/src/libluksde/libfcrypto/libfcrypto_rc4_context.c

Source (jump to first uncovered line)
/*
 * RC4 (de/en)crypt functions
 *
 * Copyright (C) 2017-2024, Joachim Metz <joachim.metz@gmail.com>
 *
 * Refer to AUTHORS for acknowledgements.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

#include <common.h>
#include <memory.h>
#include <types.h>

#include "libfcrypto_definitions.h"
#include "libfcrypto_libcerror.h"
#include "libfcrypto_rc4_context.h"

/* Creates a RC4 context
 * Make sure the value context is referencing, is set to NULL
 * Returns 1 if successful or -1 on error
 */
int libfcrypto_rc4_context_initialize(
     libfcrypto_rc4_context_t **context,
     libcerror_error_t **error )
{
  libfcrypto_internal_rc4_context_t *internal_context = NULL;
  static char *function                               = "libfcrypto_rc4_context_initialize";

  if( context == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid context.",
     function );

    return( -1 );
  }
  if( *context != NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_RUNTIME,
     LIBCERROR_RUNTIME_ERROR_VALUE_ALREADY_SET,
     "%s: invalid context value already set.",
     function );

    return( -1 );
  }
  internal_context = memory_allocate_structure(
                      libfcrypto_internal_rc4_context_t );

  if( internal_context == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_MEMORY,
     LIBCERROR_MEMORY_ERROR_INSUFFICIENT,
     "%s: unable to create context.",
     function );

    goto on_error;
  }
  if( memory_set(
       internal_context,
       0,
       sizeof( libfcrypto_internal_rc4_context_t ) ) == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_MEMORY,
     LIBCERROR_MEMORY_ERROR_SET_FAILED,
     "%s: unable to clear context.",
     function );

    goto on_error;
  }
  *context = (libfcrypto_rc4_context_t *) internal_context;

  return( 1 );

on_error:
  if( internal_context != NULL )
  {
    memory_free(
     internal_context );
  }
  return( -1 );
}

/* Frees a RC4 context
 * Returns 1 if successful or -1 on error
 */
int libfcrypto_rc4_context_free(
     libfcrypto_rc4_context_t **context,
     libcerror_error_t **error )
{
  libfcrypto_internal_rc4_context_t *internal_context = NULL;
  static char *function                               = "libfcrypto_rc4_context_free";
  int result                                          = 1;

  if( context == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid context.",
     function );

    return( -1 );
  }
  if( *context != NULL )
  {
    internal_context = (libfcrypto_internal_rc4_context_t *) *context;
    *context         = NULL;

    if( memory_set(
         internal_context,
         0,
         sizeof( libfcrypto_internal_rc4_context_t ) ) == NULL )
    {
      libcerror_error_set(
       error,
       LIBCERROR_ERROR_DOMAIN_MEMORY,
       LIBCERROR_MEMORY_ERROR_SET_FAILED,
       "%s: unable to clear context.",
       function );

      result = -1;
    }
    memory_free(
     internal_context );
  }
  return( result );
}

/* Sets the key
 * Returns 1 if successful or -1 on error
 */
int libfcrypto_rc4_context_set_key(
     libfcrypto_rc4_context_t *context,
     const uint8_t *key,
     size_t key_bit_size,
     libcerror_error_t **error )
{
  libfcrypto_internal_rc4_context_t *internal_context = NULL;
  static char *function                               = "libfcrypto_rc4_context_set_key";
  size_t key_byte_index                               = 0;
  size_t key_byte_size                                = 0;
  uint16_t byte_value                                 = 0;
  uint8_t permutation_value                           = 0;
  uint8_t values_index                                = 0;

  if( context == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid context.",
     function );

    return( -1 );
  }
  internal_context = (libfcrypto_internal_rc4_context_t *) context;

  if( key == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid key.",
     function );

    return( -1 );
  }
  if( ( key_bit_size < 40 )
   || ( key_bit_size > 2048 )
   || ( ( key_bit_size % 8 ) != 0 ) )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_UNSUPPORTED_VALUE,
     "%s: unsupported key bit size.",
     function );

    return( -1 );
  }
  key_byte_size = key_bit_size / 8;

