1 /*
2  *  RFC 1321 compliant MD5 implementation
3  *
4  *  Based on XySSL: Copyright (C) 2006-2008  Christophe Devine
5  *
6  *  Copyright (C) 2009  Paul Bakker <polarssl_maintainer at polarssl dot org>
7  *
8  *  All rights reserved.
9  *
10  *  Redistribution and use in source and binary forms, with or without
11  *  modification, are permitted provided that the following conditions
12  *  are met:
13  *
14  *    * Redistributions of source code must retain the above copyright
15  *      notice, this list of conditions and the following disclaimer.
16  *    * Redistributions in binary form must reproduce the above copyright
17  *      notice, this list of conditions and the following disclaimer in the
18  *      documentation and/or other materials provided with the distribution.
19  *    * Neither the names of PolarSSL or XySSL nor the names of its contributors
20  *      may be used to endorse or promote products derived from this software
21  *      without specific prior written permission.
22  *
23  *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24  *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25  *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
26  *  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27  *  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28  *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
29  *  TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30  *  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 /*
36  *  The MD5 algorithm was designed by Ron Rivest in 1991.
37  *
38  *  http://www.ietf.org/rfc/rfc1321.txt
39  */
40 
41 #include "netif/ppp/ppp_opts.h"
42 #if PPP_SUPPORT && LWIP_INCLUDED_POLARSSL_MD5
43 
44 #include "netif/ppp/polarssl/md5.h"
45 
46 #include <string.h>
47 
48 /*
49  * 32-bit integer manipulation macros (little endian)
50  */
51 #ifndef GET_ULONG_LE
52 #define GET_ULONG_LE(n,b,i)                             \
53 {                                                       \
54     (n) = ( (unsigned long) (b)[(i)    ]       )        \
55         | ( (unsigned long) (b)[(i) + 1] <<  8 )        \
56         | ( (unsigned long) (b)[(i) + 2] << 16 )        \
57         | ( (unsigned long) (b)[(i) + 3] << 24 );       \
58 }
59 #endif
60 
61 #ifndef PUT_ULONG_LE
62 #define PUT_ULONG_LE(n,b,i)                             \
63 {                                                       \
64     (b)[(i)    ] = (unsigned char) ( (n)       );       \
65     (b)[(i) + 1] = (unsigned char) ( (n) >>  8 );       \
66     (b)[(i) + 2] = (unsigned char) ( (n) >> 16 );       \
67     (b)[(i) + 3] = (unsigned char) ( (n) >> 24 );       \
68 }
69 #endif
70 
71 /*
72  * MD5 context setup
73  */
74 void md5_starts( md5_context *ctx )
75 {
76     ctx->total[0] = 0;
77     ctx->total[1] = 0;
78 
79     ctx->state[0] = 0x67452301;
80     ctx->state[1] = 0xEFCDAB89;
81     ctx->state[2] = 0x98BADCFE;
82     ctx->state[3] = 0x10325476;
83 }
84 
85 static void md5_process( md5_context *ctx, const unsigned char data[64] )
86 {
87     unsigned long X[16], A, B, C, D;
88 
89     GET_ULONG_LE( X[ 0], data,  0 );
90     GET_ULONG_LE( X[ 1], data,  4 );
91     GET_ULONG_LE( X[ 2], data,  8 );
92     GET_ULONG_LE( X[ 3], data, 12 );
93     GET_ULONG_LE( X[ 4], data, 16 );
