Function esp_idf_sys::mbedtls_ecp_write_public_key

pub unsafe extern "C" fn mbedtls_ecp_write_public_key(
    key: *const mbedtls_ecp_keypair,
    format: c_int,
    olen: *mut usize,
    buf: *mut c_uchar,
    buflen: usize,
) -> c_int

\brief This function exports an elliptic curve public key.

\note If the public key was not set in \p key, the output is unspecified. Future versions may return an error in that case.

\param key The public key. \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.