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
|
/********************************************************/
/* ntapi: Native API core library */
/* Copyright (C) 2013--2016 Z. Gilboa */
/* Released under GPLv2 and GPLv3; see COPYING.NTAPI. */
/********************************************************/
#include <psxtypes/psxtypes.h>
#include <pemagine/pemagine.h>
#include <ntapi/nt_object.h>
#include <ntapi/nt_crc32.h>
#include <ntapi/ntapi.h>
#include "ntapi_impl.h"
struct callback_ctx {
void * import_table;
ntapi_hashed_symbol * hash_table;
uint32_t hash_table_array_size;
};
static int __process_exported_symbol(
const void * base,
struct pe_export_hdr * exp_hdr,
struct pe_export_sym * exp_item,
enum pe_callback_reason reason,
void * context)
{
uint32_t hash_value;
struct callback_ctx * ctx;
ntapi_hashed_symbol * hashed_symbol;
uintptr_t * fnptr;
/* binary search variables */
uint32_t lower;
uint32_t upper;
uint32_t idx;
if (reason != PE_CALLBACK_REASON_ITEM)
return 1;
ctx = (struct callback_ctx *)context;
hash_value = __ntapi_tt_mbstr_crc32(exp_item->name);
/* zero-based array, binary search, idx < upper is guaranteed */
lower = 0;
upper = ctx->hash_table_array_size;
/* binary search */
while (lower < upper) {
idx = (lower + upper) / 2;
hashed_symbol = (ntapi_hashed_symbol *)
((uintptr_t)ctx->hash_table
+ idx * sizeof(ntapi_hashed_symbol));
if (hash_value == hashed_symbol->crc32_hash) {
fnptr = (uintptr_t *)(
(uintptr_t)ctx->import_table
+ (sizeof(uintptr_t)
* hashed_symbol->ordinal));
*fnptr = (uintptr_t)exp_item->addr;
return 1;
}
else {
if (hash_value > hashed_symbol->crc32_hash)
lower = idx + 1;
else
upper = idx;
}
}
return 1;
}
int32_t __cdecl __ntapi_tt_populate_hashed_import_table(
__in void * image_base,
__in void * import_table,
__in ntapi_hashed_symbol * hash_table,
__in uint32_t hash_table_array_size)
{
struct pe_export_sym exp_item;
struct callback_ctx ctx;
ctx.import_table = import_table;
ctx.hash_table = hash_table;
ctx.hash_table_array_size = hash_table_array_size;
pe_enum_image_exports(
image_base,
&__process_exported_symbol,
&exp_item,
&ctx);
return 0;
}
|
