1 // SPDX-License-Identifier: BSD-2-Clause
2 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
3  *
4  * LibTomCrypt is a library that provides various cryptographic
5  * algorithms in a highly modular and flexible manner.
6  *
7  * The library is free for all purposes without any express
8  * guarantee it works.
9  */
10 #include "tomcrypt_private.h"
11 
12 /**
13    @param md2.c
14    LTC_MD2 (RFC 1319) hash function implementation by Tom St Denis
15 */
16 
17 #ifdef LTC_MD2
18 
19 const struct ltc_hash_descriptor md2_desc =
20 {
21     "md2",
22     7,
23     16,
24     16,
25 
26     /* OID */
27    { 1, 2, 840, 113549, 2, 2,  },
28    6,
29 
30     &md2_init,
31     &md2_process,
32     &md2_done,
33     &md2_test,
34     NULL
35 };
36 
37 static const unsigned char PI_SUBST[256] = {
38   41, 46, 67, 201, 162, 216, 124, 1, 61, 54, 84, 161, 236, 240, 6,
39   19, 98, 167, 5, 243, 192, 199, 115, 140, 152, 147, 43, 217, 188,
40   76, 130, 202, 30, 155, 87, 60, 253, 212, 224, 22, 103, 66, 111, 24,
41   138, 23, 229, 18, 190, 78, 196, 214, 218, 158, 222, 73, 160, 251,
42   245, 142, 187, 47, 238, 122, 169, 104, 121, 145, 21, 178, 7, 63,
43   148, 194, 16, 137, 11, 34, 95, 33, 128, 127, 93, 154, 90, 144, 50,
44   39, 53, 62, 204, 231, 191, 247, 151, 3, 255, 25, 48, 179, 72, 165,
45   181, 209, 215, 94, 146, 42, 172, 86, 170, 198, 79, 184, 56, 210,
46   150, 164, 125, 182, 118, 252, 107, 226, 156, 116, 4, 241, 69, 157,
47   112, 89, 100, 113, 135, 32, 134, 91, 207, 101, 230, 45, 168, 2, 27,
48   96, 37, 173, 174, 176, 185, 246, 28, 70, 97, 105, 52, 64, 126, 15,
49   85, 71, 163, 35, 221, 81, 175, 58, 195, 92, 249, 206, 186, 197,
50   234, 38, 44, 83, 13, 110, 133, 40, 132, 9, 211, 223, 205, 244, 65,
51   129, 77, 82, 106, 220, 55, 200, 108, 193, 171, 250, 36, 225, 123,
52   8, 12, 189, 177, 74, 120, 136, 149, 139, 227, 99, 232, 109, 233,
53   203, 213, 254, 59, 0, 29, 57, 242, 239, 183, 14, 102, 88, 208, 228,
54   166, 119, 114, 248, 235, 117, 75, 10, 49, 68, 80, 180, 143, 237,
55   31, 26, 219, 153, 141, 51, 159, 17, 131, 20
56 };
57 
58 /* adds 16 bytes to the checksum */
md2_update_chksum(hash_state * md)59 static void md2_update_chksum(hash_state *md)
60 {
61    int j;
62    unsigned char L;
63    L = md->md2.chksum[15];
64    for (j = 0; j < 16; j++) {
65 
66 /* caution, the RFC says its "C[j] = S[M[i*16+j] xor L]" but the reference source code [and test vectors] say
67    otherwise.
68 */
69        L = (md->md2.chksum[j] ^= PI_SUBST[(int)(md->md2.buf[j] ^ L)] & 255);
70    }
71 }
72 
md2_compress(hash_state * md)73 static void md2_compress(hash_state *md)
74 {
75    int j, k;
76    unsigned char t;
77 
78    /* copy block */
79    for (j = 0; j < 16; j++) {
80        md->md2.X[16+j] = md->md2.buf[j];
81        md->md2.X[32+j] = md->md2.X[j] ^ md->md2.X[16+j];
82    }
83 
84    t = (unsigned char)0;
85 
86    /* do 18 rounds */
87    for (j = 0; j < 18; j++) {
88        for (k = 0; k < 48; k++) {
89            t = (md->md2.X[k] ^= PI_SUBST[(int)(t & 255)]);
90        }
91        t = (t + (unsigned char)j) & 255;
92    }
93 }
94 
95 /**
96    Initialize the hash state
97    @param md   The hash state you wish to initialize
98    @return CRYPT_OK if successful
99 */
md2_init(hash_state * md)100 int md2_init(hash_state *md)
101 {
102    LTC_ARGCHK(md != NULL);
103 
104    /* LTC_MD2 uses a zero'ed state... */
105    zeromem(md->md2.X, sizeof(md->md2.X));
106    zeromem(md->md2.chksum, sizeof(md->md2.chksum));
107    zeromem(md->md2.buf, sizeof(md->md2.buf));
108    md->md2.curlen = 0;
109    return CRYPT_OK;
110 }
111 
112 /**
113    Process a block of memory though the hash
114    @param md     The hash state
115    @param in     The data to hash
116    @param inlen  The length of the data (octets)
117    @return CRYPT_OK if successful
118 */
md2_process(hash_state * md,const unsigned char * in,unsigned long inlen)119 int md2_process(hash_state *md, const unsigned char *in, unsigned long inlen)
