Delphi 编写【数字签名验证】并获取签名信息

  一个客户想通过编程实现验证程序自身的数字签名来确保程序的完整性,防范病毒感染以及防止一些无聊人士的修改(通过十六进制编辑器替换一些版权、网址、LOGO..); 为此我做了一个数字签名验证的小例子,其中也有获取签名者信息的方法,以满足“自验证”的需求。

示例:

WinAPI:

  • 安全编录(CAT)
      CryptCATAdminReleaseCatalogContext
      CryptCATCatalogInfoFromContext
      CryptCATAdminEnumCatalogFromHash
      CryptCATAdminCalcHashFromFileHandle
      CryptCATAdminReleaseContext
      CryptCATAdminAcquireContext
  • 验证文件的签名(主API)
      WinVerifyTrust
  • 获取签名信息
      WTHelperProvDataFromStateData
  • 获取证书名字信息
      CertGetNameString

代码:

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
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
{
* by: HouSoft
* site: www.yryz.net
* created: 2012/02/03
}
unit Unit1;

interface

uses
Windows, Sysutils, jwaWinCrypt, WinTrustApi;

procedure Test;

implementation

procedure PrintCertChain(pCertChain: PCERT_SIMPLE_CHAIN);
var
I: Integer;
sBuf: string;
begin
// 开启指针运算
{$POINTERMATH ON}
//
// 输出书链元素
for I := pCertChain^.cElement - 1 downto 0 do
begin
SetLength(sBuf, 1024);
SetLength(sBuf,
CertGetNameString(
pCertChain^.rgpElement[I].pCertContext,
CERT_NAME_SIMPLE_DISPLAY_TYPE, // 简单名字
0,
nil,
PChar(sBuf),
Length(sBuf)) - 1);

WriteLn(#9, StringOfChar(' ', 2 * (pCertChain^.cElement - I - 1)), sBuf);
end;
end;

procedure OutSignerInfo(hWVTStateData: THANDLE);
var
provData: PCRYPT_PROVIDER_DATA;
LSysTime: TSystemTime;
begin
// 获取签名信息
// http://msdn.microsoft.com/ZH-CN/library/windows/desktop/aa388429(v=vs.85).aspx

provData := WTHelperProvDataFromStateData(hWVTStateData);
if (provData <> nil) and (provData^.pasSigners <> nil) then
begin
// 采用安全编录(CAT)签名
if provData^.pPDSip^.psSipCATSubjectInfo <> nil then
begin
WriteLn('安全编录: ');
WriteLn(#9, provData^.pPDSip^.psSipCATSubjectInfo^.pwsFileName);
WriteLn('');
end;

/// 注意: provData^.pasSigners 是数组, 但常见的都是一个元素,so...

// 时间戳
if provData^.pasSigners^.pasCounterSigners <> nil then
begin
FileTimeToSystemTime(provData^.pasSigners^.pasCounterSigners^.sftVerifyAsOf, LSysTime);
WriteLn('时间戳: ');
WriteLn(#9, FormatDateTime('yyyy-MM-dd hh:mm:ss', SystemTimeToDateTime(LSysTime)));
WriteLn('');
WriteLn('时间戳证书链: ');
PrintCertChain(provData^.pasSigners^.pasCounterSigners^.pChainContext^.rgpChain[0]);
WriteLn('');
end;

WriteLn('签名者证书链:');
PrintCertChain(provData^.pasSigners^.pChainContext^.rgpChain[0]);
WriteLn('');
end;
end;

function SignVerify(FileName: string): Boolean;
var
aByteHash: array [0 .. 255] of Byte;
iByteCount: Integer;

hCatAdminContext: HCatAdmin;
WTrustData: WINTRUST_DATA;
WTDCatalogInfo: WINTRUST_CATALOG_INFO;
WTDFileInfo: WINTRUST_FILE_INFO;
CatalogInfo: CATALOG_INFO;

hFile: THANDLE;
hCatalogContext: THANDLE;

swFilename: WideString;
swMemberTag: WideString;

ilRet: Longint;
I: Integer;
begin
Result := False;

if not FileExists(FileName) then
Exit;

swFilename := FileName;

