MD5

MD5 — MD5 hash

Synopsis


#include <gnet.h>


                    GMD5;
#define             GNET_MD5_HASH_LENGTH
GMD5*               gnet_md5_new                        (const gchar *buffer,
                                                         guint length);
GMD5*               gnet_md5_new_string                 (const gchar *str);
GMD5*               gnet_md5_clone                      (const GMD5 *md5);
void                gnet_md5_delete                     (GMD5 *md5);
GMD5*               gnet_md5_new_incremental            (void);
void                gnet_md5_update                     (GMD5 *md5,
                                                         const gchar *buffer,
                                                         guint length);
void                gnet_md5_final                      (GMD5 *md5);
gboolean            gnet_md5_equal                      (gconstpointer p1,
                                                         gconstpointer p2);
guint               gnet_md5_hash                       (gconstpointer p);
gchar*              gnet_md5_get_digest                 (const GMD5 *md5);
gchar*              gnet_md5_get_string                 (const GMD5 *md5);
void                gnet_md5_copy_string                (const GMD5 *md5,
                                                         gchar *buffer);

Description

The MD5 module provide support for computing and manipulating MD5 hashes. MD5 is a hash function with a very low probability of collision. MD5 is considered weaker than SHA.

An MD5 can be calculated at one time or incrementally. To create a MD5 at one time, call gnet_md5_new() with the data. To create a MD5 incrementally, call gnet_md5_new_incremental() to create the MD5 object, then gnet_md5_update() one or more times with data to hash, and finally call gnet_md5_final().

To get the digest, or hash value, call gnet_md5_get_digest(). This returns the raw digest as an array of GNET_MD5_HASH_LENGTH bytes. To get the digest as a human-readable hexidecimal string, call gnet_md5_get_string() or gnet_md5_copy_string(). 

gchar buffer[] = "Hello world!";
gchar buffer2[] = "Second line";
GMD5*  md5;
gchar* md5_str;

/* Compute an MD5 at one time */
md5 = gnet_md5_new (buffer, strlen(buffer));

md5_str = gnet_md5_get_string (md5);
g_print ("The MD5 of %s is %s\n", buffer, md5_str);

/* Use MD5... */

g_free (md5_str);
gnet_md5_delete (md5);

/* Compute an MD5 incrementally */
md5 = gnet_md5_new_incremental ();
gnet_md5_update (md5, buffer, strlen(buffer));
gnet_md5_update (md5, buffer2, strlen(buffer2));
gnet_md5_final (md5);

/* Use MD5... */

gnet_md5_delete (md5);

Details

GMD5

typedef struct _GMD5 GMD5;

GMD5 is a MD5 hash.

GNET_MD5_HASH_LENGTH

#define GNET_MD5_HASH_LENGTH	16

Length of the MD5 hash in bytes.

gnet_md5_new ()

GMD5*               gnet_md5_new                        (const gchar *buffer,
                                                         guint length);

Creates a GMD5 from buffer.

buffer : buffer to hash
length : length of buffer
Returns : a new GMD5.

gnet_md5_new_string ()

GMD5*               gnet_md5_new_string                 (const gchar *str);

Creates a GMD5 from str. str is a hexidecimal string representing the digest.

str : hexidecimal string
Returns : a new GMD5.

gnet_md5_clone ()

GMD5*               gnet_md5_clone                      (const GMD5 *md5);

Copies a GMD5.

md5 : a GMD5
Returns : a copy of md5.

gnet_md5_delete ()

void                gnet_md5_delete                     (GMD5 *md5);

Deletes a GMD5.

md5 : a GMD5

gnet_md5_new_incremental ()

GMD5*               gnet_md5_new_incremental            (void);

Creates a GMD5 incrementally. After creating a GMD5, call gnet_md5_update() one or more times to hash data. Finally, call gnet_md5_final() to compute the final hash value.

Returns : a new GMD5.

gnet_md5_update ()

void                gnet_md5_update                     (GMD5 *md5,
                                                         const gchar *buffer,
                                                         guint length);

Updates the hash with buffer. This may be called several times on a hash created by gnet_md5_new_incremental() before being finalized by calling gnet_md5_final().

md5 : a GMD5
buffer : buffer to add
length : length of buffer

gnet_md5_final ()

void                gnet_md5_final                      (GMD5 *md5);

Calcuates the final hash value of a GMD5. This should only be called on an GMD5 created by gnet_md5_new_incremental().

md5 : a GMD5

gnet_md5_equal ()

gboolean            gnet_md5_equal                      (gconstpointer p1,
                                                         gconstpointer p2);

Compares two GMD5's for equality.

p1 : first GMD5.
p2 : second GMD5.
Returns : TRUE if they are equal; FALSE otherwise.

gnet_md5_hash ()

guint               gnet_md5_hash                       (gconstpointer p);

Creates a hash code for a GMD5 for use with GHashTable. This hash value is not the same as the MD5 digest.

p : a GMD5
Returns : the hash code for p.

gnet_md5_get_digest ()

gchar*              gnet_md5_get_digest                 (const GMD5 *md5);

Gets the raw MD5 digest.

md5 : a GMD5
Returns : a callee-owned buffer containing the MD5 hash digest. The buffer is GNET_MD5_HASH_LENGTH bytes long.

gnet_md5_get_string ()

gchar*              gnet_md5_get_string                 (const GMD5 *md5);

Gets the digest represented a human-readable string.

md5 : a GMD5
Returns : a hexadecimal string representing the digest. The string is 2 * GNET_MD5_HASH_LENGTH bytes long and NULL terminated. The string is caller owned.

gnet_md5_copy_string ()

void                gnet_md5_copy_string                (const GMD5 *md5,
                                                         gchar *buffer);

Copies the digest, represented as a string, into buffer. The string is not NULL terminated.

md5 : a GMD5
buffer : buffer at least 2 * GNET_MD5_HASH_LENGTH bytes long