diff --git a/docs/reference/glib/glib-sections.txt b/docs/reference/glib/glib-sections.txt
index b815824..a2d2a94 100644
--- a/docs/reference/glib/glib-sections.txt
+++ b/docs/reference/glib/glib-sections.txt
@@ -2495,3 +2495,18 @@ g_base64_encode
 g_base64_decode_step
 g_base64_decode
 </SECTION>
+
+<SECTION>
+<TITLE>Data Checksums</TITLE>
+<FILE>checksum</FILE>
+GChecksumType
+g_checksum_new
+g_checksum_copy
+g_checksum_free
+g_checksum_update
+g_checksum_get_string
+g_checksum_get_digest
+<SUBSECTION>
+g_compute_checksum_for_data
+g_compute_checksum_for_string
+</SECTION>
diff --git a/glib/Makefile.am b/glib/Makefile.am
index 22ecd19..6b45b45 100644
--- a/glib/Makefile.am
+++ b/glib/Makefile.am
@@ -95,6 +95,7 @@ libglib_2_0_la_SOURCES = 	\
 	gbookmarkfile.c 	\
 	gbsearcharray.h		\
 	gcache.c		\
+	gchecksum.c		\
 	gcompletion.c		\
 	gconvert.c		\
 	gdataset.c		\
@@ -175,6 +176,7 @@ glibsubinclude_HEADERS =   \
 	gbase64.h	\
 	gbookmarkfile.h \
 	gcache.h	\
+	gchecksum.h	\
 	gcompletion.h	\
 	gconvert.h	\
 	gdataset.h	\
diff --git a/glib/gchecksum.c b/glib/gchecksum.c
new file mode 100644
index 0000000..39fcc13
--- /dev/null
+++ b/glib/gchecksum.c
@@ -0,0 +1,1396 @@
+/* gchecksum.h - data hashing functions
+ *
+ * Copyright (C) 2007  Emmanuele Bassi  <ebassi@gnome.org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include <config.h>
+
+#include <string.h>
+
+#include "glibconfig.h"
+#include "gchecksum.h"
+#include "glib.h"
+#include "glibintl.h"
+
+#include "galias.h"
+
+#define IS_VALID_TYPE(type)     ((type) >= G_CHECKSUM_MD5 && (type) <= G_CHECKSUM_SHA256)
+
+static const gchar hex_digits[] = "0123456789abcdef";
+
+#define MD5_DATASIZE    64
+#define MD5_DIGEST_LEN  16
+
+typedef struct
+{
+  guint32 buf[4];
+  guint32 bits[2];
+  
+  guchar data[MD5_DATASIZE];
+
+  guchar digest[MD5_DIGEST_LEN];
+} Md5sum;
+
+#define SHA1_DATASIZE   64
+#define SHA1_DIGEST_LEN 20
+
+typedef struct
+{
+  guint32 buf[5];
+  guint32 bits[2];
+
+  /* we pack 64 unsigned chars into 16 32-bit unsigned integers */
+  guint32 data[16];
+
+  guchar digest[SHA1_DIGEST_LEN];
+} Sha1sum;
+
+#define SHA256_DATASIZE         64
+#define SHA256_DIGEST_LEN       32
+
+typedef struct
+{
+  guint32 buf[8];
+  guint32 bits[2];
+
+  guint8 data[SHA256_DATASIZE];
+
+  guchar digest[SHA256_DIGEST_LEN];
+} Sha256sum;
+
+struct _GChecksum
+{
+  GChecksumType type;
+
+  gchar *digest_str;
+
+  union {
+    Md5sum md5;
+    Sha1sum sha1;
+    Sha256sum sha256;
+  } sum;
+};
+
+/* we need different byte swapping functions because MD5 expects buffers
+ * to be little-endian, while SHA1 and SHA256 expect them in big-endian
+ * form.
+ */
+
+#if G_BYTE_ORDER == G_LITTLE_ENDIAN
+#define md5_byte_reverse(buffer,length)
+#else
+static inline void
+md5_byte_reverse (guchar *buffer,
+                  gulong  length)
+{
+  guint32 bit;
+
+  do
+    {
+      bit = (guint32) ((unsigned) buffer[3] << 8 | buffer[2]) << 16 |
+                      ((unsigned) buffer[1] << 8 | buffer[0]);
+      * (guint32 *) buffer = bit;
+      buffer += 4;
+    }
+  while (--length);
+}
+#endif /* G_BYTE_ORDER == G_LITTLE_ENDIAN */
+
+#if G_BYTE_ORDER == G_BIG_ENDIAN
+#define sha_byte_reverse(buffer,length)
+#else
+static inline void
+sha_byte_reverse (guint32 *buffer,
+                  gint     length)
+{
+  length /= sizeof (guint32);
+  while (length--)
+    {
+      *buffer = ((guint32) (((*buffer & (guint32) 0x000000ffU) << 24) |
+                            ((*buffer & (guint32) 0x0000ff00U) <<  8) |
+                            ((*buffer & (guint32) 0x00ff0000U) >>  8) |
+                            ((*buffer & (guint32) 0xff000000U) >> 24)));
+      ++buffer;
+    }
+}
+#endif /* G_BYTE_ORDER == G_BIG_ENDIAN */
+
+static gchar *
+digest_to_string (guint8 *digest,
+                  gsize   digest_len)
+{
+  gint len = digest_len * 2;
+  gint i;
+  gchar *retval;
+
+  retval = g_new (gchar, len + 1);
+
+  for (i = 0; i < digest_len; i++)
+    {
+      guint8 byte = digest[i];
+
+      retval[2 * i] = hex_digits[byte >> 4];
+      retval[2 * i + 1] = hex_digits[byte & 0xf];
+    }
+
+  retval[len] = 0;
+
+  return retval;
+}
+
+/*
+ * MD5 Checksum
+ */
+
+/* This MD5 digest computation is based on the equivalent code
+ * written by Colin Plumb. It came with this notice:
+ *
+ * This code implements the MD5 message-digest algorithm.
+ * The algorithm is due to Ron Rivest.  This code was
+ * written by Colin Plumb in 1993, no copyright is claimed.
+ * This code is in the public domain; do with it what you wish.
+ *
+ * Equivalent code is available from RSA Data Security, Inc.
+ * This code has been tested against that, and is equivalent,
+ * except that you don't need to include two pages of legalese
+ * with every copy.
+ */
+
+static void
+md5_sum_init (Md5sum *md5)
+{
+  /* arbitrary constants */
+  md5->buf[0] = 0x67452301;
+  md5->buf[1] = 0xefcdab89;
+  md5->buf[2] = 0x98badcfe;
+  md5->buf[3] = 0x10325476;
+
+  md5->bits[0] = md5->bits[1] = 0;
+}
+
+/*
+ * The core of the MD5 algorithm, this alters an existing MD5 hash to
+ * reflect the addition of 16 longwords of new data.  md5_sum_update()
+ * blocks the data and converts bytes into longwords for this routine.
