1 files changed, 349 insertions, 0 deletions
diff --git a/plugins/checksum/checksum.c b/plugins/checksum/checksum.c
new file mode 100644
index 00000000..103a80ca
--- /dev/null
+++ b/plugins/checksum/checksum.c
@@ -0,0 +1,349 @@
+/* XChat-WDK
+ * Copyright (c) 2010-2011 Berke Viktor.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <malloc.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <openssl/sha.h>
+
+#include "xchat-plugin.h"
+
+#define BUFSIZE 32768
+#define DEFAULT_MAX_HASH_SIZE 268435456						/* default size is 256 MB */
+#define FILE_BUF_SIZE 512
+
+#ifndef snprintf
+#define snprintf _snprintf
+#endif
+#ifndef stat64
+#define stat64 _stat64
+#endif
+
+static xchat_plugin *ph;									/* plugin handle */
+static const char name[] = "Checksum";
+static const char desc[] = "Calculate checksum for DCC file transfers";
+static const char version[] = "2.0";
+static int config_fail;										/* variable for config availability */
+
+/* Use of OpenSSL SHA256 interface: http://adamlamers.com/?p=5 */
+static void
+sha256_hash_string (unsigned char hash[SHA256_DIGEST_LENGTH], char outputBuffer[65])
+{
+	int i;
+	for (i = 0; i < SHA256_DIGEST_LENGTH; i++)
+	{
+		sprintf (outputBuffer + (i * 2), "%02x", hash[i]);
+	}
+	outputBuffer[64] = 0;
+}
+
+static void
+sha256 (char *string, char outputBuffer[65])
+{
+	int i;
+	unsigned char hash[SHA256_DIGEST_LENGTH];
+	SHA256_CTX sha256;
+
+	SHA256_Init (&sha256);
+	SHA256_Update (&sha256, string, strlen (string));
+	SHA256_Final (hash, &sha256);
+
+	for (i = 0; i < SHA256_DIGEST_LENGTH; i++)
+	{
+		sprintf (outputBuffer + (i * 2), "%02x", hash[i]);
+	}
+	outputBuffer[64] = 0;
+}
+
+static int
+sha256_file (char *path, char outputBuffer[65])
+{
+	int bytesRead;
+	unsigned char *buffer;
+	unsigned char hash[SHA256_DIGEST_LENGTH];
+	SHA256_CTX sha256;
+
+	FILE *file = fopen (path, "rb");
+	if (!file)
+	{
+		return -534;
+	}
+
+	SHA256_Init (&sha256);
+	buffer = malloc (BUFSIZE);
+	bytesRead = 0;
+
+	if (!buffer)
+	{
+		return ENOMEM;
+	}
+
+	while ((bytesRead = fread (buffer, 1, BUFSIZE, file)))
+	{
+		SHA256_Update (&sha256, buffer, bytesRead);
+	}
+
+	SHA256_Final (hash, &sha256);
+	sha256_hash_string (hash, outputBuffer);
+
+	fclose (file);
+	free (buffer);
+	return 0;
+}
+
+static void
+init ()
+{
+	/* check whether the config file exists, if it doesn't, try to create it */
+	FILE * file_in;
+	FILE * file_out;
+	char buffer[FILE_BUF_SIZE];
+
+	config_fail = 0;
+	snprintf (buffer, sizeof (buffer), "%s/checksum.conf", xchat_get_info (ph, "xchatdirfs"));
+
+	if ((file_in = fopen (buffer, "r")) == NULL)
+	{
+		if ((file_out = fopen (buffer, "w")) == NULL)
+		{
+			config_fail = 1;
+		} else
+		{
+			fprintf (file_out, "%llu\n", (unsigned long long) DEFAULT_MAX_HASH_SIZE);
+			fclose (file_out);
+		}
+	} else
+	{
+		fclose (file_in);
+	}
+
+	/* nasty easter egg: if FILE_BUF_SIZE is set to 1024 and you build for x86, you can do fclose ()
+	   at the end of init (), which is plain wrong as it will only work if fopen () != 0. */
+}
+
+static unsigned long long
+get_max_hash_size ()
+{
+	FILE * file_in;
+	char buffer[FILE_BUF_SIZE];
+	unsigned long long max_hash_size;
+
+	if (config_fail)
+	{
+		return (unsigned long long) DEFAULT_MAX_HASH_SIZE;
+	} else
+	{
+		snprintf (buffer, sizeof (buffer), "%s/checksum.conf", xchat_get_info (ph, "xchatdirfs"));
+		file_in = fopen (buffer, "r");
+		fscanf (file_in, "%llu", &max_hash_size);
+
+		fclose (file_in);
+		return max_hash_size;
+	}
+}
+
+static void
+print_size ()
+{
+	unsigned long long size;
+	char suffix[3];
+	
+	size = get_max_hash_size ();
+	
+	if (size >= 1073741824)
+	{
+		size /= 1073741824;
+		snprintf (suffix, sizeof (suffix), "GB");
+	} else if (size >= 1048576)
+	{
+		size /= 1048576;
+		snprintf (suffix, sizeof (suffix), "MB");
+	} else if (size >= 1024)
+	{
+		size /= 1024;
+		snprintf (suffix, sizeof (suffix), "kB");
+	} else
+	{
+		snprintf (suffix, sizeof (suffix), "B");
+	}
+	xchat_printf (ph, "File size limit for checksums: %llu %s\n", size, suffix);
+}
+
+static void
+increase_max_hash_size ()
+{
+	unsigned long long size;
