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
|
/*
* Copyright (c) 2015 Egor Tensin <Egor.Tensin@gmail.com>
* This file is part of the "AES tools" project.
* For details, see https://github.com/egor-tensin/aes-tools.
* Distributed under the MIT License.
*/
#include <aes/all.h>
#include <assert.h>
#include <stdlib.h>
#include <string.h>
static AES_StatusCode aes_extract_padding_size_pkcs7(
const void* src,
size_t src_size,
size_t* padding_size,
AES_ErrorDetails* err_details)
{
const unsigned char* cursor = (const unsigned char*) src + src_size - 1;
*padding_size = *cursor;
for (size_t i = 1; i < *padding_size; ++i)
if (cursor[0 - i] != *padding_size)
return aes_error_invalid_pkcs7_padding(err_details);
return AES_SUCCESS;
}
AES_StatusCode aes_extract_padding_size(
AES_PaddingMethod method,
const void* src,
size_t src_size,
size_t* padding_size,
AES_ErrorDetails* err_details)
{
assert(src);
assert(padding_size);
if (src == NULL)
return aes_error_null_argument(err_details, "src");
if (padding_size == NULL)
return aes_error_null_argument(err_details, "padding_size");
switch (method)
{
case AES_PADDING_PKCS7:
return aes_extract_padding_size_pkcs7(
src, src_size, padding_size, err_details);
default:
return aes_error_not_implemented(
err_details, "unsupported padding method");
}
}
static AES_StatusCode aes_fill_with_padding_pkcs7(
void* dest,
size_t padding_size,
AES_ErrorDetails* err_details)
{
AES_UNUSED_PARAMETER(err_details);
memset(dest, (int) padding_size, padding_size);
return AES_SUCCESS;
}
AES_StatusCode aes_fill_with_padding(
AES_PaddingMethod method,
void* dest,
size_t padding_size,
AES_ErrorDetails* err_details)
{
assert(dest);
if (dest == NULL)
return aes_error_null_argument(err_details, "dest");
switch (method)
{
case AES_PADDING_PKCS7:
return aes_fill_with_padding_pkcs7(
dest, padding_size, err_details);
default:
return aes_error_not_implemented(
err_details, "unsupported padding method");
}
}
|
