PK: use alloc and free function pointers

include/polarssl/pk.h

@@ -102,6 +102,13 @@ typedef struct
     int (*verify_func)( void *ctx,
                         const unsigned char *hash, const md_info_t *md_info,
                         const unsigned char *sig, size_t sig_len );
+
+    /** Allocate a new context */
+    void * (*ctx_alloc_func)( void );
+
+    /** Free the given context */
+    void (*ctx_free_func)( void *ctx );
+
 } pk_info_t;
 
 /**

library/pk.c

@@ -65,33 +65,39 @@ void pk_init( pk_context *ctx )
  */
 void pk_free( pk_context *ctx )
 {
-    if( ctx == NULL )
+    if( ctx == NULL || ctx->info == NULL)
         return;
 
-#if defined(POLARSSL_RSA_C)
+    ctx->info->ctx_free_func( ctx->data );
-    if( ctx->type == POLARSSL_PK_RSA )
+    ctx->data = NULL;
-        rsa_free( ctx->data );
-    else
-#endif
-#if defined(POLARSSL_ECP_C)
-    if( ctx->type == POLARSSL_PK_ECKEY || ctx->type == POLARSSL_PK_ECKEY_DH )
-        ecp_keypair_free( ctx->data );
-    else
-#endif
-#if defined(POLARSSL_ECDSA_C)
-    if( ctx->type == POLARSSL_PK_ECDSA )
-        ecdsa_free( ctx->data );
-    else
-#endif
-    {
-        ; /* guard for the else's above */
-    }
-
-    polarssl_free( ctx->data );
 
     ctx->info = NULL;
     ctx->type = POLARSSL_PK_NONE;
-    ctx->data = NULL;
+}
+
+/*
+ * Get pk_info structure from type
+ */
+static const pk_info_t * pk_info_from_type( pk_type_t pk_type )
+{
+    switch( pk_type ) {
+#if defined(POLARSSL_RSA_C)
+        case POLARSSL_PK_RSA:
+            return &rsa_info;
+#endif
+#if defined(POLARSSL_ECP_C)
+        case POLARSSL_PK_ECKEY:
+            return &eckey_info;
+        case POLARSSL_PK_ECKEY_DH:
+            return &eckeydh_info;
+#endif
+#if defined(POLARSSL_ECDSA_C)
+        case POLARSSL_PK_ECDSA:
+            return &ecdsa_info;
+#endif
+        default:
+            return NULL;
+    }
 }
 
 /*
@@ -99,7 +105,6 @@ void pk_free( pk_context *ctx )
  */
 int pk_set_type( pk_context *ctx, pk_type_t type )
 {
-    size_t size;
     const pk_info_t *info;
 
     if( ctx->type == type )
@@ -108,41 +113,12 @@ int pk_set_type( pk_context *ctx, pk_type_t type )
     if( ctx->type != POLARSSL_PK_NONE )
         return( POLARSSL_ERR_PK_TYPE_MISMATCH );
 
-#if defined(POLARSSL_RSA_C)
+    if( ( info = pk_info_from_type( type ) ) == NULL )
-    if( type == POLARSSL_PK_RSA )
-    {
-        size = sizeof( rsa_context );
-        info = &rsa_info;
-    }
-    else
-#endif
-#if defined(POLARSSL_ECP_C)
-    if( type == POLARSSL_PK_ECKEY )
-    {
-        size = sizeof( ecp_keypair );
-        info = &eckey_info;
-    }
-    else if( type == POLARSSL_PK_ECKEY_DH )
-    {
-        size = sizeof( ecp_keypair );
-        info = &eckeydh_info;
-    }
-    else
-#endif
-#if defined(POLARSSL_ECDSA_C)
-    if( type == POLARSSL_PK_ECDSA )
-    {
-        size = sizeof( ecdsa_context );
-        info = &ecdsa_info;
-    }
-    else
-#endif
         return( POLARSSL_ERR_PK_TYPE_MISMATCH );
 
