base

application/sp-console(down)/Common/mcrypt-2.5.7/modes/ofb.c

@@ -0,0 +1,174 @@
+/*
+ * Copyright (C) 1998,1999,2000,2001,2002 Nikos Mavroyanopoulos
+ * 
+ * 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 <libdefs.h>
+#include <mcrypt_modules.h>
+
+#define _init_mcrypt ofb_LTX__init_mcrypt
+#define _mcrypt_set_state ofb_LTX__mcrypt_set_state
+#define _mcrypt_get_state ofb_LTX__mcrypt_get_state
+#define _end_mcrypt ofb_LTX__end_mcrypt
+#define _mcrypt ofb_LTX__mcrypt
+#define _mdecrypt ofb_LTX__mdecrypt
+#define _has_iv ofb_LTX__has_iv
+#define _is_block_mode ofb_LTX__is_block_mode
+#define _is_block_algorithm_mode ofb_LTX__is_block_algorithm_mode
+#define _mcrypt_get_modes_name ofb_LTX__mcrypt_get_modes_name
+#define _mcrypt_mode_get_size ofb_LTX__mcrypt_mode_get_size
+#define _mcrypt_mode_version ofb_LTX__mcrypt_mode_version
+
+typedef struct ofb_buf {
+	byte* s_register;
+	byte* enc_s_register;
+	int blocksize;
+} OFB_BUFFER;
+
+
+/* OFB MODE */
+
+int _init_mcrypt( OFB_BUFFER* buf, void *key, int lenofkey, void *IV, int size)
+{
+
+    buf->s_register = buf->enc_s_register = NULL;
+
+    buf->blocksize = size;
+    
+    /* For ofb */
+	buf->s_register=malloc( size);
+    if (buf->s_register==NULL) goto freeall;
+
+	buf->enc_s_register=malloc( size);
+    if (buf->enc_s_register==NULL) goto freeall;
+
+	if (IV!=NULL) {
+		memcpy(buf->s_register, IV, size);
+	} else {
+		memset(buf->s_register, 0, size);
+	}
+/* End ofb */
+
+	return 0;
+
+	freeall:
+		free(buf->s_register);
+		free(buf->enc_s_register);
+		return -1;
+}
+
+int _mcrypt_get_state( OFB_BUFFER* buf, byte *IV, int *size)
+{
+	if (*size < buf->blocksize) {
+		*size = buf->blocksize;
+		return -1;
+	}
+	*size = buf->blocksize;
+
+	memcpy( IV, buf->s_register, buf->blocksize);
+
+	return 0;
+}
+
+int _mcrypt_set_state( OFB_BUFFER* buf, void *IV, int size)
+{
+	memcpy(buf->enc_s_register, IV, size);
+	memcpy(buf->s_register, IV, size);
+
+	return 0;
+}
+
+
+void _end_mcrypt( OFB_BUFFER* buf) {
+	free(buf->s_register);
+	free(buf->enc_s_register);
+}
+
+
+int _mcrypt( OFB_BUFFER* buf,void *plaintext, int len, int blocksize, void* akey, void (*func)(void*,void*), void (*func2)(void*,void*) )
+{				/* plaintext is 1 byte (8bit ofb) */
+	char *plain = plaintext;
+	int i, j;
+	void (*_mcrypt_block_encrypt) (void *, void *);
+
+	_mcrypt_block_encrypt = func;
+
+	for (j = 0; j < len; j++) {
+
+		memcpy(buf->enc_s_register, buf->s_register, blocksize);
+
+		_mcrypt_block_encrypt(akey, buf->enc_s_register);
+
+		plain[j] ^= buf->enc_s_register[0];
+
+/* Shift the register */
+		for (i = 0; i < (blocksize - 1); i++)
+			buf->s_register[i] = buf->s_register[i + 1];
+
+		buf->s_register[blocksize - 1] = buf->enc_s_register[0];
+	}
+
+	return 0;
+
+}
+
+
+int _mdecrypt( OFB_BUFFER* buf, void *plaintext, int len, int blocksize, void* akey, void (*func)(void*,void*), void (*func2)(void*,void*))
+{				/* plaintext is 1 byte (8bit ofb) */
+	char *plain = plaintext;
+	int i, j;
+	void (*_mcrypt_block_encrypt) (void *, void *);
+
+	_mcrypt_block_encrypt = func;
+
+	for (j = 0; j < len; j++) {
+
+		memcpy(buf->enc_s_register, buf->s_register, blocksize);
+
+		_mcrypt_block_encrypt(akey, buf->enc_s_register);
+
+/* Shift the register */
+		for (i = 0; i < (blocksize - 1); i++)
+			buf->s_register[i] = buf->s_register[i + 1];
+
+		buf->s_register[blocksize - 1] = buf->enc_s_register[0];
+
+		plain[j] ^= buf->enc_s_register[0];
+
+	}
+
+	return 0;
+}
+
+int _is_block_mode() { return 0; }
+int _has_iv() { return 1; }
+int _is_block_algorithm_mode() { return 1; }
+char *_mcrypt_get_modes_name() { return "OFB"; }
+int _mcrypt_mode_get_size () {return sizeof(OFB_BUFFER);}
+
+word32 _mcrypt_mode_version() {
+	return 20010310;
+}
+
+#ifdef WIN32
+# ifdef USE_LTDL
+WIN32DLL_DEFINE int main (void)
+{
+       /* empty main function to avoid linker error (see cygwin FAQ) */
+}
+# endif
+#endif