+ */
+static void 
+md5_transform (guint32	     buf[4],
+	       guint32 const in[16])
+{
+  register guint32 a, b, c, d;
+
+/* The four core functions - F1 is optimized somewhat */
+#define F1(x, y, z)     (z ^ (x & (y ^ z)))
+#define F2(x, y, z)     F1 (z, x, y)
+#define F3(x, y, z)     (x ^ y ^ z)
+#define F4(x, y, z)     (y ^ (x | ~z))
+
+/* This is the central step in the MD5 algorithm. */
+#define md5_step(f, w, x, y, z, data, s) \
+	( w += f (x, y, z) + data,  w = w << s | w >> (32 - s),  w += x )
+
+  a = buf[0];
+  b = buf[1];
+  c = buf[2];
+  d = buf[3];
+
+  md5_step (F1, a, b, c, d, in[0]  + 0xd76aa478,  7);
+  md5_step (F1, d, a, b, c, in[1]  + 0xe8c7b756, 12);
+  md5_step (F1, c, d, a, b, in[2]  + 0x242070db, 17);
+  md5_step (F1, b, c, d, a, in[3]  + 0xc1bdceee, 22);
+  md5_step (F1, a, b, c, d, in[4]  + 0xf57c0faf,  7);
+  md5_step (F1, d, a, b, c, in[5]  + 0x4787c62a, 12);
+  md5_step (F1, c, d, a, b, in[6]  + 0xa8304613, 17);
+  md5_step (F1, b, c, d, a, in[7]  + 0xfd469501, 22);
+  md5_step (F1, a, b, c, d, in[8]  + 0x698098d8,  7);
+  md5_step (F1, d, a, b, c, in[9]  + 0x8b44f7af, 12);
+  md5_step (F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
+  md5_step (F1, b, c, d, a, in[11] + 0x895cd7be, 22);
+  md5_step (F1, a, b, c, d, in[12] + 0x6b901122,  7);
+  md5_step (F1, d, a, b, c, in[13] + 0xfd987193, 12);
+  md5_step (F1, c, d, a, b, in[14] + 0xa679438e, 17);
+  md5_step (F1, b, c, d, a, in[15] + 0x49b40821, 22);
+	
+  md5_step (F2, a, b, c, d, in[1]  + 0xf61e2562,  5);
+  md5_step (F2, d, a, b, c, in[6]  + 0xc040b340,  9);
+  md5_step (F2, c, d, a, b, in[11] + 0x265e5a51, 14);
+  md5_step (F2, b, c, d, a, in[0]  + 0xe9b6c7aa, 20);
+  md5_step (F2, a, b, c, d, in[5]  + 0xd62f105d,  5);
+  md5_step (F2, d, a, b, c, in[10] + 0x02441453,  9);
+  md5_step (F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
+  md5_step (F2, b, c, d, a, in[4]  + 0xe7d3fbc8, 20);
+  md5_step (F2, a, b, c, d, in[9]  + 0x21e1cde6,  5);
+  md5_step (F2, d, a, b, c, in[14] + 0xc33707d6,  9);
+  md5_step (F2, c, d, a, b, in[3]  + 0xf4d50d87, 14);
+  md5_step (F2, b, c, d, a, in[8]  + 0x455a14ed, 20);
+  md5_step (F2, a, b, c, d, in[13] + 0xa9e3e905,  5);
+  md5_step (F2, d, a, b, c, in[2]  + 0xfcefa3f8,  9);
+  md5_step (F2, c, d, a, b, in[7]  + 0x676f02d9, 14);
+  md5_step (F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
+
+  md5_step (F3, a, b, c, d, in[5]  + 0xfffa3942,  4);
+  md5_step (F3, d, a, b, c, in[8]  + 0x8771f681, 11);
+  md5_step (F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
+  md5_step (F3, b, c, d, a, in[14] + 0xfde5380c, 23);
+  md5_step (F3, a, b, c, d, in[1]  + 0xa4beea44,  4);
+  md5_step (F3, d, a, b, c, in[4]  + 0x4bdecfa9, 11);
+  md5_step (F3, c, d, a, b, in[7]  + 0xf6bb4b60, 16);
+  md5_step (F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
+  md5_step (F3, a, b, c, d, in[13] + 0x289b7ec6,  4);
+  md5_step (F3, d, a, b, c, in[0]  + 0xeaa127fa, 11);
+  md5_step (F3, c, d, a, b, in[3]  + 0xd4ef3085, 16);
+  md5_step (F3, b, c, d, a, in[6]  + 0x04881d05, 23);
+  md5_step (F3, a, b, c, d, in[9]  + 0xd9d4d039,  4);
+  md5_step (F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
+  md5_step (F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
+  md5_step (F3, b, c, d, a, in[2]  + 0xc4ac5665, 23);
+
+  md5_step (F4, a, b, c, d, in[0]  + 0xf4292244,  6);
+  md5_step (F4, d, a, b, c, in[7]  + 0x432aff97, 10);
+  md5_step (F4, c, d, a, b, in[14] + 0xab9423a7, 15);
+  md5_step (F4, b, c, d, a, in[5]  + 0xfc93a039, 21);
+  md5_step (F4, a, b, c, d, in[12] + 0x655b59c3,  6);
+  md5_step (F4, d, a, b, c, in[3]  + 0x8f0ccc92, 10);
+  md5_step (F4, c, d, a, b, in[10] + 0xffeff47d, 15);
+  md5_step (F4, b, c, d, a, in[1]  + 0x85845dd1, 21);
+  md5_step (F4, a, b, c, d, in[8]  + 0x6fa87e4f,  6);
+  md5_step (F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
+  md5_step (F4, c, d, a, b, in[6]  + 0xa3014314, 15);
+  md5_step (F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
+  md5_step (F4, a, b, c, d, in[4]  + 0xf7537e82,  6);
+  md5_step (F4, d, a, b, c, in[11] + 0xbd3af235, 10);
+  md5_step (F4, c, d, a, b, in[2]  + 0x2ad7d2bb, 15);
+  md5_step (F4, b, c, d, a, in[9]  + 0xeb86d391, 21);
+
+  buf[0] += a;
+  buf[1] += b;
+  buf[2] += c;
+  buf[3] += d;
+
+#undef F1
+#undef F2
+#undef F3
+#undef F4
+#undef md5_step
+}
+
+static void
+md5_sum_update (Md5sum       *md5,
+                const guchar *data,
+                gsize         length)
+{
+  guint32 bit;
+
+  bit = md5->bits[0];
+  md5->bits[0] = bit + ((guint32) length << 3);
+
+  /* carry from low to high */
+  if (md5->bits[0] < bit)
+    md5->bits[1] += 1;
+
+  md5->bits[1] += length >> 29;
+
+  /* bytes already in Md5sum->data */
+  bit = (bit >> 3) & 0x3f;
+
+  /* handle any leading odd-sized chunks */
+  if (bit)
+    {
+      guchar *p = (guchar *) md5->data + bit;
+
+      bit = MD5_DATASIZE - bit;
+      if (length < MD5_DATASIZE)
+        {
+          memcpy (p, data, bit);
+          return;
+        }
+
+      memcpy (p, data, bit);
+      
+      md5_byte_reverse (md5->data, 16);
+      md5_transform (md5->buf, (guint32 *) md5->data);
+
+      data += bit;
+      length -= bit;
+    }
+
+  /* process data in 64-byte chunks */
+  while (length >= MD5_DATASIZE)
+    {
+      memcpy (md5->data, data, MD5_DATASIZE);
+      
+      md5_byte_reverse (md5->data, 16);
+      md5_transform (md5->buf, (guint32 *) md5->data);
+
+      data += MD5_DATASIZE;
+      length -= MD5_DATASIZE;
+    }
+
+  /* handle any remaining bytes of data */
+  memcpy (md5->data, data, length);
+}
+
+/* closes a checksum */
+static void
+md5_sum_close (Md5sum *md5)
+{
+  guint count;
+  guchar *p;
+
+  /* Compute number of bytes mod 64 */
+  count = (md5->bits[0] >> 3) & 0x3F;
+
+  /* Set the first char of padding to 0x80.
+   * This is safe since there is always at least one byte free
+   */
+  p = md5->data + count;
+  *p++ = 0x80;
+
+  /* Bytes of padding needed to make 64 bytes */
+  count = MD5_DATASIZE - 1 - count;
+
+  /* Pad out to 56 mod 64 */
+  if (count < 8)
+    {
+      /* Two lots of padding:  Pad the first block to 64 bytes */
+      memset (p, 0, count);
+      
+      md5_byte_reverse (md5->data, 16);
+      md5_transform (md5->buf, (guint32 *) md5->data);
+
+      /* Now fill the next block with 56 bytes */
+      memset (md5->data, 0, MD5_DATASIZE - 8);
+    }
+  else
+    {
+      /* Pad block to 56 bytes */
+      memset (p, 0, count - 8);
+    }
+
+  md5_byte_reverse (md5->data, 14);
+
+  /* Append length in bits and transform */
+  ((guint32 *) md5->data)[14] = md5->bits[0];
+  ((guint32 *) md5->data)[15] = md5->bits[1];
+
+  md5_transform (md5->buf, (guint32 *) md5->data);
+  md5_byte_reverse ((guchar *) md5->buf, 4);
+  
+  memcpy (md5->digest, md5->buf, 16);
+
+  /* Reset buffers in case they contains sensitive data */
+  memset (md5->buf, 0, sizeof (md5->buf));
+  memset (md5->data, 0, sizeof (md5->data));
+}
+
+static gchar *
+md5_sum_to_string (Md5sum *md5)
+{
+  return digest_to_string (md5->digest, MD5_DIGEST_LEN);
+}
+
+static void
+md5_sum_digest (Md5sum *md5,
+                guint8 *digest)
+{
+  gint i;
+
+  for (i = 0; i < MD5_DIGEST_LEN; i++)
+    digest[i] = md5->digest[i];
+}
+
+/*
+ * SHA-1 Checksum
+ */
+
+/* The following implementation comes from D-Bus dbus-sha.c. I've changed
+ * it to use GLib types and to work more like the MD5 implementation above.
+ * I left the comments to have an history of this code.
+ *      -- Emmanuele Bassi, ebassi@gnome.org
+ */
+
+/* The following comments have the history of where this code
+ * comes from. I actually copied it from GNet in GNOME CVS.
+ * - hp@redhat.com
+ */
+
+/*
+ *  sha.h : Implementation of the Secure Hash Algorithm
+ *
+ * Part of the Python Cryptography Toolkit, version 1.0.0
+ *
+ * Copyright (C) 1995, A.M. Kuchling
+ *
+ * Distribute and use freely; there are no restrictions on further
+ * dissemination and usage except those imposed by the laws of your
+ * country of residence.
