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authoritsme <itsme@xs4all.nl>2021-07-09 17:13:12 +0200
committeritsme <itsme@xs4all.nl>2021-07-09 17:14:20 +0200
commit52532242ef38937387fac2303e0371860a15caa3 (patch)
treeaff67efe6a796e3335b8f420ba7d0ec13dca3189 /docs/cronos-research.md
parent277f905849f9a050089049b2c84c45fac6203045 (diff)
updated documentation
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@@ -21,44 +21,55 @@ On a default Windows installation, the CronosPro app shows with several encoding
21 21
22##Files ending in .dat 22##Files ending in .dat
23 23
24All .dat files start with the string `"CroFile\0"` and then 8 more header bytes 24All .dat files start with a 19 byte header:
25 25
26`CroStru.dat` has 26 char magic[9] // allways: 'CroFile\x00'
27 uint16 unknown
28 char version[5] // 01.02, 01.03, 01.04
29 uint16 encoding // 1 = KOD, 3 = encrypted
30 uint16 blocksize // 0040 = Bank, 0400 = Index, 0200 = Stru
31
32This is followed by a block of 0x101 or 0x100 minus 19 bytes seemingly random data.
27 33
28 xx yy 30 31 2e 30 32 01 == ? ? 0 1 . 0 2 ? 34The unknown word is unclear but seems not to be random, might be a checksum.
29 35
36In `CroBank.dat` there's a bias towards 313 times c8 05, 196 times b8 00, 116 times 4e 13, 95 times 00 00, and 81 times 98 00 out of 1964 databases.
30 37
31CroBank.dat and CroIndex.dat have (as found in the big dump) 38In `CroStru.dat` there's a bias towards 351 times c8 05, 224 times b8 00, 119 times 4e 13, 103 times 00 00 and 83 times 98 00 out of 1964 databases.
32 39
33 xx yy 30 31 2e 30 32 0[0123] == ? ? 0 1 . 0 2 ? 40In `CroIndex.dat` there's a bias towards 312 times c8 05, 194 times b8 00, 107 times 4e 13, 107 times 00 00 and 82 times 98 00 out of 1964 databases.
34 41
35 xx yy 30 31 2e 30 33 0[023] == ? ? 0 1 . 0 3 ?
36 42
37 xx yy 30 31 2e 30 34 03 == ? ? 0 1 . 0 4 ? 43##Files ending in .tad
38 44
45The first two `uint32` are the number of deleted records and the tad offset to the first deleted entry.
46The deleted entries form a linked list, with the size always 0xFFFFFFFF.
39 47
40which seems to be the version identifier. The xx yy part is unclear but seems not to be random, might be a checksum. 48Depending on the version in the `.dat` header, `.tad` use either 32 bit or 64 bit file offsets
41 49
42In `CroBank.dat` there's a bias towards 313 times c8 05, 196 times b8 00, 116 times 4e 13, 95 times 00 00, and 81 times 98 00 out of 1964 databases. 50version `01.02` and `01.04` use 32 bit offsets:
43 51
44In `CroStru.dat` there's a bias towards 351 times c8 05, 224 times b8 00, 119 times 4e 13, 103 times 00 00 and 83 times 98 00 out of 1964 databases. 52 uint32 offset
53 uint32 size // with flag in upper bit, 0 -> large record
54 uint32 checksum // but sometimes just 0x00000000, 0x00000001 or 0x00000002
45 55
46In `CroIndex.dat` there's a bias towards 312 times c8 05, 194 times b8 00, 107 times 4e 13, 107 times 00 00 and 82 times 98 00 out of 1964 databases. 56version `01.03` uses 64 bit offsets:
47 57
48##Files ending in .tad 58 uint64 offset
59 uint32 size // with flag in upper bit, 0 -> large record
60 uint32 checksum // but sometimes just 0x00000000, 0x00000001 or 0x00000002
49 61
50The first two `uint32_t` seem to be the amount and the offset to the first free block. 62where size can be 0xffffffff (indicating a free/deleted block).
63Bit 31 of the size indicates that this is an extended record.
51 64
52The original description made it look like there were different formats for the block references, but all entries in the .tads appear to follow the scheme: 65Extended records start with plaintext: { uint32 offset, uint32 size } or { uint64 offset, uint32 size }
53 66
54 uint32_t offset
55 uint32_t size // with flag in upper bit, 0 -> large record
56 uint32_t checksum // but sometimes just 0x00000000, 0x00000001 or 0x00000002
57 67
58where size can be 0xffffffff (probably to indicate a free/deleted block) some size entries have their top bits set. In some files the offset looks garbled but usually the top bit of the size then is set. 68## the 'old format'
69
70The original description made it look like there were different formats for the block references.
59 71
60large records start with plaintext: { uint32 offset, uint32 size? } 72This was found in previously existing documentation, but no sample databases with this format were found so far.
61followed by data obfuscated with 'shift==0'
62 73
63If the .dat file has a version of 01.03 or later, the corresponding .tad file looks like this: 74If the .dat file has a version of 01.03 or later, the corresponding .tad file looks like this:
64 75
@@ -69,12 +80,12 @@ If the .dat file has a version of 01.03 or later, the corresponding .tad file lo
69 80
70The old description would also assume 12 byte reference blocks but a packed struct, probably if the CroFile version is 01.01. 81The old description would also assume 12 byte reference blocks but a packed struct, probably if the CroFile version is 01.01.
