{"id":162,"date":"2011-02-07T09:37:00","date_gmt":"1970-01-01T00:00:00","guid":{"rendered":"http:\/\/www.yazilimmutfagi.com\/?p=162"},"modified":"2011-02-07T09:37:00","modified_gmt":"1970-01-01T00:00:00","slug":"verileri-sifreleme","status":"publish","type":"post","link":"https:\/\/www.yazilimmutfagi.com\/index.php\/2011\/02\/07\/verileri-sifreleme\/","title":{"rendered":"Verileri Sifreleme"},"content":{"rendered":"

Bazen Text olarak girilen verileri sifreli olarak kaydetmemiz gerekebilir. Genel olarak kullanici sifreleri veritabaninda sifrelenmis olarak tutulur, bu sayede veritabanina erisebilen birisi dahi kullanicilara ait sifreleri göremez. Peki girilen verileri nasil sifreleriz. Bu makalemizde bu islemi nasil yapacagimiz ögrenecegiz.<\/p>\n

Ilk olarak Visual Studio ile yeni bir web sitesi olusturuyoruz daha sonra Sifreleme adinda bir sinif ekliyoruz. Olusturacagimiz bu sinifi birebir kopyalayarak kendi projelerinize adapte edebilirsiniz. Olusturdugumuz sinifa ait kodlar su sekilde.
\n.<\/a><\/p>\n\n \n \n
\n

using<\/span> System;<\/o:p><\/span><\/p>\n

using<\/span> System.IO;<\/o:p><\/span><\/p>\n

using<\/span> System.Security.Cryptography;<\/o:p><\/span><\/p>\n

 <\/o:p><\/span><\/p>\n

public<\/span> class<\/span> Sifreleme<\/o:p><\/span><\/span><\/p>\n

{<\/o:p><\/span><\/p>\n

    <\/span>private<\/span> string<\/span> password = "yzSabri123"<\/span>;<\/o:p><\/span><\/p>\n

    <\/span><\/o:p><\/span><\/p>\n

    <\/span>private<\/span> byte<\/span>[] Sifrele(byte<\/span>[] SifresizVeri, byte<\/span>[] Key, byte<\/span>[] IV)<\/o:p><\/span><\/p>\n

    <\/span>{<\/o:p><\/span><\/p>\n

        <\/span>MemoryStream<\/span> ms = new<\/span> MemoryStream<\/span>();<\/o:p><\/span><\/p>\n

        <\/span>Rijndael<\/span> alg = Rijndael<\/span>.Create();<\/o:p><\/span><\/p>\n

        <\/span>alg.Key = Key;<\/o:p><\/span><\/p>\n

        <\/span>alg.IV = IV;<\/o:p><\/span><\/p>\n

        <\/span>CryptoStream<\/span> cs = new<\/span> CryptoStream<\/span>(ms,<\/o:p><\/span><\/p>\n

        <\/span>alg.CreateEncryptor(), CryptoStreamMode<\/span>.Write);<\/o:p><\/span><\/p>\n

        <\/span>cs.Write(SifresizVeri, 0, SifresizVeri.Length);<\/o:p><\/span><\/p>\n

        <\/span>cs.Close();<\/o:p><\/span><\/p>\n

        <\/span>byte<\/span>[] sifrelenmisVeri = ms.ToArray();<\/o:p><\/span><\/p>\n

        <\/span>return<\/span> sifrelenmisVeri;<\/o:p><\/span><\/p>\n

    <\/span>}<\/o:p><\/span><\/p>\n

 <\/o:p><\/span><\/p>\n

    <\/span>private<\/span> byte<\/span>[] SifreCoz(byte<\/span>[] SifreliVeri,<\/o:p><\/span><\/p>\n

                            <\/span>byte<\/span>[] Key, byte<\/span>[] IV)<\/o:p><\/span><\/p>\n

    <\/span>{<\/o:p><\/span><\/p>\n

        <\/span>MemoryStream<\/span> ms = new<\/span> MemoryStream<\/span>();<\/o:p><\/span><\/p>\n

        <\/span>Rijndael<\/span> alg = Rijndael<\/span>.Create();<\/o:p><\/span><\/p>\n

        <\/span>alg.Key = Key;<\/o:p><\/span><\/p>\n

        <\/span>alg.IV = IV;<\/o:p><\/span><\/p>\n

        <\/span>CryptoStream<\/span> cs = new<\/span> CryptoStream<\/span>(ms,<\/o:p><\/span><\/p>\n

            <\/span>alg.CreateDecryptor(), CryptoStreamMode<\/span>.Write);<\/o:p><\/span><\/p>\n

 <\/o:p><\/span><\/p>\n

        <\/span>cs.Write(SifreliVeri, 0, SifreliVeri.Length);<\/o:p><\/span><\/p>\n

        <\/span>cs.Close();<\/o:p><\/span><\/p>\n

        <\/span>byte<\/span>[] SifresiCozulmusVeri = ms.ToArray();<\/o:p><\/span><\/p>\n

        <\/span>return<\/span> SifresiCozulmusVeri;<\/o:p><\/span><\/p>\n

    <\/span>}<\/o:p><\/span><\/p>\n

 <\/o:p><\/span><\/p>\n

   <\/span><\/span> <\/span>public<\/span> string<\/span> TextSifrele(string<\/span> sifrelenecekMetin)<\/o:p><\/span><\/p>\n

