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Diffstat (limited to 'firmware/target/arm/pp/mi4-loader.c')
-rw-r--r-- | firmware/target/arm/pp/mi4-loader.c | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/firmware/target/arm/pp/mi4-loader.c b/firmware/target/arm/pp/mi4-loader.c new file mode 100644 index 0000000000..c465b898b4 --- /dev/null +++ b/firmware/target/arm/pp/mi4-loader.c | |||
@@ -0,0 +1,237 @@ | |||
1 | /*************************************************************************** | ||
2 | * __________ __ ___. | ||
3 | * Open \______ \ ____ ____ | | _\_ |__ _______ ___ | ||
4 | * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / | ||
5 | * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < | ||
6 | * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ | ||
7 | * \/ \/ \/ \/ \/ | ||
8 | * | ||
9 | * Copyright (C) 2006 by Barry Wardell | ||
10 | * | ||
11 | * Based on Rockbox iriver bootloader by Linus Nielsen Feltzing | ||
12 | * and the ipodlinux bootloader by Daniel Palffy and Bernard Leach | ||
13 | * | ||
14 | * This program is free software; you can redistribute it and/or | ||
15 | * modify it under the terms of the GNU General Public License | ||
16 | * as published by the Free Software Foundation; either version 2 | ||
17 | * of the License, or (at your option) any later version. | ||
18 | * | ||
19 | * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY | ||
20 | * KIND, either express or implied. | ||
21 | * | ||
22 | ****************************************************************************/ | ||
23 | |||
24 | #include <stdbool.h> | ||
25 | #include <stdio.h> | ||
26 | #include "config.h" | ||
27 | #include "mi4-loader.h" | ||
28 | #include "loader_strerror.h" | ||
29 | #include "crc32-mi4.h" | ||
30 | #include "file.h" | ||
31 | |||
32 | static inline unsigned int le2int(unsigned char* buf) | ||
33 | { | ||
34 | int32_t res = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0]; | ||
35 | |||
36 | return res; | ||
37 | } | ||
38 | |||
39 | static inline void int2le(unsigned int val, unsigned char* addr) | ||
40 | { | ||
41 | addr[0] = val & 0xFF; | ||
42 | addr[1] = (val >> 8) & 0xff; | ||
43 | addr[2] = (val >> 16) & 0xff; | ||
44 | addr[3] = (val >> 24) & 0xff; | ||
45 | } | ||
46 | |||
47 | static struct tea_key tea_keytable[] = { | ||
48 | { "default" , { 0x20d36cc0, 0x10e8c07d, 0xc0e7dcaa, 0x107eb080 } }, | ||
49 | { "sansa", { 0xe494e96e, 0x3ee32966, 0x6f48512b, 0xa93fbb42 } }, | ||
50 | { "sansa_gh", { 0xd7b10538, 0xc662945b, 0x1b3fce68, 0xf389c0e6 } }, | ||
51 | { "sansa_103", { 0x1d29ddc0, 0x2579c2cd, 0xce339e1a, 0x75465dfe } }, | ||
52 | { "rhapsody", { 0x7aa9c8dc, 0xbed0a82a, 0x16204cc7, 0x5904ef38 } }, | ||
53 | { "p610", { 0x950e83dc, 0xec4907f9, 0x023734b9, 0x10cfb7c7 } }, | ||
54 | { "p640", { 0x220c5f23, 0xd04df68e, 0x431b5e25, 0x4dcc1fa1 } }, | ||
55 | { "virgin", { 0xe83c29a1, 0x04862973, 0xa9b3f0d4, 0x38be2a9c } }, | ||
56 | { "20gc_eng", { 0x0240772c, 0x6f3329b5, 0x3ec9a6c5, 0xb0c9e493 } }, | ||
57 | { "20gc_fre", { 0xbede8817, 0xb23bfe4f, 0x80aa682d, 0xd13f598c } }, | ||
