Re: [edk2-devel] The API in BaseCryptLib can't seed the pseudorandom number generator properly

["Laszlo Ersek" <lersek@redhat.com>]

On 2/15/24 12:09, eddie wang wrote:
> Hi Laszlo,
> Thanks for your reply. How can I enable the DEBUGs at RandomSeed() ? Or
> any suggesting information that I can provide?

Sorry, upon a closer look, I see you had already narrowed it down to
RAND_seed() and RAND_status(), which are direct OpenSSL APIs. So my
suggestion would amount to adding DEBUGs to OpenSSL, such as to
RAND_seed() in
"CryptoPkg/Library/OpensslLib/openssl/crypto/rand/rand_lib.c".

But, I think you may be able to do just that.
"CryptoPkg/Library/Include/CrtLibSupport.h" already includes
<DebugLib.h>, and DebugLib is listed under [LibraryClasses] in each
instance of OpensslLib. So if you modify your
"CryptoPkg/Library/OpensslLib/openssl" submodule directory tree locally,
with the following patch:

| diff --git a/crypto/rand/rand_lib.c b/crypto/rand/rand_lib.c
| index 0fcf4fe3bc1e..e5f105268f52 100644
| --- a/crypto/rand/rand_lib.c
| +++ b/crypto/rand/rand_lib.c
| @@ -257,6 +257,8 @@ void RAND_seed(const void *buf, int num)
|      drbg = RAND_get0_primary(NULL);
|      if (drbg != NULL && num > 0)
|          EVP_RAND_reseed(drbg, 0, NULL, 0, buf, num);
| +
| +    DEBUG ((DEBUG_INFO, "%a: hello\n", __func__));
|  }
|
|  void RAND_add(const void *buf, int num, double randomness)

then you should get usable debug messages -- at least it builds for me.

Inserting DEBUGs like this (over multiple rounds of testing / narrowing)
should lead you to the exact location that is responsible for the
initialization failure.

You mention you have encountered the problem with a UEFI application.
That is relevant for choosing your DebugLib instance. If you already
have a function DebugLib instance for your platform (logging to the
serial port, for example), then just use that.

Otherwise, consider building your UEFI application with a module scope
override in the DSC file, one that resolves DebugLib to

  MdePkg/Library/UefiDebugLibConOut/UefiDebugLibConOut.inf

or

  MdePkg/Library/UefiDebugLibStdErr/UefiDebugLibStdErr.inf

These will send DEBUG messages to the UEFI console or standard error
devices, respectively.

hth
Laszlo

> Laszlo Ersek <lersek@redhat.com <mailto:lersek@redhat.com>> 於 2024年2月
> 8日 週四 上午5:03寫道：
>
>     On 2/6/24 08:00, eddie wang wrote:
>     > Hi all,
>     > We had an UEFI application that used the EDK2(2023/12/05), and  we
>     would
>     > like to take advantage of the services in BaseCryptLib .However,
>     the API
>     > in CryptPkg "*RandomSeed()*"(X64, in CryptRandTsc.c) always returned
>     > false because of  the pseudorandom number generator set up failed.
>     I am
>     > not sure this issue is from the *openssl configuration in
>     OpensslLib(we
>     > use the default configuration)* or is from the *openssl 3.0.9*.
>     >
>     > Is there any comments about this issue?
>
>     Can you narrow it down by inserting DEBUGs starting at RandomSeed()
>     [CryptoPkg/Library/BaseCryptLib/Rand/CryptRandTsc.c], and then digging
>     down as necessary?
>
>     Laszlo
>
>
>
>     
>
>



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