+ *
+ */
+
+/* SHA: NIST's Secure Hash Algorithm */
+
+/* Based on SHA code originally posted to sci.crypt by Peter Gutmann
+   in message <30ajo5$oe8@ccu2.auckland.ac.nz>.
+   Modified to test for endianness on creation of SHA objects by AMK.
+   Also, the original specification of SHA was found to have a weakness
+   by NSA/NIST.  This code implements the fixed version of SHA.
+*/
+
+/* Here's the first paragraph of Peter Gutmann's posting:
+
+The following is my SHA (FIPS 180) code updated to allow use of the "fixed"
+SHA, thanks to Jim Gillogly and an anonymous contributor for the information on
+what's changed in the new version.  The fix is a simple change which involves
+adding a single rotate in the initial expansion function.  It is unknown
+whether this is an optimal solution to the problem which was discovered in the
+SHA or whether it's simply a bandaid which fixes the problem with a minimum of
+effort (for example the reengineering of a great many Capstone chips).
+*/
+
+static void
+sha1_sum_init (Sha1sum *sha1)
+{
+  /* initialize constants */
+  sha1->buf[0] = 0x67452301L;
+  sha1->buf[1] = 0xEFCDAB89L;
+  sha1->buf[2] = 0x98BADCFEL;
+  sha1->buf[3] = 0x10325476L;
+  sha1->buf[4] = 0xC3D2E1F0L;
+
+  /* initialize bits */
+  sha1->bits[0] = sha1->bits[1] = 0;
+}
+
+/* The SHA f()-functions. */
+
+#define f1(x,y,z)       (z ^ (x & (y ^ z)))             /* Rounds  0-19 */
+#define f2(x,y,z)       (x ^ y ^ z)                     /* Rounds 20-39 */
+#define f3(x,y,z)       (( x & y) | (z & (x | y)))      /* Rounds 40-59 */
+#define f4(x,y,z)       (x ^ y ^ z)                     /* Rounds 60-79 */
+
+/* The SHA Mysterious Constants */
+#define K1  0x5A827999L                                 /* Rounds  0-19 */
+#define K2  0x6ED9EBA1L                                 /* Rounds 20-39 */
+#define K3  0x8F1BBCDCL                                 /* Rounds 40-59 */
+#define K4  0xCA62C1D6L                                 /* Rounds 60-79 */
+
+/* 32-bit rotate left - kludged with shifts */
+#define ROTL(n,X) (((X) << n ) | ((X) >> (32 - n)))
+
+/* The initial expanding function.  The hash function is defined over an
+   80-word expanded input array W, where the first 16 are copies of the input
+   data, and the remaining 64 are defined by
+
+        W[ i ] = W[ i - 16 ] ^ W[ i - 14 ] ^ W[ i - 8 ] ^ W[ i - 3 ]
+
+   This implementation generates these values on the fly in a circular
+   buffer - thanks to Colin Plumb, colin@nyx10.cs.du.edu for this
+   optimization.
+
+   The updated SHA changes the expanding function by adding a rotate of 1
+   bit.  Thanks to Jim Gillogly, jim@rand.org, and an anonymous contributor
+   for this information */
+
+#define expand(W,i) (W[ i & 15 ] = ROTL (1, (W[ i       & 15] ^ \
+                                             W[(i - 14) & 15] ^ \
+                                             W[(i -  8) & 15] ^ \
+                                             W[(i -  3) & 15])))
+
+
+/* The prototype SHA sub-round.  The fundamental sub-round is:
+
+        a' = e + ROTL( 5, a ) + f( b, c, d ) + k + data;
+        b' = a;
+        c' = ROTL( 30, b );
+        d' = c;
+        e' = d;
+
+   but this is implemented by unrolling the loop 5 times and renaming the
+   variables ( e, a, b, c, d ) = ( a', b', c', d', e' ) each iteration.
+   This code is then replicated 20 times for each of the 4 functions, using
+   the next 20 values from the W[] array each time */
+
+#define subRound(a, b, c, d, e, f, k, data) \
+   (e += ROTL (5, a) + f(b, c, d) + k + data, b = ROTL (30, b))
+
+static void
+sha1_transform (guint32  buf[5],
+                guint32  in[16])
+{
+  guint32 A, B, C, D, E;
+
+  A = buf[0];
+  B = buf[1];
+  C = buf[2];
+  D = buf[3];
+  E = buf[4];
+
+  /* Heavy mangling, in 4 sub-rounds of 20 interations each. */
+  subRound (A, B, C, D, E, f1, K1, in[0]);
+  subRound (E, A, B, C, D, f1, K1, in[1]);
+  subRound (D, E, A, B, C, f1, K1, in[2]);
+  subRound (C, D, E, A, B, f1, K1, in[3]);
+  subRound (B, C, D, E, A, f1, K1, in[4]);
+  subRound (A, B, C, D, E, f1, K1, in[5]);
+  subRound (E, A, B, C, D, f1, K1, in[6]);
+  subRound (D, E, A, B, C, f1, K1, in[7]);
+  subRound (C, D, E, A, B, f1, K1, in[8]);
+  subRound (B, C, D, E, A, f1, K1, in[9]);
+  subRound (A, B, C, D, E, f1, K1, in[10]);
+  subRound (E, A, B, C, D, f1, K1, in[11]);
+  subRound (D, E, A, B, C, f1, K1, in[12]);
+  subRound (C, D, E, A, B, f1, K1, in[13]);
+  subRound (B, C, D, E, A, f1, K1, in[14]);
+  subRound (A, B, C, D, E, f1, K1, in[15]);
+  subRound (E, A, B, C, D, f1, K1, expand (in, 16));
+  subRound (D, E, A, B, C, f1, K1, expand (in, 17));
+  subRound (C, D, E, A, B, f1, K1, expand (in, 18));
+  subRound (B, C, D, E, A, f1, K1, expand (in, 19));
+
+  subRound (A, B, C, D, E, f2, K2, expand (in, 20));
+  subRound (E, A, B, C, D, f2, K2, expand (in, 21));
+  subRound (D, E, A, B, C, f2, K2, expand (in, 22));
+  subRound (C, D, E, A, B, f2, K2, expand (in, 23));
+  subRound (B, C, D, E, A, f2, K2, expand (in, 24));
+  subRound (A, B, C, D, E, f2, K2, expand (in, 25));
+  subRound (E, A, B, C, D, f2, K2, expand (in, 26));
+  subRound (D, E, A, B, C, f2, K2, expand (in, 27));
+  subRound (C, D, E, A, B, f2, K2, expand (in, 28));
+  subRound (B, C, D, E, A, f2, K2, expand (in, 29));
+  subRound (A, B, C, D, E, f2, K2, expand (in, 30));
+  subRound (E, A, B, C, D, f2, K2, expand (in, 31));
+  subRound (D, E, A, B, C, f2, K2, expand (in, 32));
+  subRound (C, D, E, A, B, f2, K2, expand (in, 33));
+  subRound (B, C, D, E, A, f2, K2, expand (in, 34));
+  subRound (A, B, C, D, E, f2, K2, expand (in, 35));
+  subRound (E, A, B, C, D, f2, K2, expand (in, 36));
+  subRound (D, E, A, B, C, f2, K2, expand (in, 37));
+  subRound (C, D, E, A, B, f2, K2, expand (in, 38));