58 | { "elio_p722", { 0x6af3b9f8, 0x777483f5, 0xae8181cc, 0xfa6d8a84 } }, | ||
59 | { "c200", { 0xbf2d06fa, 0xf0e23d59, 0x29738132, 0xe2d04ca7 } }, | ||
60 | { "c200_103", { 0x2a7968de, 0x15127979, 0x142e60a7, 0xe49c1893 } }, | ||
61 | { "c200_106", { 0xa913d139, 0xf842f398, 0x3e03f1a6, 0x060ee012 } }, | ||
62 | { "view", { 0x70e19bda, 0x0c69ea7d, 0x2b8b1ad1, 0xe9767ced } }, | ||
63 | { "sa9200", { 0x33ea0236, 0x9247bdc5, 0xdfaedf9f, 0xd67c9d30 } }, | ||
64 | { "hdd1630/hdd63x0", { 0x04543ced, 0xcebfdbad, 0xf7477872, 0x0d12342e } }, | ||
65 | { "vibe500", { 0xe3a66156, 0x77c6b67a, 0xe821dca5, 0xca8ca37c } }, | ||
66 | }; | ||
67 | |||
68 | /* | ||
69 | |||
70 | tea_decrypt() from http://en.wikipedia.org/wiki/Tiny_Encryption_Algorithm | ||
71 | |||
72 | "Following is an adaptation of the reference encryption and decryption | ||
73 | routines in C, released into the public domain by David Wheeler and | ||
74 | Roger Needham:" | ||
75 | |||
76 | */ | ||
77 | |||
78 | /* NOTE: The mi4 version of TEA uses a different initial value to sum compared | ||
79 | to the reference implementation and the main loop is 8 iterations, not | ||
80 | 32. | ||
81 | */ | ||
82 | |||
83 | static void tea_decrypt(uint32_t* v0, uint32_t* v1, uint32_t* k) { | ||
84 | uint32_t sum=0xF1BBCDC8, i; /* set up */ | ||
85 | uint32_t delta=0x9E3779B9; /* a key schedule constant */ | ||
86 | uint32_t k0=k[0], k1=k[1], k2=k[2], k3=k[3]; /* cache key */ | ||
87 | for(i=0; i<8; i++) { /* basic cycle start */ | ||
88 | *v1 -= ((*v0<<4) + k2) ^ (*v0 + sum) ^ ((*v0>>5) + k3); | ||
89 | *v0 -= ((*v1<<4) + k0) ^ (*v1 + sum) ^ ((*v1>>5) + k1); | ||
90 | sum -= delta; /* end cycle */ | ||
91 | } | ||
92 | } | ||
93 | |||
94 | /* mi4 files are encrypted in 64-bit blocks (two little-endian 32-bit | ||
95 | integers) and the key is incremented after each block | ||
96 | */ | ||
97 | |||
98 | static void tea_decrypt_buf(unsigned char* src, | ||
99 | unsigned char* dest, | ||
100 | size_t n, uint32_t * key) | ||
101 | { | ||
102 | uint32_t v0, v1; | ||
103 | unsigned int i; | ||
104 | |||
105 | for (i = 0; i < (n / 8); i++) { | ||
106 | v0 = le2int(src); | ||
107 | v1 = le2int(src+4); | ||
108 | |||
109 | tea_decrypt(&v0, &v1, key); | ||
110 | |||
111 | int2le(v0, dest); | ||
112 | int2le(v1, dest+4); | ||
113 | |||
114 | src += 8; | ||
115 | dest += 8; | ||
116 | |||
117 | /* Now increment the key */ | ||
118 | key[0]++; | ||
119 | if (key[0]==0) { | ||
120 | key[1]++; | ||
121 | if (key[1]==0) { | ||
122 | key[2]++; | ||
123 | if (key[2]==0) { | ||
124 | key[3]++; | ||
125 | } | ||
126 | } | ||
127 | } | ||
128 | } | ||
129 | } | ||
130 | |||
131 | static int tea_find_key(struct mi4header_t *mi4header, unsigned char* buf) | ||
132 | { | ||
133 | unsigned int i; | ||
134 | uint32_t key[4]; | ||
135 | uint32_t keyinc; | ||
136 | unsigned char magic_dec[8]; | ||
137 | int key_found = -1; | ||
138 | unsigned int magic_location = mi4header->length-4; | ||
139 | int unaligned = 0; | ||
140 | |||
141 | if ( (magic_location % 8) != 0 ) | ||
142 | { | ||
143 | unaligned = 1; | ||