  /* Also referred to as: Key Scheduling Algorithm (KSA)
   */
  for( byte_value = 0;
       byte_value < 256;
       byte_value++ )
  {
    internal_context->permutations[ byte_value ] = (uint8_t) byte_value;
  }
  for( byte_value = 0;
       byte_value < 256;
       byte_value++ )
  {
    key_byte_index = byte_value % key_byte_size;

    /* Note that the following operations are modulus 256
     */
    values_index = ( values_index + internal_context->permutations[ byte_value ] + key[ key_byte_index ] ) & 0xff;

    permutation_value = internal_context->permutations[ byte_value ];
    internal_context->permutations[ byte_value ] = internal_context->permutations[ values_index ];
    internal_context->permutations[ values_index ] = permutation_value;
  }
  internal_context->index[ 0 ] = 0;
  internal_context->index[ 1 ] = 0;

  return( 1 );
}

/* De- or encrypts a buffer of data using RC4
 * Returns 1 if successful or -1 on error
 */
int libfcrypto_rc4_crypt(
     libfcrypto_rc4_context_t *context,
     const uint8_t *input_data,
     size_t input_data_size,
     uint8_t *output_data,
     size_t output_data_size,
     libcerror_error_t **error )
{
  libfcrypto_internal_rc4_context_t *internal_context = NULL;
  static char *function                               = "libfcrypto_rc4_crypt";
  size_t data_offset                                  = 0;
  uint8_t permutation_value                           = 0;
  uint8_t values_index1                               = 0;
  uint8_t values_index2                               = 0;

  if( context == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid context.",
     function );

    return( -1 );
  }
  internal_context = (libfcrypto_internal_rc4_context_t *) context;

  if( input_data == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid input data.",
     function );

    return( -1 );
  }
  if( input_data_size > (size_t) SSIZE_MAX )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_VALUE_EXCEEDS_MAXIMUM,
     "%s: invalid input data size value exceeds maximum.",
     function );

    return( -1 );
  }
  if( output_data == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid output data.",
     function );

    return( -1 );
  }
  if( output_data_size > (size_t) SSIZE_MAX )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_VALUE_EXCEEDS_MAXIMUM,
     "%s: invalid output data size value exceeds maximum.",
     function );

    return( -1 );
  }
  if( output_data_size < input_data_size )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_RUNTIME,
     LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,
     "%s: invalid ouput data size smaller than input data size.",
     function );

    return( -1 );
  }
  /* Also referred to as: Pseudo-Random Generator Algorithm (PRGA)
   */
  values_index1 = internal_context->index[ 0 ];
  values_index2 = internal_context->index[ 1 ];

  while( data_offset < input_data_size )
  {
    /* Note that the following operations are modulus 256
     */
    values_index1 = ( values_index1 + 1 ) & 0xff;
    values_index2 = ( values_index2 + internal_context->permutations[ values_index1 ] ) & 0xff;

    permutation_value                               = internal_context->permutations[ values_index1 ];
    internal_context->permutations[ values_index1 ] = internal_context->permutations[ values_index2 ];
    internal_context->permutations[ values_index2 ] = permutation_value;

    permutation_value = ( permutation_value + internal_context->permutations[ values_index1 ] ) & 0xff;

    output_data[ data_offset ] = input_data[ data_offset ] ^ internal_context->permutations[ permutation_value ];

    data_offset++;
  }
  internal_context->index[ 0 ] = values_index1;
  internal_context->index[ 1 ] = values_index2;