+  subRound (B, C, D, E, A, f2, K2, expand (in, 39));
+  
+  subRound (A, B, C, D, E, f3, K3, expand (in, 40));
+  subRound (E, A, B, C, D, f3, K3, expand (in, 41));
+  subRound (D, E, A, B, C, f3, K3, expand (in, 42));
+  subRound (C, D, E, A, B, f3, K3, expand (in, 43));
+  subRound (B, C, D, E, A, f3, K3, expand (in, 44));
+  subRound (A, B, C, D, E, f3, K3, expand (in, 45));
+  subRound (E, A, B, C, D, f3, K3, expand (in, 46));
+  subRound (D, E, A, B, C, f3, K3, expand (in, 47));
+  subRound (C, D, E, A, B, f3, K3, expand (in, 48));
+  subRound (B, C, D, E, A, f3, K3, expand (in, 49));
+  subRound (A, B, C, D, E, f3, K3, expand (in, 50));
+  subRound (E, A, B, C, D, f3, K3, expand (in, 51));
+  subRound (D, E, A, B, C, f3, K3, expand (in, 52));
+  subRound (C, D, E, A, B, f3, K3, expand (in, 53));
+  subRound (B, C, D, E, A, f3, K3, expand (in, 54));
+  subRound (A, B, C, D, E, f3, K3, expand (in, 55));
+  subRound (E, A, B, C, D, f3, K3, expand (in, 56));
+  subRound (D, E, A, B, C, f3, K3, expand (in, 57));
+  subRound (C, D, E, A, B, f3, K3, expand (in, 58));
+  subRound (B, C, D, E, A, f3, K3, expand (in, 59));
+
+  subRound (A, B, C, D, E, f4, K4, expand (in, 60));
+  subRound (E, A, B, C, D, f4, K4, expand (in, 61));
+  subRound (D, E, A, B, C, f4, K4, expand (in, 62));
+  subRound (C, D, E, A, B, f4, K4, expand (in, 63));
+  subRound (B, C, D, E, A, f4, K4, expand (in, 64));
+  subRound (A, B, C, D, E, f4, K4, expand (in, 65));
+  subRound (E, A, B, C, D, f4, K4, expand (in, 66));
+  subRound (D, E, A, B, C, f4, K4, expand (in, 67));
+  subRound (C, D, E, A, B, f4, K4, expand (in, 68));
+  subRound (B, C, D, E, A, f4, K4, expand (in, 69));
+  subRound (A, B, C, D, E, f4, K4, expand (in, 70));
+  subRound (E, A, B, C, D, f4, K4, expand (in, 71));
+  subRound (D, E, A, B, C, f4, K4, expand (in, 72));
+  subRound (C, D, E, A, B, f4, K4, expand (in, 73));
+  subRound (B, C, D, E, A, f4, K4, expand (in, 74));
+  subRound (A, B, C, D, E, f4, K4, expand (in, 75));
+  subRound (E, A, B, C, D, f4, K4, expand (in, 76));
+  subRound (D, E, A, B, C, f4, K4, expand (in, 77));
+  subRound (C, D, E, A, B, f4, K4, expand (in, 78));
+  subRound (B, C, D, E, A, f4, K4, expand (in, 79));
+
+  /* Build message digest */
+  buf[0] += A;
+  buf[1] += B;
+  buf[2] += C;
+  buf[3] += D;
+  buf[4] += E;
+}
+
+#undef K1
+#undef K2
+#undef K3
+#undef K4
+#undef f1
+#undef f2
+#undef f3
+#undef f4
+#undef ROTL
+#undef expand
+#undef subRound
+
+static void
+sha1_sum_update (Sha1sum      *sha1,
+                 const guchar *buffer,
+                 gsize         count)
+{
+  guint32 tmp;
+  guint dataCount;
+
+  /* Update bitcount */
+  tmp = sha1->bits[0];
+  if ((sha1->bits[0] = tmp + ((guint32) count << 3) ) < tmp)
+    sha1->bits[1] += 1;             /* Carry from low to high */
+  sha1->bits[1] += count >> 29;
+
+  /* Get count of bytes already in data */
+  dataCount = (guint) (tmp >> 3) & 0x3F;
+
+  /* Handle any leading odd-sized chunks */
+  if (dataCount)
+    {
+      guchar *p = (guchar *) sha1->data + dataCount;
+
+      dataCount = SHA1_DATASIZE - dataCount;
+      if (count < dataCount)
+        {
+          memcpy (p, buffer, count);
+          return;
+        }
+      
+      memcpy (p, buffer, dataCount);
+
+      sha_byte_reverse (sha1->data, SHA1_DATASIZE);
+      sha1_transform (sha1->buf, sha1->data);
+
+      buffer += dataCount;
+      count -= dataCount;
+    }
+
+  /* Process data in SHA1_DATASIZE chunks */
+  while (count >= SHA1_DATASIZE)
+    {
+      memcpy (sha1->data, buffer, SHA1_DATASIZE);
+      
+      sha_byte_reverse (sha1->data, SHA1_DATASIZE);
+      sha1_transform (sha1->buf, sha1->data);
+
+      buffer += SHA1_DATASIZE;
+      count -= SHA1_DATASIZE;
+    }
+
+  /* Handle any remaining bytes of data. */
+  memcpy (sha1->data, buffer, count);
+}
+
+/* Final wrapup - pad to SHA_DATASIZE-byte boundary with the bit pattern
+   1 0* (64-bit count of bits processed, MSB-first) */
+static void
+sha1_sum_close (Sha1sum *sha1)
+{
+  gint count;
+  guchar *data_p;
+
+  /* Compute number of bytes mod 64 */
+  count = (gint) ((sha1->bits[0] >> 3) & 0x3f);
+
+  /* Set the first char of padding to 0x80.  This is safe since there is
+     always at least one byte free */
+  data_p = (guchar *) sha1->data + count;
+  *data_p++ = 0x80;
+
+  /* Bytes of padding needed to make 64 bytes */
+  count = SHA1_DATASIZE - 1 - count;
+
+  /* Pad out to 56 mod 64 */
+  if (count < 8)
+    {
+      /* Two lots of padding:  Pad the first block to 64 bytes */
+      memset (data_p, 0, count);
+
+      sha_byte_reverse (sha1->data, SHA1_DATASIZE);
+      sha1_transform (sha1->buf, sha1->data);
+
+      /* Now fill the next block with 56 bytes */
+      memset (sha1->data, 0, SHA1_DATASIZE - 8);
+    }
+  else
+    {
+      /* Pad block to 56 bytes */
+      memset (data_p, 0, count - 8);
+    }
+
+  /* Append length in bits and transform */
+  sha1->data[14] = sha1->bits[1];
+  sha1->data[15] = sha1->bits[0];
+
+  sha_byte_reverse (sha1->data, SHA1_DATASIZE - 8);
+  sha1_transform (sha1->buf, sha1->data);
+  sha_byte_reverse (sha1->buf, SHA1_DIGEST_LEN);
+
+  memcpy (sha1->digest, sha1->buf, SHA1_DIGEST_LEN);
+
+  /* Reset buffers in case they contains sensitive data */
+  memset (sha1->buf, 0, sizeof (sha1->buf));
+  memset (sha1->data, 0, sizeof (sha1->data));
+}
+
+static gchar *
+sha1_sum_to_string (Sha1sum *sha1)
+{
+  return digest_to_string (sha1->digest, SHA1_DIGEST_LEN);
+}
+
+static void
+sha1_sum_digest (Sha1sum *sha1,
+                 guint8  *digest)
+{
+  gint i;
+
+  for (i = 0; i < SHA1_DIGEST_LEN; i++)
+    digest[i] = sha1->digest[i];
+}
+
+/*
+ * SHA-256 Checksum
+ */
+
+/* adapted from the SHA256 implementation in gsk/src/hash/gskhash.c.