120 {
121     unsigned long n;
122     LTC_ARGCHK(md != NULL);
123     LTC_ARGCHK(in != NULL);
124     if (md-> md2 .curlen > sizeof(md-> md2 .buf)) {
125        return CRYPT_INVALID_ARG;
126     }
127     while (inlen > 0) {
128         n = MIN(inlen, (16 - md->md2.curlen));
129         XMEMCPY(md->md2.buf + md->md2.curlen, in, (size_t)n);
130         md->md2.curlen += n;
131         in             += n;
132         inlen          -= n;
133 
134         /* is 16 bytes full? */
135         if (md->md2.curlen == 16) {
136             md2_compress(md);
137             md2_update_chksum(md);
138             md->md2.curlen = 0;
139         }
140     }
141     return CRYPT_OK;
142 }
143 
144 /**
145    Terminate the hash to get the digest
146    @param md  The hash state
147    @param out [out] The destination of the hash (16 bytes)
148    @return CRYPT_OK if successful
149 */
md2_done(hash_state * md,unsigned char * out)150 int md2_done(hash_state * md, unsigned char *out)
151 {
152     unsigned long i, k;
153 
154     LTC_ARGCHK(md  != NULL);
155     LTC_ARGCHK(out != NULL);
156 
157     if (md->md2.curlen >= sizeof(md->md2.buf)) {
158        return CRYPT_INVALID_ARG;
159     }
160 
161 
162     /* pad the message */
163     k = 16 - md->md2.curlen;
164     for (i = md->md2.curlen; i < 16; i++) {
165         md->md2.buf[i] = (unsigned char)k;
166     }
167 
168     /* hash and update */
169     md2_compress(md);
170     md2_update_chksum(md);
171 
172     /* hash checksum */
173     XMEMCPY(md->md2.buf, md->md2.chksum, 16);
174     md2_compress(md);
175 
176     /* output is lower 16 bytes of X */
177     XMEMCPY(out, md->md2.X, 16);
178 
179 #ifdef LTC_CLEAN_STACK
180     zeromem(md, sizeof(hash_state));
181 #endif
182     return CRYPT_OK;
183 }
184 
185 /**
186   Self-test the hash
187   @return CRYPT_OK if successful, CRYPT_NOP if self-tests have been disabled
188 */
md2_test(void)189 int md2_test(void)
190 {
191  #ifndef LTC_TEST
192     return CRYPT_NOP;
193  #else
194    static const struct {
195         const char *msg;
196         unsigned char hash[16];
197    } tests[] = {
198       { "",
199         {0x83,0x50,0xe5,0xa3,0xe2,0x4c,0x15,0x3d,
200          0xf2,0x27,0x5c,0x9f,0x80,0x69,0x27,0x73
201         }
202       },
203       { "a",
204         {0x32,0xec,0x01,0xec,0x4a,0x6d,0xac,0x72,
205          0xc0,0xab,0x96,0xfb,0x34,0xc0,0xb5,0xd1
206         }
207       },
208       { "message digest",
209         {0xab,0x4f,0x49,0x6b,0xfb,0x2a,0x53,0x0b,
210          0x21,0x9f,0xf3,0x30,0x31,0xfe,0x06,0xb0
211         }
212       },
213       { "abcdefghijklmnopqrstuvwxyz",
214         {0x4e,0x8d,0xdf,0xf3,0x65,0x02,0x92,0xab,
215          0x5a,0x41,0x08,0xc3,0xaa,0x47,0x94,0x0b
216         }
217       },
218       { "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789",
219         {0xda,0x33,0xde,0xf2,0xa4,0x2d,0xf1,0x39,
220          0x75,0x35,0x28,0x46,0xc3,0x03,0x38,0xcd
221         }
222       },
223       { "12345678901234567890123456789012345678901234567890123456789012345678901234567890",
224         {0xd5,0x97,0x6f,0x79,0xd8,0x3d,0x3a,0x0d,
225          0xc9,0x80,0x6c,0x3c,0x66,0xf3,0xef,0xd8
226         }
227       }
228    };
229 
230    int i;
231    unsigned char tmp[16];
232    hash_state md;
233 
234    for (i = 0; i < (int)(sizeof(tests) / sizeof(tests[0])); i++) {
235        md2_init(&md);
236        md2_process(&md, (unsigned char*)tests[i].msg, (unsigned long)strlen(tests[i].msg));
237        md2_done(&md, tmp);
238        if (compare_testvector(tmp, sizeof(tmp), tests[i].hash, sizeof(tests[i].hash), "MD2", i)) {
239           return CRYPT_FAIL_TESTVECTOR;
240        }
241    }
242    return CRYPT_OK;
243   #endif
244 }
245 
246 #endif
247 
248 
249 /* ref:         $Format:%D$ */
250 /* git commit:  $Format:%H$ */
251 /* commit time: $Format:%ai$ */
252