- Generating Symmetric Private Key In C# and.NET. Major symmetric algorithms are AES, DES, RC2, Rijndael, and TripleDES. The GenerateKey and GenerateIV methods return the private secret key and initialization vector.
- C-SPAN.org gives you access to C-SPAN's daily coverage of Washington and more than 200,000 hours of extensively indexed and archived C-SPAN video.
- Arrays allow to define type of variables that can hold several data items of the same kind. Similarly structure is another user defined data type available in C that allows to combine data items of different kinds. Structures are used to represent a record. Suppose you want to keep track of your.
- I am doing AES Key Generation in c# and passing the key generated for AES 128 bit Encryption. The case is while generating the key I am getting byte length as 16 while the key string length is getting higher than 16. While trying online I am getting length as 16 itself. What I have tried: Core Code is as below: AES Key 128 bit Generation.
Encryption Key Generator. The all-in-one ultimate online toolbox that generates all kind of keys! Every coder needs All Keys Generator in its favorites! It is provided.
- C Programming Tutorial
- C Programming useful Resources
- Selected Reading
An operator is a symbol that tells the compiler to perform specific mathematical or logical functions. C language is rich in built-in operators and provides the following types of operators −
- Arithmetic Operators
- Relational Operators
- Logical Operators
- Bitwise Operators
- Assignment Operators
- Misc Operators
We will, in this chapter, look into the way each operator works.
Arithmetic Operators
The following table shows all the arithmetic operators supported by the C language. Assume variable A holds 10 and variable B holds 20 then −
Operator | Description | Example |
---|---|---|
+ | Adds two operands. | A + B = 30 |
− | Subtracts second operand from the first. | A − B = -10 |
* | Multiplies both operands. | A * B = 200 |
/ | Divides numerator by de-numerator. | B / A = 2 |
% | Modulus Operator and remainder of after an integer division. | B % A = 0 |
++ | Increment operator increases the integer value by one. | A++ = 11 |
-- | Decrement operator decreases the integer value by one. | A-- = 9 |
Relational Operators
The following table shows all the relational operators supported by C. Assume variable A holds 10 and variable B holds 20 then −
Operator | Description | Example |
---|---|---|
Checks if the values of two operands are equal or not. If yes, then the condition becomes true. | (A B) is not true. | |
!= | Checks if the values of two operands are equal or not. If the values are not equal, then the condition becomes true. | (A != B) is true. |
> | Checks if the value of left operand is greater than the value of right operand. If yes, then the condition becomes true. | (A > B) is not true. |
< | Checks if the value of left operand is less than the value of right operand. If yes, then the condition becomes true. | (A < B) is true. |
>= | Checks if the value of left operand is greater than or equal to the value of right operand. If yes, then the condition becomes true. | (A >= B) is not true. |
<= | Checks if the value of left operand is less than or equal to the value of right operand. If yes, then the condition becomes true. | (A <= B) is true. |
Logical Operators
Following table shows all the logical operators supported by C language. Assume variable A holds 1 and variable B holds 0, then −
More information on SSH keys can be found.You can generate an SSH key pair directly in cPanel, or you can generate the keys yourself and just upload the public one in cPanel to use with your hosting account.When generating SSH keys yourself under Linux, you can use the ssh-keygen command. This has proven more secure over standard username/password authentication. To do so follow these steps:. Ubuntu ssh generate key pair 1.
