crypto_hash_file.c File Reference

incremental hashing of files More...

#include "platform.h"
#include "gnunet_util_lib.h"
#include <gcrypt.h>

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Go to the source code of this file.

Data Structures
struct	GNUNET_CRYPTO_FileHashContext
	Context used when hashing a file. More...

Macros
#define	LOG(kind, ...)
#define	LOG_STRERROR_FILE(kind, syscall, filename)

Functions
static void	file_hash_finish (struct GNUNET_CRYPTO_FileHashContext *fhc, const struct GNUNET_HashCode *res)
	Report result of hash computation to callback and free associated resources.
static void	file_hash_task (void *cls)
	File hashing task.
struct GNUNET_CRYPTO_FileHashContext *	GNUNET_CRYPTO_hash_file (enum GNUNET_SCHEDULER_Priority priority, const char *filename, size_t blocksize, GNUNET_CRYPTO_HashCompletedCallback callback, void *callback_cls)
	Compute the hash of an entire file.
void	GNUNET_CRYPTO_hash_file_cancel (struct GNUNET_CRYPTO_FileHashContext *fhc)
	Cancel a file hashing operation.

Detailed Description

incremental hashing of files

Author

Christian Grothoff

Definition in file crypto_hash_file.c.

Macro Definition Documentation

LOG

#define LOG	(		kind,
			...
	)

Value:

                                        GNUNET_log_from (kind, "util-crypto-hash-file", \
                                        __VA_ARGS__)

Definition at line 31 of file crypto_hash_file.c.

{
  GNUNET_CRYPTO_HashCompletedCallback callback;
 
  void *callback_cls;
 
  unsigned char *buffer;
 
  char *filename;
 
  struct GNUNET_DISK_FileHandle *fh;
 
  gcry_md_hd_t md;
 
  uint64_t fsize;
 
  uint64_t offset;
 
  struct GNUNET_SCHEDULER_Task *task;
 
  enum GNUNET_SCHEDULER_Priority priority;
 
  size_t bsize;
};
 
 
static void
file_hash_finish (struct GNUNET_CRYPTO_FileHashContext *fhc,
                  const struct GNUNET_HashCode *res)
{
  fhc->callback (fhc->callback_cls, res);
  GNUNET_free (fhc->filename);
  if (! GNUNET_DISK_handle_invalid (fhc->fh))
    GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fhc->fh));
  gcry_md_close (fhc->md);
  GNUNET_free (fhc);             /* also frees fhc->buffer */
}
 
 
static void
file_hash_task (void *cls)
{
  struct GNUNET_CRYPTO_FileHashContext *fhc = cls;
  struct GNUNET_HashCode *res;
  size_t delta;
  ssize_t sret;
 
  fhc->task = NULL;
  GNUNET_assert (fhc->offset <= fhc->fsize);
  delta = fhc->bsize;
  if (fhc->fsize - fhc->offset < delta)
    delta = fhc->fsize - fhc->offset;
  sret = GNUNET_DISK_file_read (fhc->fh,
                                fhc->buffer,
                                delta);
  if ((sret < 0) ||
      (delta != (size_t) sret))
  {
    LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING,
                       "read",
                       fhc->filename);
    file_hash_finish (fhc,
                      NULL);
    return;
  }
  gcry_md_write (fhc->md,
                 fhc->buffer,
                 delta);
  fhc->offset += delta;
  if (fhc->offset == fhc->fsize)
  {
    res = (struct GNUNET_HashCode *) gcry_md_read (fhc->md,
                                                   GCRY_MD_SHA512);
    file_hash_finish (fhc, res);
    return;
  }
  fhc->task = GNUNET_SCHEDULER_add_with_priority (fhc->priority,
                                                  &file_hash_task,
                                                  fhc);
}
 
 
struct GNUNET_CRYPTO_FileHashContext *
GNUNET_CRYPTO_hash_file (enum GNUNET_SCHEDULER_Priority priority,
                         const char *filename,
                         size_t blocksize,
                         GNUNET_CRYPTO_HashCompletedCallback callback,
                         void *callback_cls)
{
  struct GNUNET_CRYPTO_FileHashContext *fhc;
 
  GNUNET_assert (blocksize > 0);
  GNUNET_assert (blocksize <= (SIZE_MAX - sizeof (*fhc)));
  fhc =
    GNUNET_malloc (sizeof(*fhc) + blocksize);
  fhc->callback = callback;
  fhc->callback_cls = callback_cls;
  fhc->buffer = (unsigned char *) &fhc[1];
  fhc->filename = GNUNET_strdup (filename);
  if (GPG_ERR_NO_ERROR != gcry_md_open (&fhc->md, GCRY_MD_SHA512, 0))
  {
    GNUNET_break (0);
    GNUNET_free (fhc->filename);
    GNUNET_free (fhc);
    return NULL;
  }
  fhc->bsize = blocksize;
  if (GNUNET_OK !=
      GNUNET_DISK_file_size (filename,
                             &fhc->fsize,
                             GNUNET_NO,
                             GNUNET_YES))
  {
    GNUNET_free (fhc->filename);
    GNUNET_free (fhc);
    return NULL;
  }
  fhc->fh = GNUNET_DISK_file_open (filename,
                                   GNUNET_DISK_OPEN_READ,
                                   GNUNET_DISK_PERM_NONE);
  if (! fhc->fh)
  {
    GNUNET_free (fhc->filename);
    GNUNET_free (fhc);
    return NULL;
  }
  fhc->priority = priority;
  fhc->task = GNUNET_SCHEDULER_add_with_priority (priority,
                                                  &file_hash_task,
                                                  fhc);
  return fhc;
}
 