  return( 1 );
}


Coverage Report

Created: 2025-06-13 07:22

Line	Count	Source (jump to first uncovered line)
1		/*
2		* RC4 (de/en)crypt functions
3		*
4		* Copyright (C) 2017-2024, Joachim Metz <joachim.metz@gmail.com>
5		*
6		* Refer to AUTHORS for acknowledgements.
7		*
8		* This program is free software: you can redistribute it and/or modify
9		* it under the terms of the GNU Lesser General Public License as published by
10		* the Free Software Foundation, either version 3 of the License, or
11		* (at your option) any later version.
12		*
13		* This program is distributed in the hope that it will be useful,
14		* but WITHOUT ANY WARRANTY; without even the implied warranty of
15		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16		* GNU General Public License for more details.
17		*
18		* You should have received a copy of the GNU Lesser General Public License
19		* along with this program. If not, see <https://www.gnu.org/licenses/>.
20		*/
21
22		#include <common.h>
23		#include <memory.h>
24		#include <types.h>
25
26		#include "libfcrypto_definitions.h"
27		#include "libfcrypto_libcerror.h"
28		#include "libfcrypto_rc4_context.h"
29
30		/* Creates a RC4 context
31		* Make sure the value context is referencing, is set to NULL
32		* Returns 1 if successful or -1 on error
33		*/
34		int libfcrypto_rc4_context_initialize(
35		libfcrypto_rc4_context_t **context,
36		libcerror_error_t **error )
37	47	{
38	47	libfcrypto_internal_rc4_context_t *internal_context = NULL;
39	47	static char *function = "libfcrypto_rc4_context_initialize";
40
41	47	if( context == NULL )
42	0	{
43	0	libcerror_error_set(
44	0	error,
45	0	LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
46	0	LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
47	0	"%s: invalid context.",
48	0	function );
49
50	0	return( -1 );
51	0	}
52	47	if( *context != NULL )
53	0	{
54	0	libcerror_error_set(
55	0	error,
56	0	LIBCERROR_ERROR_DOMAIN_RUNTIME,
57	0	LIBCERROR_RUNTIME_ERROR_VALUE_ALREADY_SET,
58	0	"%s: invalid context value already set.",
59	0	function );
60
61	0	return( -1 );
62	0	}
63	47	internal_context = memory_allocate_structure(
64	47	libfcrypto_internal_rc4_context_t );
65
66	47	if( internal_context == NULL )
67	0	{
68	0	libcerror_error_set(
69	0	error,
70	0	LIBCERROR_ERROR_DOMAIN_MEMORY,
71	0	LIBCERROR_MEMORY_ERROR_INSUFFICIENT,
72	0	"%s: unable to create context.",
73	0	function );
74
75	0	goto on_error;
76	0	}
77	47	if( memory_set(
78	47	internal_context,
79	47	0,
80	47	sizeof( libfcrypto_internal_rc4_context_t ) ) == NULL )
81	0	{
82	0	libcerror_error_set(
83	0	error,
84	0	LIBCERROR_ERROR_DOMAIN_MEMORY,
85	0	LIBCERROR_MEMORY_ERROR_SET_FAILED,
86	0	"%s: unable to clear context.",
87	0	function );
88
89	0	goto on_error;
90	0	}
91	47	context = (libfcrypto_rc4_context_t ) internal_context;
92
93	47	return( 1 );
94
95	0	on_error:
96	0	if( internal_context != NULL )
97	0	{
98	0	memory_free(
99	0	internal_context );
100	0	}
101	0	return( -1 );
102	47	}
103
104		/* Frees a RC4 context
105		* Returns 1 if successful or -1 on error
106		*/
107		int libfcrypto_rc4_context_free(
108		libfcrypto_rc4_context_t **context,
109		libcerror_error_t **error )
110	47	{
111	47	libfcrypto_internal_rc4_context_t *internal_context = NULL;
112	47	static char *function = "libfcrypto_rc4_context_free";
113	47	int result = 1;
114
115	47	if( context == NULL )
116	0	{
117	0	libcerror_error_set(
118	0	error,
119	0	LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