94     GET_ULONG_LE( X[ 5], data, 20 );
95     GET_ULONG_LE( X[ 6], data, 24 );
96     GET_ULONG_LE( X[ 7], data, 28 );
97     GET_ULONG_LE( X[ 8], data, 32 );
98     GET_ULONG_LE( X[ 9], data, 36 );
99     GET_ULONG_LE( X[10], data, 40 );
100     GET_ULONG_LE( X[11], data, 44 );
101     GET_ULONG_LE( X[12], data, 48 );
102     GET_ULONG_LE( X[13], data, 52 );
103     GET_ULONG_LE( X[14], data, 56 );
104     GET_ULONG_LE( X[15], data, 60 );
105 
106 #define S(x,n) ((x << n) | ((x & 0xFFFFFFFF) >> (32 - n)))
107 
108 #define P(a,b,c,d,k,s,t)                                \
109 {                                                       \
110     a += F(b,c,d) + X[k] + t; a = S(a,s) + b;           \
111 }
112 
113     A = ctx->state[0];
114     B = ctx->state[1];
115     C = ctx->state[2];
116     D = ctx->state[3];
117 
118 #define F(x,y,z) (z ^ (x & (y ^ z)))
119 
120     P( A, B, C, D,  0,  7, 0xD76AA478 );
121     P( D, A, B, C,  1, 12, 0xE8C7B756 );
122     P( C, D, A, B,  2, 17, 0x242070DB );
123     P( B, C, D, A,  3, 22, 0xC1BDCEEE );
124     P( A, B, C, D,  4,  7, 0xF57C0FAF );
125     P( D, A, B, C,  5, 12, 0x4787C62A );
126     P( C, D, A, B,  6, 17, 0xA8304613 );
127     P( B, C, D, A,  7, 22, 0xFD469501 );
128     P( A, B, C, D,  8,  7, 0x698098D8 );
129     P( D, A, B, C,  9, 12, 0x8B44F7AF );
130     P( C, D, A, B, 10, 17, 0xFFFF5BB1 );
131     P( B, C, D, A, 11, 22, 0x895CD7BE );
132     P( A, B, C, D, 12,  7, 0x6B901122 );
133     P( D, A, B, C, 13, 12, 0xFD987193 );
134     P( C, D, A, B, 14, 17, 0xA679438E );
135     P( B, C, D, A, 15, 22, 0x49B40821 );
136 
137 #undef F
138 
139 #define F(x,y,z) (y ^ (z & (x ^ y)))
140 
141     P( A, B, C, D,  1,  5, 0xF61E2562 );
142     P( D, A, B, C,  6,  9, 0xC040B340 );
143     P( C, D, A, B, 11, 14, 0x265E5A51 );
144     P( B, C, D, A,  0, 20, 0xE9B6C7AA );
145     P( A, B, C, D,  5,  5, 0xD62F105D );
146     P( D, A, B, C, 10,  9, 0x02441453 );
147     P( C, D, A, B, 15, 14, 0xD8A1E681 );
148     P( B, C, D, A,  4, 20, 0xE7D3FBC8 );
149     P( A, B, C, D,  9,  5, 0x21E1CDE6 );
150     P( D, A, B, C, 14,  9, 0xC33707D6 );
151     P( C, D, A, B,  3, 14, 0xF4D50D87 );
152     P( B, C, D, A,  8, 20, 0x455A14ED );
153     P( A, B, C, D, 13,  5, 0xA9E3E905 );
154     P( D, A, B, C,  2,  9, 0xFCEFA3F8 );
155     P( C, D, A, B,  7, 14, 0x676F02D9 );
156     P( B, C, D, A, 12, 20, 0x8D2A4C8A );
157 
158 #undef F
159 
160 #define F(x,y,z) (x ^ y ^ z)
161 
162     P( A, B, C, D,  5,  4, 0xFFFA3942 );
163     P( D, A, B, C,  8, 11, 0x8771F681 );
164     P( C, D, A, B, 11, 16, 0x6D9D6122 );
165     P( B, C, D, A, 14, 23, 0xFDE5380C );
166     P( A, B, C, D,  1,  4, 0xA4BEEA44 );
167     P( D, A, B, C,  4, 11, 0x4BDECFA9 );
168     P( C, D, A, B,  7, 16, 0xF6BB4B60 );
169     P( B, C, D, A, 10, 23, 0xBEBFBC70 );
170     P( A, B, C, D, 13,  4, 0x289B7EC6 );
171     P( D, A, B, C,  0, 11, 0xEAA127FA );
172     P( C, D, A, B,  3, 16, 0xD4EF3085 );
173     P( B, C, D, A,  6, 23, 0x04881D05 );
174     P( A, B, C, D,  9,  4, 0xD9D4D039 );
175     P( D, A, B, C, 12, 11, 0xE6DB99E5 );
176     P( C, D, A, B, 15, 16, 0x1FA27CF8 );
177     P( B, C, D, A,  2, 23, 0xC4AC5665 );
178 
179 #undef F
180 
181 #define F(x,y,z) (y ^ (x | ~z))
182 
183     P( A, B, C, D,  0,  6, 0xF4292244 );