ZeroMemory(@CatalogInfo, SizeOf(CatalogInfo));
ZeroMemory(@WTDFileInfo, SizeOf(WTDFileInfo));
ZeroMemory(@WTDCatalogInfo, SizeOf(WTDCatalogInfo));
ZeroMemory(@WTrustData, SizeOf(WTrustData));

hCatalogContext := 0;
hCatAdminContext := 0;

try
// 先查询安全编目
if not CryptCATAdminAcquireContext(@hCatAdminContext,
nil,
0) then
Exit;

hFile := CreateFile(PChar(FileName),
GENERIC_READ,
FILE_SHARE_READ,
nil,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL,
0);

if hFile = INVALID_HANDLE_VALUE then
Exit;

iByteCount := SizeOf(aByteHash);

// 文件哈希函数计算的
CryptCATAdminCalcHashFromFileHandle(hFile,
@iByteCount,
@aByteHash,
0);

for i := 0 to iByteCount - 1 do
begin
swMemberTag := swMemberTag + IntToHex(aByteHash[i], 2);
end;

CloseHandle(hFile);

// 枚举目录包含一个指定的哈希
hCatalogContext := CryptCATAdminEnumCatalogFromHash(hCatAdminContext,
@aByteHash,
iByteCount,
0,
nil);

// 准备验证参数
// http://msdn.microsoft.com/en-us/library/windows/desktop/aa388205(v=vs.85).aspx

WTrustData.dwUIChoice := WTD_UI_NONE;
WTrustData.fdwRevocationChecks := WTD_REVOKE_NONE;
WTrustData.dwStateAction := WTD_STATEACTION_VERIFY; // 获取信息后需要手动 WTD_STATEACTION_CLOSE
WTrustData.dwProvFlags := WTD_REVOCATION_CHECK_NONE;

if hCatalogContext = 0 then // 未找到包含此文件的安全编目
begin
WTDFileInfo.cbStruct := SizeOf(WTDFileInfo);
WTDFileInfo.pcwszFilePath := PWideChar(swFilename);

WTrustData.cbStruct := SizeOf(WTrustData);
WTrustData.dwUnionChoice := WTD_CHOICE_FILE;
WTrustData.union.pFile := @WTDFileInfo;

end
else
begin
CryptCATCatalogInfoFromContext(hCatalogContext, @CatalogInfo, 0);

WTDCatalogInfo.cbStruct := SizeOf(WTDCatalogInfo);
WTDCatalogInfo.pcwszCatalogFilePath := CatalogInfo.sCatalogFile;
WTDCatalogInfo.pcwszMemberFilePath := PWideChar(swFilename);
WTDCatalogInfo.pcwszMemberTag := PWideChar(swMemberTag);

WTrustData.cbStruct := SizeOf(WTrustData);
WTrustData.dwUnionChoice := WTD_CHOICE_CATALOG;
WTrustData.union.pCatalog := @WTDCatalogInfo;

// WriteLn(CatalogInfo.sCatalogFile);
end;

// 验证
// http://msdn.microsoft.com/en-us/library/windows/desktop/aa388208(v=vs.85).aspx
ilRet := WinVerifyTrust(INVALID_HANDLE_VALUE,
@WINTRUST_ACTION_GENERIC_VERIFY_V2,
@WTrustData);

Result := ilRet = 0;

// 输出签名信息
OutSignerInfo(WTrustData.hWVTStateData);

// 释放
WTrustData.dwStateAction := WTD_STATEACTION_CLOSE;
WinVerifyTrust(INVALID_HANDLE_VALUE,
@WINTRUST_ACTION_GENERIC_VERIFY_V2,
@WTrustData);
finally
if hCatAdminContext > 0 then
begin
if hCatalogContext > 0 then
CryptCATAdminReleaseCatalogContext(hCatAdminContext,
hCatalogContext, 0);

CryptCATAdminReleaseContext(hCatAdminContext, 0);
end;
end;
end;

procedure Test;
begin
if ParamCount < 1 then
begin
WriteLn('请输入要验证的文件名!');
Exit;
end;

if SignVerify(ParamStr(1)) then
WriteLn('签名有效.')
else
WriteLn('签名无效.');
end;

end.