120	0	LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
121	0	"%s: invalid context.",
122	0	function );
123
124	0	return( -1 );
125	0	}
126	47	if( *context != NULL )
127	47	{
128	47	internal_context = (libfcrypto_internal_rc4_context_t ) context;
129	47	*context = NULL;
130
131	47	if( memory_set(
132	47	internal_context,
133	47	0,
134	47	sizeof( libfcrypto_internal_rc4_context_t ) ) == NULL )
135	0	{
136	0	libcerror_error_set(
137	0	error,
138	0	LIBCERROR_ERROR_DOMAIN_MEMORY,
139	0	LIBCERROR_MEMORY_ERROR_SET_FAILED,
140	0	"%s: unable to clear context.",
141	0	function );
142
143	0	result = -1;
144	0	}
145	47	memory_free(
146	47	internal_context );
147	47	}
148	47	return( result );
149	47	}
150
151		/* Sets the key
152		* Returns 1 if successful or -1 on error
153		*/
154		int libfcrypto_rc4_context_set_key(
155		libfcrypto_rc4_context_t *context,
156		const uint8_t *key,
157		size_t key_bit_size,
158		libcerror_error_t **error )
159	47	{
160	47	libfcrypto_internal_rc4_context_t *internal_context = NULL;
161	47	static char *function = "libfcrypto_rc4_context_set_key";
162	47	size_t key_byte_index = 0;
163	47	size_t key_byte_size = 0;
164	47	uint16_t byte_value = 0;
165	47	uint8_t permutation_value = 0;
166	47	uint8_t values_index = 0;
167
168	47	if( context == NULL )
169	0	{
170	0	libcerror_error_set(
171	0	error,
172	0	LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
173	0	LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
174	0	"%s: invalid context.",
175	0	function );
176
177	0	return( -1 );
178	0	}
179	47	internal_context = (libfcrypto_internal_rc4_context_t *) context;
180
181	47	if( key == NULL )
182	0	{
183	0	libcerror_error_set(
184	0	error,
185	0	LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
186	0	LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
187	0	"%s: invalid key.",
188	0	function );
189
190	0	return( -1 );
191	0	}
192	47	if( ( key_bit_size < 40 )
193	47	\|\| ( key_bit_size > 2048 )
194	47	\|\| ( ( key_bit_size % 8 ) != 0 ) )
195	0	{
196	0	libcerror_error_set(
197	0	error,
198	0	LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
199	0	LIBCERROR_ARGUMENT_ERROR_UNSUPPORTED_VALUE,
200	0	"%s: unsupported key bit size.",
201	0	function );
202
203	0	return( -1 );
204	0	}
205	47	key_byte_size = key_bit_size / 8;
206
207		/* Also referred to as: Key Scheduling Algorithm (KSA)
208		*/
209	47	for( byte_value = 0;
210	12.0k	byte_value < 256;
211	12.0k	byte_value++ )
212	12.0k	{
213	12.0k	internal_context->permutations[ byte_value ] = (uint8_t) byte_value;
214	12.0k	}
215	47	for( byte_value = 0;
216	12.0k	byte_value < 256;
217	12.0k	byte_value++ )
218	12.0k	{
219	12.0k	key_byte_index = byte_value % key_byte_size;
220
221		/* Note that the following operations are modulus 256
222		*/
223	12.0k	values_index = ( values_index + internal_context->permutations[ byte_value ] + key[ key_byte_index ] ) & 0xff;
224
225	12.0k	permutation_value = internal_context->permutations[ byte_value ];
226	12.0k	internal_context->permutations[ byte_value ] = internal_context->permutations[ values_index ];
227	12.0k	internal_context->permutations[ values_index ] = permutation_value;
228	12.0k	}
229	47	internal_context->index[ 0 ] = 0;
230	47	internal_context->index[ 1 ] = 0;
231
232	47	return( 1 );
233	47	}
234
235		/* De- or encrypts a buffer of data using RC4
236		* Returns 1 if successful or -1 on error
237		*/
238		int libfcrypto_rc4_crypt(
239		libfcrypto_rc4_context_t *context,