 
void
GNUNET_CRYPTO_hash_file_cancel (struct GNUNET_CRYPTO_FileHashContext *fhc)
{
  GNUNET_SCHEDULER_cancel (fhc->task);
  GNUNET_free (fhc->filename);
  GNUNET_break (GNUNET_OK ==
                GNUNET_DISK_file_close (fhc->fh));
  gcry_md_close (fhc->md);
  GNUNET_free (fhc);
}
 
 
/* end of crypto_hash_file.c */

LOG_STRERROR_FILE

#define LOG_STRERROR_FILE	(		kind,
			syscall,
			filename
	)

Value:

                                                                   GNUNET_log_from_strerror_file (kind, \
                                                                   "util-crypto-hash-file", \
                                                                   syscall, \
                                                                   filename)

Definition at line 34 of file crypto_hash_file.c.

Function Documentation

file_hash_finish()

static void file_hash_finish ( struct GNUNET_CRYPTO_FileHashContext *  fhc, const struct GNUNET_HashCode *  res  )

static

Report result of hash computation to callback and free associated resources.

Definition at line 108 of file crypto_hash_file.c.

{
  fhc->callback (fhc->callback_cls, res);
  GNUNET_free (fhc->filename);
  if (! GNUNET_DISK_handle_invalid (fhc->fh))
    GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fhc->fh));
  gcry_md_close (fhc->md);
  GNUNET_free (fhc);             /* also frees fhc->buffer */
}

References GNUNET_CRYPTO_FileHashContext::callback, GNUNET_CRYPTO_FileHashContext::callback_cls, GNUNET_CRYPTO_FileHashContext::fh, GNUNET_CRYPTO_FileHashContext::filename, GNUNET_break, GNUNET_DISK_file_close(), GNUNET_DISK_handle_invalid(), GNUNET_free, GNUNET_OK, GNUNET_CRYPTO_FileHashContext::md, and res.

Referenced by file_hash_task().

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file_hash_task()

static void file_hash_task ( void *  cls )

static

File hashing task.

Parameters

cls

closure

Definition at line 126 of file crypto_hash_file.c.

{
  struct GNUNET_CRYPTO_FileHashContext *fhc = cls;
  struct GNUNET_HashCode *res;
  size_t delta;
  ssize_t sret;
 
  fhc->task = NULL;
  GNUNET_assert (fhc->offset <= fhc->fsize);
  delta = fhc->bsize;
  if (fhc->fsize - fhc->offset < delta)
    delta = fhc->fsize - fhc->offset;
  sret = GNUNET_DISK_file_read (fhc->fh,
                                fhc->buffer,
                                delta);
  if ((sret < 0) ||
      (delta != (size_t) sret))
  {
    LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING,
                       "read",
                       fhc->filename);
    file_hash_finish (fhc,
                      NULL);
    return;
  }
  gcry_md_write (fhc->md,
                 fhc->buffer,
                 delta);
  fhc->offset += delta;
  if (fhc->offset == fhc->fsize)
  {
    res = (struct GNUNET_HashCode *) gcry_md_read (fhc->md,
                                                   GCRY_MD_SHA512);
    file_hash_finish (fhc, res);
    return;
  }
  fhc->task = GNUNET_SCHEDULER_add_with_priority (fhc->priority,
                                                  &file_hash_task,
                                                  fhc);
}

References GNUNET_CRYPTO_FileHashContext::bsize, GNUNET_CRYPTO_FileHashContext::buffer, delta, GNUNET_CRYPTO_FileHashContext::fh, file_hash_finish(), file_hash_task(), GNUNET_CRYPTO_FileHashContext::filename, GNUNET_CRYPTO_FileHashContext::fsize, GNUNET_assert, GNUNET_DISK_file_read(), GNUNET_ERROR_TYPE_WARNING, GNUNET_SCHEDULER_add_with_priority(), LOG_STRERROR_FILE, GNUNET_CRYPTO_FileHashContext::md, GNUNET_CRYPTO_FileHashContext::offset, GNUNET_CRYPTO_FileHashContext::priority, res, and GNUNET_CRYPTO_FileHashContext::task.

Referenced by file_hash_task(), and GNUNET_CRYPTO_hash_file().

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