184     P( D, A, B, C,  7, 10, 0x432AFF97 );
185     P( C, D, A, B, 14, 15, 0xAB9423A7 );
186     P( B, C, D, A,  5, 21, 0xFC93A039 );
187     P( A, B, C, D, 12,  6, 0x655B59C3 );
188     P( D, A, B, C,  3, 10, 0x8F0CCC92 );
189     P( C, D, A, B, 10, 15, 0xFFEFF47D );
190     P( B, C, D, A,  1, 21, 0x85845DD1 );
191     P( A, B, C, D,  8,  6, 0x6FA87E4F );
192     P( D, A, B, C, 15, 10, 0xFE2CE6E0 );
193     P( C, D, A, B,  6, 15, 0xA3014314 );
194     P( B, C, D, A, 13, 21, 0x4E0811A1 );
195     P( A, B, C, D,  4,  6, 0xF7537E82 );
196     P( D, A, B, C, 11, 10, 0xBD3AF235 );
197     P( C, D, A, B,  2, 15, 0x2AD7D2BB );
198     P( B, C, D, A,  9, 21, 0xEB86D391 );
199 
200 #undef F
201 
202     ctx->state[0] += A;
203     ctx->state[1] += B;
204     ctx->state[2] += C;
205     ctx->state[3] += D;
206 }
207 
208 /*
209  * MD5 process buffer
210  */
211 void md5_update( md5_context *ctx, const unsigned char *input, int ilen )
212 {
213     int fill;
214     unsigned long left;
215 
216     if( ilen <= 0 )
217         return;
218 
219     left = ctx->total[0] & 0x3F;
220     fill = 64 - left;
221 
222     ctx->total[0] += ilen;
223     ctx->total[0] &= 0xFFFFFFFF;
224 
225     if( ctx->total[0] < (unsigned long) ilen )
226         ctx->total[1]++;
227 
228     if( left && ilen >= fill )
229     {
230         MEMCPY( (void *) (ctx->buffer + left),
231                 input, fill );
232         md5_process( ctx, ctx->buffer );
233         input += fill;
234         ilen  -= fill;
235         left = 0;
236     }
237 
238     while( ilen >= 64 )
239     {
240         md5_process( ctx, input );
241         input += 64;
242         ilen  -= 64;
243     }
244 
245     if( ilen > 0 )
246     {
247         MEMCPY( (void *) (ctx->buffer + left),
248                 input, ilen );
249     }
250 }
251 
252 static const unsigned char md5_padding[64] =
253 {
254  0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
255     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
256     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
257     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
258 };
259 
260 /*
261  * MD5 final digest
262  */
263 void md5_finish( md5_context *ctx, unsigned char output[16] )
264 {
265     unsigned long last, padn;
266     unsigned long high, low;
267     unsigned char msglen[8];
268 
269     high = ( ctx->total[0] >> 29 )
270          | ( ctx->total[1] <<  3 );
271     low  = ( ctx->total[0] <<  3 );
272 
273     PUT_ULONG_LE( low,  msglen, 0 );
274     PUT_ULONG_LE( high, msglen, 4 );
275 
276     last = ctx->total[0] & 0x3F;
277     padn = ( last < 56 ) ? ( 56 - last ) : ( 120 - last );
278 
279     md5_update( ctx, md5_padding, padn );
280     md5_update( ctx, msglen, 8 );
281 
282     PUT_ULONG_LE( ctx->state[0], output,  0 );
283     PUT_ULONG_LE( ctx->state[1], output,  4 );
284     PUT_ULONG_LE( ctx->state[2], output,  8 );
285     PUT_ULONG_LE( ctx->state[3], output, 12 );
286 }
287 
288 /*
289  * output = MD5( input buffer )
290  */
291 void md5( unsigned char *input, int ilen, unsigned char output[16] )
292 {
293     md5_context ctx;
294 
295     md5_starts( &ctx );
296     md5_update( &ctx, input, ilen );
297     md5_finish( &ctx, output );
298 }
299 
300 #endif /* PPP_SUPPORT && LWIP_INCLUDED_POLARSSL_MD5 */
301