pigweed / third_party / github / ARMmbed / mbedtls / 029cc2f97b2d2d7ec7cb8809ef1b87a9b3b72bae / . / include / mbedtls / ecp.h

/** | |

* \file ecp.h | |

* | |

* \brief This file provides an API for Elliptic Curves over GF(P) (ECP). | |

* | |

* The use of ECP in cryptography and TLS is defined in | |

* <em>Standards for Efficient Cryptography Group (SECG): SEC1 | |

* Elliptic Curve Cryptography</em> and | |

* <em>RFC-4492: Elliptic Curve Cryptography (ECC) Cipher Suites | |

* for Transport Layer Security (TLS)</em>. | |

* | |

* <em>RFC-2409: The Internet Key Exchange (IKE)</em> defines ECP | |

* group types. | |

* | |

*/ | |

/* | |

* 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_ECP_H | |

#define MBEDTLS_ECP_H | |

#include "mbedtls/private_access.h" | |

#if !defined(MBEDTLS_CONFIG_FILE) | |

#include "mbedtls/config.h" | |

#else | |

#include MBEDTLS_CONFIG_FILE | |

#endif | |

#include "mbedtls/bignum.h" | |

/* | |

* ECP error codes | |

*/ | |

#define MBEDTLS_ERR_ECP_BAD_INPUT_DATA -0x4F80 /**< Bad input parameters to function. */ | |

#define MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL -0x4F00 /**< The buffer is too small to write to. */ | |

#define MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE -0x4E80 /**< The requested feature is not available, for example, the requested curve is not supported. */ | |

#define MBEDTLS_ERR_ECP_VERIFY_FAILED -0x4E00 /**< The signature is not valid. */ | |

#define MBEDTLS_ERR_ECP_ALLOC_FAILED -0x4D80 /**< Memory allocation failed. */ | |

#define MBEDTLS_ERR_ECP_RANDOM_FAILED -0x4D00 /**< Generation of random value, such as ephemeral key, failed. */ | |

#define MBEDTLS_ERR_ECP_INVALID_KEY -0x4C80 /**< Invalid private or public key. */ | |

#define MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH -0x4C00 /**< The buffer contains a valid signature followed by more data. */ | |

#define MBEDTLS_ERR_ECP_IN_PROGRESS -0x4B00 /**< Operation in progress, call again with the same parameters to continue. */ | |

/* Flags indicating whether to include code that is specific to certain | |

* types of curves. These flags are for internal library use only. */ | |

#if defined(MBEDTLS_ECP_DP_SECP192R1_ENABLED) || \ | |

defined(MBEDTLS_ECP_DP_SECP224R1_ENABLED) || \ | |

defined(MBEDTLS_ECP_DP_SECP256R1_ENABLED) || \ | |

defined(MBEDTLS_ECP_DP_SECP384R1_ENABLED) || \ | |

defined(MBEDTLS_ECP_DP_SECP521R1_ENABLED) || \ | |

defined(MBEDTLS_ECP_DP_BP256R1_ENABLED) || \ | |

defined(MBEDTLS_ECP_DP_BP384R1_ENABLED) || \ | |

defined(MBEDTLS_ECP_DP_BP512R1_ENABLED) || \ | |

defined(MBEDTLS_ECP_DP_SECP192K1_ENABLED) || \ | |

defined(MBEDTLS_ECP_DP_SECP224K1_ENABLED) || \ | |

defined(MBEDTLS_ECP_DP_SECP256K1_ENABLED) | |

#define MBEDTLS_ECP_SHORT_WEIERSTRASS_ENABLED | |

#endif | |

#if defined(MBEDTLS_ECP_DP_CURVE25519_ENABLED) || \ | |

defined(MBEDTLS_ECP_DP_CURVE448_ENABLED) | |

#define MBEDTLS_ECP_MONTGOMERY_ENABLED | |

#endif | |

#ifdef __cplusplus | |

extern "C" { | |

#endif | |

/** | |

* Domain-parameter identifiers: curve, subgroup, and generator. | |

* | |

* \note Only curves over prime fields are supported. | |

* | |

* \warning This library does not support validation of arbitrary domain | |

* parameters. Therefore, only standardized domain parameters from trusted | |

* sources should be used. See mbedtls_ecp_group_load(). | |

*/ | |

/* Note: when adding a new curve: | |

* - Add it at the end of this enum, otherwise you'll break the ABI by | |

* changing the numerical value for existing curves. | |

* - Increment MBEDTLS_ECP_DP_MAX below if needed. | |

* - Update the calculation of MBEDTLS_ECP_MAX_BITS below. | |

* - Add the corresponding MBEDTLS_ECP_DP_xxx_ENABLED macro definition to | |

* config.h. | |

* - List the curve as a dependency of MBEDTLS_ECP_C and | |

* MBEDTLS_ECDSA_C if supported in check_config.h. | |

* - Add the curve to the appropriate curve type macro | |

* MBEDTLS_ECP_yyy_ENABLED above. | |

* - Add the necessary definitions to ecp_curves.c. | |

* - Add the curve to the ecp_supported_curves array in ecp.c. | |

* - Add the curve to applicable profiles in x509_crt.c. | |

* - Add the curve to applicable presets in ssl_tls.c. | |

*/ | |

typedef enum | |

{ | |

MBEDTLS_ECP_DP_NONE = 0, /*!< Curve not defined. */ | |

MBEDTLS_ECP_DP_SECP192R1, /*!< Domain parameters for the 192-bit curve defined by FIPS 186-4 and SEC1. */ | |

MBEDTLS_ECP_DP_SECP224R1, /*!< Domain parameters for the 224-bit curve defined by FIPS 186-4 and SEC1. */ | |

MBEDTLS_ECP_DP_SECP256R1, /*!< Domain parameters for the 256-bit curve defined by FIPS 186-4 and SEC1. */ | |

MBEDTLS_ECP_DP_SECP384R1, /*!< Domain parameters for the 384-bit curve defined by FIPS 186-4 and SEC1. */ | |

MBEDTLS_ECP_DP_SECP521R1, /*!< Domain parameters for the 521-bit curve defined by FIPS 186-4 and SEC1. */ | |

MBEDTLS_ECP_DP_BP256R1, /*!< Domain parameters for 256-bit Brainpool curve. */ | |

MBEDTLS_ECP_DP_BP384R1, /*!< Domain parameters for 384-bit Brainpool curve. */ | |

MBEDTLS_ECP_DP_BP512R1, /*!< Domain parameters for 512-bit Brainpool curve. */ | |

MBEDTLS_ECP_DP_CURVE25519, /*!< Domain parameters for Curve25519. */ | |

MBEDTLS_ECP_DP_SECP192K1, /*!< Domain parameters for 192-bit "Koblitz" curve. */ | |

MBEDTLS_ECP_DP_SECP224K1, /*!< Domain parameters for 224-bit "Koblitz" curve. */ | |

MBEDTLS_ECP_DP_SECP256K1, /*!< Domain parameters for 256-bit "Koblitz" curve. */ | |

