1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
|
/* Copyright (C) 2022 June McEnroe <june@causal.agency>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <SDL_rwops.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
static void errx(int eval, const char *fmt, ...) {
va_list ap;
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
putc('\n', stderr);
exit(eval);
}
static void err(int eval, const char *fmt, ...) {
va_list ap;
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
fprintf(stderr, ": %s\n", SDL_GetError());
exit(eval);
}
int main(int argc, char *argv[]) {
if (argc < 2) return 1;
const char *exePath = argv[1];
const char *name = strrchr(exePath, '/');
name = (name ? &name[1] : exePath);
char icoPath[256];
snprintf(
icoPath, sizeof(icoPath), "%.*s.ICO", (int)strcspn(name, "."), name
);
SDL_RWops *exe = SDL_RWFromFile(exePath, "rb");
if (!exe) err(1, "%s", exePath);
SDL_RWops *ico = SDL_RWFromFile(icoPath, "wb");
if (!ico) err(1, "%s", icoPath);
// Read the EXE header
if (SDL_ReadU8(exe) != 'M' || SDL_ReadU8(exe) != 'Z') {
errx(1, "%s: invalid MZ signature", exePath);
}
SDL_RWseek(exe, 0x3C, RW_SEEK_SET);
Uint16 neOffset = SDL_ReadLE16(exe);
SDL_RWseek(exe, neOffset, RW_SEEK_SET);
Uint8 sig[2] = { SDL_ReadU8(exe), SDL_ReadU8(exe) };
if (sig[0] == 'P' && sig[1] == 'E') {
errx(1, "%s: not implemented for PE", exePath);
}
if (sig[0] != 'N' || sig[1] != 'E') {
errx(1, "%s: invalid NE/PE signature", exePath);
}
// Read the NE header
SDL_RWseek(exe, neOffset + 0x24, RW_SEEK_SET);
Uint16 resourceTableOffset = neOffset + SDL_ReadLE16(exe);
// Find the RT_GROUP_ICON resource
SDL_RWseek(exe, resourceTableOffset, RW_SEEK_SET);
Uint16 alignmentShift = SDL_ReadLE16(exe);
for (;;) {
Uint16 typeID = SDL_ReadLE16(exe);
Uint16 count = SDL_ReadLE16(exe);
SDL_ReadLE32(exe); // reserved
if (!typeID) {
errx(1, "%s: no group icon resource", exePath);
}
if (typeID == 0x800E) break;
SDL_RWseek(exe, 0x0C * count, RW_SEEK_CUR);
}
// Copy the ICONHEADER
// https://devblogs.microsoft.com/oldnewthing/20101018-00/?p=12513
SDL_RWseek(exe, (Uint32)SDL_ReadLE16(exe) << alignmentShift, RW_SEEK_SET);
SDL_WriteLE16(ico, SDL_ReadLE16(exe)); // reserved
SDL_WriteLE16(ico, SDL_ReadLE16(exe)); // type
Uint16 iconDirCount = SDL_ReadLE16(exe);
SDL_WriteLE16(ico, iconDirCount);
// Copy ICONDIRENTRY's. The entries in the RT_GROUP_ICON resource differ
// from those in ICO in their last field. In ICO, it is a 32-bit offset
// of the icon data in the ICO file. In the resource, it is a 16-bit
// resource ID of an RT_ICON resource. Here we assume the resources are
// in the same order as the entries referencing them. We translate the
// resource IDs into data offsets by simply tallying up the data lengths
// so far. The data offsets need to be aligned to alignmentShift to match
// up with the lengths of the icon resources.
Uint32 iconDirLength = 0x06 + 0x10 * iconDirCount;
Uint32 dataOffset = iconDirLength;
dataOffset += -dataOffset & ((1 << alignmentShift) - 1);
for (Uint16 i = 0; i < iconDirCount; ++i) {
SDL_WriteU8(ico, SDL_ReadU8(exe)); // width
SDL_WriteU8(ico, SDL_ReadU8(exe)); // height
SDL_WriteU8(ico, SDL_ReadU8(exe)); // colors
SDL_WriteU8(ico, SDL_ReadU8(exe)); // reserved
SDL_WriteLE16(ico, SDL_ReadLE16(exe)); // color planes
SDL_WriteLE16(ico, SDL_ReadLE16(exe)); // bits per pixel
Uint32 dataLength = SDL_ReadLE32(exe);
SDL_ReadLE16(exe); // resource ID, assumed sequential
SDL_WriteLE32(ico, dataLength);
SDL_WriteLE32(ico, dataOffset);
dataOffset += dataLength;
dataOffset += -dataOffset & ((1 << alignmentShift) - 1);
}
// Padding before the first aligned data offset
for (Uint8 i = 0; i < (-iconDirLength & ((1 << alignmentShift) - 1)); ++i) {
SDL_WriteU8(ico, 0);
}
// Find the RT_ICON resources
SDL_RWseek(exe, resourceTableOffset + 0x02, RW_SEEK_SET);
Uint16 resourceCount;
for (;;) {
Uint16 typeID = SDL_ReadLE16(exe);
resourceCount = SDL_ReadLE16(exe);
SDL_ReadLE32(exe); // reserved
if (!typeID) {
errx(1, "%s: no icon resources", exePath);
}
if (typeID == 0x8003) break;
SDL_RWseek(exe, 0x0C * resourceCount, RW_SEEK_CUR);
}
// Copy all icon data sequentially
Uint8 *data = NULL;
for (Uint16 i = 0; i < resourceCount; ++i) {
Uint32 dataOffset = (Uint32)SDL_ReadLE16(exe) << alignmentShift;
Uint32 dataLength = (Uint32)SDL_ReadLE16(exe) << alignmentShift;
SDL_ReadLE16(exe); // flags
SDL_ReadLE16(exe); // resource ID
SDL_ReadLE32(exe); // reserved
Sint64 nextResource = SDL_RWtell(exe);
if (nextResource < 0) err(1, "%s", exePath);
SDL_RWseek(exe, dataOffset, RW_SEEK_SET);
data = realloc(data, dataLength);
if (!data) errx(1, "malloc failed");
size_t num = SDL_RWread(exe, data, dataLength, 1);
if (!num) err(1, "%s", exePath);
num = SDL_RWwrite(ico, data, dataLength, 1);
if (!num) err(1, "%s", icoPath);
SDL_RWseek(exe, nextResource, RW_SEEK_SET);
}
free(data);
SDL_RWclose(ico);
SDL_RWclose(exe);
}
|