英文:
How do I properly map CERT_SELECT_STRUCT in JNA
问题
public class Crypto {
public interface Cryptdlg extends Library {
Cryptdlg INSTANCE = (Cryptdlg) Native.loadLibrary("Cryptdlg", Cryptdlg.class, W32APIOptions.DEFAULT_OPTIONS);
public boolean CertSelectCertificate(CERT_SELECT_STRUCT pCertSelectInfo);
public static class CERT_SELECT_STRUCT extends Structure {
// Structure fields and methods definition...
}
}
public void CertSelect() {
Cryptdlg cryptdlg = Cryptdlg.INSTANCE;
Cryptdlg.CERT_SELECT_STRUCT certSel = new Cryptdlg.CERT_SELECT_STRUCT();
certSel.hwndParent = parentHwnd;
certSel.szTitle = "title";
certSel.cCertStore = 1;
certSel.setArrayCertStore(new WinCrypt.HCERTSTORE[] {hCertStore});
pCertSelectInfo.cCertContext = 1;
pCertSelectInfo.arrayCertContext = new Memory(Native.POINTER_SIZE);
pCertSelectInfo.arrayCertContext.setPointer(0, Pointer.NULL);
cryptdlg.CertSelectCertificate(certSel);
// ...
}
}
Note: The code provided is a direct translation of the given Java code, removing any comments or unnecessary information. Please ensure that you have the required dependencies and imports for the classes and methods used in the code.
英文:
I am using jna-4.5.1 in my Java Project.
This is cryptdlg structure CERT_SELECT_STRUCT I want to replicate.
typedef struct tagCSSA {
DWORD dwSize;
HWND hwndParent;
HINSTANCE hInstance;
LPCSTR pTemplateName;
DWORD dwFlags;
LPCSTR szTitle;
DWORD cCertStore;
HCERTSTORE *arrayCertStore;
LPCSTR szPurposeOid;
DWORD cCertContext;
PCCERT_CONTEXT *arrayCertContext;
LPARAM lCustData;
PFNCMHOOKPROC pfnHook;
PFNCMFILTERPROC pfnFilter;
LPCSTR szHelpFileName;
DWORD dwHelpId;
HCRYPTPROV hprov;
} CERT_SELECT_STRUCT_A, *PCERT_SELECT_STRUCT_A;
Sample Java code for my project.
public class Crypto {
public interface Cryptdlg extends Library {
Cryptdlg INSTANCE = (Cryptdlg) Native.loadLibrary("Cryptdlg", Cryptdlg.class, W32APIOptions.DEFAULT_OPTIONS);
public boolean CertSelectCertificate(CERT_SELECT_STRUCT pCertSelectInfo);
public static class CERT_SELECT_STRUCT extends Structure {
private static final List<String> fieldOrder = createFieldsOrder("dwSize", "hwndParent", "hInstance",
"pTemplateName", "dwFlags", "szTitle", "cCertStore", "arrayCertStore", "szPurposeOid",
"cCertContext", "arrayCertContext", "lCustData", "pfnHook", "pfnFilter", "szHelpFileName",
"dwHelpId", "hprov");
public static class ByReference extends CERT_SELECT_STRUCT implements Structure.ByReference {
}
public int dwSize = size();
public HWND hwndParent;
public HINSTANCE hInstance;
public String pTemplateName;
public int dwFlags;
public String szTitle;
public int cCertStore;
public Pointer arrayCertStore;
public String szPurposeOid;
public int cCertContext;
public Pointer arrayCertContext;
public WinDef.LPARAM lCustData;
public Pointer pfnHook = null;
public Pointer pfnFilter = null;
public String szHelpFileName;
public int dwHelpId;
public HCRYPTPROV hprov;
public CERT_SELECT_STRUCT() {
super();
}
public WinCrypt.CERT_CONTEXT[] getArrayCertContext() {
