type_t md_alg ) MBEDTLS_DEPRECATED;
#undef MBEDTLS_DEPRECATED
#endif /* MBEDTLS_DEPRECATED_REMOVED */
#endif /* MBEDTLS_ECDSA_DETERMINISTIC */
/**
* \brief This function reads and verifies an ECDSA signature.
*
* \note If the bitlength of the message hash is larger than the
* bitlength of the group order, then the hash is truncated as
* defined in <em>Standards for Efficient Cryptography Group
* (SECG): SEC1 Elliptic Curve Cryptography</em>, section
* 4.1.4, step 3.
*
* \see ecp.h
*
* \param ctx The ECDSA context to use. This must be initialized
* and have a group and public key bound to it.
* \param hash The message hash that was signed. This must be a readable
* buffer of length \p size Bytes.
* \param hlen The size of the hash \p hash.
* \param sig The signature to read and verify. This must be a readable
* buffer of length \p slen Bytes.
* \param slen The size of \p sig in Bytes.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if signature is invalid.
* \return #MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH if there is a valid
* signature in \p sig, but its length is less than \p siglen.
* \return An \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_ERR_MPI_XXX
* error code on failure for any other reason.
*/
int mbedtls_ecdsa_read_signature( mbedtls_ecdsa_context *ctx,
const unsigned char *hash, size_t hlen,
const unsigned char *sig, size_t slen );
/**
* \brief This function reads and verifies an ECDSA signature,
* in a restartable way.
*
* \see \c mbedtls_ecdsa_read_signature()
*
* \note This function is like \c mbedtls_ecdsa_read_signature()
* but it can return early and restart according to the limit
* set with \c mbedtls_ecp_set_max_ops() to reduce blocking.
*
* \param ctx The ECDSA context to use. This must be initialized
* and have a group and public key bound to it.
* \param hash The message hash that was signed. This must be a readable
* buffer of length \p size Bytes.
* \param hlen The size of the hash \p hash.
* \param sig The signature to read and verify. This must be a readable
* buffer of length \p slen Bytes.
* \param slen The size of \p sig in Bytes.
* \param rs_ctx The restart context to use. This may be \c NULL to disable
* restarting. If it is not \c NULL, it must point to an
* initialized restart context.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if signature is invalid.
* \return #MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH if there is a valid
* signature in \p sig, but its length is less than \p siglen.
* \return #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of
* operations was reached: see \c mbedtls_ecp_set_max_ops().
* \return Another \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_ERR_MPI_XXX
* error code on failure for any other reason.
*/
int mbedtls_ecdsa_read_signature_restartable( mbedtls_ecdsa_context *ctx,
const unsigned char *hash, size_t hlen,
const unsigned char *sig, size_t slen,
mbedtls_ecdsa_restart_ctx *rs_ctx );
/**
* \brief This function generates an ECDSA keypair on the given curve.
*
* \see ecp.h
*
* \param ctx The ECDSA context to store the keypair in.
* This must be initialized.
* \param gid The elliptic curve to use. One of the various
* \c MBEDTLS_ECP_DP_XXX macros depending on configuration.
* \param f_rng The RNG function to use. This must not be \c NULL.
* \param p_rng The RNG context to be passed to \p f_rng. This may be
* \c NULL if \p f_rng doesn't need a context argument.
*
* \return \c 0 on success.
* \return An \c MBEDTLS_ERR_ECP_XXX code on failure.
*/
int mbedtls_ecdsa_genkey( mbedtls_ecdsa_context *ctx, mbedtls_ecp_group_id gid,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
/**
* \brief This function sets up an ECDSA context from an EC key pair.
*
* \see ecp.h
*
* \param ctx The ECDSA context to setup. This must be initialized.
* \param key The EC key to use. This must be initialized and hold
* a private-public key pair or a public key. In the former
* case, the ECDSA context may be used for signature creation
* and verification after this call. In the latter case, it
* may be used for signature verification.
*
* \return \c 0 on success.
* \return An \c MBEDTLS_ERR_ECP_XXX code on failure.
*/
int mbedtls_ecdsa_from_keypair( mbedtls_ecdsa_context *ctx,
const mbedtls_ecp_keypair *key );
/**
* \brief This function initializes an ECDSA context.
*
* \param ctx The ECDSA context to initialize.
* This must not be \c NULL.
*/
void mbedtls_ecdsa_init( mbedtls_ecdsa_context *ctx );
/**
* \brief This function frees an ECDSA context.
*
* \param ctx The ECDSA context to free. This may be \c NULL,
* in which case this function does nothing. If it
* is not \c NULL, it must be initialized.
*/
void mbedtls_ecdsa_free( mbedtls_ecdsa_context *ctx );
#if defined(MBEDTLS_ECP_RESTARTABLE)
/**
* \brief Initialize a restart context.
*
* \param ctx The restart context to initialize.
* This must not be \c NULL.
*/
void mbedtls_ecdsa_restart_init( mbedtls_ecdsa_restart_ctx *ctx );
/**
* \brief Free the components of a restart context.
*
* \param ctx The restart context to free. This may be \c NULL,
* in which case this function does nothing. If it
* is not \c NULL, it must be initialized.
*/
void mbedtls_ecdsa_restart_free( mbedtls_ecdsa_restart_ctx *ctx );
#endif /* MBEDTLS_ECP_RESTARTABLE */
/// \}
/// \}
#ifdef __cplusplus
}
#endif
#endif /* ecdsa.h */
