Doug Anson
mbed TLS library
Dependents: HTTPClient-SSL WS_SERVER
Diff: include/polarssl/ecp.h
- Revision:
- 0:137634ff4186
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/include/polarssl/ecp.h Thu Jun 11 03:27:03 2015 +0000
@@ -0,0 +1,665 @@
+/**
+ * \file ecp.h
+ *
+ * \brief Elliptic curves over GF(p)
+ *
+ * Copyright (C) 2006-2013, ARM Limited, All Rights Reserved
+ *
+ * This file is part of mbed TLS (https://tls.mbed.org)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+#ifndef POLARSSL_ECP_H
+#define POLARSSL_ECP_H
+
+#include "bignum.h"
+
+/*
+ * ECP error codes
+ */
+#define POLARSSL_ERR_ECP_BAD_INPUT_DATA -0x4F80 /**< Bad input parameters to function. */
+#define POLARSSL_ERR_ECP_BUFFER_TOO_SMALL -0x4F00 /**< The buffer is too small to write to. */
+#define POLARSSL_ERR_ECP_FEATURE_UNAVAILABLE -0x4E80 /**< Requested curve not available. */
+#define POLARSSL_ERR_ECP_VERIFY_FAILED -0x4E00 /**< The signature is not valid. */
+#define POLARSSL_ERR_ECP_MALLOC_FAILED -0x4D80 /**< Memory allocation failed. */
+#define POLARSSL_ERR_ECP_RANDOM_FAILED -0x4D00 /**< Generation of random value, such as (ephemeral) key, failed. */
+#define POLARSSL_ERR_ECP_INVALID_KEY -0x4C80 /**< Invalid private or public key. */
+#define POLARSSL_ERR_ECP_SIG_LEN_MISMATCH -0x4C00 /**< Signature is valid but shorter than the user-supplied length. */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * Domain parameters (curve, subgroup and generator) identifiers.
+ *
+ * Only curves over prime fields are supported.
+ *
+ * \warning This library does not support validation of arbitrary domain
+ * parameters. Therefore, only well-known domain parameters from trusted
+ * sources should be used. See ecp_use_known_dp().
+ */
+typedef enum
+{
+ POLARSSL_ECP_DP_NONE = 0,
+ POLARSSL_ECP_DP_SECP192R1, /*!< 192-bits NIST curve */
+ POLARSSL_ECP_DP_SECP224R1, /*!< 224-bits NIST curve */
+ POLARSSL_ECP_DP_SECP256R1, /*!< 256-bits NIST curve */
+ POLARSSL_ECP_DP_SECP384R1, /*!< 384-bits NIST curve */
+ POLARSSL_ECP_DP_SECP521R1, /*!< 521-bits NIST curve */
+ POLARSSL_ECP_DP_BP256R1, /*!< 256-bits Brainpool curve */
+ POLARSSL_ECP_DP_BP384R1, /*!< 384-bits Brainpool curve */
+ POLARSSL_ECP_DP_BP512R1, /*!< 512-bits Brainpool curve */
+ POLARSSL_ECP_DP_M221, /*!< (not implemented yet) */
+ POLARSSL_ECP_DP_M255, /*!< Curve25519 */
+ POLARSSL_ECP_DP_M383, /*!< (not implemented yet) */
+ POLARSSL_ECP_DP_M511, /*!< (not implemented yet) */
+ POLARSSL_ECP_DP_SECP192K1, /*!< 192-bits "Koblitz" curve */
+ POLARSSL_ECP_DP_SECP224K1, /*!< 224-bits "Koblitz" curve */
+ POLARSSL_ECP_DP_SECP256K1, /*!< 256-bits "Koblitz" curve */
+} ecp_group_id;
+
+/**
+ * Number of supported curves (plus one for NONE).
+ *
+ * (Montgomery curves excluded for now.)