WinCrypt.CERT_CONTEXT[] elements = new WinCrypt.CERT_CONTEXT[cCertContext];
for (int i = 0; i < elements.length; i++) {
elements[i] = (WinCrypt.CERT_CONTEXT) Structure.newInstance(WinCrypt.CERT_CONTEXT.class,
arrayCertContext.getPointer(i * Native.POINTER_SIZE));
elements[i].read();
}
return elements;
}
public void setArrayCertContext(WinCrypt.CERT_CONTEXT[] arrayCertContexts) {
if (arrayCertContexts == null || arrayCertContexts.length == 0) {
arrayCertContext = null;
cCertContext = 0;
} else {
cCertContext = arrayCertContexts.length;
Memory mem = new Memory(Native.POINTER_SIZE * arrayCertContexts.length);
for (int i = 0; i < arrayCertContexts.length; i++) {
mem.setPointer(i * Native.POINTER_SIZE, arrayCertContexts[i].getPointer());
}
arrayCertContext = mem;
}
}
public void setArrayCertStore(WinCrypt.HCERTSTORE[] stores) {
if (stores == null || stores.length == 0) {
arrayCertStore = null;
cCertStore = 0;
} else {
Memory mem = new Memory(Native.POINTER_SIZE * stores.length);
for (int i = 0; i < stores.length; i++) {
mem.setPointer(i * Native.POINTER_SIZE, stores[i].getPointer());
}
cCertStore = stores.length;
arrayCertStore = mem;
}
}
public WinCrypt.HCERTSTORE[] getArrayCertStore() {
if (arrayCertStore == null || cCertStore == 0) {
return new WinCrypt.HCERTSTORE[0];
} else {
WinCrypt.HCERTSTORE[] result = new WinCrypt.HCERTSTORE[cCertStore];
for (int i = 0; i < result.length; i++) {
result[i] = new WinCrypt.HCERTSTORE(arrayCertStore.getPointer(i * Native.POINTER_SIZE));
}
return result;
}
}
@Override
protected List<String> getFieldOrder() {
return fieldOrder;
}
}
}
public void CertSelect() {
Cryptdlg cryptdlg = Cryptdlg.INSTANCE;
...// parentHwnd and hCertStore are initalized and passed to this method
Cryptdlg.CERT_SELECT_STRUCT certSel = new Cryptdlg.CERT_SELECT_STRUCT();
WinCrypt.CERT_CONTEXT[] pContexts = new WinCrypt.CERT_CONTEXT[1];
certSel.hwndParent = parentHwnd;
certSel.szTitle = "title";
certSel.cCertStore = 1;
certSel.setArrayCertStore(new WinCrypt.HCERTSTORE[] {hCertStore});
pCertSelectInfo.cCertContext = 1;
pContexts[0] = new WinCrypt.CERT_CONTEXT.ByReference();
certSel.setArrayCertContext(pContexts);
cryptdlg.CertSelectCertificate(certSel); //line 60
...
}
}
When I call this method I get "java.lang.Error: Invalid memory access" at the dll call cryptdlg.CertSelectCertificate(certSel) at line 60 above.
java.lang.Error: Invalid memory access
at com.sun.jna.Native.invokeInt(Native Method)
at com.sun.jna.Function.invoke(Function.java:419)
at com.sun.jna.Function.invoke(Function.java:354)
at com.sun.jna.Library$Handler.invoke(Library.java:244)
at com.sun.proxy.$Proxy13.CertSelect(Unknown Source)
at com.project.Crypto.CertSelect(Crypto.java:60)
I am not sure why we are getting the exception. I followed the example mentioned here.
[UPDATE]
For what its worth,
When I modify the type of "setArrayCertStore" from Pointer to HCERTSTORE[] I am not getting any exception but no certificate are getting pulled.
It makes me think if arrayCertStore is initalized correctly or not.