+ *
+ * Copyright (C) 2006 Dave Benson
+ * Released under the terms of the GNU Lesser General Public License
+ */
+
+static void
+sha256_sum_init (Sha256sum *sha256)
+{
+  sha256->buf[0] = 0x6a09e667;
+  sha256->buf[1] = 0xbb67ae85;
+  sha256->buf[2] = 0x3c6ef372;
+  sha256->buf[3] = 0xa54ff53a;
+  sha256->buf[4] = 0x510e527f;
+  sha256->buf[5] = 0x9b05688c;
+  sha256->buf[6] = 0x1f83d9ab;
+  sha256->buf[7] = 0x5be0cd19;
+
+  sha256->bits[0] = sha256->bits[1] = 0;
+}
+
+#define GET_UINT32(n,b,i)               G_STMT_START{   \
+    (n) = ((guint32) (b)[(i)    ] << 24)                \
+        | ((guint32) (b)[(i) + 1] << 16)                \
+        | ((guint32) (b)[(i) + 2] <<  8)                \
+        | ((guint32) (b)[(i) + 3]      ); } G_STMT_END
+
+#define PUT_UINT32(n,b,i)               G_STMT_START{   \
+    (b)[(i)    ] = (guint8) ((n) >> 24);                \
+    (b)[(i) + 1] = (guint8) ((n) >> 16);                \
+    (b)[(i) + 2] = (guint8) ((n) >>  8);                \
+    (b)[(i) + 3] = (guint8) ((n)      ); } G_STMT_END
+
+static void
+sha256_transform (guint32      buf[8],
+                  guint8 const data[64])
+{
+  guint32 temp1, temp2, W[64];
+  guint32 A, B, C, D, E, F, G, H;
+
+  GET_UINT32 (W[0],  data,  0);
+  GET_UINT32 (W[1],  data,  4);
+  GET_UINT32 (W[2],  data,  8);
+  GET_UINT32 (W[3],  data, 12);
+  GET_UINT32 (W[4],  data, 16);
+  GET_UINT32 (W[5],  data, 20);
+  GET_UINT32 (W[6],  data, 24);
+  GET_UINT32 (W[7],  data, 28);
+  GET_UINT32 (W[8],  data, 32);
+  GET_UINT32 (W[9],  data, 36);
+  GET_UINT32 (W[10], data, 40);
+  GET_UINT32 (W[11], data, 44);
+  GET_UINT32 (W[12], data, 48);
+  GET_UINT32 (W[13], data, 52);
+  GET_UINT32 (W[14], data, 56);
+  GET_UINT32 (W[15], data, 60);
+
+#define SHR(x,n)        ((x & 0xFFFFFFFF) >> n)
+#define ROTR(x,n)       (SHR (x,n) | (x << (32 - n)))
+
+#define S0(x) (ROTR (x, 7) ^ ROTR (x,18) ^  SHR (x, 3))
+#define S1(x) (ROTR (x,17) ^ ROTR (x,19) ^  SHR (x,10))
+#define S2(x) (ROTR (x, 2) ^ ROTR (x,13) ^ ROTR (x,22))
+#define S3(x) (ROTR (x, 6) ^ ROTR (x,11) ^ ROTR (x,25))
+
+#define F0(x,y,z) ((x & y) | (z & (x | y)))
+#define F1(x,y,z) (z ^ (x & (y ^ z)))
+
+#define R(t)    (W[t] = S1(W[t -  2]) + W[t -  7] + \
+                        S0(W[t - 15]) + W[t - 16])
+
+#define P(a,b,c,d,e,f,g,h,x,K)          G_STMT_START {  \
+        temp1 = h + S3(e) + F1(e,f,g) + K + x;          \
+        temp2 = S2(a) + F0(a,b,c);                      \
+        d += temp1; h = temp1 + temp2; } G_STMT_END
+
+  A = buf[0];
+  B = buf[1];
+  C = buf[2];
+  D = buf[3];
+  E = buf[4];
+  F = buf[5];
+  G = buf[6];
+  H = buf[7];
+
+  P (A, B, C, D, E, F, G, H, W[ 0], 0x428A2F98);
+  P (H, A, B, C, D, E, F, G, W[ 1], 0x71374491);
+  P (G, H, A, B, C, D, E, F, W[ 2], 0xB5C0FBCF);
+  P (F, G, H, A, B, C, D, E, W[ 3], 0xE9B5DBA5);
+  P (E, F, G, H, A, B, C, D, W[ 4], 0x3956C25B);
+  P (D, E, F, G, H, A, B, C, W[ 5], 0x59F111F1);
+  P (C, D, E, F, G, H, A, B, W[ 6], 0x923F82A4);
+  P (B, C, D, E, F, G, H, A, W[ 7], 0xAB1C5ED5);
+  P (A, B, C, D, E, F, G, H, W[ 8], 0xD807AA98);
+  P (H, A, B, C, D, E, F, G, W[ 9], 0x12835B01);
+  P (G, H, A, B, C, D, E, F, W[10], 0x243185BE);
+  P (F, G, H, A, B, C, D, E, W[11], 0x550C7DC3);
+  P (E, F, G, H, A, B, C, D, W[12], 0x72BE5D74);
+  P (D, E, F, G, H, A, B, C, W[13], 0x80DEB1FE);
+  P (C, D, E, F, G, H, A, B, W[14], 0x9BDC06A7);
+  P (B, C, D, E, F, G, H, A, W[15], 0xC19BF174);
+  P (A, B, C, D, E, F, G, H, R(16), 0xE49B69C1);
+  P (H, A, B, C, D, E, F, G, R(17), 0xEFBE4786);
+  P (G, H, A, B, C, D, E, F, R(18), 0x0FC19DC6);
+  P (F, G, H, A, B, C, D, E, R(19), 0x240CA1CC);
+  P (E, F, G, H, A, B, C, D, R(20), 0x2DE92C6F);
+  P (D, E, F, G, H, A, B, C, R(21), 0x4A7484AA);
+  P (C, D, E, F, G, H, A, B, R(22), 0x5CB0A9DC);
+  P (B, C, D, E, F, G, H, A, R(23), 0x76F988DA);
+  P (A, B, C, D, E, F, G, H, R(24), 0x983E5152);
+  P (H, A, B, C, D, E, F, G, R(25), 0xA831C66D);
+  P (G, H, A, B, C, D, E, F, R(26), 0xB00327C8);
+  P (F, G, H, A, B, C, D, E, R(27), 0xBF597FC7);
+  P (E, F, G, H, A, B, C, D, R(28), 0xC6E00BF3);
+  P (D, E, F, G, H, A, B, C, R(29), 0xD5A79147);
+  P (C, D, E, F, G, H, A, B, R(30), 0x06CA6351);
+  P (B, C, D, E, F, G, H, A, R(31), 0x14292967);
+  P (A, B, C, D, E, F, G, H, R(32), 0x27B70A85);
+  P (H, A, B, C, D, E, F, G, R(33), 0x2E1B2138);
+  P (G, H, A, B, C, D, E, F, R(34), 0x4D2C6DFC);
+  P (F, G, H, A, B, C, D, E, R(35), 0x53380D13);
+  P (E, F, G, H, A, B, C, D, R(36), 0x650A7354);
+  P (D, E, F, G, H, A, B, C, R(37), 0x766A0ABB);
+  P (C, D, E, F, G, H, A, B, R(38), 0x81C2C92E);
+  P (B, C, D, E, F, G, H, A, R(39), 0x92722C85);
+  P (A, B, C, D, E, F, G, H, R(40), 0xA2BFE8A1);
+  P (H, A, B, C, D, E, F, G, R(41), 0xA81A664B);
+  P (G, H, A, B, C, D, E, F, R(42), 0xC24B8B70);
+  P (F, G, H, A, B, C, D, E, R(43), 0xC76C51A3);
+  P (E, F, G, H, A, B, C, D, R(44), 0xD192E819);
+  P (D, E, F, G, H, A, B, C, R(45), 0xD6990624);
+  P (C, D, E, F, G, H, A, B, R(46), 0xF40E3585);
+  P (B, C, D, E, F, G, H, A, R(47), 0x106AA070);
+  P (A, B, C, D, E, F, G, H, R(48), 0x19A4C116);
+  P (H, A, B, C, D, E, F, G, R(49), 0x1E376C08);
+  P (G, H, A, B, C, D, E, F, R(50), 0x2748774C);
+  P (F, G, H, A, B, C, D, E, R(51), 0x34B0BCB5);
+  P (E, F, G, H, A, B, C, D, R(52), 0x391C0CB3);
+  P (D, E, F, G, H, A, B, C, R(53), 0x4ED8AA4A);
+  P (C, D, E, F, G, H, A, B, R(54), 0x5B9CCA4F);
+  P (B, C, D, E, F, G, H, A, R(55), 0x682E6FF3);
+  P (A, B, C, D, E, F, G, H, R(56), 0x748F82EE);
+  P (H, A, B, C, D, E, F, G, R(57), 0x78A5636F);
+  P (G, H, A, B, C, D, E, F, R(58), 0x84C87814);
+  P (F, G, H, A, B, C, D, E, R(59), 0x8CC70208);
+  P (E, F, G, H, A, B, C, D, R(60), 0x90BEFFFA);
+  P (D, E, F, G, H, A, B, C, R(61), 0xA4506CEB);
+  P (C, D, E, F, G, H, A, B, R(62), 0xBEF9A3F7);
+  P (B, C, D, E, F, G, H, A, R(63), 0xC67178F2);
+
+#undef SHR
+#undef ROTR
+#undef S0
+#undef S1
+#undef S2
+#undef S3
+#undef F0
+#undef F1
+#undef R
+#undef P
+
+  buf[0] += A;
+  buf[1] += B;
+  buf[2] += C;
+  buf[3] += D;
+  buf[4] += E;
+  buf[5] += F;
+  buf[6] += G;
+  buf[7] += H;
+}
+
+static void
+sha256_sum_update (Sha256sum    *sha256,
+                   const guchar *buffer,
+                   gsize         length)
+{
+  guint32 left, fill;
+  const guint8 *input = buffer;
+
+  if (length == 0)
+    return;
+
+  left = sha256->bits[0] & 0x3F;
+  fill = 64 - left;
+
+  sha256->bits[0] += length;
+  sha256->bits[0] &= 0xFFFFFFFF;
+
+  if (sha256->bits[0] < length)
+      sha256->bits[1]++;
+
+  if (left > 0 && length >= fill)
+    {
+      memcpy ((sha256->data + left), input, fill);
+
+      sha256_transform (sha256->buf, sha256->data);
+      length -= fill;
+      input += fill;
+
+      left = 0;
+    }
+
+  while (length >= SHA256_DATASIZE)
+    {
+      sha256_transform (sha256->buf, input);
+
+      length -= 64;
+      input += 64;
+    }
+
+  if (length)
+    memcpy (sha256->data + left, input, length);
+}
+
+static guint8 sha256_padding[64] =
+{
+ 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+};
+
+static void
+sha256_sum_close (Sha256sum *sha256)
+{
+  guint32 last, padn;
+  guint32 high, low;
+  guint8 msglen[8];
+
+  high = (sha256->bits[0] >> 29)
+       | (sha256->bits[1] <<  3);
+  low  = (sha256->bits[0] <<  3);
+
+  PUT_UINT32 (high, msglen, 0);
+  PUT_UINT32 (low, msglen, 4);
+
+  last = sha256->bits[0] & 0x3F;
+  padn = (last < 56) ? (56 - last) : (120 - last);
+
+  sha256_sum_update (sha256, sha256_padding, padn);
+  sha256_sum_update (sha256, msglen, 8);
+
+  PUT_UINT32 (sha256->buf[0], sha256->digest,  0);
+  PUT_UINT32 (sha256->buf[1], sha256->digest,  4);
+  PUT_UINT32 (sha256->buf[2], sha256->digest,  8);
+  PUT_UINT32 (sha256->buf[3], sha256->digest, 12);
+  PUT_UINT32 (sha256->buf[4], sha256->digest, 16);
+  PUT_UINT32 (sha256->buf[5], sha256->digest, 20);
+  PUT_UINT32 (sha256->buf[6], sha256->digest, 24);
+  PUT_UINT32 (sha256->buf[7], sha256->digest, 28);
+}
+
+#undef PUT_UINT32
+#undef GET_UINT32
+
+static gchar *
+sha256_sum_to_string (Sha256sum *sha256)
+{
+  return digest_to_string (sha256->digest, SHA256_DIGEST_LEN);
+}
+
+static void
+sha256_sum_digest (Sha256sum *sha256,
+                   guint8    *digest)
+{
+  gint i;
+
+  for (i = 0; i < SHA256_DIGEST_LEN; i++)
+    digest[i] = sha256->digest[i];
+}
+
+
+/*
+ * Public API
+ */
+
+/**
+ * g_checksum_new:
+ * @checksum_type: the desired type of checksum
+ *
+ * Creates a new #GChecksum, using the checksum algorithm @type. 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.