MBEDTLS_ECP_DP_CURVE448, /*!< Domain parameters for Curve448. */ | |

} mbedtls_ecp_group_id; | |

/** | |

* The number of supported curves, plus one for #MBEDTLS_ECP_DP_NONE. | |

* | |

* \note Montgomery curves are currently excluded. | |

*/ | |

#define MBEDTLS_ECP_DP_MAX 12 | |

/* | |

* Curve types | |

*/ | |

typedef enum | |

{ | |

MBEDTLS_ECP_TYPE_NONE = 0, | |

MBEDTLS_ECP_TYPE_SHORT_WEIERSTRASS, /* y^2 = x^3 + a x + b */ | |

MBEDTLS_ECP_TYPE_MONTGOMERY, /* y^2 = x^3 + a x^2 + x */ | |

} mbedtls_ecp_curve_type; | |

/** | |

* Curve information, for use by other modules. | |

*/ | |

typedef struct mbedtls_ecp_curve_info | |

{ | |

mbedtls_ecp_group_id MBEDTLS_PRIVATE(grp_id); /*!< An internal identifier. */ | |

uint16_t MBEDTLS_PRIVATE(tls_id); /*!< The TLS NamedCurve identifier. */ | |

uint16_t MBEDTLS_PRIVATE(bit_size); /*!< The curve size in bits. */ | |

const char *MBEDTLS_PRIVATE(name); /*!< A human-friendly name. */ | |

} mbedtls_ecp_curve_info; | |

/** | |

* \brief The ECP point structure, in Jacobian coordinates. | |

* | |

* \note All functions expect and return points satisfying | |

* the following condition: <code>Z == 0</code> or | |

* <code>Z == 1</code>. Other values of \p Z are | |

* used only by internal functions. | |

* The point is zero, or "at infinity", if <code>Z == 0</code>. | |

* Otherwise, \p X and \p Y are its standard (affine) | |

* coordinates. | |

*/ | |

typedef struct mbedtls_ecp_point | |

{ | |

mbedtls_mpi MBEDTLS_PRIVATE(X); /*!< The X coordinate of the ECP point. */ | |

mbedtls_mpi MBEDTLS_PRIVATE(Y); /*!< The Y coordinate of the ECP point. */ | |

mbedtls_mpi MBEDTLS_PRIVATE(Z); /*!< The Z coordinate of the ECP point. */ | |

} | |

mbedtls_ecp_point; | |

#if !defined(MBEDTLS_ECP_ALT) | |

/* | |

* default mbed TLS elliptic curve arithmetic implementation | |

* | |

* (in case MBEDTLS_ECP_ALT is defined then the developer has to provide an | |

* alternative implementation for the whole module and it will replace this | |

* one.) | |

*/ | |

/** | |

* \brief The ECP group structure. | |

* | |

* We consider two types of curve equations: | |

* <ul><li>Short Weierstrass: <code>y^2 = x^3 + A x + B mod P</code> | |

* (SEC1 + RFC-4492)</li> | |

* <li>Montgomery: <code>y^2 = x^3 + A x^2 + x mod P</code> (Curve25519, | |

* Curve448)</li></ul> | |

* In both cases, the generator (\p G) for a prime-order subgroup is fixed. | |

* | |

* For Short Weierstrass, this subgroup is the whole curve, and its | |

* cardinality is denoted by \p N. Our code requires that \p N is an | |

* odd prime as mbedtls_ecp_mul() requires an odd number, and | |

* mbedtls_ecdsa_sign() requires that it is prime for blinding purposes. | |

* | |

* For Montgomery curves, we do not store \p A, but <code>(A + 2) / 4</code>, | |

* which is the quantity used in the formulas. Additionally, \p nbits is | |

* not the size of \p N but the required size for private keys. | |

* | |

* If \p modp is NULL, reduction modulo \p P is done using a generic algorithm. | |

* Otherwise, \p modp must point to a function that takes an \p mbedtls_mpi in the | |

* range of <code>0..2^(2*pbits)-1</code>, and transforms it in-place to an integer | |

* which is congruent mod \p P to the given MPI, and is close enough to \p pbits | |

* in size, so that it may be efficiently brought in the 0..P-1 range by a few | |

* additions or subtractions. Therefore, it is only an approximative modular | |

* reduction. It must return 0 on success and non-zero on failure. | |

* | |

* \note Alternative implementations of the ECP module must obey the | |

* following constraints. | |

* * Group IDs must be distinct: if two group structures have | |

* the same ID, then they must be identical. | |

* * The fields \c id, \c P, \c A, \c B, \c G, \c N, | |

* \c pbits and \c nbits must have the same type and semantics | |

* as in the built-in implementation. | |

* They must be available for reading, but direct modification | |

* of these fields does not need to be supported. | |

* They do not need to be at the same offset in the structure. | |

*/ | |

typedef struct mbedtls_ecp_group | |

{ | |

mbedtls_ecp_group_id id; /*!< An internal group identifier. */ | |

mbedtls_mpi P; /*!< The prime modulus of the base field. */ | |

mbedtls_mpi A; /*!< For Short Weierstrass: \p A in the equation. For | |

Montgomery curves: <code>(A + 2) / 4</code>. */ | |

mbedtls_mpi B; /*!< For Short Weierstrass: \p B in the equation. | |

For Montgomery curves: unused. */ | |

mbedtls_ecp_point G; /*!< The generator of the subgroup used. */ | |

mbedtls_mpi N; /*!< The order of \p G. */ | |

size_t pbits; /*!< The number of bits in \p P.*/ | |

size_t nbits; /*!< For Short Weierstrass: The number of bits in \p P. | |

For Montgomery curves: the number of bits in the | |

private keys. */ | |

/* End of public fields */ | |

unsigned int MBEDTLS_PRIVATE(h); /*!< \internal 1 if the constants are static. */ | |

int (*MBEDTLS_PRIVATE(modp))(mbedtls_mpi *); /*!< The function for fast pseudo-reduction | |

mod \p P (see above).*/ | |

int (*MBEDTLS_PRIVATE(t_pre))(mbedtls_ecp_point *, void *); /*!< Unused. */ | |

int (*MBEDTLS_PRIVATE(t_post))(mbedtls_ecp_point *, void *); /*!< Unused. */ | |

void *MBEDTLS_PRIVATE(t_data); /*!< Unused. */ | |

mbedtls_ecp_point *MBEDTLS_PRIVATE(T); /*!< Pre-computed points for ecp_mul_comb(). */ | |

size_t MBEDTLS_PRIVATE(T_size); /*!< The number of dynamic allocated pre-computed points. */ | |

} | |

mbedtls_ecp_group; | |

/** | |

* \name SECTION: Module settings | |

* | |

* The configuration options you can set for this module are in this section. | |

* Either change them in config.h, or define them using the compiler command line. | |

