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Functions
gssize | g_checksum_type_get_length () |
GChecksum * | g_checksum_new () |
GChecksum * | g_checksum_copy () |
void | g_checksum_free () |
void | g_checksum_reset () |
void | g_checksum_update () |
const gchar * | g_checksum_get_string () |
void | g_checksum_get_digest () |
gchar * | g_compute_checksum_for_data () |
gchar * | g_compute_checksum_for_string () |
gchar * | g_compute_checksum_for_bytes () |
Description
GLib provides a generic API for computing checksums (or "digests") for a sequence of arbitrary bytes, using various hashing algorithms like MD5, SHA-1 and SHA-256. Checksums are commonly used in various environments and specifications.
GLib supports incremental checksums using the GChecksum data
structure, by calling g_checksum_update()
as long as there's data
available and then using g_checksum_get_string()
or
g_checksum_get_digest()
to compute the checksum and return it either
as a string in hexadecimal form, or as a raw sequence of bytes. To
compute the checksum for binary blobs and NUL-terminated strings in
one go, use the convenience functions g_compute_checksum_for_data()
and g_compute_checksum_for_string()
, respectively.
Support for checksums has been added in GLib 2.16
Functions
g_checksum_type_get_length ()
gssize
g_checksum_type_get_length (GChecksumType checksum_type
);
Gets the length in bytes of digests of type checksum_type
Since 2.16
g_checksum_new ()
GChecksum *
g_checksum_new (GChecksumType checksum_type
);
Creates a new GChecksum, using the checksum algorithm checksum_type
.
If the checksum_type
is not known, NULL
is returned.
A GChecksum can be used to compute the checksum, or digest, of an
arbitrary binary blob, using different hashing algorithms.
A GChecksum works by feeding a binary blob through g_checksum_update()
until there is data to be checked; the digest can then be extracted
using g_checksum_get_string()
, which will return the checksum as a
hexadecimal string; or g_checksum_get_digest()
, which will return a
vector of raw bytes. Once either g_checksum_get_string()
or
g_checksum_get_digest()
have been called on a GChecksum, the checksum
will be closed and it won't be possible to call g_checksum_update()
on it anymore.
Returns
the newly created GChecksum, or NULL
.
Use g_checksum_free()
to free the memory allocated by it.
[transfer full]
Since 2.16
g_checksum_copy ()
GChecksum *
g_checksum_copy (const GChecksum *checksum
);
Copies a GChecksum. If checksum
has been closed, by calling
g_checksum_get_string()
or g_checksum_get_digest()
, the copied
checksum will be closed as well.
Since 2.16
g_checksum_free ()
void
g_checksum_free (GChecksum *checksum
);
Frees the memory allocated for checksum
.
Since 2.16
g_checksum_reset ()
void
g_checksum_reset (GChecksum *checksum
);
Resets the state of the checksum
back to its initial state.
Since 2.18
g_checksum_update ()
void g_checksum_update (GChecksum *checksum
,const guchar *data
,gssize length
);
Feeds data
into an existing GChecksum. The checksum must still be
open, that is g_checksum_get_string()
or g_checksum_get_digest()
must
not have been called on checksum
.
Parameters
checksum |
||
data |
buffer used to compute the checksum. |
[array length=length][element-type guint8] |
length |
size of the buffer, or -1 if it is a null-terminated string. |
Since 2.16
g_checksum_get_string ()
const gchar *
g_checksum_get_string (GChecksum *checksum
);
Gets the digest as an hexadecimal string.
Once this function has been called the GChecksum can no longer be
updated with g_checksum_update()
.
The hexadecimal characters will be lower case.
Returns
the hexadecimal representation of the checksum. The returned string is owned by the checksum and should not be modified or freed.
Since 2.16
g_checksum_get_digest ()
void g_checksum_get_digest (GChecksum *checksum
,guint8 *buffer
,gsize *digest_len
);
Gets the digest from checksum
as a raw binary vector and places it
into buffer
. The size of the digest depends on the type of checksum.
Once this function has been called, the GChecksum is closed and can
no longer be updated with g_checksum_update()
.
Parameters
checksum |
||
buffer |
output buffer |
|
digest_len |
an inout parameter. The caller initializes it to the size of |
Since 2.16
g_compute_checksum_for_data ()
gchar * g_compute_checksum_for_data (GChecksumType checksum_type
,const guchar *data
,gsize length
);
Computes the checksum for a binary data
of length
. This is a
convenience wrapper for g_checksum_new()
, g_checksum_get_string()
and g_checksum_free()
.
The hexadecimal string returned will be in lower case.
Parameters
checksum_type |
||
data |
binary blob to compute the digest of. |
[array length=length][element-type guint8] |
length |
length of |
Returns
the digest of the binary data as a string in hexadecimal.
The returned string should be freed with g_free()
when done using it.
Since 2.16
g_compute_checksum_for_string ()
gchar * g_compute_checksum_for_string (GChecksumType checksum_type
,const gchar *str
,gssize length
);
Computes the checksum of a string.
The hexadecimal string returned will be in lower case.
Parameters
checksum_type |
||
str |
the string to compute the checksum of |
|
length |
the length of the string, or -1 if the string is null-terminated. |
Returns
the checksum as a hexadecimal string. The returned string
should be freed with g_free()
when done using it.
Since 2.16
g_compute_checksum_for_bytes ()
gchar * g_compute_checksum_for_bytes (GChecksumType checksum_type
,GBytes *data
);
Computes the checksum for a binary data
. This is a
convenience wrapper for g_checksum_new()
, g_checksum_get_string()
and g_checksum_free()
.
The hexadecimal string returned will be in lower case.
Returns
the digest of the binary data as a string in hexadecimal.
The returned string should be freed with g_free()
when done using it.
Since 2.34
Types and Values
enum GChecksumType
The hashing algorithm to be used by GChecksum when performing the digest of some data.
Note that the GChecksumType enumeration may be extended at a later date to include new hashing algorithm types.
Since 2.16
GChecksum
typedef struct _GChecksum GChecksum;
An opaque structure representing a checksumming operation.
To create a new GChecksum, use g_checksum_new()
. To free
a GChecksum, use g_checksum_free()
.
Since 2.16