equal.c File Reference

#include "precomp.h"

Include dependency graph for equal.c:

Go to the source code of this file.

Functions
BOOLEAN SYMCRYPT_CALL	SymCryptEqual (_In_reads_(cbBytes) PCBYTE pbSrc1, _In_reads_(cbBytes) PCBYTE pbSrc2, SIZE_T cbBytes)

Function Documentation

SymCryptEqual()

BOOLEAN SYMCRYPT_CALL SymCryptEqual	(	_In_reads_(cbBytes) PCBYTE	pbSrc1,
		_In_reads_(cbBytes) PCBYTE	pbSrc2,
		SIZE_T	cbBytes
	)

Definition at line 11 of file equal.c.

{
    UINT32 neq = 0;
    BYTE b;
    volatile BYTE * p1 = (volatile BYTE *) pbSrc1;
    volatile BYTE * p2 = (volatile BYTE *) pbSrc2;
 
    //
    // We use forced-access memory reads to ensure that the compiler doesn't get
    // smart and implement an early-out solution.
    //
 
    while( cbBytes >= 4 )
    {
        neq |= SYMCRYPT_FORCE_READ32( (volatile UINT32 *) p1 ) ^ SYMCRYPT_FORCE_READ32( (volatile UINT32 *) p2 );
        p1 += 4;
        p2 += 4;
        cbBytes -= 4;
    }
 
    // We have to deal with the remaining bytes using a separate accumulator to work around an issue in the ARM64 compiler.
    if( cbBytes > 0 )
    {
        b = 0;
        while( cbBytes > 0 )
        {
            b |= SYMCRYPT_FORCE_READ8( p1 ) ^ SYMCRYPT_FORCE_READ8( p2 );
            p1++;
            p2++;
            cbBytes--;
        }
        neq |= b;
    }
 
    return neq == 0;
}

Referenced by SymCryptCcmDecryptFinal(), SymCryptChaCha20Poly1305Decrypt(), SymCryptGcmDecrypt(), SymCryptGcmDecryptFinal(), SymCryptLmskeyVerifyRoot(), SymCryptLmsVerifyInternal(), SymCryptMlDsaVerifyEx(), SymCryptMlKemDecapsulate(), SymCryptMlKemkeyGenerate(), SymCryptMlKemkeySetValue(), SymCryptRsaOaepRemoveEncryptionPadding(), SymCryptRsaPkcs1CheckSignaturePadding(), SymCryptRsaPssVerifySignaturePadding(), SymCryptXmsskeyVerifyRoot(), SymCryptXmssVerifyInternal(), and SymCryptXtsAesExpandKeyEx().