The CryptGenRandom function fills a buffer with random bytes.
BOOL CRYPTFUNC CryptGenRandom(
HCRYPTPROV hProv, | |
DWORD dwLen, | |
BYTE *pbBuffer | |
); |
Optionally, the application can fill this buffer with data to use as an auxiliary random seed. This is explained further in the “Remarks” section.
The data produced by this function is “cryptographically random.” It is far more random than the data generated by the typical random number generator such as the one shipped with your “C” compiler.
This function is often used to generate random initialization vectors and salt values.
All software random number generators work in fundamentally the same way. They start with one truly random number, known as the “seed,” and then use an algorithm to generate a pseudo-random sequence of bits based on it. The most difficult part of this process is to get a seed that is truly random. This is usually based on user input latency, or the jitter from one or more hardware components.
If your application has access to a good random source, then it can fill the pbBuffer buffer with some amount of random data before calling CryptGenRandom. The CSP will then use this data to further randomize its internal seed. Failing to initialize the pbBuffer buffer before calling CryptGenRandom is acceptable.
If the function succeeds, the return value is nonzero.
If the function fails, the return value is zero. To retrieve extended error information, use the GetLastError function.
The following table lists the error codes most commonly returned by the GetLastError function. The error codes prefaced by “NTE” are generated by the particular CSP you are using.
Error |
Description |
ERROR_INVALID_HANDLE |
One of the parameters specifies an invalid handle. |
ERROR_INVALID_PARAMETER |
One of the parameters contains an invalid value. This is most often an illegal pointer. |
NTE_BAD_UID |
The hProv parameter does not contain a valid context handle. |
NTE_FAIL |
The function failed in some unexpected way. |
See the “Example” section in the CryptSetKeyParam function.
CryptAcquireContext, CryptGenRandom, CryptSetKeyParam
file: /Techref/os/win/api/win32/func/src/f12_6.htm, 5KB, , updated: 2000/4/7 12:19, local time: 2024/8/18 00:26,
18.188.203.142:LOG IN
|
©2024 These pages are served without commercial sponsorship. (No popup ads, etc...).Bandwidth abuse increases hosting cost forcing sponsorship or shutdown. This server aggressively defends against automated copying for any reason including offline viewing, duplication, etc... Please respect this requirement and DO NOT RIP THIS SITE. Questions? <A HREF="http://techref.massmind.org/techref/os/win/api/win32/func/src/f12_6.htm"> CryptGenRandom Release 2]</A> |
Did you find what you needed? |
Welcome to massmind.org! |
Welcome to techref.massmind.org! |
.