Add infrastructure for ecdsa_verify_restartable()
diff --git a/include/mbedtls/ecdsa.h b/include/mbedtls/ecdsa.h
index c7b9f27..d2f83b2 100644
--- a/include/mbedtls/ecdsa.h
+++ b/include/mbedtls/ecdsa.h
@@ -58,11 +58,19 @@
#if defined(MBEDTLS_ECP_RESTARTABLE)
/**
+ * \brief Internal restart context for ecdsa_verify()
+ *
+ * \note Opaque struct
+ */
+typedef struct mbedtls_ecdsa_restart_ver mbedtls_ecdsa_restart_ver_ctx;
+
+/**
* \brief General context for resuming ECDSA operations
*/
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_ctx;
#else /* MBEDTLS_ECP_RESTARTABLE */
diff --git a/include/mbedtls/ecp.h b/include/mbedtls/ecp.h
index 420c6d0..3e5c605 100644
--- a/include/mbedtls/ecp.h
+++ b/include/mbedtls/ecp.h
@@ -341,6 +341,14 @@
* \note This setting is currently ignored by Curve25519
*/
void mbedtls_ecp_set_max_ops( unsigned max_ops );
+
+/**
+ * \brief Check if restart is enabled (max_ops != 0)
+ *
+ * \return 0 if max_ops == 0 (restart disabled)
+ * 1 otherwise (restart enabled)
+ */
+int mbedtls_ecp_restart_enabled( void );
#endif /* MBEDTLS_ECP_RESTARTABLE */
/**
diff --git a/library/ecdsa.c b/library/ecdsa.c
index 19f9d5e..8e1f62a 100644
--- a/library/ecdsa.c
+++ b/library/ecdsa.c
@@ -42,6 +42,50 @@
#include "mbedtls/hmac_drbg.h"
#endif
+#if defined(MBEDTLS_PLATFORM_C)
+#include "mbedtls/platform.h"
+#else
+#include <stdlib.h>
+#define mbedtls_calloc calloc
+#define mbedtls_free free
+#endif
+
+#if defined(MBEDTLS_ECP_RESTARTABLE)
+/*
+ * Sub-contect for ecdsa_verify()
+ */
+struct mbedtls_ecdsa_restart_ver
+{
+ int state; /* dummy */
+};
+
+/*
+ * Init verify restart sub-context
+ */
+static void ecdsa_restart_ver_init( mbedtls_ecdsa_restart_ver_ctx *ctx )
+{
+ memset( ctx, 0, sizeof( *ctx ) );
+}
+
+/*
+ * Free the components of a verify restart sub-context
+ */
+static void ecdsa_restart_ver_free( mbedtls_ecdsa_restart_ver_ctx *ctx )
+{
+ if( ctx == NULL )
+ return;
+
+ memset( ctx, 0, sizeof( *ctx ) );
+}
+
+#define ECDSA_RS_ECP &rs_ctx->ecp
+
+#else /* MBEDTLS_ECP_RESTARTABLE */
+
+#define ECDSA_RS_ECP NULL
+
+#endif /* MBEDTLS_ECP_RESTARTABLE */
+
/*
* Derive a suitable integer for group grp from a buffer of length len
* SEC1 4.1.3 step 5 aka SEC1 4.1.4 step 3
@@ -206,7 +250,9 @@
mbedtls_mpi e, s_inv, u1, u2;
mbedtls_ecp_point R;
- (void) rs_ctx; // temporary
+#if !defined(MBEDTLS_ECP_RESTARTABLE)
+ (void) rs_ctx;
+#endif
mbedtls_ecp_point_init( &R );
mbedtls_mpi_init( &e ); mbedtls_mpi_init( &s_inv );
@@ -216,6 +262,22 @@
if( grp->N.p == NULL )
return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
+#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 );
+ }
+#endif /* MBEDTLS_ECP_RESTARTABLE */
+
/*
* Step 1: make sure r and s are in range 1..n-1
*/
@@ -250,7 +312,8 @@
/*
* Step 5: R = u1 G + u2 Q
*/
- MBEDTLS_MPI_CHK( mbedtls_ecp_muladd( grp, &R, &u1, &grp->G, &u2, Q ) );
+ MBEDTLS_MPI_CHK( mbedtls_ecp_muladd_restartable( grp,
+ &R, &u1, &grp->G, &u2, Q, ECDSA_RS_ECP ) );
if( mbedtls_ecp_is_zero( &R ) )
{
@@ -278,6 +341,18 @@
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 */
+
return( ret );
}
@@ -477,6 +552,8 @@
void mbedtls_ecdsa_restart_init( mbedtls_ecdsa_restart_ctx *ctx )
{
mbedtls_ecp_restart_init( &ctx->ecp );
+
+ ctx->ver = NULL;
}
/*
@@ -485,6 +562,10 @@
void mbedtls_ecdsa_restart_free( mbedtls_ecdsa_restart_ctx *ctx )
{
mbedtls_ecp_restart_free( &ctx->ecp );
+
+ ecdsa_restart_ver_free( ctx->ver );
+ mbedtls_free( ctx->ver );
+ ctx->ver = NULL;
}
#endif /* MBEDTLS_ECP_RESTARTABLE */
diff --git a/library/ecp.c b/library/ecp.c
index 9d4721e..40daa67 100644
--- a/library/ecp.c
+++ b/library/ecp.c
@@ -101,6 +101,14 @@
}
/*
+ * Check if restart is enabled
+ */
+int mbedtls_ecp_restart_enabled( void )
+{
+ return( ecp_max_ops != 0 );
+}
+
+/*
* Restart sub-context for ecp_mul_comb()
*/
struct mbedtls_ecp_restart_mul