Start introducing mbedtls_ecjpake_context
diff --git a/include/mbedtls/ecjpake.h b/include/mbedtls/ecjpake.h
index 57f4b15..0b20ff6 100644
--- a/include/mbedtls/ecjpake.h
+++ b/include/mbedtls/ecjpake.h
@@ -30,6 +30,52 @@
extern "C" {
#endif
+typedef struct
+{
+ const mbedtls_md_info_t *md_info; /**< Hash to use */
+ mbedtls_ecp_group grp; /**< Elliptic curve */
+
+ mbedtls_ecp_point X1; /**< Public key one */
+ mbedtls_ecp_point X2; /**< Public key two */
+ mbedtls_ecp_point X3; /**< Public key three */
+ mbedtls_ecp_point X4; /**< Public key four */
+
+ mbedtls_mpi xa; /**< Our first secret (x1 or x3) */
+ mbedtls_mpi xb; /**< Our second secret (x2 or x4) */
+} mbedtls_ecjpake_context;
+
+/*
+ * \brief Initialize a context
+ * (just makes it ready for setup() or free()).
+ *
+ * \param ctx context to initialize
+ */
+void mbedtls_ecjpake_init( mbedtls_ecjpake_context *ctx );
+
+/*
+ * \brief Free a context's content
+ *
+ * \param ctx context to free
+ */
+void mbedtls_ecjpake_free( mbedtls_ecjpake_context *ctx );
+
+/*
+ * \brief Set up a context for use
+ *
+ * \note Currently the only values for hash/curve allowed by the
+ * standard are MBEDTLS_MD_SHA256/MBEDTLS_ECP_DP_SECP256R1.
+ *
+ * \param ctx context to set up
+ * \param hash hash function to use (MBEDTLS_MD_XXX)
+ * \param curve elliptic curve identifier (MBEDTLS_ECP_DP_XXX)
+ *
+ * \return 0 if successfull,
+ * a negative error code otherwise
+ */
+int mbedtls_ecjpake_setup( mbedtls_ecjpake_context *ctx,
+ mbedtls_md_type_t hash,
+ mbedtls_ecp_group_id curve );
+
#if defined(MBEDTLS_SELF_TEST)
/**
* \brief Checkup routine
diff --git a/library/ecjpake.c b/library/ecjpake.c
index a61c146..678112c 100644
--- a/library/ecjpake.c
+++ b/library/ecjpake.c
@@ -37,6 +37,64 @@
#include <string.h>
/*
+ * Initialize context
+ */
+void mbedtls_ecjpake_init( mbedtls_ecjpake_context *ctx )
+{
+ if( ctx == NULL )
+ return;
+
+ ctx->md_info = NULL;
+ mbedtls_ecp_group_init( &ctx->grp );
+
+ mbedtls_ecp_point_init( &ctx->X1 );
+ mbedtls_ecp_point_init( &ctx->X2 );
+ mbedtls_ecp_point_init( &ctx->X3 );
+ mbedtls_ecp_point_init( &ctx->X4 );
+
+ mbedtls_mpi_init( &ctx->xa );
+ mbedtls_mpi_init( &ctx->xb );
+}
+
+/*
+ * Free context
+ */
+void mbedtls_ecjpake_free( mbedtls_ecjpake_context *ctx )
+{
+ if( ctx == NULL )
+ return;
+
+ ctx->md_info = NULL;
+ mbedtls_ecp_group_free( &ctx->grp );
+
+ mbedtls_ecp_point_free( &ctx->X1 );
+ mbedtls_ecp_point_free( &ctx->X2 );
+ mbedtls_ecp_point_free( &ctx->X3 );
+ mbedtls_ecp_point_free( &ctx->X4 );
+
+ mbedtls_mpi_free( &ctx->xa );
+ mbedtls_mpi_free( &ctx->xb );
+}
+
+/*
+ * Setup context
+ */
+int mbedtls_ecjpake_setup( mbedtls_ecjpake_context *ctx,
+ mbedtls_md_type_t hash,
+ mbedtls_ecp_group_id curve )
+{
+ int ret;
+
+ if( ( ctx->md_info = mbedtls_md_info_from_type( hash ) ) == NULL )
+ return( MBEDTLS_ERR_MD_FEATURE_UNAVAILABLE );
+
+ if( ( ret = mbedtls_ecp_group_load( &ctx->grp, curve ) ) != 0 )
+ return( ret );
+
+ return( 0 );
+}
+
+/*
* Write a point plus its length to a buffer
*/
static int ecjpake_write_len_point( unsigned char **p,