+ */
+#define POLARSSL_ECP_DP_MAX 12
+
+/**
+ * Curve information for use by other modules
+ */
+typedef struct
+{
+ ecp_group_id grp_id; /*!< Internal identifier */
+ uint16_t tls_id; /*!< TLS NamedCurve identifier */
+ uint16_t size; /*!< Curve size in bits */
+ const char *name; /*!< Human-friendly name */
+} ecp_curve_info;
+
+/**
+ * \brief ECP point structure (jacobian coordinates)
+ *
+ * \note All functions expect and return points satisfying
+ * the following condition: Z == 0 or Z == 1. (Other
+ * values of Z are used by internal functions only.)
+ * The point is zero, or "at infinity", if Z == 0.
+ * Otherwise, X and Y are its standard (affine) coordinates.
+ */
+typedef struct
+{
+ mpi X; /*!< the point's X coordinate */
+ mpi Y; /*!< the point's Y coordinate */
+ mpi Z; /*!< the point's Z coordinate */
+}
+ecp_point;
+
+/**
+ * \brief ECP group structure
+ *
+ * We consider two types of curves equations:
+ * 1. Short Weierstrass y^2 = x^3 + A x + B mod P (SEC1 + RFC 4492)
+ * 2. Montgomery, y^2 = x^3 + A x^2 + x mod P (M255 + draft)
+ * In both cases, a generator G for a prime-order subgroup is fixed. In the
+ * short weierstrass, this subgroup is actually the whole curve, and its
+ * cardinal is denoted by N.
+ *
+ * In the case of Short Weierstrass curves, our code requires that N is an odd
+ * prime. (Use odd in ecp_mul() and prime in ecdsa_sign() for blinding.)
+ *
+ * In the case of Montgomery curves, we don't store A but (A + 2) / 4 which is
+ * the quantity actually used in the formulas. Also, nbits is not the size of N
+ * but the required size for private keys.
+ *
+ * If modp is NULL, reduction modulo P is done using a generic algorithm.
+ * Otherwise, it must point to a function that takes an mpi in the range
+ * 0..2^(2*pbits)-1 and transforms it in-place in an integer of little more
+ * than pbits, so that the integer may be efficiently brought in the 0..P-1
+ * range by a few additions or substractions. It must return 0 on success and
+ * non-zero on failure.
+ */
+typedef struct
+{
+ ecp_group_id id; /*!< internal group identifier */
+ mpi P; /*!< prime modulus of the base field */
+ mpi A; /*!< 1. A in the equation, or 2. (A + 2) / 4 */
+ mpi B; /*!< 1. B in the equation, or 2. unused */
+ ecp_point G; /*!< generator of the (sub)group used */
+ mpi N; /*!< 1. the order of G, or 2. unused */
+ size_t pbits; /*!< number of bits in P */
+ size_t nbits; /*!< number of bits in 1. P, or 2. private keys */
+ unsigned int h; /*!< internal: 1 if the constants are static */
+ int (*modp)(mpi *); /*!< function for fast reduction mod P */
+ int (*t_pre)(ecp_point *, void *); /*!< unused */
+ int (*t_post)(ecp_point *, void *); /*!< unused */
+ void *t_data; /*!< unused */
+ ecp_point *T; /*!< pre-computed points for ecp_mul_comb() */
+ size_t T_size; /*!< number for pre-computed points */
+}
+ecp_group;
+
+/**
+ * \brief ECP key pair structure
+ *
+ * A generic key pair that could be used for ECDSA, fixed ECDH, etc.
+ *
+ * \note Members purposefully in the same order as struc ecdsa_context.
+ */
+typedef struct
+{
+ ecp_group grp; /*!< Elliptic curve and base point */
+ mpi d; /*!< our secret value */
+ ecp_point Q; /*!< our public value */
+}
+ecp_keypair;
+
+/**
+ * \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 on the compiler command line.