-    if( ( ctx->data = polarssl_malloc( size ) ) == NULL )
+    if( ( ctx->data = info->ctx_alloc_func() ) == NULL )
         return( POLARSSL_ERR_PK_MALLOC_FAILED );
 
-    memset( ctx->data, 0, size );
     ctx->type = type;
     ctx->info = info;
 

library/pk_wrap.c

@@ -39,6 +39,14 @@
 #include "polarssl/ecdsa.h"
 #endif
 
+#if defined(POLARSSL_MEMORY_C)
+#include "polarssl/memory.h"
+#else
+#include <stdlib.h>
+#define polarssl_malloc     malloc
+#define polarssl_free       free
+#endif
+
 #if defined(POLARSSL_RSA_C)
 static int rsa_can_do( pk_type_t type )
 {
@@ -60,12 +68,30 @@ static int rsa_verify_wrap( void *ctx,
                 RSA_PUBLIC, md_info->type, 0, hash, sig ) );
 }
 
+static void *rsa_alloc_wrap( void )
+{
+    void *ctx = polarssl_malloc( sizeof( rsa_context ) );
+
+    if( ctx != NULL )
+        rsa_init( (rsa_context *) ctx, 0, 0 );
+
+    return ctx;
+}
+
+static void rsa_free_wrap( void *ctx )
+{
+    rsa_free( (rsa_context *) ctx );
+    polarssl_free( ctx );
+}
+
 const pk_info_t rsa_info = {
     POLARSSL_PK_RSA,
     "RSA",
     rsa_get_size,
     rsa_can_do,
     rsa_verify_wrap,
+    rsa_alloc_wrap,
+    rsa_free_wrap,
 };
 #endif /* POLARSSL_RSA_C */
 
@@ -88,12 +114,30 @@ int ecdsa_verify_wrap( void *ctx,
                 hash, md_info->size, sig, sig_len ) );
 }
 
+static void *ecdsa_alloc_wrap( void )
+{
+    void *ctx = polarssl_malloc( sizeof( ecdsa_context ) );
+
+    if( ctx != NULL )
+        ecdsa_init( (ecdsa_context *) ctx );
+
+    return( ctx );
+}
+
+static void ecdsa_free_wrap( void *ctx )
+{
+    ecdsa_free( (ecdsa_context *) ctx );
+    polarssl_free( ctx );
+}
+
 const pk_info_t ecdsa_info = {
     POLARSSL_PK_ECDSA,
     "ECDSA",
     ecdsa_get_size,
     ecdsa_can_do,
     ecdsa_verify_wrap,
+    ecdsa_alloc_wrap,
+    ecdsa_free_wrap,
 };
 #endif /* POLARSSL_ECDSA_C */
 
@@ -140,12 +184,30 @@ static int eckey_verify_wrap( void *ctx,
 #endif /* POLARSSL_ECDSA_C */
 }
 
+static void *eckey_alloc_wrap( void )
+{
+    void *ctx = polarssl_malloc( sizeof( ecp_keypair ) );
+
+    if( ctx != NULL )
+        ecp_keypair_init( ctx );
+
+    return( ctx );
+}
+
+static void eckey_free_wrap( void *ctx )
+{
+    ecp_keypair_free( (ecp_keypair *) ctx );
+    polarssl_free( ctx );
+}
+
 const pk_info_t eckey_info = {
     POLARSSL_PK_ECKEY,
     "EC",
     eckey_get_size,
     eckey_can_do,
     eckey_verify_wrap,
+    eckey_alloc_wrap,
+    eckey_free_wrap,
 };
 
 /*
@@ -176,5 +238,7 @@ const pk_info_t eckeydh_info = {
     eckey_get_size,         /* Same underlying key structure */
     eckeydh_can_do,
     eckeydh_verify_wrap,
+    eckey_alloc_wrap,       /* Same underlying key structure */
+    eckey_free_wrap,        /* Same underlying key structure */
 };
 #endif /* POLARSSL_ECP_C */