* \{ | |

*/ | |

#if !defined(MBEDTLS_ECP_WINDOW_SIZE) | |

/* | |

* Maximum "window" size used for point multiplication. | |

* Default: a point where higher memory usage yields disminishing performance | |

* returns. | |

* Minimum value: 2. Maximum value: 7. | |

* | |

* Result is an array of at most ( 1 << ( MBEDTLS_ECP_WINDOW_SIZE - 1 ) ) | |

* points used for point multiplication. This value is directly tied to EC | |

* peak memory usage, so decreasing it by one should roughly cut memory usage | |

* by two (if large curves are in use). | |

* | |

* Reduction in size may reduce speed, but larger curves are impacted first. | |

* Sample performances (in ECDHE handshakes/s, with FIXED_POINT_OPTIM = 1): | |

* w-size: 6 5 4 3 2 | |

* 521 145 141 135 120 97 | |

* 384 214 209 198 177 146 | |

* 256 320 320 303 262 226 | |

* 224 475 475 453 398 342 | |

* 192 640 640 633 587 476 | |

*/ | |

#define MBEDTLS_ECP_WINDOW_SIZE 4 /**< The maximum window size used. */ | |

#endif /* MBEDTLS_ECP_WINDOW_SIZE */ | |

#if !defined(MBEDTLS_ECP_FIXED_POINT_OPTIM) | |

/* | |

* Trade code size for speed on fixed-point multiplication. | |

* | |

* This speeds up repeated multiplication of the generator (that is, the | |

* multiplication in ECDSA signatures, and half of the multiplications in | |

* ECDSA verification and ECDHE) by a factor roughly 3 to 4. | |

* | |

* For each n-bit Short Weierstrass curve that is enabled, this adds 4n bytes | |

* of code size if n < 384 and 8n otherwise. | |

* | |

* Change this value to 0 to reduce code size. | |

*/ | |

#define MBEDTLS_ECP_FIXED_POINT_OPTIM 1 /**< Enable fixed-point speed-up. */ | |

#endif /* MBEDTLS_ECP_FIXED_POINT_OPTIM */ | |

/* \} name SECTION: Module settings */ | |

#else /* MBEDTLS_ECP_ALT */ | |

#include "ecp_alt.h" | |

#endif /* MBEDTLS_ECP_ALT */ | |

/** | |

* The maximum size of the groups, that is, of \c N and \c P. | |

*/ | |

#if !defined(MBEDTLS_ECP_C) | |

/* Dummy definition to help code that has optional ECP support and | |

* defines an MBEDTLS_ECP_MAX_BYTES-sized array unconditionally. */ | |

#define MBEDTLS_ECP_MAX_BITS 1 | |

/* Note: the curves must be listed in DECREASING size! */ | |

#elif defined(MBEDTLS_ECP_DP_SECP521R1_ENABLED) | |

#define MBEDTLS_ECP_MAX_BITS 521 | |

#elif defined(MBEDTLS_ECP_DP_BP512R1_ENABLED) | |

#define MBEDTLS_ECP_MAX_BITS 512 | |

#elif defined(MBEDTLS_ECP_DP_CURVE448_ENABLED) | |

#define MBEDTLS_ECP_MAX_BITS 448 | |

#elif defined(MBEDTLS_ECP_DP_BP384R1_ENABLED) | |

#define MBEDTLS_ECP_MAX_BITS 384 | |

#elif defined(MBEDTLS_ECP_DP_SECP384R1_ENABLED) | |

#define MBEDTLS_ECP_MAX_BITS 384 | |

#elif defined(MBEDTLS_ECP_DP_BP256R1_ENABLED) | |

#define MBEDTLS_ECP_MAX_BITS 256 | |

#elif defined(MBEDTLS_ECP_DP_SECP256K1_ENABLED) | |

#define MBEDTLS_ECP_MAX_BITS 256 | |

#elif defined(MBEDTLS_ECP_DP_SECP256R1_ENABLED) | |

#define MBEDTLS_ECP_MAX_BITS 256 | |

#elif defined(MBEDTLS_ECP_DP_CURVE25519_ENABLED) | |

#define MBEDTLS_ECP_MAX_BITS 255 | |

#elif defined(MBEDTLS_ECP_DP_SECP224K1_ENABLED) | |

#define MBEDTLS_ECP_MAX_BITS 225 // n is slightly above 2^224 | |

#elif defined(MBEDTLS_ECP_DP_SECP224R1_ENABLED) | |

#define MBEDTLS_ECP_MAX_BITS 224 | |

#elif defined(MBEDTLS_ECP_DP_SECP192K1_ENABLED) | |

#define MBEDTLS_ECP_MAX_BITS 192 | |

#elif defined(MBEDTLS_ECP_DP_SECP192R1_ENABLED) | |

#define MBEDTLS_ECP_MAX_BITS 192 | |

#else | |

#error "Missing definition of MBEDTLS_ECP_MAX_BITS" | |

#endif | |

#define MBEDTLS_ECP_MAX_BYTES ( ( MBEDTLS_ECP_MAX_BITS + 7 ) / 8 ) | |

#define MBEDTLS_ECP_MAX_PT_LEN ( 2 * MBEDTLS_ECP_MAX_BYTES + 1 ) | |

#if defined(MBEDTLS_ECP_RESTARTABLE) | |

/** | |

* \brief Internal restart context for multiplication | |

* | |

* \note Opaque struct | |

*/ | |

typedef struct mbedtls_ecp_restart_mul mbedtls_ecp_restart_mul_ctx; | |

/** | |

* \brief Internal restart context for ecp_muladd() | |

* | |

* \note Opaque struct | |

*/ | |

typedef struct mbedtls_ecp_restart_muladd mbedtls_ecp_restart_muladd_ctx; | |

/** | |

* \brief General context for resuming ECC operations | |

*/ | |

typedef struct | |

{ | |

unsigned MBEDTLS_PRIVATE(ops_done); /*!< current ops count */ | |

unsigned MBEDTLS_PRIVATE(depth); /*!< call depth (0 = top-level) */ | |

mbedtls_ecp_restart_mul_ctx *MBEDTLS_PRIVATE(rsm); /*!< ecp_mul_comb() sub-context */ | |

mbedtls_ecp_restart_muladd_ctx *MBEDTLS_PRIVATE(ma); /*!< ecp_muladd() sub-context */ | |

} mbedtls_ecp_restart_ctx; | |

/* | |

* Operation counts for restartable functions | |

*/ | |

#define MBEDTLS_ECP_OPS_CHK 3 /*!< basic ops count for ecp_check_pubkey() */ | |

#define MBEDTLS_ECP_OPS_DBL 8 /*!< basic ops count for ecp_double_jac() */ | |

#define MBEDTLS_ECP_OPS_ADD 11 /*!< basic ops count for see ecp_add_mixed() */ | |

#define MBEDTLS_ECP_OPS_INV 120 /*!< empirical equivalent for mpi_mod_inv() */ | |