+ * \{
+ */
+
+#if !defined(POLARSSL_ECP_MAX_BITS)
+/**
+ * Maximum size of the groups (that is, of N and P)
+ */
+#define POLARSSL_ECP_MAX_BITS 521 /**< Maximum bit size of groups */
+#endif
+
+#define POLARSSL_ECP_MAX_BYTES ( ( POLARSSL_ECP_MAX_BITS + 7 ) / 8 )
+#define POLARSSL_ECP_MAX_PT_LEN ( 2 * POLARSSL_ECP_MAX_BYTES + 1 )
+
+#if !defined(POLARSSL_ECP_WINDOW_SIZE)
+/*
+ * Maximum "window" size used for point multiplication.
+ * Default: 6.
+ * Minimum value: 2. Maximum value: 7.
+ *
+ * Result is an array of at most ( 1 << ( POLARSSL_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 POLARSSL_ECP_WINDOW_SIZE 6 /**< Maximum window size used */
+#endif /* POLARSSL_ECP_WINDOW_SIZE */
+
+#if !defined(POLARSSL_ECP_FIXED_POINT_OPTIM)
+/*
+ * Trade memory 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.
+ *
+ * The cost is increasing EC peak memory usage by a factor roughly 2.
+ *
+ * Change this value to 0 to reduce peak memory usage.
+ */
+#define POLARSSL_ECP_FIXED_POINT_OPTIM 1 /**< Enable fixed-point speed-up */
+#endif /* POLARSSL_ECP_FIXED_POINT_OPTIM */
+
+/* \} name SECTION: Module settings */
+
+/*
+ * Point formats, from RFC 4492's enum ECPointFormat
+ */
+#define POLARSSL_ECP_PF_UNCOMPRESSED 0 /**< Uncompressed point format */
+#define POLARSSL_ECP_PF_COMPRESSED 1 /**< Compressed point format */
+
+/*
+ * Some other constants from RFC 4492
+ */
+#define POLARSSL_ECP_TLS_NAMED_CURVE 3 /**< ECCurveType's named_curve */
+
+/**
+ * \brief Get the list of supported curves in order of preferrence
+ * (full information)
+ *
+ * \return A statically allocated array, the last entry is 0.
+ */
+const ecp_curve_info *ecp_curve_list( void );
+
+/**
+ * \brief Get the list of supported curves in order of preferrence
+ * (grp_id only)
+ *
+ * \return A statically allocated array,
+ * terminated with POLARSSL_ECP_DP_NONE.
+ */
+const ecp_group_id *ecp_grp_id_list( void );
+
+/**
+ * \brief Get curve information from an internal group identifier
+ *
+ * \param grp_id A POLARSSL_ECP_DP_XXX value
+ *
+ * \return The associated curve information or NULL
+ */
+const ecp_curve_info *ecp_curve_info_from_grp_id( ecp_group_id grp_id );
+
+/**
+ * \brief Get curve information from a TLS NamedCurve value
+ *
+ * \param tls_id A POLARSSL_ECP_DP_XXX value
+ *
+ * \return The associated curve information or NULL
+ */
+const ecp_curve_info *ecp_curve_info_from_tls_id( uint16_t tls_id );
+
+/**
+ * \brief Get curve information from a human-readable name
+ *
+ * \param name The name
+ *
+ * \return The associated curve information or NULL
+ */
+const ecp_curve_info *ecp_curve_info_from_name( const char *name );
+
+/**
+ * \brief Initialize a point (as zero)
+ */
+void ecp_point_init( ecp_point *pt );
+
+/**
+ * \brief Initialize a group (to something meaningless)
+ */
+void ecp_group_init( ecp_group *grp );
+
+/**
+ * \brief Initialize a key pair (as an invalid one)
+ */
+void ecp_keypair_init( ecp_keypair *key );
+
+/**
+ * \brief Free the components of a point
+ */
+void ecp_point_free( ecp_point *pt );
+
+/**
+ * \brief Free the components of an ECP group
+ */
+void ecp_group_free( ecp_group *grp );
+
+/**
+ * \brief Free the components of a key pair
+ */
+void ecp_keypair_free( ecp_keypair *key );
+
+/**
+ * \brief Copy the contents of point Q into P
+ *
+ * \param P Destination point
+ * \param Q Source point
+ *
+ * \return 0 if successful,
+ * POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed
+ */
+int ecp_copy( ecp_point *P, const ecp_point *Q );
+
+/**
+ * \brief Copy the contents of a group object
+ *
+ * \param dst Destination group
+ * \param src Source group
+ *
+ * \return 0 if successful,
+ * POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed
+ */
+int ecp_group_copy( ecp_group *dst, const ecp_group *src );
+
+/**
+ * \brief Set a point to zero
+ *
+ * \param pt Destination point
+ *
+ * \return 0 if successful,
+ * POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed
+ */
+int ecp_set_zero( ecp_point *pt );
+
+/**
+ * \brief Tell if a point is zero
+ *
+ * \param pt Point to test
+ *
+ * \return 1 if point is zero, 0 otherwise
+ */
+int ecp_is_zero( ecp_point *pt );
+
+/**
+ * \brief Import a non-zero point from two ASCII strings
+ *
+ * \param P Destination point
+ * \param radix Input numeric base
+ * \param x First affine coordinate as a null-terminated string
+ * \param y Second affine coordinate as a null-terminated string
+ *
+ * \return 0 if successful, or a POLARSSL_ERR_MPI_XXX error code
+ */
+int ecp_point_read_string( ecp_point *P, int radix,
+ const char *x, const char *y );
+
+/**
+ * \brief Export a point into unsigned binary data
+ *
+ * \param grp Group to which the point should belong
+ * \param P Point to export
+ * \param format Point format, should be a POLARSSL_ECP_PF_XXX macro
+ * \param olen Length of the actual output
+ * \param buf Output buffer
+ * \param buflen Length of the output buffer
+ *
+ * \return 0 if successful,
+ * or POLARSSL_ERR_ECP_BAD_INPUT_DATA
+ * or POLARSSL_ERR_ECP_BUFFER_TOO_SMALL
+ */
+int ecp_point_write_binary( const ecp_group *grp, const ecp_point *P,
+ int format, size_t *olen,
+ unsigned char *buf, size_t buflen );
+
+/**
+ * \brief Import a point from unsigned binary data
+ *
+ * \param grp Group to which the point should belong
+ * \param P Point to import
+ * \param buf Input buffer
+ * \param ilen Actual length of input
+ *
+ * \return 0 if successful,
+ * POLARSSL_ERR_ECP_BAD_INPUT_DATA if input is invalid,
+ * POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed,
+ * POLARSSL_ERR_ECP_FEATURE_UNAVAILABLE if the point format
+ * is not implemented.
+ *
+ * \note This function does NOT check that the point actually
+ * belongs to the given group, see ecp_check_pubkey() for
+ * that.
+ */
+int ecp_point_read_binary( const ecp_group *grp, ecp_point *P,
+ const unsigned char *buf, size_t ilen );
+
+/**
+ * \brief Import a point from a TLS ECPoint record
+ *
+ * \param grp ECP group used
+ * \param pt Destination point
+ * \param buf $(Start of input buffer)
+ * \param len Buffer length
+ *
+ * \note buf is updated to point right after the ECPoint on exit
+ *
+ * \return 0 if successful,
+ * POLARSSL_ERR_MPI_XXX if initialization failed
+ * POLARSSL_ERR_ECP_BAD_INPUT_DATA if input is invalid
+ */
+int ecp_tls_read_point( const ecp_group *grp, ecp_point *pt,
+ const unsigned char **buf, size_t len );
+
+/**
+ * \brief Export a point as a TLS ECPoint record
+ *
+ * \param grp ECP group used
+ * \param pt Point to export
+ * \param format Export format
+ * \param olen length of data written
+ * \param buf Buffer to write to
+ * \param blen Buffer length
+ *
+ * \return 0 if successful,
+ * or POLARSSL_ERR_ECP_BAD_INPUT_DATA
+ * or POLARSSL_ERR_ECP_BUFFER_TOO_SMALL
+ */
+int ecp_tls_write_point( const ecp_group *grp, const ecp_point *pt,
+ int format, size_t *olen,
+ unsigned char *buf, size_t blen );
+
+/**
+ * \brief Import an ECP group from null-terminated ASCII strings
+ *
+ * \param grp Destination group
+ * \param radix Input numeric base
+ * \param p Prime modulus of the base field
+ * \param b Constant term in the equation
+ * \param gx The generator's X coordinate
+ * \param gy The generator's Y coordinate
+ * \param n The generator's order
+ *
+ * \return 0 if successful, or a POLARSSL_ERR_MPI_XXX error code
+ *
+ * \note Sets all fields except modp.