+ *
+ * Return value: the newly created #GChecksum. Use g_checksum_free() to
+ *   free the memory allocated by it.
+ *
+ * Since: 2.16
+ */
+GChecksum *
+g_checksum_new (GChecksumType checksum_type)
+{
+  GChecksum *checksum;
+
+  g_return_val_if_fail (IS_VALID_TYPE (checksum_type), NULL);
+
+  checksum = g_slice_new (GChecksum);
+  checksum->type = checksum_type;
+
+  switch (checksum_type)
+    {
+    case G_CHECKSUM_MD5:
+      md5_sum_init (&(checksum->sum.md5));
+      break;
+    case G_CHECKSUM_SHA1:
+      sha1_sum_init (&(checksum->sum.sha1));
+      break;
+    case G_CHECKSUM_SHA256:
+      sha256_sum_init (&(checksum->sum.sha256));
+      break;
+    default:
+      g_assert_not_reached ();
+      break;
+    }
+
+  return checksum;
+}
+
+/**
+ * g_checksum_copy:
+ * @checksum: the #GChecksum to copy
+ *
+ * Copies a #GChecksum. If @checksum has been closed, by calling
+ * g_checksum_get_string() or g_checksum_get_digest(), the copied
+ * checksum will still be open, and g_checksum_update() will work
+ * on the copy.
+ *
+ * Return value: the copy of the passed #GChecksum. Use g_checksum_free()
+ *   when finished using it.
+ *
+ * Since: 2.16
+ */
+GChecksum *
+g_checksum_copy (const GChecksum *checksum)
+{
+  GChecksum *copy;
+
+  g_return_val_if_fail (checksum != NULL, NULL);
+
+  copy = g_slice_new (GChecksum);
+  *copy = *checksum;
+
+  copy->digest_str = NULL;
+  
+  return copy;
+}
+
+/**
+ * g_checksum_free:
+ * @checksum: a #GChecksum
+ *
+ * Frees the memory allocated for @checksum.
+ *
+ * Since: 2.16
+ */
+void
+g_checksum_free (GChecksum *checksum)
+{
+  if (G_LIKELY (checksum))
+    {
+      g_free (checksum->digest_str);
+
+      g_slice_free (GChecksum, checksum);
+    }
+}
+
+/**
+ * g_checksum_update:
+ * @checksum: a #GChecksum
+ * @data: buffer used to compute the checksum
+ * @length: size of the buffer
+ *
+ * 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.
+ *
+ * Since: 2.16
+ */
+void
+g_checksum_update (GChecksum    *checksum,
+                   const guchar *data,
+                   gsize         length)
+{
+  g_return_if_fail (checksum != NULL);
+  g_return_if_fail (data != NULL);
+  g_return_if_fail (length > 1);
+
+  if (checksum->digest_str)
+    {
+      g_warning ("The checksum `%s' has been closed and cannot be updated "
+                 "anymore.",
+                 checksum->digest_str);
+      return;
+    }
+
+  switch (checksum->type)
+    {
+    case G_CHECKSUM_MD5:
+      md5_sum_update (&(checksum->sum.md5), data, length);
+      break;
+    case G_CHECKSUM_SHA1:
+      sha1_sum_update (&(checksum->sum.sha1), data, length);
+      break;
+    case G_CHECKSUM_SHA256:
+      sha256_sum_update (&(checksum->sum.sha256), data, length);
+      break;
+    default:
+      g_assert_not_reached ();
+      break;
+    }
+}
+
+/**
+ * g_checksum_get_string:
+ * @checksum: a #GChecksum
+ *
+ * Gets the digest as an hexadecimal string.
+ *
+ * Once this function has been called the #GChecksum can no longer be
+ * updated with g_checksum_update().
+ *
+ * Return value: 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_CONST_RETURN gchar *
+g_checksum_get_string (GChecksum *checksum)
+{
+  gchar *str = NULL;
+
+  g_return_val_if_fail (checksum != NULL, NULL);
+  
+  if (checksum->digest_str)
+    return checksum->digest_str;
+
+  switch (checksum->type)
+    {
+    case G_CHECKSUM_MD5:
+      md5_sum_close (&(checksum->sum.md5));
+      str = md5_sum_to_string (&(checksum->sum.md5));
+      break;
+    case G_CHECKSUM_SHA1:
+      sha1_sum_close (&(checksum->sum.sha1));
+      str = sha1_sum_to_string (&(checksum->sum.sha1));
+      break;
+    case G_CHECKSUM_SHA256:
+      sha256_sum_close (&(checksum->sum.sha256));
+      str = sha256_sum_to_string (&(checksum->sum.sha256));
+      break;
+    default:
+      g_assert_not_reached ();
+      break;
+    }
+
+  checksum->digest_str = str;
+
+  return checksum->digest_str;
+}
+
+/**
+ * g_checksum_get_digest:
+ * @checksum: a #GChecksum
+ * @digest: return location for the digest
+ * @digest_len: return location for the length of the digest, or %NULL
+ *
+ * Gets the digest from @checksum as a raw binary vector and places it
+ * into @digest. 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().
+ *
+ * Since: 2.16
+ */
+void
+g_checksum_get_digest (GChecksum  *checksum,
+                       guint8    **digest,
+                       gsize      *digest_len)
+{
+  gboolean checksum_open = FALSE;
+  guint8 *new;
+  gchar *str = NULL;
+  gsize len = 0;
+
+  g_return_if_fail (checksum != NULL);
+  g_return_if_fail (digest == NULL || *digest == NULL);
+
+  checksum_open = !!(checksum->digest_str == NULL);
+
+  switch (checksum->type)
+    {
+    case G_CHECKSUM_MD5:
+      if (checksum_open)
+        {
+          md5_sum_close (&(checksum->sum.md5));
+          str = md5_sum_to_string (&(checksum->sum.md5));
+        }
+      new = g_new (guint8, MD5_DIGEST_LEN);
+      md5_sum_digest (&(checksum->sum.md5), new);
+      len = MD5_DIGEST_LEN;
+      break;
+    case G_CHECKSUM_SHA1:
+      if (checksum_open)
+        {
+          sha1_sum_close (&(checksum->sum.sha1));
+          str = sha1_sum_to_string (&(checksum->sum.sha1));
+        }
+      new = g_new (guint8, SHA1_DIGEST_LEN);
+      sha1_sum_digest (&(checksum->sum.sha1), new);
+      len = SHA1_DIGEST_LEN;
+      break;
+    case G_CHECKSUM_SHA256:
+      if (checksum_open)
+        {
+          sha256_sum_close (&(checksum->sum.sha256));
+          str = sha256_sum_to_string (&(checksum->sum.sha256));
+        }
+      new = g_new (guint8, SHA256_DIGEST_LEN);
+      sha256_sum_digest (&(checksum->sum.sha256), new);
+      len = SHA256_DIGEST_LEN;
+      break;
+    default:
+      new = NULL;
+      len = 0;
+      g_assert_not_reached ();
+      break;
+    }
+
+  if (str)
+    checksum->digest_str = str;
+
+  if (digest == NULL)
+    g_free (new);
+  else
+    {
+      if (*digest == NULL)
+        *digest = new;
+      else
+        g_warning ("Digest set on top of a previous digest or uninitialized "
+                   "memory\n"
+                   "This indicates a bug in someone's code. You must ensure "
+                   "a digest is NULL before it's set.");
+    }
+
+  if (digest_len)
+    *digest_len = len;
+}
+
+/**
+ * g_compute_checksum_for_data:
+ * @checksum_type: a #GChecksumType
+ * @data: binary blob to compute the digest of
+ * @length: length of @data
+ *
+ * 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().