/** | |

* \brief Internal; for restartable functions in other modules. | |

* Check and update basic ops budget. | |

* | |

* \param grp Group structure | |

* \param rs_ctx Restart context | |

* \param ops Number of basic ops to do | |

* | |

* \return \c 0 if doing \p ops basic ops is still allowed, | |

* \return #MBEDTLS_ERR_ECP_IN_PROGRESS otherwise. | |

*/ | |

int mbedtls_ecp_check_budget( const mbedtls_ecp_group *grp, | |

mbedtls_ecp_restart_ctx *rs_ctx, | |

unsigned ops ); | |

/* Utility macro for checking and updating ops budget */ | |

#define MBEDTLS_ECP_BUDGET( ops ) \ | |

MBEDTLS_MPI_CHK( mbedtls_ecp_check_budget( grp, rs_ctx, \ | |

(unsigned) (ops) ) ); | |

#else /* MBEDTLS_ECP_RESTARTABLE */ | |

#define MBEDTLS_ECP_BUDGET( ops ) /* no-op; for compatibility */ | |

/* We want to declare restartable versions of existing functions anyway */ | |

typedef void mbedtls_ecp_restart_ctx; | |

#endif /* MBEDTLS_ECP_RESTARTABLE */ | |

/** | |

* \brief The ECP key-pair structure. | |

* | |

* A generic key-pair that may be used for ECDSA and fixed ECDH, for example. | |

* | |

* \note Members are deliberately in the same order as in the | |

* ::mbedtls_ecdsa_context structure. | |

*/ | |

typedef struct mbedtls_ecp_keypair | |

{ | |

mbedtls_ecp_group MBEDTLS_PRIVATE(grp); /*!< Elliptic curve and base point */ | |

mbedtls_mpi MBEDTLS_PRIVATE(d); /*!< our secret value */ | |

mbedtls_ecp_point MBEDTLS_PRIVATE(Q); /*!< our public value */ | |

} | |

mbedtls_ecp_keypair; | |

/* | |

* Point formats, from RFC 4492's enum ECPointFormat | |

*/ | |

#define MBEDTLS_ECP_PF_UNCOMPRESSED 0 /**< Uncompressed point format. */ | |

#define MBEDTLS_ECP_PF_COMPRESSED 1 /**< Compressed point format. */ | |

/* | |

* Some other constants from RFC 4492 | |

*/ | |

#define MBEDTLS_ECP_TLS_NAMED_CURVE 3 /**< The named_curve of ECCurveType. */ | |

#if defined(MBEDTLS_ECP_RESTARTABLE) | |

/** | |

* \brief Set the maximum number of basic operations done in a row. | |

* | |

* If more operations are needed to complete a computation, | |

* #MBEDTLS_ERR_ECP_IN_PROGRESS will be returned by the | |

* function performing the computation. It is then the | |

* caller's responsibility to either call again with the same | |

* parameters until it returns 0 or an error code; or to free | |

* the restart context if the operation is to be aborted. | |

* | |

* It is strictly required that all input parameters and the | |

* restart context be the same on successive calls for the | |

* same operation, but output parameters need not be the | |

* same; they must not be used until the function finally | |

* returns 0. | |

* | |

* This only applies to functions whose documentation | |

* mentions they may return #MBEDTLS_ERR_ECP_IN_PROGRESS (or | |

* #MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS for functions in the | |

* SSL module). For functions that accept a "restart context" | |

* argument, passing NULL disables restart and makes the | |

* function equivalent to the function with the same name | |

* with \c _restartable removed. For functions in the ECDH | |

* module, restart is disabled unless the function accepts | |

* an "ECDH context" argument and | |

* mbedtls_ecdh_enable_restart() was previously called on | |

* that context. For function in the SSL module, restart is | |

* only enabled for specific sides and key exchanges | |

* (currently only for clients and ECDHE-ECDSA). | |

* | |

* \param max_ops Maximum number of basic operations done in a row. | |

* Default: 0 (unlimited). | |

* Lower (non-zero) values mean ECC functions will block for | |

* a lesser maximum amount of time. | |

* | |

* \note A "basic operation" is defined as a rough equivalent of a | |

* multiplication in GF(p) for the NIST P-256 curve. | |

* As an indication, with default settings, a scalar | |

* multiplication (full run of \c mbedtls_ecp_mul()) is: | |

* - about 3300 basic operations for P-256 | |

* - about 9400 basic operations for P-384 | |

* | |

* \note Very low values are not always respected: sometimes | |

* functions need to block for a minimum number of | |

* operations, and will do so even if max_ops is set to a | |

* lower value. That minimum depends on the curve size, and | |

* can be made lower by decreasing the value of | |

* \c MBEDTLS_ECP_WINDOW_SIZE. As an indication, here is the | |

* lowest effective value for various curves and values of | |

* that parameter (w for short): | |

* w=6 w=5 w=4 w=3 w=2 | |

* P-256 208 208 160 136 124 | |

* P-384 682 416 320 272 248 | |

* P-521 1364 832 640 544 496 | |

* | |

* \note This setting is currently ignored by Curve25519. | |

*/ | |

void mbedtls_ecp_set_max_ops( unsigned max_ops ); | |

/** | |

* \brief Check if restart is enabled (max_ops != 0) | |

* | |

* \return \c 0 if \c max_ops == 0 (restart disabled) | |

* \return \c 1 otherwise (restart enabled) | |

*/ | |

int mbedtls_ecp_restart_is_enabled( void ); | |

#endif /* MBEDTLS_ECP_RESTARTABLE */ | |

/* | |

* Get the type of a curve | |

*/ | |

mbedtls_ecp_curve_type mbedtls_ecp_get_type( const mbedtls_ecp_group *grp ); | |

/** | |

* \brief This function retrieves the information defined in | |

* mbedtls_ecp_curve_info() for all supported curves. | |

* | |

* \note This function returns information about all curves | |

* supported by the library. Some curves may not be | |

* supported for all algorithms. Call mbedtls_ecdh_can_do() | |

* or mbedtls_ecdsa_can_do() to check if a curve is | |

* supported for ECDH or ECDSA. | |

* | |

* \return A statically allocated array. The last entry is 0. | |

*/ | |

const mbedtls_ecp_curve_info *mbedtls_ecp_curve_list( void ); | |

/** | |

* \brief This function retrieves the list of internal group | |

* identifiers of all supported curves in the order of | |

* preference. | |

* | |

* \note This function returns information about all curves | |

* supported by the library. Some curves may not be | |

* supported for all algorithms. Call mbedtls_ecdh_can_do() | |

* or mbedtls_ecdsa_can_do() to check if a curve is | |

* supported for ECDH or ECDSA. | |

* | |

* \return A statically allocated array, | |

* terminated with MBEDTLS_ECP_DP_NONE. | |

*/ | |

const mbedtls_ecp_group_id *mbedtls_ecp_grp_id_list( void ); | |

/** | |

* \brief This function retrieves curve information from an internal | |

* group identifier. | |

* | |

* \param grp_id An \c MBEDTLS_ECP_DP_XXX value. | |

* | |

* \return The associated curve information on success. | |

* \return NULL on failure. | |

*/ | |

const mbedtls_ecp_curve_info *mbedtls_ecp_curve_info_from_grp_id( mbedtls_ecp_group_id grp_id ); | |

/** | |

* \brief This function retrieves curve information from a TLS | |

* NamedCurve value. | |

* | |

* \param tls_id An \c MBEDTLS_ECP_DP_XXX value. | |

* | |

* \return The associated curve information on success. | |

* \return NULL on failure. | |

*/ | |

const mbedtls_ecp_curve_info *mbedtls_ecp_curve_info_from_tls_id( uint16_t tls_id ); | |

