I have a .cer file. I can read it and write a buffer via ReadFile() function.
Now I have buffer and datalen which I had.
And I use that buffer and len for calling CryptDecodeObjectEx() function like below line
if ( !CryptDecodeObjectEx( X509_ASN_ENCODING,
X509_PUBLIC_KEY_INFO,
(BYTE* )pemPubKey,
readLen,
CRYPT_DECODE_ALLOC_FLAG,
NULL,
&publicKeyInfo,
(DWORD *)&publicKeyInfoLen ) )
But when I run it through debug, I get 0x8009310B error code via GetLastError() func.
How can I fix it?
Thanks for your advice.
Additional Information
If I use X509_ANY_STRING instead of X509_PUBLIC_KEY_INFO; it works.
But it does not fill my publicKeyInfo struct. Because of that I
cannot get public key in it .
I have a DER formatted certificate.
Related
I've got a C project that I'm working on and I'm having a problem.
The program reads a string that is echoed by a .php page. It uses this code
to read the data and appoint it to a variable, which get sent to the Commands() function:
LPSTR szBuffer=(LPSTR)chunk+0x1000;
DWORD dwRead;
if (CWA(_HttpSendRequestA, wininet, hHttpRequest, szHeaders, lpstrlenA(szHeaders), szReq, lpstrlenA(szReq)) != 0)
{
CWA(_InternetReadFileA, wininet, hHttpRequest, szBuffer, 0x400, &dwRead);
if (dwRead)
Commands((LPBYTE)szBuffer, dwRead);
}
As you can see the data is sent to the Commands() function, which receives the LPBYTE szBuffer (named "command" in the function) and the DWORD dwRead (named "size" in the function).
In the Commands() function, it's supposed to read the string that it read from the .php page. However, since the data seems to be stored as LPBYTE, I've done a lot of things trying to get that to a char*. When I thought I had finally got it however, I tried outputting it using a MessageBox (to see if it displays the string it should have read). However, this returns me Chinese characters (while the original string should be this:
"TASKci=0C73CCFD206BBD011E7087CE0806E6F6E69630,job=dlex,ti=AD62A5950B76F3812C542C24040EACE9,pr=https,ur=//test.com/test.txt,cl=".
Screenshot of what it returns me: http://prntscr.com/h0p5iw
How the code inside Commands() looks:
BOOL Commands(LPBYTE command, DWORD size) {
LPTSTR x = (LPTSTR)((char*)command);
{
int msgboxID = MessageBox(
NULL,
x,
(LPCWSTR)L"Woop",
MB_ICONWARNING | MB_CANCELTRYCONTINUE | MB_DEFBUTTON2 );
}
CWA(Sleep, kernel32, 100);
return 1; }
I'm new at C (I've only written stuff in C# before) so I am sorry if I am asking any dumb questions, I've really tried my best but I cannot seem to find any solution by myself.
Also, keep in mind that everything except for the stuff inside the Commands() function is not coded by me but by someone who is way more experienced. That code should be fine and I am sure that it is reading the data from the page, it's probably just me screwing up a conversion somewhere.
A narrow string (char*) tends to look like Chinese when you use it somewhere that expects a wide UTF-16 Unicode string.
You cannot just cast the string to change its type, you need to call MultiByteToWideChar.
I want to make a program (network server-client).
One of the specification for this program is next:
The server will receive the sent packages and save it into a file, with a unique name (generated by the server at the moment the transfer starts.
Ex __tf_"unique_random_string".txt
I made a function that returns a pointer to a "unique" string created.
The problem is: If i stop the server and then start it again it will generate the same names.
Ex:this file names were generated and then i stopped the server.
__ft_apqfwk.txt
__ft_arzowk.txt
__ft_cdyggx.txt
I start it again and i try to generate 3 file names. Them will be the same.
Sorry for my english. I'm still learning it.
My function to generate this "unique string" is:
char *create_random_name(void)
{
const char charset[] = "abcdefghijklmnopqrstuvwxyz";
char *file_name;
int i=0;
int key;
if((file_name = malloc(16 * sizeof ( char )) ) == NULL)
{
printf("Failed to alloc memory space\n");
return NULL;
}
strcpy(file_name,"__ft_");
for(i=5 ; i<11 ; i++)
{
key = rand() % (int)(sizeof(charset)-1);
file_name[i]=charset[key];
}
strcat(file_name,".txt");
file_name[15] = '\0';
return file_name;
}
One option is saving to a file the names that have been used, and using them as a checklist. You also want to seed rand with something like srand(time(NULL)).
another is ignoring the randomisation, and just going in order, e.g. aaa, aab aac...aba ,abb etc. Again, save where your cycle is up to on a file.
Your question seems a little bit unclear but if you want to generate a unique string there are a couple of things you can consider:
Get System timestamp ( yyyy-MM-dd-HH-mm-ss-fff-tt)
Use Random function to generate a random number
Combine this with your function and I am sure you will get a unique string.
Hope it helps !
If it's available, you could avoid manually generating random names that might collide and let the system do it for you (and handle collision resolution by creating a new name) by using mkstemps. This is also safer because it opens the file for you, removing the risk of a random name being generated, verified to be unique, then trying to open it and discovering another thread/process raced in and created it.
char name[] = "/path/to/put/files/in/__ft_XXXXXX.txt";
int fd = mkstemps(name, strlen(".txt"));
if (fd == -1) { ... handle error ... }
After mkstemps succeeds, name will hold the path to the file (it's mutated in place, replacing the XXXXXX string), and fd will be an open file descriptor to that newly created file; if you need a FILE*, use fdopen to convert to a stdio type.
