From b90883dc1dc42891354c0f40a908e298d8d0af32 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Manuel=20P=C3=A9gouri=C3=A9-Gonnard?= Date: Tue, 25 Apr 2017 11:33:10 +0200 Subject: [PATCH] Prepare infra for restartable sign --- include/mbedtls/ecdsa.h | 20 +++++ library/ecdsa.c | 176 ++++++++++++++++++++++++++++++++-------- 2 files changed, 161 insertions(+), 35 deletions(-) diff --git a/include/mbedtls/ecdsa.h b/include/mbedtls/ecdsa.h index f557a4de2..ce94af871 100644 --- a/include/mbedtls/ecdsa.h +++ b/include/mbedtls/ecdsa.h @@ -64,6 +64,22 @@ typedef mbedtls_ecp_keypair mbedtls_ecdsa_context; */ 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 */ @@ -71,6 +87,10 @@ typedef struct { mbedtls_ecp_restart_ctx ecp; /*!< base context (admin+ecp info) */ mbedtls_ecdsa_restart_ver_ctx *ver; /*!< ecdsa_verify() sub-context */ + mbedtls_ecdsa_restart_sig_ctx *sig; /*!< ecdsa_sign() sub-context */ +#if defined(MBEDTLS_ECDSA_DETERMINISTIC) + mbedtls_ecdsa_restart_det_ctx *det; /*!< ecdsa_sign_det() sub-context */ +#endif } mbedtls_ecdsa_restart_ctx; #else /* MBEDTLS_ECP_RESTARTABLE */ diff --git a/library/ecdsa.c b/library/ecdsa.c index ec1e5872d..4c0b61462 100644 --- a/library/ecdsa.c +++ b/library/ecdsa.c @@ -86,18 +86,110 @@ static void ecdsa_restart_ver_free( mbedtls_ecdsa_restart_ver_ctx *ctx ) memset( ctx, 0, sizeof( *ctx ) ); } +/* + * Sub-contect for ecdsa_sign() + */ +struct mbedtls_ecdsa_restart_sig +{ + enum { /* what to do next? */ + ecdsa_sig_init = 0, /* getting started */ + } state; +}; + +/* + * Init verify sign sub-context + */ +static void ecdsa_restart_sig_init( mbedtls_ecdsa_restart_sig_ctx *ctx ) +{ + memset( ctx, 0, sizeof( *ctx ) ); +} + +/* + * Free the components of a sign restart sub-context + */ +static void ecdsa_restart_sig_free( mbedtls_ecdsa_restart_sig_ctx *ctx ) +{ + if( ctx == NULL ) + return; + + memset( ctx, 0, sizeof( *ctx ) ); +} + +#if defined(MBEDTLS_ECDSA_DETERMINISTIC) +/* + * Sub-contect for ecdsa_sign_det() + */ +struct mbedtls_ecdsa_restart_det +{ + enum { /* what to do next? */ + ecdsa_det_init = 0, /* getting started */ + } state; +}; + +/* + * Init verify sign_det sub-context + */ +static void ecdsa_restart_det_init( mbedtls_ecdsa_restart_det_ctx *ctx ) +{ + memset( ctx, 0, sizeof( *ctx ) ); +} + +/* + * Free the components of a sign_det restart sub-context + */ +static void ecdsa_restart_det_free( mbedtls_ecdsa_restart_det_ctx *ctx ) +{ + if( ctx == NULL ) + return; + + memset( ctx, 0, sizeof( *ctx ) ); +} +#endif /* MBEDTLS_ECDSA_DETERMINISTIC */ + #define ECDSA_RS_ECP &rs_ctx->ecp /* Utility macro for checking and updating ops budget */ #define ECDSA_BUDGET( ops ) \ MBEDTLS_MPI_CHK( mbedtls_ecp_check_budget( grp, &rs_ctx->ecp, ops ) ); +#define ECDSA_RS_ENTER( SUB ) do { \ + /* reset ops