/** | |

* \brief This function retrieves curve information from a | |

* human-readable name. | |

* | |

* \param name The human-readable name. | |

* | |

* \return The associated curve information on success. | |

* \return NULL on failure. | |

*/ | |

const mbedtls_ecp_curve_info *mbedtls_ecp_curve_info_from_name( const char *name ); | |

/** | |

* \brief This function initializes a point as zero. | |

* | |

* \param pt The point to initialize. | |

*/ | |

void mbedtls_ecp_point_init( mbedtls_ecp_point *pt ); | |

/** | |

* \brief This function initializes an ECP group context | |

* without loading any domain parameters. | |

* | |

* \note After this function is called, domain parameters | |

* for various ECP groups can be loaded through the | |

* mbedtls_ecp_group_load() or mbedtls_ecp_tls_read_group() | |

* functions. | |

*/ | |

void mbedtls_ecp_group_init( mbedtls_ecp_group *grp ); | |

/** | |

* \brief This function initializes a key pair as an invalid one. | |

* | |

* \param key The key pair to initialize. | |

*/ | |

void mbedtls_ecp_keypair_init( mbedtls_ecp_keypair *key ); | |

/** | |

* \brief This function frees the components of a point. | |

* | |

* \param pt The point to free. | |

*/ | |

void mbedtls_ecp_point_free( mbedtls_ecp_point *pt ); | |

/** | |

* \brief This function frees the components of an ECP group. | |

* | |

* \param grp The group to free. This may be \c NULL, in which | |

* case this function returns immediately. If it is not | |

* \c NULL, it must point to an initialized ECP group. | |

*/ | |

void mbedtls_ecp_group_free( mbedtls_ecp_group *grp ); | |

/** | |

* \brief This function frees the components of a key pair. | |

* | |

* \param key The key pair to free. This may be \c NULL, in which | |

* case this function returns immediately. If it is not | |

* \c NULL, it must point to an initialized ECP key pair. | |

*/ | |

void mbedtls_ecp_keypair_free( mbedtls_ecp_keypair *key ); | |

#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_ecp_restart_init( mbedtls_ecp_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 returns immediately. If it is not | |

* \c NULL, it must point to an initialized restart context. | |

*/ | |

void mbedtls_ecp_restart_free( mbedtls_ecp_restart_ctx *ctx ); | |

#endif /* MBEDTLS_ECP_RESTARTABLE */ | |

/** | |

* \brief This function copies the contents of point \p Q into | |

* point \p P. | |

* | |

* \param P The destination point. This must be initialized. | |

* \param Q The source point. This must be initialized. | |

* | |

* \return \c 0 on success. | |

* \return #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure. | |

* \return Another negative error code for other kinds of failure. | |

*/ | |

int mbedtls_ecp_copy( mbedtls_ecp_point *P, const mbedtls_ecp_point *Q ); | |

/** | |

* \brief This function copies the contents of group \p src into | |

* group \p dst. | |

* | |

* \param dst The destination group. This must be initialized. | |

* \param src The source group. This must be initialized. | |

* | |

* \return \c 0 on success. | |

* \return #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure. | |

* \return Another negative error code on other kinds of failure. | |

*/ | |

int mbedtls_ecp_group_copy( mbedtls_ecp_group *dst, | |

const mbedtls_ecp_group *src ); | |

/** | |

* \brief This function sets a point to the point at infinity. | |

* | |

* \param pt The point to set. This must be initialized. | |

* | |

* \return \c 0 on success. | |

* \return #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure. | |

* \return Another negative error code on other kinds of failure. | |

*/ | |

int mbedtls_ecp_set_zero( mbedtls_ecp_point *pt ); | |

/** | |

* \brief This function checks if a point is the point at infinity. | |

* | |

* \param pt The point to test. This must be initialized. | |

* | |

* \return \c 1 if the point is zero. | |

* \return \c 0 if the point is non-zero. | |

* \return A negative error code on failure. | |

*/ | |

int mbedtls_ecp_is_zero( mbedtls_ecp_point *pt ); | |

/** | |

* \brief This function compares two points. | |

* | |

* \note This assumes that the points are normalized. Otherwise, | |

* they may compare as "not equal" even if they are. | |

* | |

* \param P The first point to compare. This must be initialized. | |

* \param Q The second point to compare. This must be initialized. | |

* | |

* \return \c 0 if the points are equal. | |

* \return #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if the points are not equal. | |

*/ | |

int mbedtls_ecp_point_cmp( const mbedtls_ecp_point *P, | |

const mbedtls_ecp_point *Q ); | |

/** | |

* \brief This function imports a non-zero point from two ASCII | |

* strings. | |

* | |

* \param P The destination point. This must be initialized. | |

* \param radix The numeric base of the input. | |

* \param x The first affine coordinate, as a null-terminated string. | |

* \param y The second affine coordinate, as a null-terminated string. | |

* | |

* \return \c 0 on success. | |

* \return An \c MBEDTLS_ERR_MPI_XXX error code on failure. | |

*/ | |

int mbedtls_ecp_point_read_string( mbedtls_ecp_point *P, int radix, | |

const char *x, const char *y ); | |

/** | |

* \brief This function exports a point into unsigned binary data. | |

* | |

* \param grp The group to which the point should belong. | |

* This must be initialized and have group parameters | |

* set, for example through mbedtls_ecp_group_load(). | |

* \param P The point to export. This must be initialized. | |

* \param format The point format. This must be either | |

* #MBEDTLS_ECP_PF_COMPRESSED or #MBEDTLS_ECP_PF_UNCOMPRESSED. | |

* (For groups without these formats, this parameter is | |

* ignored. But it still has to be either of the above | |

* values.) | |

* \param olen The address at which to store the length of | |

* the output in Bytes. This must not be \c NULL. | |

* \param buf The output buffer. This must be a writable buffer | |

* of length \p buflen Bytes. | |

* \param buflen The length of the output buffer \p buf in Bytes. | |

* | |

* \return \c 0 on success. | |

* \return #MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL if the output buffer | |

* is too small to hold the point. | |

* \return #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if the point format | |

* or the export for the given group is not implemented. | |

* \return Another negative error code on other kinds of failure. | |

*/ | |

int mbedtls_ecp_point_write_binary( const mbedtls_ecp_group *grp, | |

const mbedtls_ecp_point *P, | |

int format, size_t *olen, | |

unsigned char *buf, size_t buflen ); | |

/** | |

* \brief This function imports a point from unsigned binary data. | |

* | |

* \note This function does not check that the point actually | |

* belongs to the given group, see mbedtls_ecp_check_pubkey() | |

* for that. | |

* | |

* \param grp The group to which the point should belong. | |

* This must be initialized and have group parameters | |

* set, for example through mbedtls_ecp_group_load(). | |

* \param P The destination context to import the point to. | |

* This must be initialized. | |

* \param buf The input buffer. This must be a readable buffer | |

* of length \p ilen Bytes. | |

* \param ilen The length of the input buffer \p buf in Bytes. | |

* | |

* \return \c 0 on success. | |

* \return #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if the input is invalid. | |