Operator | Description | Example |
---|---|---|
&& | Called Logical AND operator. If both the operands are non-zero, then the condition becomes true. | (A && B) is false. |
|| | Called Logical OR Operator. If any of the two operands is non-zero, then the condition becomes true. | (A || B) is true. |
! | Called Logical NOT Operator. It is used to reverse the logical state of its operand. If a condition is true, then Logical NOT operator will make it false. | !(A && B) is true. |
Bitwise Operators
Bitwise operator works on bits and perform bit-by-bit operation. The truth tables for &, |, and ^ is as follows −
p | q | p & q | p | q | p ^ q |
---|---|---|---|---|
0 | 0 | 0 | 0 | 0 |
0 | 1 | 0 | 1 | 1 |
1 | 1 | 1 | 1 | 0 |
1 | 0 | 0 | 1 | 1 |
Assume A = 60 and B = 13 in binary format, they will be as follows −
A = 0011 1100
B = 0000 1101
-----------------
A&B = 0000 1100
A|B = 0011 1101
A^B = 0011 0001
~A = 1100 0011
The following table lists the bitwise operators supported by C. Assume variable 'A' holds 60 and variable 'B' holds 13, then −
Operator | Description | Example |
---|---|---|
& | Binary AND Operator copies a bit to the result if it exists in both operands. | (A & B) = 12, i.e., 0000 1100 |
| | Binary OR Operator copies a bit if it exists in either operand. | (A | B) = 61, i.e., 0011 1101 |
^ | Binary XOR Operator copies the bit if it is set in one operand but not both. | (A ^ B) = 49, i.e., 0011 0001 |
~ | Binary One's Complement Operator is unary and has the effect of 'flipping' bits. | (~A ) = ~(60), i.e,. -0111101 |
<< | Binary Left Shift Operator. The left operands value is moved left by the number of bits specified by the right operand. | A << 2 = 240 i.e., 1111 0000 |
>> | Binary Right Shift Operator. The left operands value is moved right by the number of bits specified by the right operand. | A >> 2 = 15 i.e., 0000 1111 |
Assignment Operators
The following table lists the assignment operators supported by the C language −
Operator | Description | Example |
---|---|---|
= | Simple assignment operator. Assigns values from right side operands to left side operand | C = A + B will assign the value of A + B to C |
+= | Add AND assignment operator. It adds the right operand to the left operand and assign the result to the left operand. | C += A is equivalent to C = C + A |
-= | Subtract AND assignment operator. It subtracts the right operand from the left operand and assigns the result to the left operand. | C -= A is equivalent to C = C - A |
*= | Multiply AND assignment operator. It multiplies the right operand with the left operand and assigns the result to the left operand. | C *= A is equivalent to C = C * A |
/= | Divide AND assignment operator. It divides the left operand with the right operand and assigns the result to the left operand. | C /= A is equivalent to C = C / A |
%= | Modulus AND assignment operator. It takes modulus using two operands and assigns the result to the left operand. | C %= A is equivalent to C = C % A |
<<= | Left shift AND assignment operator. | C <<= 2 is same as C = C << 2 |
>>= | Right shift AND assignment operator. | C >>= 2 is same as C = C >> 2 |
&= | Bitwise AND assignment operator. | C &= 2 is same as C = C & 2 |
^= | Bitwise exclusive OR and assignment operator. | C ^= 2 is same as C = C ^ 2 |
|= | Bitwise inclusive OR and assignment operator. | C |= 2 is same as C = C | 2 |
Misc Operators ↦ sizeof & ternary
Besides the operators discussed above, there are a few other important operators including sizeof and ? : supported by the C Language.
Operator | Description | Example |
---|---|---|
sizeof() | Returns the size of a variable. | sizeof(a), where a is integer, will return 4. |
& | Returns the address of a variable. | &a; returns the actual address of the variable. |
* | Pointer to a variable. | *a; |
? : | Conditional Expression. | If Condition is true ? then value X : otherwise value Y |
Operators Precedence in C
C-reactive Protein
Operator precedence determines the grouping of terms in an expression and decides how an expression is evaluated. Certain operators have higher precedence than others; for example, the multiplication operator has a higher precedence than the addition operator.
For example, x = 7 + 3 * 2; here, x is assigned 13, not 20 because operator * has a higher precedence than +, so it first gets multiplied with 3*2 and then adds into 7.
Here, operators with the highest precedence appear at the top of the table, those with the lowest appear at the bottom. Within an expression, higher precedence operators will be evaluated first.