Before calling rand(),--- once and only once---, call srand(time()) to initialize the random number generator.
Before settling on any specific file name, call stat() to assure that file name does not already exist.
I am fiddling around with mailslots and now I've run into a problem.
Whenever I try to run, I get the error message in the title, but I don't know how I should go about fixing it.
What I am trying to do is "fixing" the full path of the mailslot, but it seems to not like the strcat_s-part.
HANDLE mailslotCreate (char *name) {
char fullName[50] = "\\\\.\\mailslot\\";
strcat_s(fullName, strlen(fullName), name);
return CreateMailslot(fullName, 0, TIME_OUT, NULL);
}
Imgur link to error
EDIT: Changing the strlen to sizeof merely changed the error to "Buffer size too small" instead.
See documentation on strcat_s. It says that second parameter should be the size of destination buffer. As you pass strlen(fullName), there is no room for terminating \0.
Change it to be sizeof(fullName) and your error should disappear.
I want to use Libextractor to get keywords/metadata for files.
The basic example for it is -
struct EXTRACTOR_PluginList *plugins
= EXTRACTOR_plugin_add_defaults (EXTRACTOR_OPTION_DEFAULT_POLICY);
EXTRACTOR_extract (plugins, argv[1],
NULL, 0,
&EXTRACTOR_meta_data_print, stdout);
EXTRACTOR_plugin_remove_all (plugins);
However, this calls the function EXTRACTOR_meta_data_print which "prints" it to "stdout"
I'm looking at a way to get this information to another function - i.e. pass or store this in memory for further working. The documentation was not clear to me. Any help or experience regarding this?
I've tried to install libextractor and failed to get it working (it always returns a NULL plugin pointer upon call to EXTRACTOR_plugin_add_defaults()), so what I will write next is NOT TESTED:
from : http://www.gnu.org/software/libextractor/manual/libextractor.html#Extracting
Function Pointer: int
(*EXTRACTOR_MetaDataProcessor)(void *cls,
const char *plugin_name,
enum EXTRACTOR_MetaType type,
enum EXTRACTOR_MetaFormat format,
const char *data_mime_type,
const char *data,
size_t data_len)
and
Type of a function that libextractor calls for each meta data item found.
cls
closure (user-defined)
plugin_name
name of the plugin that produced this value;
special values can be used (i.e. '<zlib>' for
zlib being used in the main libextractor library
and yielding meta data);
type
libextractor-type describing the meta data;
format basic
format information about data
data_mime_type
mime-type of data (not of the original file);
can be NULL (if mime-type is not known);
data
actual meta-data found
data_len
number of bytes in data
Return 0 to continue extracting, 1 to abort.
So you would just have to write your own function called whatever you want, and have this declaration be like:
int whateveryouwant(void *cls,
const char *plugin_name,
enum EXTRACTOR_MetaType type,
enum EXTRACTOR_MetaFormat format,
const char *data_mime_type,
const char *data,
size_t data_len)
{
// Do your stuff here
if(stop)
return 1; // Stops
else
return 0; // Continues
}
and call it via:
EXTRACTOR_extract (plugins, argv[1],
NULL, 0,
&whateveryouwant,
NULL/* here be dragons */);
Like described in http://www.gnu.org/software/libextractor/manual/libextractor.html#Generalities "3.3 Introduction to the libextractor library"
[here be dragons]: That is a parameter left for the user's use (even if it's redundant to say so). As defined in the doc: "For each meta data item found, GNU libextractor will call the ‘proc’ function, passing ‘proc_cls’ as the first argument to ‘proc’."
Where "the proc function" being the function you added (whateveryouwant() here) and proc_cls being an arbitrary pointer (can be anything) for you to pass data to the function. Like a pointer to stdout in the example, in order to print to stdout. That being said, I suspect that the function writes to a FILE* and not inevitably to stdout; so if you open a file for writing, and pass its "file decriptor" as last EXTRACTOR_extract()'s parameter you would probably end with a file filled with the information you can currently read on your screen. That wouldn't be a proper way to access the information, but if you're looking into a quick and dirty way to test some behavior or some feature; that could do it, until you write a proper function.
Good luck with your code!
I'm trying to use the OpenSSL crypto lib and it's crashing in a call that's a staple in every example I've seen. Here's how it's set up:
BIO* bp = BIO_new_mem_buf(_publicKey, -1); // Create a new memory buffer BIO.
RSA* pubKey = PEM_read_bio_RSA_PUBKEY(bp, 0, 0, 0); // And read the RSA key from it.
unsigned char encryptedRandKey[RSA_size(pubKey)];
BIO_free(bp);
_publicKey is a null-terminated character string containing a PEM-formatted RSA key (with the -----BEGIN XXX----- and so forth). It crashes with bad access in RSA_size.
It doesn't matter if I remove the BIO_free.
Any ideas? Thanks!
You need to check the return value of PEM_read_bio_RSA_PUBKEY() to make sure it is non-null. Most likely the contents of _publicKey are not quite a correctly formatted key and as a consequence pubKey is NULL.
Try PEM_read_bio_RSAPublicKey instead of PEM_read_bio_RSA_PUBKEY.