* \return #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure. | |

* \return #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if the import for the | |

* given group is not implemented. | |

*/ | |

int mbedtls_ecp_point_read_binary( const mbedtls_ecp_group *grp, | |

mbedtls_ecp_point *P, | |

const unsigned char *buf, size_t ilen ); | |

/** | |

* \brief This function imports a point from a TLS ECPoint record. | |

* | |

* \note On function return, \p *buf is updated to point immediately | |

* after the ECPoint record. | |

* | |

* \param grp The ECP group to use. | |

* This must be initialized and have group parameters | |

* set, for example through mbedtls_ecp_group_load(). | |

* \param pt The destination point. | |

* \param buf The address of the pointer to the start of the input buffer. | |

* \param len The length of the buffer. | |

* | |

* \return \c 0 on success. | |

* \return An \c MBEDTLS_ERR_MPI_XXX error code on initialization | |

* failure. | |

* \return #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if input is invalid. | |

*/ | |

int mbedtls_ecp_tls_read_point( const mbedtls_ecp_group *grp, | |

mbedtls_ecp_point *pt, | |

const unsigned char **buf, size_t len ); | |

/** | |

* \brief This function exports a point as a TLS ECPoint record | |

* defined in RFC 4492, Section 5.4. | |

* | |

* \param grp The ECP group to use. | |

* This must be initialized and have group parameters | |

* set, for example through mbedtls_ecp_group_load(). | |

* \param pt The point to be exported. This must be initialized. | |

* \param format The point format to use. This must be either | |

* #MBEDTLS_ECP_PF_COMPRESSED or #MBEDTLS_ECP_PF_UNCOMPRESSED. | |

* \param olen The address at which to store the length in Bytes | |

* of the data written. | |

* \param buf The target buffer. This must be a writable buffer of | |

* length \p blen Bytes. | |

* \param blen The length of the target buffer \p buf in Bytes. | |

* | |

* \return \c 0 on success. | |

* \return #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if the input is invalid. | |

* \return #MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL if the target buffer | |

* is too small to hold the exported point. | |

* \return Another negative error code on other kinds of failure. | |

*/ | |

int mbedtls_ecp_tls_write_point( const mbedtls_ecp_group *grp, | |

const mbedtls_ecp_point *pt, | |

int format, size_t *olen, | |

unsigned char *buf, size_t blen ); | |

/** | |

* \brief This function sets up an ECP group context | |

* from a standardized set of domain parameters. | |

* | |

* \note The index should be a value of the NamedCurve enum, | |

* as defined in <em>RFC-4492: Elliptic Curve Cryptography | |

* (ECC) Cipher Suites for Transport Layer Security (TLS)</em>, | |

* usually in the form of an \c MBEDTLS_ECP_DP_XXX macro. | |

* | |

* \param grp The group context to setup. This must be initialized. | |

* \param id The identifier of the domain parameter set to load. | |

* | |

* \return \c 0 on success. | |

* \return #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if \p id doesn't | |

* correspond to a known group. | |

* \return Another negative error code on other kinds of failure. | |

*/ | |

int mbedtls_ecp_group_load( mbedtls_ecp_group *grp, mbedtls_ecp_group_id id ); | |

/** | |

* \brief This function sets up an ECP group context from a TLS | |

* ECParameters record as defined in RFC 4492, Section 5.4. | |

* | |

* \note The read pointer \p buf is updated to point right after | |

* the ECParameters record on exit. | |

* | |

* \param grp The group context to setup. This must be initialized. | |

* \param buf The address of the pointer to the start of the input buffer. | |

* \param len The length of the input buffer \c *buf in Bytes. | |

* | |

* \return \c 0 on success. | |

* \return #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if input is invalid. | |

* \return #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if the group is not | |

* recognized. | |

* \return Another negative error code on other kinds of failure. | |

*/ | |

int mbedtls_ecp_tls_read_group( mbedtls_ecp_group *grp, | |

const unsigned char **buf, size_t len ); | |

/** | |

* \brief This function extracts an elliptic curve group ID from a | |

* TLS ECParameters record as defined in RFC 4492, Section 5.4. | |

* | |

* \note The read pointer \p buf is updated to point right after | |

* the ECParameters record on exit. | |

* | |

* \param grp The address at which to store the group id. | |

* This must not be \c NULL. | |

* \param buf The address of the pointer to the start of the input buffer. | |

* \param len The length of the input buffer \c *buf in Bytes. | |

* | |

* \return \c 0 on success. | |

* \return #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if input is invalid. | |

* \return #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if the group is not | |

* recognized. | |

* \return Another negative error code on other kinds of failure. | |

*/ | |

int mbedtls_ecp_tls_read_group_id( mbedtls_ecp_group_id *grp, | |

const unsigned char **buf, | |

size_t len ); | |

/** | |

* \brief This function exports an elliptic curve as a TLS | |

* ECParameters record as defined in RFC 4492, Section 5.4. | |

* | |

* \param grp The ECP group to be exported. | |

* This must be initialized and have group parameters | |

* set, for example through mbedtls_ecp_group_load(). | |

* \param olen The address at which to store the number of Bytes written. | |

* This must not be \c NULL. | |

* \param buf The buffer to write to. This must be a writable buffer | |

* of length \p blen Bytes. | |

* \param blen The length of the output buffer \p buf in Bytes. | |

* | |

* \return \c 0 on success. | |

* \return #MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL if the output | |