240		const uint8_t *input_data,
241		size_t input_data_size,
242		uint8_t *output_data,
243		size_t output_data_size,
244		libcerror_error_t **error )
245	47	{
246	47	libfcrypto_internal_rc4_context_t *internal_context = NULL;
247	47	static char *function = "libfcrypto_rc4_crypt";
248	47	size_t data_offset = 0;
249	47	uint8_t permutation_value = 0;
250	47	uint8_t values_index1 = 0;
251	47	uint8_t values_index2 = 0;
252
253	47	if( context == NULL )
254	0	{
255	0	libcerror_error_set(
256	0	error,
257	0	LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
258	0	LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
259	0	"%s: invalid context.",
260	0	function );
261
262	0	return( -1 );
263	0	}
264	47	internal_context = (libfcrypto_internal_rc4_context_t *) context;
265
266	47	if( input_data == NULL )
267	0	{
268	0	libcerror_error_set(
269	0	error,
270	0	LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
271	0	LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
272	0	"%s: invalid input data.",
273	0	function );
274
275	0	return( -1 );
276	0	}
277	47	if( input_data_size > (size_t) SSIZE_MAX )
278	0	{
279	0	libcerror_error_set(
280	0	error,
281	0	LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
282	0	LIBCERROR_ARGUMENT_ERROR_VALUE_EXCEEDS_MAXIMUM,
283	0	"%s: invalid input data size value exceeds maximum.",
284	0	function );
285
286	0	return( -1 );
287	0	}
288	47	if( output_data == NULL )
289	0	{
290	0	libcerror_error_set(
291	0	error,
292	0	LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
293	0	LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
294	0	"%s: invalid output data.",
295	0	function );
296
297	0	return( -1 );
298	0	}
299	47	if( output_data_size > (size_t) SSIZE_MAX )
300	0	{
301	0	libcerror_error_set(
302	0	error,
303	0	LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
304	0	LIBCERROR_ARGUMENT_ERROR_VALUE_EXCEEDS_MAXIMUM,
305	0	"%s: invalid output data size value exceeds maximum.",
306	0	function );
307
308	0	return( -1 );
309	0	}
310	47	if( output_data_size < input_data_size )
311	31	{
312	31	libcerror_error_set(
313	31	error,
314	31	LIBCERROR_ERROR_DOMAIN_RUNTIME,
315	31	LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,
316	31	"%s: invalid ouput data size smaller than input data size.",
317	31	function );
318
319	31	return( -1 );
320	31	}
321		/* Also referred to as: Pseudo-Random Generator Algorithm (PRGA)
322		*/
323	16	values_index1 = internal_context->index[ 0 ];
324	16	values_index2 = internal_context->index[ 1 ];
325
326	437	while( data_offset < input_data_size )
327	421	{
328		/* Note that the following operations are modulus 256
329		*/
330	421	values_index1 = ( values_index1 + 1 ) & 0xff;
331	421	values_index2 = ( values_index2 + internal_context->permutations[ values_index1 ] ) & 0xff;
332
333	421	permutation_value = internal_context->permutations[ values_index1 ];
334	421	internal_context->permutations[ values_index1 ] = internal_context->permutations[ values_index2 ];
335	421	internal_context->permutations[ values_index2 ] = permutation_value;
336
337	421	permutation_value = ( permutation_value + internal_context->permutations[ values_index1 ] ) & 0xff;
338
339	421	output_data[ data_offset ] = input_data[ data_offset ] ^ internal_context->permutations[ permutation_value ];
340
341	421	data_offset++;
342	421	}
343	16	internal_context->index[ 0 ] = values_index1;
344	16	internal_context->index[ 1 ] = values_index2;
345
346	16	return( 1 );
347	47	}
348