diff options
Diffstat (limited to 'thirdparty/mbedtls/include/mbedtls/ecdsa.h')
| -rw-r--r-- | thirdparty/mbedtls/include/mbedtls/ecdsa.h | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/thirdparty/mbedtls/include/mbedtls/ecdsa.h b/thirdparty/mbedtls/include/mbedtls/ecdsa.h index f8b28507c2..932acc6d14 100644 --- a/thirdparty/mbedtls/include/mbedtls/ecdsa.h +++ b/thirdparty/mbedtls/include/mbedtls/ecdsa.h @@ -175,6 +175,19 @@ int mbedtls_ecdsa_sign( mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi *s, * (SECG): SEC1 Elliptic Curve Cryptography</em>, section * 4.1.3, step 5. * + * \warning Since the output of the internal RNG is always the same for + * the same key and message, this limits the efficiency of + * blinding and leaks information through side channels. For + * secure behavior use mbedtls_ecdsa_sign_det_ext() instead. + * + * (Optimally the blinding is a random value that is different + * on every execution. In this case the blinding is still + * random from the attackers perspective, but is the same on + * each execution. This means that this blinding does not + * prevent attackers from recovering secrets by combining + * several measurement traces, but may prevent some attacks + * that exploit relationships between secret data.) + * * \see ecp.h * * \param grp The context for the elliptic curve to use. @@ -200,6 +213,52 @@ 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 ); +/** + * \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 */ /** |