+ */
+int ecp_group_read_string( ecp_group *grp, int radix,
+ const char *p, const char *b,
+ const char *gx, const char *gy, const char *n);
+
+/**
+ * \brief Set a group using well-known domain parameters
+ *
+ * \param grp Destination group
+ * \param index Index in the list of well-known domain parameters
+ *
+ * \return 0 if successful,
+ * POLARSSL_ERR_MPI_XXX if initialization failed
+ * POLARSSL_ERR_ECP_FEATURE_UNAVAILABLE for unkownn groups
+ *
+ * \note Index should be a value of RFC 4492's enum NamdeCurve,
+ * possibly in the form of a POLARSSL_ECP_DP_XXX macro.
+ */
+int ecp_use_known_dp( ecp_group *grp, ecp_group_id index );
+
+/**
+ * \brief Set a group from a TLS ECParameters record
+ *
+ * \param grp Destination group
+ * \param buf &(Start of input buffer)
+ * \param len Buffer length
+ *
+ * \note buf is updated to point right after ECParameters on exit
+ *
+ * \return 0 if successful,
+ * POLARSSL_ERR_MPI_XXX if initialization failed
+ * POLARSSL_ERR_ECP_BAD_INPUT_DATA if input is invalid
+ */
+int ecp_tls_read_group( ecp_group *grp, const unsigned char **buf, size_t len );
+
+/**
+ * \brief Write the TLS ECParameters record for a group
+ *
+ * \param grp ECP group used
+ * \param olen Number of bytes actually written
+ * \param buf Buffer to write to
+ * \param blen Buffer length
+ *
+ * \return 0 if successful,
+ * or POLARSSL_ERR_ECP_BUFFER_TOO_SMALL
+ */
+int ecp_tls_write_group( const ecp_group *grp, size_t *olen,
+ unsigned char *buf, size_t blen );
+
+/**
+ * \brief Addition: R = P + Q
+ *
+ * \param grp ECP group
+ * \param R Destination point
+ * \param P Left-hand point
+ * \param Q Right-hand point
+ *
+ * \return 0 if successful,
+ * POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed
+ *
+ * \note This function does not support Montgomery curves, such as
+ * Curve25519.
+ */
+int ecp_add( const ecp_group *grp, ecp_point *R,
+ const ecp_point *P, const ecp_point *Q );
+
+/**
+ * \brief Subtraction: R = P - Q
+ *
+ * \param grp ECP group
+ * \param R Destination point
+ * \param P Left-hand point
+ * \param Q Right-hand point
+ *
+ * \return 0 if successful,
+ * POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed
+ *
+ * \note This function does not support Montgomery curves, such as
+ * Curve25519.
+ */
+int ecp_sub( const ecp_group *grp, ecp_point *R,
+ const ecp_point *P, const ecp_point *Q );
+
+/**
+ * \brief Multiplication by an integer: R = m * P
+ * (Not thread-safe to use same group in multiple threads)
+ *
+ * \param grp ECP group
+ * \param R Destination point
+ * \param m Integer by which to multiply
+ * \param P Point to multiply
+ * \param f_rng RNG function (see notes)
+ * \param p_rng RNG parameter
+ *
+ * \return 0 if successful,
+ * POLARSSL_ERR_ECP_INVALID_KEY if m is not a valid privkey
+ * or P is not a valid pubkey,
+ * POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed
+ *
+ * \note In order to prevent timing attacks, this function
+ * executes the exact same sequence of (base field)
+ * operations for any valid m. It avoids any if-branch or
+ * array index depending on the value of m.