+ *
+ * Return value: 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
+ */
+gchar *
+g_compute_checksum_for_data (GChecksumType  checksum_type,
+                             const guchar  *data,
+                             gsize          length)
+{
+  GChecksum *checksum;
+  gchar *retval;
+
+  g_return_val_if_fail (data != NULL, NULL);
+  g_return_val_if_fail (length > 1, NULL);
+
+  checksum = g_checksum_new (checksum_type);
+  if (!checksum)
+    return NULL;
+
+  g_checksum_update (checksum, data, length);
+  retval = g_strdup (g_checksum_get_string (checksum));
+  g_checksum_free (checksum);
+
+  return retval;
+}
+
+/**
+ * g_compute_checksum_for_string:
+ * @checksum_type: a #GChecksumType
+ * @str: the string to compute the checksum of
+ * @length: the length of the string, or -1
+ *
+ * Computes the checksum of a string.
+ *
+ * Return value: the checksum as a hexadecimal string. The returned string
+ *   should be freed with g_free() when done using it.
+ *
+ * Since: 2.16
+ */
+gchar *
+g_compute_checksum_for_string (GChecksumType  checksum_type,
+                               const gchar   *str,
+                               gsize          length)
+{
+  g_return_val_if_fail (str != NULL, NULL);
+
+  if (length < 0)
+    length = strlen (str);
+
+  return g_compute_checksum_for_data (checksum_type, (const guchar *) str, length);
+}
+
+#define __G_CHECKSUM_C__
+#include "galiasdef.c"
diff --git a/glib/gchecksum.h b/glib/gchecksum.h
new file mode 100644
index 0000000..4fbb984
--- /dev/null
+++ b/glib/gchecksum.h
@@ -0,0 +1,56 @@
+/* gchecksum.h - data hashing functions
+ *
+ * Copyright (C) 2007  Emmanuele Bassi  <ebassi@gnome.org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifndef __G_CHECKSUM_H__
+#define __G_CHECKSUM_H__
+
+#include <glib/gtypes.h>
+
+G_BEGIN_DECLS
+
+typedef enum {
+  G_CHECKSUM_MD5,
+  G_CHECKSUM_SHA1,
+  G_CHECKSUM_SHA256
+} GChecksumType;
+
+typedef struct _GChecksum       GChecksum;
+
+GChecksum *           g_checksum_new        (GChecksumType     checksum_type);
+GChecksum *           g_checksum_copy       (const GChecksum  *checksum);
+void                  g_checksum_free       (GChecksum        *checksum);
+void                  g_checksum_update     (GChecksum        *checksum,
+                                             const guchar     *data,
+                                             gsize             length);
+G_CONST_RETURN gchar *g_checksum_get_string (GChecksum        *checksum);
+void                  g_checksum_get_digest (GChecksum        *checksum,
+                                             guint8          **digest,
+                                             gsize            *digest_len);
+
+gchar *g_compute_checksum_for_data   (GChecksumType  checksum_type,
+                                      const guchar  *data,
+                                      gsize          length);
+gchar *g_compute_checksum_for_string (GChecksumType  checksum_type,
+                                      const gchar   *str,
+                                      gsize          length);
+
+G_END_DECLS
+
+#endif /* __G_CHECKSUM_H__ */
diff --git a/glib/glib.h b/glib/glib.h
index b45d3b7..6be58a5 100644
--- a/glib/glib.h
+++ b/glib/glib.h
@@ -35,6 +35,7 @@
 #include <glib/gbase64.h>
 #include <glib/gbookmarkfile.h>
 #include <glib/gcache.h>
+#include <glib/gchecksum.h>
 #include <glib/gcompletion.h>
 #include <glib/gconvert.h>
 #include <glib/gdataset.h>
diff --git a/glib/glib.symbols b/glib/glib.symbols
index ac0907f..4405d5f 100644
--- a/glib/glib.symbols
+++ b/glib/glib.symbols
@@ -171,6 +171,19 @@ g_cache_value_foreach
 #endif
 #endif
 
+#if IN_HEADER(__G_CHECKSUM_H__)
+#if IN_FILE(__G_CHECKSUM_C__)
+g_checksum_new
+g_checksum_copy
+g_checksum_free
+g_checksum_update
+g_checksum_get_string
+g_checksum_get_digest
+g_compute_checksum_for_data
+g_compute_checksum_for_string
+#endif
+#endif
+
 #if IN_HEADER(__G_COMPLETION_H__)
 #if IN_FILE(__G_COMPLETION_C__)
 g_completion_add_items
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 5bed3e4..62734a7 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -74,6 +74,7 @@ test_programs =					\
 	base64-test				\
 	bit-test				\
 	$(CXX_TEST)				\
+	checksum-test				\
 	child-test				\
 	completion-test				\
 	convert-test				\
@@ -145,6 +146,7 @@ array_test_LDADD = $(progs_ldadd)
 base64_test_LDADD = $(progs_ldadd)
 bit_test_LDADD = $(progs_ldadd)
 bookmarkfile_test_LDADD = $(progs_ldadd)
+checksum_test_LDADD = $(progs_ldadd)
 child_test_LDADD = $(thread_ldadd)
 completion_test_LDADD = $(progs_ldadd)
 convert_test_LDADD = $(progs_ldadd)
diff --git a/tests/checksum-test.c b/tests/checksum-test.c
new file mode 100644
index 0000000..1313821
--- /dev/null
+++ b/tests/checksum-test.c
@@ -0,0 +1,380 @@
+#include "config.h"
+
+#include <glib.h>
+#include <string.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#include <stdlib.h>
+
+#define FIXED_STR               "The quick brown fox jumps over the lazy dog"
+#define FIXED_LEN               (strlen (FIXED_STR))
+
+#define MD5_FIXED_SUM           "9e107d9d372bb6826bd81d3542a419d6"
+#define SHA1_FIXED_SUM          "2fd4e1c67a2d28fced849ee1bb76e7391b93eb12"
+#define SHA256_FIXED_SUM        "d7a8fbb307d7809469ca9abcb0082e4f8d5651e46d3cdb762d02d0bf37c9e592"
+
+#define BLOCK_SIZE      256
+
+static gchar *
+digest_to_string (guint8 *digest,
+                  gsize   digest_len)
+{
+  static const gchar hex_digits[] = "0123456789abcdef";
+  gint len = digest_len * 2;
+  gchar *retval;
+  gint i;
+
+  retval = g_new (gchar, len + 1);
+
+  for (i = 0; i < digest_len; i++)
+    {
+      retval[2 * i] = hex_digits[digest[i] >> 4];
+      retval[2 * i + 1] = hex_digits[digest[i] & 0xf];
+    }
+
+  retval[len] = 0;
+
+  return retval;
+}
+
+static void
+test_sha256 (const gchar *filename)
+{
+  GChecksum *checksum0, *checksum1, *checksum2;
+  gchar *data;
+  guchar *p;
+  gsize data_len;
+  guint8 *digest1, *digest2;
+  gsize len1, len2;
+  gchar *digest_str1, *digest_str2;
+
+  checksum0 = g_checksum_new (G_CHECKSUM_SHA256);
+  g_checksum_update (checksum0, (const guchar *) FIXED_STR, FIXED_LEN);
+  if (strcmp (g_checksum_get_string (checksum0), SHA256_FIXED_SUM) != 0)
+    {
+      g_print ("Invalid SHA1 checksum for `%s': %s (expecting: %s)\n",
+               FIXED_STR,
+               g_checksum_get_string (checksum0),
+               SHA256_FIXED_SUM);
+      exit (1);
+    }
+
+  g_checksum_free (checksum0);
+
+  checksum1 = g_checksum_new (G_CHECKSUM_SHA256);
+  checksum2 = g_checksum_new (G_CHECKSUM_SHA256);
+
+  if (!g_file_get_contents (filename, &data, &data_len, NULL))
+    {
+      g_print ("Could not load `%s' contents\n", filename);
+      exit (1);
+    }
+
+  g_checksum_update (checksum1, (const guchar *) data, data_len);
+
+  p = (guchar *) data;
+  do
+    {
+      if (data_len > BLOCK_SIZE)
+        {
+          g_checksum_update (checksum2, p, BLOCK_SIZE);
+          data_len -= BLOCK_SIZE;
+          p += BLOCK_SIZE;
+        }
+      else
+        {