Category | Operator | Associativity |
---|---|---|
Postfix | () [] -> . ++ - - | Left to right |
Unary | + - ! ~ ++ - - (type)* & sizeof | Right to left |
Multiplicative | * / % | Left to right |
Additive | + - | Left to right |
Shift | << >> | Left to right |
Relational | < <= > >= | Left to right |
Equality | != | Left to right |
Bitwise AND | & | Left to right |
Bitwise XOR | ^ | Left to right |
Bitwise OR | | | Left to right |
Logical AND | && | Left to right |
Logical OR | || | Left to right |
Conditional | ?: | Right to left |
Assignment | = += -= *= /= %=>>= <<= &= ^= |= | Right to left |
Comma | , | Left to right |
- C Programming Tutorial
- C Programming useful Resources
- Selected Reading
Pointers in C are easy and fun to learn. Some C programming tasks are performed more easily with pointers, and other tasks, such as dynamic memory allocation, cannot be performed without using pointers. So it becomes necessary to learn pointers to become a perfect C programmer. Let's start learning them in simple and easy steps.
As you know, every variable is a memory location and every memory location has its address defined which can be accessed using ampersand (&) operator, which denotes an address in memory. Consider the following example, which prints the address of the variables defined −
When the above code is compiled and executed, it produces the following result −
What are Pointers?
A pointer is a variable whose value is the address of another variable, i.e., direct address of the memory location. Like any variable or constant, you must declare a pointer before using it to store any variable address. The general form of a pointer variable declaration is −
Here, type is the pointer's base type; it must be a valid C data type and var-name is the name of the pointer variable. The asterisk * used to declare a pointer is the same asterisk used for multiplication. However, in this statement the asterisk is being used to designate a variable as a pointer. Take a look at some of the valid pointer declarations −
Pfx to crt file. Below is the steps used for the scenario requested. Select Current Type = PEM. Change for = PFX. Upload your certificate. Upload your private key. If you have ROOT CA cert or intermediate certs upload them too. Set a password of your choosing, used in IIS. Click the reCaptcha to prove you're not a bot. Extracting certificate and private key information from a Personal Information Exchange (.pfx) file with OpenSSL: Open Windows File Explorer. Copy your.pfx file to a computer that has OpenSSL installed, notating the file path. Certificate.pfx files are usually password protected. Obtain the password for your.pfx. Jun 19, 2015 pkcs12 – the file utility for PKCS#12 files in OpenSSL-export -out certificate.pfx – export and save the PFX file as certificate.pfx-inkey privateKey.key – use the private key file privateKey.key as the private key to combine with the certificate.-in certificate.crt – use certificate.crt as the certificate the private key will be combined with.
The actual data type of the value of all pointers, whether integer, float, character, or otherwise, is the same, a long hexadecimal number that represents a memory address. The only difference between pointers of different data types is the data type of the variable or constant that the pointer points to.
How to Use Pointers?
There are a few important operations, which we will do with the help of pointers very frequently. (a) We define a pointer variable, (b) assign the address of a variable to a pointer and (c) finally access the value at the address available in the pointer variable. This is done by using unary operator * that returns the value of the variable located at the address specified by its operand. The following example makes use of these operations −
When the above code is compiled and executed, it produces the following result − Windows xp service pack 2 cd key generator.
NULL Pointers
It is always a good practice to assign a NULL value to a pointer variable in case you do not have an exact address to be assigned. This is done at the time of variable declaration. A pointer that is assigned NULL is called a null pointer.
The NULL pointer is a constant with a value of zero defined in several standard libraries. Consider the following program −
When the above code is compiled and executed, it produces the following result −
In most of the operating systems, programs are not permitted to access memory at address 0 because that memory is reserved by the operating system. However, the memory address 0 has special significance; it signals that the pointer is not intended to point to an accessible memory location. But by convention, if a pointer contains the null (zero) value, it is assumed to point to nothing.
To check for a null pointer, you can use an 'if' statement as follows −
Pointers in Detail
Pointers have many but easy concepts and they are very important to C programming. The following important pointer concepts should be clear to any C programmer −
Sr.No. | Concept & Description |
---|---|
1 | Pointer arithmetic There are four arithmetic operators that can be used in pointers: ++, --, +, - |
2 | Array of pointers You can define arrays to hold a number of pointers. |
3 | Pointer to pointer C allows you to have pointer on a pointer and so on. |
4 | Passing pointers to functions in C Passing an argument by reference or by address enable the passed argument to be changed in the calling function by the called function. |
5 | Return pointer from functions in C C allows a function to return a pointer to the local variable, static variable, and dynamically allocated memory as well. |