I was addicted to security when I was in college and always wanted to write a small program that handles strings.
Unfortunately, there was not much time at that time, so I delayed until this winter vacation.
I have nothing to do during the winter vacation, so I wrote a mini program to practice and review the forms and basics.
The functions implemented are as follows:
Convert to capital
Convert to lowercase
Invert string
Match the number of occurrences of a string
Regular Match
base64 encryption
base64 decryption
ROT13 encryption and decryption
MD5 32-bit encryption
The program is still very simple, without robustness, and no input verification.
Create a bug with your heart (Bitsin
Also, please don’t complain about my variable naming and method naming. If you didn’t learn pinyin since elementary school, you will definitely not understand it :)
Because at the beginning, I did this in a blind test project.
I'm really too lazy to translate
There is a method to convert to uppercase and lowercase
(());//Convert to capital(());//Convert to lowercase
Output reverse string
public static void fanxiang(string s)
{
char[] arrey = ();
StringBuilder s1 = new StringBuilder("");
for (int i = - 1; i >= 0; i--)
{
((arrey[i]));
}
("The reverse string is{0}",s1);
}
View the number of a short string in it
public static void pipei(string s)
{
int count = 0;
int i;
("Please enter a short string");
string s2 = ();
while ((i=(s2)) >= 0)
{
count++;
s = (i + );
}
("Appears in the string{0}Second-rate{1}", count, s2);
}
Regular Match
I have never learned the knowledge of regularity, and I have read a lot of them online, most of them talk about regularity rather than regularity. I wrote this for about a day and I still have a bug now.
When there is no matching result, or is it matched to empty? It will cause multiple lines to break. I also forgot how I tested the bug at that time.
Anyone who has any ideas can tell me.
public static void zzpipei(string s)
{
("Please enter regular expression");
string zz = ();
Regex re = new Regex(zz);
string s2 = "";
if ((s))
{
("Match Successfully");
MatchCollection mc = (s);
foreach (Match ma in mc)
{
s2 += ;
s2 += ("\r\n");
}
("One behavior, one match result");
(s2);
}
else
{ ("No matching result"); }
}
base64 encryption
The method used is also in-house, and the encryption of Chinese characters is different from that of some websites.
public static void basejiami(string s)
{
byte[] bytes = (s);
("Stringbase64Encrypted as{0}", Convert.ToBase64String(bytes));
}
base64 decryption
public static void basejiemi(string s)
{
byte[] bytes = Convert.FromBase64String(s);
("Stringbase64Decrypted as{0}", (bytes));
}
ROT13 encryption and decryption
ROT13 is a simple replacement code. ROT13 is also a variant of Caesar Encryption, which was developed in ancient Rome in the past.
ROT13 replaces 13 bits backwards, that is, A is converted to N, B is converted to O and so on.
The Caesar password is to replace 3 digits backwards. Change this method can also achieve the explosion of Caesar's password, and this method is case-sensitive.
ROT13 is its own reversal; that is, to restore ROT13, you can use the same encryption algorithm, so the same operation can be re-encrypted and decrypted.
This algorithm does not provide real cryptographic protection, so it should not be applied to purposes that require protection. It is often regarded as a typical example of weak encryption.
public static void rotjm(string s)
{
string jmzf = "";//Decrypt the encrypted string char[] arrey = ();
("The string length is{0}", );
for (int i = 0; i < ; i++)
{
int zfcode = (int)arrey[i];
if (zfcode >= 97 && zfcode <= 109)
zfcode = zfcode + 13;
else if (zfcode >= 110 && zfcode <= 122)
zfcode = zfcode - 13;
else if (zfcode >= 65 && zfcode <= 77)
zfcode = zfcode + 13;
else if (zfcode >= 78 && zfcode <= 90)
zfcode = zfcode - 13;
jmzf = jmzf + (char)zfcode;
}
("The result is{0}", jmzf);
}
Replace string
public static void thzf(string s)
{
("Please enter the string you want to be replaced");
string str1 = ();
("Please enter the string you want to replace");
string str2 = ();
((str1, str2));
}
32-bit MD5 encryption
public static void md5jm(string s)
{
MD5 md5 = new MD5CryptoServiceProvider();
//Encode characters into byte sequence byte[] data = (s);
byte[] md5data = (data);
();
//Transfer the encrypted array and encrypted bytes. This method is 32-bit encryption string str = "";
for (int i = 0; i < ; i++)
{
str += md5data[i].ToString("x").PadLeft(2, '0');
}
("The encryption result is{0}",str);
}
My program, using .NET framework 4.0.
download
The above is all the content of this article. I hope that the content of this article will help you study or work. I also hope to support me more!