WinCrypt.HCERTSTORE[] cStoreArray = new WinCrypt.HCERTSTORE[1];
pCertSelectInfo.cCertStore = 1;
cStoreArray[0] = hCertStore;
pCertSelectInfo.arrayCertStore = cStoreArray;
And the structure definition is changed as follows
public WinCrypt.HCERTSTORE[] arrayCertStore;
And HCRYPTPROV is defined as
public static class HCRYPTPROV extends BaseTSD.ULONG_PTR {
public HCRYPTPROV() {}
public HCRYPTPROV(long value) {
super(value);
}
}
==================================
[EDIT]
After discussion with Daniel and other people. Here is the updated code which works
public class Crypto {
public interface Cryptdlg extends Library {
Cryptdlg INSTANCE = (Cryptdlg) Native.loadLibrary("Cryptdlg", Cryptdlg.class, W32APIOptions.DEFAULT_OPTIONS);
public boolean CertSelectCertificate(CERT_SELECT_STRUCT pCertSelectInfo);
public static class CERT_SELECT_STRUCT extends Structure {
private static final List<String> fieldOrder = createFieldsOrder("dwSize", "hwndParent", "hInstance",
"pTemplateName", "dwFlags", "szTitle", "cCertStore", "arrayCertStore", "szPurposeOid",
"cCertContext", "arrayCertContext", "lCustData", "pfnHook", "pfnFilter", "szHelpFileName",
"dwHelpId", "hprov");
public static class ByReference extends CERT_SELECT_STRUCT implements Structure.ByReference {
}
public int dwSize;
public HWND hwndParent;
public HINSTANCE hInstance;
public String pTemplateName;
public int dwFlags;
public String szTitle;
public int cCertStore;
public Pointer arrayCertStore;
public String szPurposeOid;
public int cCertContext;
public Pointer arrayCertContext;
public WinDef.LPARAM lCustData;
public Pointer pfnHook = null;
public Pointer pfnFilter = null;
public String szHelpFileName;
public int dwHelpId;
public HCRYPTPROV hprov;
public CERT_SELECT_STRUCT() {
super();
}
public WinCrypt.CERT_CONTEXT[] getArrayCertContext() {
WinCrypt.CERT_CONTEXT[] elements = new WinCrypt.CERT_CONTEXT[cCertContext];
for (int i = 0; i < elements.length; i++) {
elements[i] = (WinCrypt.CERT_CONTEXT) Structure.newInstance(WinCrypt.CERT_CONTEXT.class,
arrayCertContext.getPointer(i * Native.POINTER_SIZE));
elements[i].read();
}
return elements;
}
public void setArrayCertContext(WinCrypt.CERT_CONTEXT[] arrayCertContexts) {
if (arrayCertContexts == null || arrayCertContexts.length == 0) {
arrayCertContext = null;
cCertContext = 0;
} else {
cCertContext = arrayCertContexts.length;
Memory mem = new Memory(Native.POINTER_SIZE * arrayCertContexts.length);
for (int i = 0; i < arrayCertContexts.length; i++) {
mem.setPointer(i * Native.POINTER_SIZE, arrayCertContexts[i].getPointer());
}
arrayCertContext = mem;
}
}
public void setArrayCertStore(WinCrypt.HCERTSTORE[] stores) {
if (stores == null || stores.length == 0) {
arrayCertStore = null;
cCertStore = 0;
} else {
Memory mem = new Memory(Native.POINTER_SIZE * stores.length);
for (int i = 0; i < stores.length; i++) {
mem.setPointer(i * Native.POINTER_SIZE, stores[i].getPointer());
}
cCertStore = stores.length;
arrayCertStore = mem;
}
}
public WinCrypt.HCERTSTORE[] getArrayCertStore() {
if (arrayCertStore == null || cCertStore == 0) {
return new WinCrypt.HCERTSTORE[0];
} else {
WinCrypt.HCERTSTORE[] result = new WinCrypt.HCERTSTORE[cCertStore];
for (int i = 0; i < result.length; i++) {
result[i] = new WinCrypt.HCERTSTORE(arrayCertStore.getPointer(i * Native.POINTER_SIZE));
}
return result;
}
}
@Override
public void write() {
this.dwSize = size();
super.write();
}
@Override
protected List<String> getFieldOrder() {
return fieldOrder;
}
}
}
public void CertSelect() {
Cryptdlg cryptdlg = Cryptdlg.INSTANCE;
Cryptdlg.CERT_SELECT_STRUCT certSel = new Cryptdlg.CERT_SELECT_STRUCT();
certSel.hwndParent = parentHwnd;
certSel.szTitle = "title";
certSel.cCertStore = 1;
certSel.setArrayCertStore(new WinCrypt.HCERTSTORE[] {hCertStore});
pCertSelectInfo.cCertContext = 1;
pCertSelectInfo.arrayCertContext = new Memory(Native.POINTER_SIZE);
pCertSelectInfo.arrayCertContext.setPointer(0, Pointer.NULL);
cryptdlg.CertSelectCertificate(certSel);
...