+ *
+ * \note If f_rng is not NULL, it is used to randomize intermediate
+ * results in order to prevent potential timing attacks
+ * targeting these results. It is recommended to always
+ * provide a non-NULL f_rng (the overhead is negligible).
+ */
+int ecp_mul( ecp_group *grp, ecp_point *R,
+ const mpi *m, const ecp_point *P,
+ int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
+
+/**
+ * \brief Check that a point is a valid public key on this curve
+ *
+ * \param grp Curve/group the point should belong to
+ * \param pt Point to check
+ *
+ * \return 0 if point is a valid public key,
+ * POLARSSL_ERR_ECP_INVALID_KEY otherwise.
+ *
+ * \note This function only checks the point is non-zero, has valid
+ * coordinates and lies on the curve, but not that it is
+ * indeed a multiple of G. This is additional check is more
+ * expensive, isn't required by standards, and shouldn't 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 Uses bare components rather than an ecp_keypair structure
+ * in order to ease use with other structures such as
+ * ecdh_context of ecdsa_context.
+ */
+int ecp_check_pubkey( const ecp_group *grp, const ecp_point *pt );
+
+/**
+ * \brief Check that an mpi is a valid private key for this curve
+ *
+ * \param grp Group used
+ * \param d Integer to check
+ *
+ * \return 0 if point is a valid private key,
+ * POLARSSL_ERR_ECP_INVALID_KEY otherwise.
+ *
+ * \note Uses bare components rather than an ecp_keypair structure
+ * in order to ease use with other structures such as
+ * ecdh_context of ecdsa_context.
+ */
+int ecp_check_privkey( const ecp_group *grp, const mpi *d );
+
+/**
+ * \brief Generate a keypair
+ *
+ * \param grp ECP group
+ * \param d Destination MPI (secret part)
+ * \param Q Destination point (public part)
+ * \param f_rng RNG function
+ * \param p_rng RNG parameter
+ *
+ * \return 0 if successful,
+ * or a POLARSSL_ERR_ECP_XXX or POLARSSL_MPI_XXX error code
+ *
+ * \note Uses bare components rather than an ecp_keypair structure
+ * in order to ease use with other structures such as
+ * ecdh_context of ecdsa_context.
+ */
+int ecp_gen_keypair( ecp_group *grp, mpi *d, ecp_point *Q,
+ int (*f_rng)(void *, unsigned char *, size_t),
+ void *p_rng );
+
+/**
+ * \brief Generate a keypair
+ *
+ * \param grp_id ECP group identifier
+ * \param key Destination keypair
+ * \param f_rng RNG function
+ * \param p_rng RNG parameter
+ *
+ * \return 0 if successful,
+ * or a POLARSSL_ERR_ECP_XXX or POLARSSL_MPI_XXX error code
+ */
+int ecp_gen_key( ecp_group_id grp_id, ecp_keypair *key,
+ int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
+
+/**
+ * \brief Check a public-private key pair
+ *
+ * \param pub Keypair structure holding a public key
+ * \param prv Keypair structure holding a private (plus public) key
+ *
+ * \return 0 if successful (keys are valid and match), or
+ * POLARSSL_ERR_ECP_BAD_INPUT_DATA, or
+ * a POLARSSL_ERR_ECP_XXX or POLARSSL_ERR_MPI_XXX code.
+ */
+int ecp_check_pub_priv( const ecp_keypair *pub, const ecp_keypair *prv );
+
+#if defined(POLARSSL_SELF_TEST)
+/**
+ * \brief Checkup routine
+ *
+ * \return 0 if successful, or 1 if a test failed
+ */
+int ecp_self_test( int verbose );
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ecp.h */
+