02-01-2016
Quote:
Originally Posted by
GSalisbury
It seems that, for all practical purposes, the compiler treats sizeof as a placeholder for substituting the literal value of the size of the referenced item. That's good enough and is as far we need take it
It hardwires it at compile time. As such, it gives a completely literal, unchanging result.
9 More Discussions You Might Find Interesting
1. Programming
we know that sizeof never returns zero when used with structure
then why in this case it is returning zero
struct foo
{
char c;
};
void main()
{
struct foo f;
cout<<sizeof(f);
}
i am working on solaris 5.8
isn't the above function should return the size of empty structure (7 Replies)
Discussion started by: ramneek
7 Replies
2. UNIX for Dummies Questions & Answers
Hi,
we are converting from IBM-AIX(xl c/c++ compiler) to Linux(GCC complier).
As a part of this i need to change the CFLAGS.
The xl c/c++ complier CFLAGS is
CFLAGS := $(CDEBUG) $(PROJECT_INCLUDE_DIRS) $(COBJECT_MODE) -qcpluscmt -qmakedep -qcheck=all \
-qalign=bit_packed $(LINT_FLAGS)... (0 Replies)
Discussion started by: pbattu1
0 Replies
3. Programming
To make a programming language you need a compiler, so what was the first programming language and how was is created if you need the compiler first?
The compiler itself is considered as a high language comparing to the machine! since the compiler is not created in 1's and 0's...
Eventhough i... (12 Replies)
Discussion started by: f.ben.isaac
12 Replies
4. Programming
Hi All,
is it possible to find out the size of an array of structures ( without using 'sizeof' operator). The condition is we have the array of structure instant but we are not aware of the elements inside the structure.
Can someone help me out?
Thanks in advance. (18 Replies)
Discussion started by: rvan
18 Replies
5. Programming
The below code throws the error, since the size of x = 19 is not passed to the cstrCopy function.
using namespace std;
static void cstrCopy(char *x, const char*y);
int main ()
{
char x;
const string y = "UNIX FORUM";
cstrCopy(x,y.c_str());
return 0;
}
void cstrCopy(char *x,... (3 Replies)
Discussion started by: SamRoj
3 Replies
6. Programming
Hi,
There are some bewildering sizeof() questions I have in my mind. Could anyone shed some light on this?
int main() {
printf("%d\n", sizeof(main)); // Ans: 1
}
That is, the sizeof() a function identifier though it is treated internally as a pointer gives 1 byte always, why?
... (5 Replies)
Discussion started by: royalibrahim
5 Replies
7. UNIX for Dummies Questions & Answers
hi,
can we install gcc compiler in unix based OS(sun solar,IBM AIX,HP,etc) and also
can we install sun cc compiler in AIX environment and vice versa.
and more ..is linux support cc compiler
regards
Ajay (3 Replies)
Discussion started by: ajaysahoo
3 Replies
8. Programming
Hi,
I have defined the class and call the sizeof(object to class) to get the size.
# include <iostream>
# include <iomanip>
using namespace std;
class sample
{
private:
int i;
float j;
char k;
public:
sample()
{
} (2 Replies)
Discussion started by: ramkrix
2 Replies
9. Shell Programming and Scripting
Hai
how to find size of a file??
ex : /home/kiran/pdk/sample/calibre this is a path
In that I have to find size of a files in side a calibre(it is the folder) like .results or .summary (1 Reply)
Discussion started by: kiran425
1 Replies
LEARN ABOUT CENTOS
tpm_quote_tools
TPM QUOTE
TOOLS(8) TPM QUOTE TOOLS(8)
NAME
TPM Quote Tools
PROGRAMS
tpm_mkuuid, tpm_mkaik, tpm_loadkey, tpm_unloadkey, tpm_getpcrhash, tpm_updatepcrhash, tpm_getquote, tpm_verifyquote
DESCRIPTION
TPM Quote Tools is a collection of programs that provide support for TPM based attestation using the TPM quote operation.
A TPM contains a set of Platform Configuration Registers (PCRs). In a well configured machine, some of these registers are set to known
values during the boot up process or at other times. For example, a PCR might contain the hash of a boot loader in memory before it is
run.
The TPM quote operation is used to authoritatively verify the contents of a TPM's Platform Configuration Registers (PCRs). During provi-
sioning, a composite hash of a selected set of PCRs is computed. The TPM quote operation produces a composite hash that can be compared
with the one computed while provisioning.
To use the TPM quote operation, keys must be generated. During provisioning, an Attestation Identity Key (AIK) is generated for each TPM,
and the public part of the key is made available to entities that validate quotes.
The TPM quote operation returns signed data and a signature. The data that is signed contains the PCRs selected for the operation, the
composite hash for the selected PCRs, and a nonce provided as input, and used to prevent replay attacks. At provisioning time, the data
that is signed is stored, not just the composite hash. The signature is discarded.
An entity that wishes to evaluate a machine generates a nonce, and sends it along with the set of PCR used to generate the composite PCR
hash at provisioning time. For this use of the TPM quote operation, the signed data is ignored, and the signature returned is used to val-
idate the state of the TPM's PCRs. Given the signature, the evaluating entity replaces the nonce in the signed data generated at provi-
sioning time, and checks to see if the signature is valid for the data. If so, this check ensures the selected PCRs contain values that
match the ones measured during provisioning.
A typical scenario for an enterprise using these tools follows. The tools expect AIKs to be referenced via one enterprise-wide Universally
Unique Identifier (UUID). The program tpm_mkuuid creates one.
For each machine being checked, an AIK is created using tpm_mkaik. The key blob produced is bound to the UUID on its machine using
tpm_loadkey. The public key associated with the AIK is sent to the entities that verify quotes. Finally, the expected PCR composite hash
is obtained using tpm_getpcrhash. When the expected PCR values change, a new hash can be generated with tpm_updatepcrhash.
The program to obtain a quote, and thus measure the current state of the PCRs is tpm_getquote. The program that verifies the quote
describes the same PCR composite hash as was measured initially is tpm_verifyquote.
SEE ALSO
tpm_mkuuid(8), tpm_mkaik(8), tpm_loadkey(8), tpm_unloadkey(8), tpm_getpcrhash(8), tpm_updatepcrhash(8), tpm_getquote(8), tpm_verifyquote(8)
Oct 2010 TPM QUOTE TOOLS(8)