144 | magic_location -= 4; | ||
145 | } | ||
146 | |||
147 | for (i=0; i < NUM_KEYS && (key_found<0) ; i++) { | ||
148 | key[0] = tea_keytable[i].key[0]; | ||
149 | key[1] = tea_keytable[i].key[1]; | ||
150 | key[2] = tea_keytable[i].key[2]; | ||
151 | key[3] = tea_keytable[i].key[3]; | ||
152 | |||
153 | /* Now increment the key */ | ||
154 | keyinc = (magic_location-mi4header->plaintext)/8; | ||
155 | if ((key[0]+keyinc) < key[0]) key[1]++; | ||
156 | key[0] += keyinc; | ||
157 | if (key[1]==0) key[2]++; | ||
158 | if (key[2]==0) key[3]++; | ||
159 | |||
160 | /* Decrypt putative magic */ | ||
161 | tea_decrypt_buf(&buf[magic_location], magic_dec, 8, key); | ||
162 | |||
163 | if (le2int(&magic_dec[4*unaligned]) == 0xaa55aa55) | ||
164 | { | ||
165 | key_found = i; | ||
166 | } | ||
167 | } | ||
168 | |||
169 | return key_found; | ||
170 | } | ||
171 | |||
172 | /* Load mi4 format firmware image */ | ||
173 | int load_mi4(unsigned char* buf, | ||
174 | const char* firmware, | ||
175 | unsigned int buffer_size) | ||
176 | { | ||
177 | int fd; | ||
178 | struct mi4header_t mi4header; | ||
179 | int rc; | ||
180 | unsigned long sum; | ||
181 | char filename[MAX_PATH]; | ||
182 | |||
183 | snprintf(filename,sizeof(filename), BOOTDIR "/%s",firmware); | ||
184 | fd = open(filename, O_RDONLY); | ||
185 | if(fd < 0) | ||
186 | { | ||
187 | snprintf(filename,sizeof(filename),"/%s",firmware); | ||
188 | fd = open(filename, O_RDONLY); | ||
189 | if(fd < 0) | ||
190 | return EFILE_NOT_FOUND; | ||
191 | } | ||
192 | |||
193 | read(fd, &mi4header, MI4_HEADER_SIZE); | ||
194 | |||
195 | /* MI4 file size */ | ||
196 | if ((mi4header.mi4size-MI4_HEADER_SIZE) > buffer_size) | ||
197 | { | ||
198 | close(fd); | ||
199 | return EFILE_TOO_BIG; | ||
200 | } | ||
201 | |||
202 | /* Load firmware file */ | ||
203 | lseek(fd, MI4_HEADER_SIZE, SEEK_SET); | ||
204 | rc = read(fd, buf, mi4header.mi4size-MI4_HEADER_SIZE); | ||
205 | close(fd); | ||
206 | if(rc < (int)mi4header.mi4size-MI4_HEADER_SIZE) | ||
207 | return EREAD_IMAGE_FAILED; | ||
208 | |||
209 | /* Check CRC32 to see if we have a valid file */ | ||
210 | sum = chksum_crc32 (buf, mi4header.mi4size - MI4_HEADER_SIZE); | ||
211 | |||
212 | if(sum != mi4header.crc32) | ||
213 | return EBAD_CHKSUM; | ||
214 | |||
215 | if( (mi4header.plaintext + MI4_HEADER_SIZE) != mi4header.mi4size) | ||
216 | { | ||
217 | /* Load encrypted firmware */ | ||
218 | int key_index = tea_find_key(&mi4header, buf); | ||
219 | |||
220 | if (key_index < 0) | ||
221 | return EINVALID_FORMAT; | ||
222 | |||
223 | /* Plaintext part is already loaded */ | ||
224 | buf += mi4header.plaintext; | ||
225 | |||
226 | /* Decrypt in-place */ | ||
227 | tea_decrypt_buf(buf, buf, | ||
228 | mi4header.mi4size-(mi4header.plaintext+MI4_HEADER_SIZE), | ||
229 | tea_keytable[key_index].key); | ||
230 | |||
231 | /* Check decryption was successfull */ | ||
232 | if(le2int(&buf[mi4header.length-mi4header.plaintext-4]) != 0xaa55aa55) | ||
233 | return EREAD_IMAGE_FAILED; | ||
234 | } | ||
235 | |||
236 | return mi4header.mi4size - MI4_HEADER_SIZE; | ||
237 | } | ||