+          g_checksum_update (checksum2, p, data_len);
+          break;
+        }
+    }
+  while (*p != '\0');
+ 
+  g_free (data);
+
+  digest1 = NULL;
+  g_checksum_get_digest (checksum1, &digest1, &len1);
+  if (!digest1)
+    {
+      g_print ("No SHA256 digest found for checksum1\n");
+      exit (1);
+    }
+
+  digest2 = NULL;
+  g_checksum_get_digest (checksum2, &digest2, &len2);
+  if (!digest2)
+    {
+      g_print ("No SHA256 digest found for checksum2\n");
+      exit (1);
+    }
+  
+  digest_str1 = digest_to_string (digest1, len1);
+  digest_str2 = digest_to_string (digest2, len2);
+
+  if (strcmp (digest_str1, digest_str2) != 0)
+    {
+      g_print ("Wrong SHA256 digest `%s' (expecting: %s)\n",
+               digest_str1,
+               digest_str2);
+      exit (1);
+    }
+
+  g_free (digest_str1);
+  g_free (digest_str2);
+  g_free (digest1);
+  g_free (digest2);
+
+  digest_str1 = g_strdup (g_checksum_get_string (checksum1));
+  digest_str2 = g_strdup (g_checksum_get_string (checksum2));
+
+  if (!digest_str1 || !digest_str2)
+    {
+      g_print ("No SHA256 digest string found\n");
+      exit (1);
+    }
+
+  if (strcmp (digest_str1, digest_str2) != 0)
+    {
+      g_print ("Wrong SHA256 digest string `%s' (expecting: %s)\n",
+               digest_str1,
+               digest_str2);
+      exit (1);
+    }
+
+  g_free (digest_str1);
+  g_free (digest_str2);
+
+  g_checksum_free (checksum1);
+  g_checksum_free (checksum2);
+}
+
+static void
+test_sha1 (const gchar *filename)
+{
+  GChecksum *checksum0, *checksum1, *checksum2;
+  gchar *data;
+  guchar *p;
+  gsize data_len;
+  guint8 *digest1, *digest2;
+  gsize len1, len2;
+  gchar *digest_str1, *digest_str2;
+
+  checksum0 = g_checksum_new (G_CHECKSUM_SHA1);
+  g_checksum_update (checksum0, (const guchar *) FIXED_STR, FIXED_LEN);
+  if (strcmp (g_checksum_get_string (checksum0), SHA1_FIXED_SUM) != 0)
+    {
+      g_print ("Invalid SHA1 checksum for `%s': %s (expecting: %s)\n",
+               FIXED_STR,
+               g_checksum_get_string (checksum0),
+               SHA1_FIXED_SUM);
+      exit (1);
+    }
+
+  g_checksum_free (checksum0);
+
+  checksum1 = g_checksum_new (G_CHECKSUM_SHA1);
+  checksum2 = g_checksum_new (G_CHECKSUM_SHA1);
+
+  if (!g_file_get_contents (filename, &data, &data_len, NULL))
+    {
+      g_print ("Could not load `%s' contents\n", filename);
+      exit (1);
+    }
+
+  g_checksum_update (checksum1, (const guchar *) data, data_len);
+
+  p = (guchar *) data;
+  do
+    {
+      if (data_len > BLOCK_SIZE)
+        {
+          g_checksum_update (checksum2, p, BLOCK_SIZE);
+          data_len -= BLOCK_SIZE;
+          p += BLOCK_SIZE;
+        }
+      else
+        {
+          g_checksum_update (checksum2, p, data_len);
+          break;
+        }
+    }
+  while (*p != '\0');
+ 
+  g_free (data);
+
+  digest1 = NULL;
+  g_checksum_get_digest (checksum1, &digest1, &len1);
+  if (!digest1)
+    {
+      g_print ("No SHA1 digest found for checksum1\n");
+      exit (1);
+    }
+
+  digest2 = NULL;
+  g_checksum_get_digest (checksum2, &digest2, &len2);
+  if (!digest2)
+    {
+      g_print ("No SHA1 digest found for checksum2\n");
+      exit (1);
+    }
+  
+  digest_str1 = digest_to_string (digest1, len1);
+  digest_str2 = digest_to_string (digest2, len2);
+
+  if (strcmp (digest_str1, digest_str2) != 0)
+    {
+      g_print ("Wrong SHA1 digest `%s' (expecting: %s)\n",
+               digest_str1,
+               digest_str2);
+      exit (1);
+    }
+
+  g_free (digest_str1);
+  g_free (digest_str2);
+  g_free (digest1);
+  g_free (digest2);
+
+  digest_str1 = g_strdup (g_checksum_get_string (checksum1));
+  digest_str2 = g_strdup (g_checksum_get_string (checksum2));
+
+  if (!digest_str1 || !digest_str2)
+    {
+      g_print ("No SHA1 digest string found\n");
+      exit (1);
+    }
+
+  if (strcmp (digest_str1, digest_str2) != 0)
+    {
+      g_print ("Wrong SHA1 digest string `%s' (expecting: %s)\n",
+               digest_str1,
+               digest_str2);
+      exit (1);
+    }
+
+  g_free (digest_str1);
+  g_free (digest_str2);
+
+  g_checksum_free (checksum1);
+  g_checksum_free (checksum2);
+}
+
+static void
+test_md5 (const gchar *filename)
+{
+  GChecksum *checksum0, *checksum1, *checksum2;
+  gchar *data;
+  guchar *p;
+  gsize data_len;
+  guint8 *digest1, *digest2;
+  gsize len1, len2;
+  gchar *digest_str1, *digest_str2;
+
+  checksum0 = g_checksum_new (G_CHECKSUM_MD5);
+  g_checksum_update (checksum0, (const guchar *) FIXED_STR, FIXED_LEN);
+  if (strcmp (g_checksum_get_string (checksum0), MD5_FIXED_SUM) != 0)
+    {
+      g_print ("Invalid MD5 checksum for `%s': %s (expecting: %s)\n",
+               FIXED_STR,
+               g_checksum_get_string (checksum0),
+               MD5_FIXED_SUM);
+      exit (1);
+
+    }
+
+  g_checksum_free (checksum0);
+
+  checksum1 = g_checksum_new (G_CHECKSUM_MD5);
+  checksum2 = g_checksum_new (G_CHECKSUM_MD5);
+
+  if (!g_file_get_contents (filename, &data, &data_len, NULL))
+    {
+      g_print ("Could not load `%s' contents\n", filename);
+      exit (1);
+    }
+
+  g_checksum_update (checksum1, (const guchar *) data, data_len);
+
+  digest1 = NULL;
+  g_checksum_get_digest (checksum1, &digest1, &len1);
+  if (!digest1)
+    {
+      g_print ("Unable to get MD5 digest from checksum1\n");
+      exit (1);
+    }
+
+  p = (guchar *) data;
+  do
+    {
+      if (data_len > BLOCK_SIZE)
+        {
+          g_checksum_update (checksum2, p, BLOCK_SIZE);
+          data_len -= BLOCK_SIZE;
+          p += BLOCK_SIZE;
+        }
+      else
+        {
+          g_checksum_update (checksum2, p, data_len);
+          break;
+        }
+    }
+  while (*p != '\0');
+ 
+  g_free (data);
+  
+  digest2 = NULL;
+  g_checksum_get_digest (checksum2, &digest2, &len2);
+  if (!digest2)
+    {
+      g_print ("Unable to get MD5 digest from checksum2\n");
+      exit (1);
+    }
+
+  digest_str1 = digest_to_string (digest1, len1);
+  digest_str2 = digest_to_string (digest2, len2);
+
+  if (strcmp (digest_str1, digest_str2) != 0)
+    {
+      g_print ("Wrong MD5 digest `%s' (expecting: %s)\n",
+               digest_str1,
+               digest_str2);
+      exit (1);
+    }
+
+  g_free (digest_str1);
+  g_free (digest_str2);
+  g_free (digest1);
+  g_free (digest2);
+
+  digest_str1 = g_strdup (g_checksum_get_string (checksum1));
+  digest_str2 = g_strdup (g_checksum_get_string (checksum2));
+
+  if (!digest_str1 || !digest_str2)
+    {
+      g_print ("No MD5 digest string found\n");
+      exit (1);
+    }
+
+  if (strcmp (digest_str1, digest_str2) != 0)
+    {
+      g_print ("Wrong MD5 digest string `%s' (expecting: %s)\n",
+               digest_str1,
+               digest_str2);
+      exit (1);
+    }
+
+  g_free (digest_str1);
+  g_free (digest_str2);
+
+  g_checksum_free (checksum1);
+  g_checksum_free (checksum2);
+}
+
+int
+main (int argc, char *argv[])
+{
+  test_md5 (__FILE__);
+  test_sha1 (__FILE__);
+  test_sha256 (__FILE__);
+
+  return EXIT_SUCCESS;
+}