count for this call if top-level */ \ + if( rs_ctx != NULL && rs_ctx->ecp.depth++ == 0 ) \ + rs_ctx->ecp.ops_done = 0; \ + \ + /* set up our own sub-context if needed */ \ + if( mbedtls_ecp_restart_enabled() && \ + rs_ctx != NULL && rs_ctx->SUB == NULL ) \ + { \ + rs_ctx->SUB = mbedtls_calloc( 1, sizeof( *rs_ctx->SUB ) ); \ + if( rs_ctx->SUB == NULL ) \ + return( MBEDTLS_ERR_ECP_ALLOC_FAILED ); \ + \ + ecdsa_restart_## SUB ##_init( rs_ctx->SUB ); \ + } \ +} while( 0 ) + +#define ECDSA_RS_LEAVE( SUB ) do { \ + /* clear our sub-context when not in progress (done or error) */ \ + if( rs_ctx != NULL && ret != MBEDTLS_ERR_ECP_IN_PROGRESS ) { \ + ecdsa_restart_## SUB ##_free( rs_ctx->SUB ); \ + mbedtls_free( rs_ctx->SUB ); \ + rs_ctx->SUB = NULL; \ + } \ + \ + if( rs_ctx != NULL ) \ + rs_ctx->ecp.depth--; \ +} while( 0 ) + #else /* MBEDTLS_ECP_RESTARTABLE */ #define ECDSA_RS_ECP NULL #define ECDSA_BUDGET( ops ) /* no-op; for compatibility */ +#define ECDSA_RS_ENTER( SUB ) (void) rs_ctx +#define ECDSA_RS_LEAVE( SUB ) (void) rs_ctx + #endif /* MBEDTLS_ECP_RESTARTABLE */ /* @@ -137,8 +229,6 @@ static int ecdsa_sign_restartable( mbedtls_ecp_group *grp, mbedtls_ecp_point R; mbedtls_mpi k, e, t; - (void) rs_ctx; // temporary - /* Fail cleanly on curves such as Curve25519 that can't be used for ECDSA */ if( grp->N.p == NULL ) return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA ); @@ -146,6 +236,19 @@ static int ecdsa_sign_restartable( mbedtls_ecp_group *grp, mbedtls_ecp_point_init( &R ); mbedtls_mpi_init( &k ); mbedtls_mpi_init( &e ); mbedtls_mpi_init( &t ); + ECDSA_RS_ENTER( sig ); + +#if defined(MBEDTLS_ECP_RESTARTABLE) + if( rs_ctx != NULL && rs_ctx->sig != NULL ) + { + /* redirect to our context */ + // TODO + + /* jump to current step */ + // TODO + } +#endif /* MBEDTLS_ECP_RESTARTABLE */ + sign_tries = 0; do { @@ -213,6 +316,8 @@ cleanup: mbedtls_ecp_point_free( &R ); mbedtls_mpi_free( &k ); mbedtls_mpi_free( &e ); mbedtls_mpi_free( &t ); + ECDSA_RS_LEAVE( sig ); + return( ret ); } @@ -244,27 +349,40 @@ static int ecdsa_sign_det_restartable( mbedtls_ecp_group *grp, const mbedtls_md_info_t *md_info; mbedtls_mpi h; - (void) rs_ctx; // temporary - if( ( md_info = mbedtls_md_info_from_type( md_alg ) ) == NULL ) return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA ); mbedtls_mpi_init( &h ); mbedtls_hmac_drbg_init( &rng_ctx ); + ECDSA_RS_ENTER( det ); + +#if defined(MBEDTLS_ECP_RESTARTABLE) + if( rs_ctx != NULL && rs_ctx->det != NULL ) + { + /* redirect to our context */ + // TODO + + /* jump to current step */ + // TODO + } +#endif /* MBEDTLS_ECP_RESTARTABLE */ + /* Use private key and message hash (reduced) to initialize HMAC_DRBG */ MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( d, data, grp_len ) ); MBEDTLS_MPI_CHK( derive_mpi( grp, &h, buf, blen ) ); MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &h, data + grp_len, grp_len ) ); mbedtls_hmac_drbg_seed_buf( &rng_ctx, md_info, data, 2 * grp_len ); - ret = mbedtls_ecdsa_sign( grp, r, s, d, buf, blen, - mbedtls_hmac_drbg_random, &rng_ctx ); + ret = ecdsa_sign_restartable( grp, r, s, d, buf, blen, + mbedtls_hmac_drbg_random, &rng_ctx, rs_ctx ); cleanup: mbedtls_hmac_drbg_free( &rng_ctx ); mbedtls_mpi_free( &h ); + ECDSA_RS_LEAVE( det ); + return( ret ); } @@ -294,10 +412,6 @@ static int ecdsa_verify_restartable( mbedtls_ecp_group *grp, mbedtls_ecp_point R; mbedtls_mpi *pu1 = &u1, *pu2 = &u2; -#if !defined(MBEDTLS_ECP_RESTARTABLE) - (void) rs_ctx; -#endif - mbedtls_ecp_point_init( &R ); mbedtls_mpi_init( &e ); mbedtls_mpi_init( &s_inv ); mbedtls_mpi_init( &u1 ); mbedtls_mpi_init( &u2 ); @@ -306,21 +420,9 @@ static int ecdsa_verify_restartable( mbedtls_ecp_group *grp, if( grp->N.p == NULL ) return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA ); + ECDSA_RS_ENTER( ver ); + #if defined(MBEDTLS_ECP_RESTARTABLE) - /* reset ops count for this call if top-level */ - if( rs_ctx != NULL && rs_ctx->ecp.depth++ == 0 ) - rs_ctx->ecp.ops_done = 0; - - /* set up our own sub-context if needed */ - if( mbedtls_ecp_restart_enabled() && rs_ctx != NULL && rs_ctx->ver == NULL ) - { - rs_ctx->ver = mbedtls_calloc( 1, sizeof( mbedtls_ecdsa_restart_ver_ctx ) ); - if( rs_ctx->ver == NULL ) - return( MBEDTLS_ERR_ECP_ALLOC_FAILED ); - - ecdsa_restart_ver_init( rs_ctx->ver ); - } - if( rs_ctx != NULL && rs_ctx->ver != NULL ) { /* redirect to our context */ @@ -404,17 +506,7 @@ cleanup: mbedtls_mpi_free( &e ); mbedtls_mpi_free( &s_inv ); mbedtls_mpi_free( &u1 ); mbedtls_mpi_free( &u2 ); -#if defined(MBEDTLS_ECP_RESTARTABLE) - /* clear our sub-context when not in progress (done or error) */ - if( rs_ctx != NULL && ret != MBEDTLS_ERR_ECP_IN_PROGRESS ) { - ecdsa_restart_ver_free( rs_ctx->ver ); - mbedtls_free( rs_ctx->ver ); - rs_ctx->ver = NULL; - } - - if( rs_ctx != NULL ) - rs_ctx->ecp.depth--; -#endif /* MBEDTLS_ECP_RESTARTABLE */ + ECDSA_RS_LEAVE( ver ); return( ret ); } @@ -632,6 +724,10 @@ void mbedtls_ecdsa_restart_init( mbedtls_ecdsa_restart_ctx *ctx ) mbedtls_ecp_restart_init( &ctx->ecp ); ctx->ver = NULL; + ctx->sig = NULL; +#if defined(MBEDTLS_ECDSA_DETERMINISTIC) + ctx->det = NULL; +#endif } /* @@ -644,6 +740,16 @@ void mbedtls_ecdsa_restart_free( mbedtls_ecdsa_restart_ctx *ctx ) ecdsa_restart_ver_free( ctx->ver ); mbedtls_free( ctx->ver ); ctx->ver = NULL; + + ecdsa_restart_sig_free( ctx->sig ); + mbedtls_free( ctx->sig ); + ctx->sig = NULL; + +#if defined(MBEDTLS_ECDSA_DETERMINISTIC) + ecdsa_restart_det_free( ctx->det ); + mbedtls_free( ctx->det ); + ctx->det = NULL; +#endif } #endif /* MBEDTLS_ECP_RESTARTABLE */