| /** |
| * \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 |
| #include "mbedtls/private_access.h" |
| |
| #include "mbedtls/build_info.h" |
| |
| #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 MBEDTLS_PRIVATE(ecp); /*!< base context for ECP restart and |
| shared administrative info */ |
| mbedtls_ecdsa_restart_ver_ctx *MBEDTLS_PRIVATE(ver); /*!< ecdsa_verify() sub-context */ |
| mbedtls_ecdsa_restart_sig_ctx *MBEDTLS_PRIVATE(sig); /*!< ecdsa_sign() sub-context */ |
| #if defined(MBEDTLS_ECDSA_DETERMINISTIC) |
| mbedtls_ecdsa_restart_det_ctx *MBEDTLS_PRIVATE(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_ext() 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) |
| /** |
| * \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 sig_size The size of the \p sig buffer in bytes. |
| * \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 sig_size, 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 sig_size The size of the \p sig buffer in bytes. |
| * \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 sig_size, size_t *slen, |
| int (*f_rng)(void *, unsigned char *, size_t), |
| void *p_rng, |
| mbedtls_ecdsa_restart_ctx *rs_ctx ); |
| |
| /** |
| * \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 */ |