fuchsia / third_party / github.com / ARMmbed / mbedtls / refs/tags/v2.25.0 / . / include / mbedtls / ecdsa.h

/** | |

* \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" | |

/** | |

* \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 */ |