--- /dev/null
+/**
+ * \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 (C) 2006-2018, Arm Limited (or its affiliates), All Rights Reserved
+ * SPDX-License-Identifier: GPL-2.0
+ *
+ * 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.
+ *
+ * This file is part of Mbed TLS (https://tls.mbed.org)
+ */
+
+#ifndef MBEDTLS_ECDSA_H
+#define MBEDTLS_ECDSA_H
+
+#include "ecp.h"
+#include "md.h"
+
+/*
+ * RFC-4492 page 20:
+ *
+ * Ecdsa-Sig-Value ::= SEQUENCE {
+ * r INTEGER,
+ * s INTEGER
+ * }
+ *
+ * Size is at most
+ * 1 (tag) + 1 (len) + 1 (initial 0) + ECP_MAX_BYTES for each of r and s,
+ * twice that + 1 (tag) + 2 (len) for the sequence
+ * (assuming ECP_MAX_BYTES is less than 126 for r and s,
+ * and less than 124 (total len <= 255) for the sequence)
+ */
+#if MBEDTLS_ECP_MAX_BYTES > 124
+#error "MBEDTLS_ECP_MAX_BYTES bigger than expected, please fix MBEDTLS_ECDSA_MAX_LEN"
+#endif
+/** The maximal size of an ECDSA signature in Bytes. */
+#define MBEDTLS_ECDSA_MAX_LEN ( 3 + 2 * ( 3 + MBEDTLS_ECP_MAX_BYTES ) )
+
+/**
+ * \brief The ECDSA context structure.
+ */
+typedef mbedtls_ecp_keypair mbedtls_ecdsa_context;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief This function computes the ECDSA signature of a
+ * previously-hashed message.
+ *
+ * \note The deterministic version 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 ECP group.
+ * \param r The first output integer.
+ * \param s The second output integer.
+ * \param d The private signing key.
+ * \param buf The message hash.
+ * \param blen The length of \p buf.
+ * \param f_rng The RNG function.
+ * \param p_rng The RNG context.
+ *
+ * \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)
+/**
+ * \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 ECP group.
+ * \param r The first output integer.
+ * \param s The second output integer.
+ * \param d The private signing key.
+ * \param buf The message hash.
+ * \param blen The length of \p buf.
+ * \param md_alg The MD algorithm used to hash the message.
+ *
+ * \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 );
+#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.
+ * \param buf The message hash.
+ * \param blen The length of \p buf.
+ * \param Q The public key to use for verification.
+ * \param r The first integer of the signature.
+ * \param s The second integer of the signature.
+ *
+ * \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 The \p sig buffer must be 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.
+ *
+ * \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.
+ * \param md_alg The message digest that was used to hash the message.
+ * \param hash The message hash.
+ * \param hlen The length of the hash.
+ * \param sig The buffer that holds the signature.
+ * \param slen The length of the signature written.
+ * \param f_rng The RNG function.
+ * \param p_rng The RNG 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 );
+
+#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 The \p sig buffer must be 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.
+ *
+ * \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.
+ * \param hash The message hash.
+ * \param hlen The length of the hash.
+ * \param sig The buffer that holds the signature.
+ * \param slen The length of the signature written.
+ * \param md_alg The MD algorithm 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.
+ * \param hash The message hash.
+ * \param hlen The size of the hash.
+ * \param sig The signature to read and verify.
+ * \param slen The size of \p sig.
+ *
+ * \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 generates an ECDSA keypair on the given curve.
+ *
+ * \see ecp.h
+ *
+ * \param ctx The ECDSA context to store the keypair in.
+ * \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.
+ * \param p_rng The RNG context.
+ *
+ * \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 an ECDSA context from an EC key pair.
+ *
+ * \see ecp.h
+ *
+ * \param ctx The ECDSA context to set.
+ * \param key The EC key to use.
+ *
+ * \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.
+ */
+void mbedtls_ecdsa_init( mbedtls_ecdsa_context *ctx );
+
+/**
+ * \brief This function frees an ECDSA context.
+ *
+ * \param ctx The ECDSA context to free.
+ */
+void mbedtls_ecdsa_free( mbedtls_ecdsa_context *ctx );
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ecdsa.h */
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