71 82
72 uint32_t offset1 83 uint32 offset1
73 uint16_t size1 84 uint16 size1
74 uint32_t offset2 85 uint32 offset2
75 uint16_t size2 86 uint16 size2
76 87
77with the first chunk read from offset1 with length size1 and potentially more parts with total length of size2 starting at file offset offset2 with the first `uint32_t` of the 256 byte chunk being the next chunk's offset and a maximum of 252 bytes being actual data. 88with the first chunk read from offset1 with length size1 and potentially more parts with total length of size2 starting at file offset offset2 with the first `uint32` of the 256 byte chunk being the next chunk's offset and a maximum of 252 bytes being actual data.
78 89
79However, I never found files with .tad like that. Also the original description insisted on those chunks needing the decode-magic outlined below, but the python implementation only does that for CroStru files and still seems to produce results. 90However, I never found files with .tad like that. Also the original description insisted on those chunks needing the decode-magic outlined below, but the python implementation only does that for CroStru files and still seems to produce results.
80 91
@@ -114,7 +125,14 @@ Interesting files are CroStru.dat containing metadata on the database within blo
114 0x7e, 0xab, 0x59, 0x52, 0x54, 0x9c, 0xd2, 0xe9, 125 0x7e, 0xab, 0x59, 0x52, 0x54, 0x9c, 0xd2, 0xe9,
115 0xef, 0xdd, 0x37, 0x1e, 0x8f, 0xcb, 0x8a, 0x90, 126 0xef, 0xdd, 0x37, 0x1e, 0x8f, 0xcb, 0x8a, 0x90,
116 0xfc, 0x84, 0xe5, 0xf9, 0x14, 0x19, 0xdf, 0x6e, 127 0xfc, 0x84, 0xe5, 0xf9, 0x14, 0x19, 0xdf, 0x6e,
117 0x23, 0xc4, 0x66, 0xeb, 0xcc, 0x22, 0x1c, 0x5c }; 128 0x23, 0xc4, 0x66, 0xeb, 0xcc, 0x22, 0x1c, 0x5c,
129 };
130
131
132given the `shift`, the encoded data: `a[0]..a[n-1]` and the decoded data: `b[0]..b[n-1]`, the encoding works as follows:
133
134 decode: b[i] = KOD[a[i]] - (i+shift)
135 encode: a[i] = INV[b[i] + (i+shift)]
118 136
119 137
120The original description of an older database format called the per block counter start offset 'sistN' which seems to imply it to be constant for certain entries. They correspond to a "system number" of meta entries visible in the database software. Where these offsets come from is currently unknown, the existing code just brute forces through all offsets and looks for certain sentinels. 138The original description of an older database format called the per block counter start offset 'sistN' which seems to imply it to be constant for certain entries. They correspond to a "system number" of meta entries visible in the database software. Where these offsets come from is currently unknown, the existing code just brute forces through all offsets and looks for certain sentinels.
@@ -136,11 +154,11 @@ Names are stored as: `byte strlen + char value[strlen]`
136 154
137The first entry contains: 155The first entry contains:
138 156
139 byte 157 uint8
140 array { 158 array {
141 Name keyname 159 Name keyname
142 uint32_t index_or_size; // size when bit31 is set. 160 uint32 index_or_size; // size when bit31 is set.
143 byte data[size] 161 uint8 data[size]
144 } 162 }
145 163
146this results in a dictionary, with keys like: `Bank`, `BankId`, `BankTable`, `Base`nnn, etc. 164this results in a dictionary, with keys like: `Bank`, `BankId`, `BankTable`, `Base`nnn, etc.
@@ -149,27 +167,27 @@ the `Base000` entry contains the record number for the table definition of the f
149 167
150## table definitions 168## table definitions
151 169
152 byte version 170 uint8 version
153 word16 unk1 171 uint16 unk1
154 word16 unk2 172 uint16 unk2
155 word16 unk3 173 uint16 unk3
156 word32 unk4 174 uint32 unk4
157 word32 unk5 175 uint32 unk5
158 Name tablename 176 Name tablename
159 Name unk6 177 Name unk6
160 word32 unk7 178 uint32 unk7
161 word32 nrfields 179 uint32 nrfields
162 180
163 array { 181 array {
164 word16 entrysize -- total nr of bytes in this entry. 182 uint16 entrysize -- total nr of bytes in this entry.
165 word16 fieldtype 0 = sysnum, 2 = text, 4 = number 183 uint16 fieldtype 0 = sysnum, 2 = text, 4 = number
166 word32 fieldindex ?? 184 uint32 fieldindex ??
167 Name fieldname 185 Name fieldname
168 word32 186 uint32
169 byte 187 uint8
170 word32 fieldindex ?? 188 uint32 fieldindex ??
171 word32 fieldsize 189 uint32 fieldsize
172 word32 ? 190 uint32 ?
173 ... 191 ...
174 } fields[nrfields] 192 } fields[nrfields]
175 193
@@ -180,9 +198,9 @@ the `Base000` entry contains the record number for the table definition of the f
180 198
181some records are compressed, the format is like this: 199some records are compressed, the format is like this:
182 200
183 word16 size 201 uint16 size
184 byte head[2] = { 8, 0 } 202 uint8 head[2] = { 8, 0 }
185 word32 crc32 203 uint32 crc32
186 byte compdata[size-4] 204 uint8 compdata[size-4]
187 byte tail[3] = { 0, 0, 2 } 205 uint8 tail[3] = { 0, 0, 2 }
188 206