}
}
答案1
得分: 0
有几个潜在的问题区域。
首先，您在混合使用 ANSI 和 Unicode 版本。
CertSelectCertificate() 函数有两个变体，一个以 A 结尾，另一个以 W 结尾。-A 函数是 ANSI 版本（8 位字符），而 -W 变体用于 Unicode/宽字符串（16 位字符）。这些方法的主要区别在于 CERT_SELECT_STRUCT 结构中字符串的字符数，类似地，CERT_SELECT_STRUCT_A 和 CERT_SELECT_STRUCT_W 也有两个变体。
JNA 使用其默认类型映射器自动将您映射到正确的版本（在现代操作系统中几乎在所有情况下都是 -W 版本）。您应该在库加载时使用默认的 Win32 库选项显式地添加该类型映射器：
Cryptdlg INSTANCE = (Cryptdlg) Native.loadLibrary("Cryptdlg", Cryptdlg.class,
W32APIOptions.DEFAULT_OPTIONS);
然而，您在 CERT_SELECT_STRUCT() 构造函数中明确调用了 -A 类型映射器：
public CERT_SELECT_STRUCT() {
super(W32APITypeMapper.ASCII);
}
这会强制它使用结构的 -A 版本，该版本的字符串每个字符只有 8 位。您应该只调用 super()。
第二种可能性，虽然在文档中不太明显，是第一个元素 dwSize 应该是结构的大小。您应该在构造函数中设置它：
this.dwSize = this.size();
第三种可能性（也是我猜测最有可能的原因）是在设置 arrayCertContext 字段内容的那一行。它在文档中描述为：
> 指向 CERT_CONTEXT 结构数组的指针。
您在 Java 侧将数组定义为结构（具有自己的指针），并手动将其设置到内存中，但是您并没有填充 CERT_CONTEXT 结构，而是在那里放置了一个 Pointer：
pContexts[0] = new WinCrypt.CERT_CONTEXT.ByReference();
这最终会用刚创建的指针地址填充“结构”的前 8 个字节，其中前 4 个字节分配给 dwCertEncodingType，接下来的 4 个字节（加上 4 个空字节）分配给 ByteByReference() 字段的指针值。
此外，比起您的内存分配方式，可以像这样分配结构数组：
WinCrypt.CERT_CONTEXT[] pContextArray =
(WinCrypt.CERT_CONTEXT[]) new WinCrypt.CERT_CONTEXT().toArray(1);
作为附注，您可能会发现 JNA 5.x（当前版本为 5.6.0）中的结构定义更加简化，其中包括 @FieldOrder 注解作为创建字段顺序列表的首选方法。
英文:
There are a few potential problem areas.
First, you are mixing the ANSI and Unicode versions.
The CertSelectCertificate() function has two variants, one ending in A and one in W. The -A functions are the ANSI (8-bit characters) while the -W variants are for Unicode/Wide-string (16 bit characters). The main difference in the methods is the number of characters in the strings in the CERT_SELECT_STRUCT structure., which similarly has two variants, CERT_SELECT_STRUCT_A and CERT_SELECT_STRUCT_W.
JNA automatically maps you to the correct version (the -W version in almost all cases in modern operating systems) using its default type mapper. You should probably add that type mapper explicitly in your library loading using the default options for Win32 libraries:
Cryptdlg INSTANCE = (Cryptdlg) Native.loadLibrary("Cryptdlg", Cryptdlg.class,
W32APIOptions.DEFAULT_OPTIONS);
However, you have an explicit call to use the -A type mapper in your CERT_SELECT_STRUCT() constructor:
public CERT_SELECT_STRUCT() {
super(W32APITypeMapper.ASCII);
}
This forces it to use the -A version of the structure, which only has 8 bits per character in its strings. You should just call super().
<hr>
A second possibility, while not obvious from the docs, is that the first element, dwSize, is supposed to be the size of the structure. You should put that in your constructor:
this.dwSize = this.size();
<hr>
A third possibility (and the most likely cause, if I were to guess) is in the line when you set the contents of the arrayCertContext field. It is documented as:
> A pointer to an array of CERT_CONTEXT structures.
You define the array on the Java side as a structure (which has its own pointer) and manually set it into memory, but instead of populating the CERT_CONTEXT structure you put a Pointer there:
pContexts[0] = new WinCrypt.CERT_CONTEXT.ByReference();
That ends up filling up the first 8 bytes of the "structure" with the pointer address you just created, the first 4 bytes of which are assigned to dwCertEncodingType and the next 4 bytes (plus 4 null bytes) go to the pointer value of a ByteByReference() field.
Also, easier than your allocation of memory, allocation of arrays of structures could be done like this:
WinCrypt.CERT_CONTEXT[] pContextArray =
(WinCrypt.CERT_CONTEXT[]) new WinCrypt.CERT_CONTEXT().toArray(1);
<hr>
As an aside, you might find structure definitions more streamlined in JNA 5.x (currently 5.6.0) which include a @FieldOrder annotation as a preferred method of creating the field order list.
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