Symbian计算MD5(转)

Symbian计算MD5

2010年03月25日, 18:16

LOCAL_C HBufC8* Md5HexDigestLC(const TDes8& aString)
{
CMD5* md5 = CMD5::NewL();
CleanupStack::PushL(md5);

TPtrC8 hashedSig(md5->Hash(aString));

HBufC8* buf = HBufC8::NewL(hashedSig.Length() * 2);
TPtr8 bufPtr = buf->Des();

    for(TInt i=0; i< hashedSig.Length(); i++)
    {
        bufPtr.AppendFormat(_L8(“%+02x”),hashedSig[i]);
    }
    CleanupStack::PopAndDestroy(md5);
    CleanupStack::PushL(buf);
    return buf;
}

改成更简单的
LOCAL_C HBufC8* DoMD5(const TDes8& aString)
{
CMD5* MD5 = CMD5::NewL();

    CleanupStack::PushL(MD5);
    HBufC8 *HashSigned=(MD5->Hash(aFileName)).AllocL();
    //TPtrC8 bytes = md5->Hash(aSource);
    CleanupStack::PopAndDestroy(MD5);

return HashSigned;
}

注意:
CMD5包含头文件hash.h,并需要链接hash.lib

LOCAL_C void Md5HexDigestLC(const TDes8& aString)
{
CMD5* md5 = CMD5::NewL();
CleanupStack::PushL(md5);

TPtrC8 hashedSig = md5->Hash(aString);

CleanupStack::PopAndDestroy(md5);
}

我们看看IDA反汇编出来的结果

PUSH {R4,R5,LR}
SUB SP, SP, #0xC

MOVS R5, R0

BLX _ZN4CMD54NewLEv ; CMD5::NewL(void)
MOVS R4, R0

BLX _ZN12CleanupStack5PushLEP5CBase ; CleanupStack::PushL(CBase *)

LDR     R3, [R4]
MOV     R0, SP
MOVS    R2, R5
LDR     R3, [R3,#0x10]
MOVS    R1, R4
BLX     R3                              ;这里就是调用 md5->Hash()

BLX _ZN12CleanupStack13PopAndDestroyEv ; CleanupStack::PopAndDestroy(void)

ADD SP, SP, #0xC
POP {R4,R5,PC}

类似地, 下面的这段代码,是从某个实际的应用程序中提取到的

                LDR     R12, [R7,#4]    ; 载入md5对象
                MOV     R0, R8
                 MOV     R2, R4
                 MOV     R1, R12
                 LDR     R3, [R12]       ; 读取虚函数表指针
                 MOV     LR, PC          ; 保存返回地址
                 LDR     PC, [R3,#0x10] ; 调用hash的虚函数