* buffer is too small to hold the exported group. | |

* \return Another negative error code on other kinds of failure. | |

*/ | |

int mbedtls_ecp_tls_write_group( const mbedtls_ecp_group *grp, | |

size_t *olen, | |

unsigned char *buf, size_t blen ); | |

/** | |

* \brief This function performs a scalar multiplication of a point | |

* by an integer: \p R = \p m * \p P. | |

* | |

* It is not thread-safe to use same group in multiple threads. | |

* | |

* \note To prevent timing attacks, this function | |

* executes the exact same sequence of base-field | |

* operations for any valid \p m. It avoids any if-branch or | |

* array index depending on the value of \p m. If also uses | |

* \p f_rng to randomize some intermediate results. | |

* | |

* \param grp The ECP group to use. | |

* This must be initialized and have group parameters | |

* set, for example through mbedtls_ecp_group_load(). | |

* \param R The point in which to store the result of the calculation. | |

* This must be initialized. | |

* \param m The integer by which to multiply. This must be initialized. | |

* \param P The point to multiply. This must be initialized. | |

* \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. | |

* | |

* \return \c 0 on success. | |

* \return #MBEDTLS_ERR_ECP_INVALID_KEY if \p m is not a valid private | |

* key, or \p P is not a valid public key. | |

* \return #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure. | |

* \return Another negative error code on other kinds of failure. | |

*/ | |

int mbedtls_ecp_mul( mbedtls_ecp_group *grp, mbedtls_ecp_point *R, | |

const mbedtls_mpi *m, const mbedtls_ecp_point *P, | |

int (*f_rng)(void *, unsigned char *, size_t), void *p_rng ); | |

/** | |

* \brief This function performs multiplication of a point by | |

* an integer: \p R = \p m * \p P in a restartable way. | |

* | |

* \see mbedtls_ecp_mul() | |

* | |

* \note This function does the same as \c mbedtls_ecp_mul(), but | |

* it can return early and restart according to the limit set | |

* with \c mbedtls_ecp_set_max_ops() to reduce blocking. | |

* | |

* \param grp The ECP group to use. | |

* This must be initialized and have group parameters | |

* set, for example through mbedtls_ecp_group_load(). | |

* \param R The point in which to store the result of the calculation. | |

* This must be initialized. | |

* \param m The integer by which to multiply. This must be initialized. | |

* \param P The point to multiply. This must be initialized. | |

* \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. | |

* \param rs_ctx The restart context (NULL disables restart). | |

* | |

* \return \c 0 on success. | |

* \return #MBEDTLS_ERR_ECP_INVALID_KEY if \p m is not a valid private | |

* key, or \p P is not a valid public key. | |

* \return #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure. | |

* \return #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of | |

* operations was reached: see \c mbedtls_ecp_set_max_ops(). | |

* \return Another negative error code on other kinds of failure. | |

*/ | |

int mbedtls_ecp_mul_restartable( mbedtls_ecp_group *grp, mbedtls_ecp_point *R, | |

const mbedtls_mpi *m, const mbedtls_ecp_point *P, | |

int (*f_rng)(void *, unsigned char *, size_t), void *p_rng, | |

mbedtls_ecp_restart_ctx *rs_ctx ); | |

#if defined(MBEDTLS_ECP_SHORT_WEIERSTRASS_ENABLED) | |

/** | |

* \brief This function performs multiplication and addition of two | |

* points by integers: \p R = \p m * \p P + \p n * \p Q | |

* | |

* It is not thread-safe to use same group in multiple threads. | |

* | |

* \note In contrast to mbedtls_ecp_mul(), this function does not | |

* guarantee a constant execution flow and timing. | |

* | |

* \note This function is only defined for short Weierstrass curves. | |

* It may not be included in builds without any short | |

* Weierstrass curve. | |

* | |

* \param grp The ECP group to use. | |

* This must be initialized and have group parameters | |

* set, for example through mbedtls_ecp_group_load(). | |

* \param R The point in which to store the result of the calculation. | |

* This must be initialized. | |

* \param m The integer by which to multiply \p P. | |

* This must be initialized. | |

* \param P The point to multiply by \p m. This must be initialized. | |

* \param n The integer by which to multiply \p Q. | |

* This must be initialized. | |

* \param Q The point to be multiplied by \p n. | |

* This must be initialized. | |

* | |

* \return \c 0 on success. | |

* \return #MBEDTLS_ERR_ECP_INVALID_KEY if \p m or \p n are not | |

* valid private keys, or \p P or \p Q are not valid public | |

* keys. | |

* \return #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure. | |

* \return #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if \p grp does not | |

* designate a short Weierstrass curve. | |

* \return Another negative error code on other kinds of failure. | |

*/ | |

int mbedtls_ecp_muladd( mbedtls_ecp_group *grp, mbedtls_ecp_point *R, | |

const mbedtls_mpi *m, const mbedtls_ecp_point *P, | |

const mbedtls_mpi *n, const mbedtls_ecp_point *Q ); | |

/** | |

* \brief This function performs multiplication and addition of two | |

* points by integers: \p R = \p m * \p P + \p n * \p Q in a | |

* restartable way. | |

* | |

* \see \c mbedtls_ecp_muladd() | |

* | |

* \note This function works the same as \c mbedtls_ecp_muladd(), | |

* but it can return early and restart according to the limit | |

* set with \c mbedtls_ecp_set_max_ops() to reduce blocking. | |

* | |

* \note This function is only defined for short Weierstrass curves. | |

* It may not be included in builds without any short | |

* Weierstrass curve. | |

* | |

* \param grp The ECP group to use. | |

* This must be initialized and have group parameters | |

* set, for example through mbedtls_ecp_group_load(). | |

* \param R The point in which to store the result of the calculation. | |

* This must be initialized. | |

* \param m The integer by which to multiply \p P. | |

* This must be initialized. | |

* \param P The point to multiply by \p m. This must be initialized. | |

* \param n The integer by which to multiply \p Q. | |

* This must be initialized. | |

* \param Q The point to be multiplied by \p n. | |

* This must be initialized. | |

* \param rs_ctx The restart context (NULL disables restart). | |

* | |

* \return \c 0 on success. | |

* \return #MBEDTLS_ERR_ECP_INVALID_KEY if \p m or \p n are not | |

* valid private keys, or \p P or \p Q are not valid public | |

* keys. | |

* \return #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure. | |

* \return #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if \p grp does not | |