+	FILE * file_out;
+	char buffer[FILE_BUF_SIZE];
+
+	if (config_fail)
+	{
+		xchat_printf (ph, "Config file is unavailable, falling back to the default value\n");
+		print_size ();
+	} else
+	{
+		size = get_max_hash_size ();
+		if (size <= ULLONG_MAX/2)
+		{
+			size *= 2;
+		}
+		
+		snprintf (buffer, sizeof (buffer), "%s/checksum.conf", xchat_get_info (ph, "xchatdirfs"));
+		file_out = fopen (buffer, "w");
+		fprintf (file_out, "%llu\n", size);
+		fclose (file_out);
+		print_size ();
+	}
+}
+
+static void
+decrease_max_hash_size ()
+{
+	unsigned long long size;
+	FILE * file_out;
+	char buffer[FILE_BUF_SIZE];
+
+	if (config_fail)
+	{
+		xchat_printf (ph, "Config file is unavailable, falling back to the default value\n");
+		print_size ();
+	} else
+	{
+		size = get_max_hash_size ();
+		if (size >= 2)
+		{
+			size /= 2;
+		}
+		
+		snprintf (buffer, sizeof (buffer), "%s/checksum.conf", xchat_get_info (ph, "xchatdirfs"));
+		file_out = fopen (buffer, "w");
+		fprintf (file_out, "%llu\n", size);
+		fclose (file_out);
+		print_size ();
+	}
+}
+
+static int
+dccrecv_cb (char *word[], void *userdata)
+{
+	int result;
+	struct stat64 buffer;									/* buffer for storing file info */
+	char sum[65];											/* buffer for checksum */
+
+	result = stat64 (word[2], &buffer);
+	if (result == 0)										/* stat returns 0 on success */
+	{
+		if (buffer.st_size <= get_max_hash_size ())
+		{
+			sha256_file (word[2], sum);						/* word[2] is the full filename */
+			/* try to print the checksum in the privmsg tab of the sender */
+			xchat_set_context (ph, xchat_find_context (ph, NULL, word[3]));
+			xchat_printf (ph, "SHA-256 checksum for %s (local):  %s\n", word[1], sum);
+		} else
+		{
+			xchat_set_context (ph, xchat_find_context (ph, NULL, word[3]));
+			xchat_printf (ph, "SHA-256 checksum for %s (local):  (size limit reached, no checksum calculated, you can increase it with /CHECKSUM INC)\n", word[1]);
+		}
+	} else
+	{
+		xchat_printf (ph, "File access error\n");
+	}
+
+	return XCHAT_EAT_NONE;
+}
+
+static int
+dccoffer_cb (char *word[], void *userdata)
+{
+	int result;
+	struct stat64 buffer;									/* buffer for storing file info */
+	char sum[65];											/* buffer for checksum */
+
+	result = stat64 (word[3], &buffer);
+	if (result == 0)										/* stat returns 0 on success */
+	{
+		if (buffer.st_size <= get_max_hash_size ())
+		{
+			sha256_file (word[3], sum);						/* word[3] is the full filename */
+			xchat_commandf (ph, "quote PRIVMSG %s :SHA-256 checksum for %s (remote): %s", word[2], word[1], sum);
+		} else
+		{
+			xchat_set_context (ph, xchat_find_context (ph, NULL, word[3]));
+			xchat_printf (ph, "quote PRIVMSG %s :SHA-256 checksum for %s (remote): (size limit reached, no checksum calculated)", word[2], word[1]);
+		}
+	} else
+	{
+		xchat_printf (ph, "File access error\n");
+	}
+
+	return XCHAT_EAT_NONE;
+}
+
+static void
+checksum (char *word[], void *userdata)
+{
+	if (!stricmp ("GET", word[2]))
+	{
+		print_size ();
+	} else if (!stricmp ("INC", word[2]))
+	{
+		increase_max_hash_size ();
+	} else if (!stricmp ("DEC", word[2]))
+	{
+		decrease_max_hash_size ();
+	} else
+	{
+		xchat_printf (ph, "Usage: /CHECKSUM GET|INC|DEC\n");
+		xchat_printf (ph, "  GET - print the maximum file size to be hashed\n");
+		xchat_printf (ph, "  INC - double the maximum file size to be hashed\n");
+		xchat_printf (ph, "  DEC - halve the maximum file size to be hashed\n");
+	}
+}
+
+int
+xchat_plugin_init (xchat_plugin *plugin_handle, char **plugin_name, char **plugin_desc, char **plugin_version, char *arg)
+{
+	ph = plugin_handle;
+
+	*plugin_name = name;
+	*plugin_desc = desc;
+	*plugin_version = version;
+
+	init ();
+
+	xchat_hook_command (ph, "CHECKSUM", XCHAT_PRI_NORM, checksum, "Usage: /CHECKSUM GET|INC|DEC", 0);
+	xchat_hook_print (ph, "DCC RECV Complete", XCHAT_PRI_NORM, dccrecv_cb, NULL);
+	xchat_hook_print (ph, "DCC Offer", XCHAT_PRI_NORM, dccoffer_cb, NULL);
+
+	xchat_printf (ph, "%s plugin loaded\n", name);
+	return 1;
+}
+
+int
+xchat_plugin_deinit (void)
+{
+	xchat_printf (ph, "%s plugin unloaded\n", name);
+	return 1;
+}