On Thu, 2008-08-07 at 11:08 +0200, Luka Napotnik wrote: > Hello. > > I have this small example where I create a GChecksum and apply some > data. The problem is when I request the digest, the program prints out > the following error: > > (process:8422): GLib-CRITICAL **: g_checksum_get_digest: assertion > `*digest_len >= len' failed > > My GChecksum code is: > ------------------------------------------------------------ > char data[] = "Hello, World"; > int len; > GChecksum *checksum; > guint8 *b_digest; > gsize b_digest_len; > > checksum = g_checksum_new(G_CHECKSUM_MD5); > len = strlen(data) + 1; > b_digest_len = len; > g_checksum_update(checksum, data, len); > g_checksum_get_digest(checksum, b_digest, &b_digest_len); > ------------------------------------------------------------ > > I initialize the digest len with the length of data. Am I doing > something wrong?
yes, you're not reading the documentation: @digest_len: The caller initializes it to the size of @buffer. After the call it contains the length of the digest. the buffer is a pointer to an array of bytes, since g_checksum_get_digest() doesn't handle the string you pass to g_checksum_update(). as GChecksum handles different hashing algorithms, the array size must be at least big enough to fit the actual size of the digest. the size of the digest for a particular checksum algorithm is obtained using: gsize digest_len = g_checksum_type_get_length (G_CHECKSUM_MD5); which can then be used to allocate an array of bytes: guint8 *digest = g_new (guint8, digest_len); and then you can get the digest: g_checksum_get_digest (checksum, digest, &digest_len); you then obviously need to free the digest when you're done using it: g_free (digest); this obviously implies you want the digest as a raw binary vector. if you want the hexadecimal version in string you're much better off using g_compute_checksum_for_string() instead. ciao, Emmanuele. -- Emmanuele Bassi, W: http://www.emmanuelebassi.net B: http://log.emmanuelebassi.net _______________________________________________ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