* designate a short Weierstrass curve. | |

* \return #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of | |

* operations was reached: see \c mbedtls_ecp_set_max_ops(). | |

* \return Another negative error code on other kinds of failure. | |

*/ | |

int mbedtls_ecp_muladd_restartable( | |

mbedtls_ecp_group *grp, mbedtls_ecp_point *R, | |

const mbedtls_mpi *m, const mbedtls_ecp_point *P, | |

const mbedtls_mpi *n, const mbedtls_ecp_point *Q, | |

mbedtls_ecp_restart_ctx *rs_ctx ); | |

#endif /* MBEDTLS_ECP_SHORT_WEIERSTRASS_ENABLED */ | |

/** | |

* \brief This function checks that a point is a valid public key | |

* on this curve. | |

* | |

* It only checks that the point is non-zero, has | |

* valid coordinates and lies on the curve. It does not verify | |

* that it is indeed a multiple of \p G. This additional | |

* check is computationally more expensive, is not required | |

* by standards, and should not be necessary if the group | |

* used has a small cofactor. In particular, it is useless for | |

* the NIST groups which all have a cofactor of 1. | |

* | |

* \note This function uses bare components rather than an | |

* ::mbedtls_ecp_keypair structure, to ease use with other | |

* structures, such as ::mbedtls_ecdh_context or | |

* ::mbedtls_ecdsa_context. | |

* | |

* \param grp The ECP group the point should belong to. | |

* This must be initialized and have group parameters | |

* set, for example through mbedtls_ecp_group_load(). | |

* \param pt The point to check. This must be initialized. | |

* | |

* \return \c 0 if the point is a valid public key. | |

* \return #MBEDTLS_ERR_ECP_INVALID_KEY if the point is not | |

* a valid public key for the given curve. | |

* \return Another negative error code on other kinds of failure. | |

*/ | |

int mbedtls_ecp_check_pubkey( const mbedtls_ecp_group *grp, | |

const mbedtls_ecp_point *pt ); | |

/** | |

* \brief This function checks that an \p mbedtls_mpi is a | |

* valid private key for this curve. | |

* | |

* \note This function uses bare components rather than an | |

* ::mbedtls_ecp_keypair structure to ease use with other | |

* structures, such as ::mbedtls_ecdh_context or | |

* ::mbedtls_ecdsa_context. | |

* | |

* \param grp The ECP group the private key should belong to. | |

* This must be initialized and have group parameters | |

* set, for example through mbedtls_ecp_group_load(). | |

* \param d The integer to check. This must be initialized. | |

* | |

* \return \c 0 if the point is a valid private key. | |

* \return #MBEDTLS_ERR_ECP_INVALID_KEY if the point is not a valid | |

* private key for the given curve. | |

* \return Another negative error code on other kinds of failure. | |

*/ | |

int mbedtls_ecp_check_privkey( const mbedtls_ecp_group *grp, | |

const mbedtls_mpi *d ); | |

/** | |

* \brief This function generates a private key. | |

* | |

* \param grp The ECP group to generate a private key for. | |

* This must be initialized and have group parameters | |

* set, for example through mbedtls_ecp_group_load(). | |

* \param d The destination MPI (secret part). This must be initialized. | |

* \param f_rng The RNG function. This must not be \c NULL. | |

* \param p_rng The RNG parameter 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 or \c MBEDTLS_MPI_XXX error code | |

* on failure. | |

*/ | |

int mbedtls_ecp_gen_privkey( const mbedtls_ecp_group *grp, | |

mbedtls_mpi *d, | |

int (*f_rng)(void *, unsigned char *, size_t), | |

void *p_rng ); | |

/** | |

* \brief This function generates a keypair with a configurable base | |

* point. | |

* | |

* \note This function uses bare components rather than an | |

* ::mbedtls_ecp_keypair structure to ease use with other | |

* structures, such as ::mbedtls_ecdh_context or | |

* ::mbedtls_ecdsa_context. | |

* | |

* \param grp The ECP group to generate a key pair for. | |

* This must be initialized and have group parameters | |

* set, for example through mbedtls_ecp_group_load(). | |

* \param G The base point to use. This must be initialized | |

* and belong to \p grp. It replaces the default base | |

* point \c grp->G used by mbedtls_ecp_gen_keypair(). | |

* \param d The destination MPI (secret part). | |

* This must be initialized. | |

* \param Q The destination point (public part). | |

* This must be initialized. | |

* \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 argument. | |

* | |

* \return \c 0 on success. | |

* \return An \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_MPI_XXX error code | |

* on failure. | |

*/ | |

int mbedtls_ecp_gen_keypair_base( mbedtls_ecp_group *grp, | |

const mbedtls_ecp_point *G, | |

mbedtls_mpi *d, mbedtls_ecp_point *Q, | |

int (*f_rng)(void *, unsigned char *, size_t), | |

void *p_rng ); | |

/** | |

* \brief This function generates an ECP keypair. | |

* | |

* \note This function uses bare components rather than an | |

* ::mbedtls_ecp_keypair structure to ease use with other | |

* structures, such as ::mbedtls_ecdh_context or | |

* ::mbedtls_ecdsa_context. | |

* | |

* \param grp The ECP group to generate a key pair for. | |

* This must be initialized and have group parameters | |

* set, for example through mbedtls_ecp_group_load(). | |

* \param d The destination MPI (secret part). | |

* This must be initialized. | |

* \param Q The destination point (public part). | |

* This must be initialized. | |

* \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 argument. | |

* | |

* \return \c 0 on success. | |

* \return An \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_MPI_XXX error code | |

* on failure. | |

*/ | |

int mbedtls_ecp_gen_keypair( mbedtls_ecp_group *grp, mbedtls_mpi *d, | |

mbedtls_ecp_point *Q, | |

int (*f_rng)(void *, unsigned char *, size_t), | |

void *p_rng ); | |

/** | |

* \brief This function generates an ECP key. | |

* | |

* \param grp_id The ECP group identifier. | |

* \param key The destination key. This must be initialized. | |

* \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 or \c MBEDTLS_MPI_XXX error code | |

* on failure. | |

*/ | |

int mbedtls_ecp_gen_key( mbedtls_ecp_group_id grp_id, mbedtls_ecp_keypair *key, | |

int (*f_rng)(void *, unsigned char *, size_t), | |

void *p_rng ); | |

/** | |

* \brief This function reads an elliptic curve private key. | |

* | |

* \param grp_id The ECP group identifier. | |

* \param key The destination key. | |

* \param buf The buffer containing the binary representation of the | |

* key. (Big endian integer for Weierstrass curves, byte | |

* string for Montgomery curves.) | |

* \param buflen The length of the buffer in bytes. | |

* | |

* \return \c 0 on success. | |

* \return #MBEDTLS_ERR_ECP_INVALID_KEY error if the key is | |

* invalid. | |

* \return #MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed. | |

* \return #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if the operation for | |

* the group is not implemented. | |

* \return Another negative error code on different kinds of failure. | |

*/ | |

int mbedtls_ecp_read_key( mbedtls_ecp_group_id grp_id, mbedtls_ecp_keypair *key, | |

const unsigned char *buf, size_t buflen ); | |

/** | |

* \brief This function exports an elliptic curve private key. | |

* | |

* \param key The private key. | |

* \param buf The output buffer for containing the binary representation | |

* of the key. (Big endian integer for Weierstrass curves, byte | |

* string for Montgomery curves.) | |

* \param buflen The total length of the buffer in bytes. | |

* | |

* \return \c 0 on success. | |

* \return #MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL if the \p key | |

representation is larger than the available space in \p buf. | |

* \return #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if the operation for | |

* the group is not implemented. | |

* \return Another negative error code on different kinds of failure. | |

*/ | |

int mbedtls_ecp_write_key( mbedtls_ecp_keypair *key, | |

unsigned char *buf, size_t buflen ); | |

/** | |

* \brief This function checks that the keypair objects | |

* \p pub and \p prv have the same group and the | |

* same public point, and that the private key in | |

* \p prv is consistent with the public key. | |

* | |

* \param pub The keypair structure holding the public key. This | |

* must be initialized. If it contains a private key, that | |

* part is ignored. | |

* \param prv The keypair structure holding the full keypair. | |

* This must be initialized. | |

* \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. | |

* | |

* \return \c 0 on success, meaning that the keys are valid and match. | |

* \return #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if the keys are invalid or do not match. | |

* \return An \c MBEDTLS_ERR_ECP_XXX or an \c MBEDTLS_ERR_MPI_XXX | |

* error code on calculation failure. | |

*/ | |

int mbedtls_ecp_check_pub_priv( | |

const mbedtls_ecp_keypair *pub, const mbedtls_ecp_keypair *prv, | |

int (*f_rng)(void *, unsigned char *, size_t), void *p_rng ); | |

#if defined(MBEDTLS_SELF_TEST) | |

/** | |

* \brief The ECP checkup routine. | |

* | |

* \return \c 0 on success. | |

* \return \c 1 on failure. | |

*/ | |

int mbedtls_ecp_self_test( int verbose ); | |

#endif /* MBEDTLS_SELF_TEST */ | |

#ifdef __cplusplus | |

} | |

#endif | |

#endif /* ecp.h */ |