LCOV - code coverage report
Current view: top level - src - context.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 28 40 70.0 %
Date: 2016-09-12 12:23:59 Functions: 4 4 100.0 %

          Line data    Source code
       1             : /* context.c - Context management
       2             :  * Copyright (C) 2013  g10 Code GmbH
       3             :  *
       4             :  * This file is part of Libgcrypt.
       5             :  *
       6             :  * Libgcrypt is free software; you can redistribute it and/or modify
       7             :  * it under the terms of the GNU Lesser General Public License as
       8             :  * published by the Free Software Foundation; either version 2.1 of
       9             :  * the License, or (at your option) any later version.
      10             :  *
      11             :  * Libgcrypt is distributed in the hope that it will be useful,
      12             :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      13             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      14             :  * GNU Lesser General Public License for more details.
      15             :  *
      16             :  * You should have received a copy of the GNU Lesser General Public
      17             :  * License along with this program; if not, see <http://www.gnu.org/licenses/>.
      18             :  */
      19             : 
      20             : #include <config.h>
      21             : #include <stdio.h>
      22             : #include <stdlib.h>
      23             : #include <string.h>
      24             : #include <stdarg.h>
      25             : #include <unistd.h>
      26             : 
      27             : #include "g10lib.h"
      28             : #include "mpi.h"
      29             : #include "context.h"
      30             : 
      31             : #define CTX_MAGIC "cTx"
      32             : #define CTX_MAGIC_LEN 3
      33             : 
      34             : 
      35             : /* The definition of the generic context object.  The public typedef
      36             :    gcry_ctx_t is used to access it.  */
      37             : struct gcry_context
      38             : {
      39             :   char magic[CTX_MAGIC_LEN]; /* Magic value to cross check that this
      40             :                                 is really a context object. */
      41             :   char type;     /* The type of the context (CONTEXT_TYPE_foo).  */
      42             : 
      43             :   void (*deinit)(void*); /* Function used to free the private part. */
      44             :   PROPERLY_ALIGNED_TYPE u;
      45             : };
      46             : 
      47             : 
      48             : /* Allocate a fresh generic context of contect TYPE and allocate
      49             :    LENGTH extra bytes for private use of the type handler. DEINIT is a
      50             :    function used called to deinitialize the private part; it may be
      51             :    NULL if de-initialization is not required.  Returns NULL and sets
      52             :    ERRNO if memory allocation failed.  */
      53             : gcry_ctx_t
      54          14 : _gcry_ctx_alloc (int type, size_t length, void (*deinit)(void*))
      55             : {
      56             :   gcry_ctx_t ctx;
      57             : 
      58          14 :   switch (type)
      59             :     {
      60             :     case CONTEXT_TYPE_EC:
      61          14 :       break;
      62             :     default:
      63           0 :       log_bug ("bad context type %d given to _gcry_ctx_alloc\n", type);
      64             :       break;
      65             :     }
      66             : 
      67          14 :   if (length < sizeof (PROPERLY_ALIGNED_TYPE))
      68           0 :     length = sizeof (PROPERLY_ALIGNED_TYPE);
      69             : 
      70          14 :   ctx = xtrycalloc (1, sizeof *ctx - sizeof (PROPERLY_ALIGNED_TYPE) + length);
      71          14 :   if (!ctx)
      72           0 :     return NULL;
      73          14 :   memcpy (ctx->magic, CTX_MAGIC, CTX_MAGIC_LEN);
      74          14 :   ctx->type = type;
      75          14 :   ctx->deinit = deinit;
      76             : 
      77          14 :   return ctx;
      78             : }
      79             : 
      80             : 
      81             : /* Return a pointer to the private part of the context CTX.  TYPE is
      82             :    the requested context type.  Using an explicit type allows to cross
      83             :    check the type and eventually allows to store several private
      84             :    contexts in one context object.  The function does not return an
      85             :    error but aborts if the provided CTX is not valid.  */
      86             : void *
      87        2115 : _gcry_ctx_get_pointer (gcry_ctx_t ctx, int type)
      88             : {
      89        2115 :   if (!ctx || memcmp (ctx->magic, CTX_MAGIC, CTX_MAGIC_LEN))
      90           0 :     log_fatal ("bad pointer %p passed to _gcry_ctx_get_pointer\n", ctx);
      91        2115 :   if (ctx->type != type)
      92           0 :     log_fatal ("wrong context type %d request for context %p of type %d\n",
      93           0 :                type, ctx, ctx->type);
      94        2115 :   return &ctx->u;
      95             : }
      96             : 
      97             : /* Return a pointer to the private part of the context CTX.  TYPE is
      98             :    the requested context type.  Using an explicit type allows to cross
      99             :    check the type and eventually allows to store several private
     100             :    contexts in one context object.  In contrast to
     101             :    _gcry_ctx_get_pointer, this function returns NULL if no context for
     102             :    the given type was found.  If CTX is NULL the function does not
     103             :    abort but returns NULL.  */
     104             : void *
     105          11 : _gcry_ctx_find_pointer (gcry_ctx_t ctx, int type)
     106             : {
     107          11 :   if (!ctx)
     108           0 :     return NULL;
     109          11 :   if (memcmp (ctx->magic, CTX_MAGIC, CTX_MAGIC_LEN))
     110           0 :     log_fatal ("bad pointer %p passed to _gcry_ctx_get_pointer\n", ctx);
     111          11 :   if (ctx->type != type)
     112           0 :     return NULL;
     113          11 :   return &ctx->u;
     114             : }
     115             : 
     116             : 
     117             : /* Release the generic context CTX.  */
     118             : void
     119          31 : _gcry_ctx_release (gcry_ctx_t ctx)
     120             : {
     121          31 :   if (!ctx)
     122          48 :     return;
     123          14 :   if (memcmp (ctx->magic, CTX_MAGIC, CTX_MAGIC_LEN))
     124           0 :     log_fatal ("bad pointer %p passed to gcry_ctx_relase\n", ctx);
     125          14 :   switch (ctx->type)
     126             :     {
     127             :     case CONTEXT_TYPE_EC:
     128          14 :       break;
     129             :     default:
     130           0 :       log_fatal ("bad context type %d detected in gcry_ctx_relase\n",
     131           0 :                  ctx->type);
     132             :       break;
     133             :     }
     134          14 :   if (ctx->deinit)
     135          14 :     ctx->deinit (&ctx->u);
     136          14 :   xfree (ctx);
     137             : }

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