    <\/span>{<\/o:p><\/span><\/p>\n

        <\/span>byte<\/span>[] sifrelenecekByteDizisi = System.Text.Encoding<\/span>.Unicode.GetBytes(sifrelenecekMetin);<\/o:p><\/span><\/p>\n

        <\/span>PasswordDeriveBytes<\/span> pdb = new<\/span> PasswordDeriveBytes<\/span>(password, new<\/span> byte<\/span>[] {0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, <\/o:p><\/span><\/p>\n

            <\/span>0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76});<\/o:p><\/span><\/p>\n

 <\/o:p><\/span><\/p>\n

        <\/span>byte<\/span>[] SifrelenmisVeri = Sifrele(sifrelenecekByteDizisi,<\/o:p><\/span><\/p>\n

             <\/span>pdb.GetBytes(32), pdb.GetBytes(16));<\/o:p><\/span><\/p>\n

        <\/span>return<\/span> Convert<\/span>.ToBase64String(SifrelenmisVeri);<\/o:p><\/span><\/p>\n

    <\/span>}    <\/span><\/o:p><\/span><\/span><\/p>\n

 <\/o:p><\/span><\/p>\n

    <\/span>public<\/span> string<\/span> TextSifreCoz(string<\/span> text)<\/o:p><\/span><\/p>\n

    <\/span>{<\/o:p><\/span><\/p>\n

        <\/span>byte<\/span>[] SifrelenmisByteDizisi = Convert<\/span>.FromBase64String(text);<\/o:p><\/span><\/p>\n

        <\/span>PasswordDeriveBytes<\/span> pdb = new<\/span> PasswordDeriveBytes<\/span>(password,<\/o:p><\/span><\/p>\n

            <\/span>new<\/span> byte<\/span>[] {0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, <\/o:p><\/span><\/p>\n

            <\/span>0x64, 0x76, 0x65, 0x64, 0x65, 0x76});<\/o:p><\/span><\/p>\n

 <\/o:p><\/span><\/p>\n

        <\/span>byte<\/span>[] SifresiCozulmusVeri = SifreCoz(SifrelenmisByteDizisi,<\/o:p><\/span><\/p>\n

            <\/span>pdb.GetBytes(32), pdb.GetBytes(16));<\/o:p><\/span><\/p>\n

 <\/o:p><\/span><\/p>\n

        <\/span>return<\/span> System.Text.Encoding<\/span>.Unicode.GetString(SifresiCozulmusVeri);<\/o:p><\/span><\/p>\n

    <\/span>}<\/o:p><\/span><\/p>\n

}<\/span><\/o:p><\/span><\/p>\n <\/td>\n <\/tr>\n <\/tbody>\n<\/table>\n

 <\/o:p><\/p>\n

Simdi ise sifrelenecek metni girecegimiz aspx sayfamizi olusturalim. Aspx sayfamiza iki adet textbox ekleyip sifreleme islemini yapalim.<\/p>\n\n \n \n
\n

<<\/span>table<\/span>><\/o:p><\/span><\/p>\n

    <\/span><<\/span>tr<\/span>><\/o:p><\/span><\/span><\/p>\n

        <\/span><<\/span>td<\/span>><\/o:p><\/span><\/span><\/p>\n

            <\/span>Sifrelenecek Metin<\/o:p><\/span><\/p>\n

        <\/span><\/<\/span>td<\/span>><\/o:p><\/span><\/span><\/p>\n

        <\/span><<\/span>td<\/span>><\/o:p><\/span><\/span><\/p>\n

            <\/span><<\/span>asp<\/span>:<\/span>TextBox<\/span> Width<\/span>="200px"<\/span> ID<\/span>="TextBoxSifrelenecekMetin"<\/span> runat<\/span>="server"><\/<\/span>asp<\/span>:<\/span>TextBox<\/span>><\/o:p><\/span><\/span><\/p>\n

            <\/span><<\/span>asp<\/span>:<\/span>Button<\/span> ID<\/span>="ButtonSifrele"<\/span> runat<\/span>="server"<\/span> Text<\/span>="Sifrele"<\/span> <\/o:p><\/span><\/p>\n

                <\/span>onclick<\/span>="ButtonSifrele_Click"<\/span> \/><\/o:p><\/span><\/span><\/p>\n

        <\/span><\/<\/span>td<\/span>><\/o:p><\/span><\/span><\/p>\n

    <\/span><\/<\/span>tr<\/span>><\/o:p><\/span><\/span><\/p>\n

    <\/span><<\/span>tr<\/span>><\/o:p><\/span><\/span><\/p>\n

        <\/span><<\/span>td<\/span>><\/o:p><\/span><\/span><\/p>\n

            <\/span>Sifrelenmis Metin<\/o:p><\/span><\/p>\n

        <\/span><\/<\/span>td<\/span>><\/o:p><\/span><\/span><\/p>\n

        <\/span><<\/span>td<\/span>><\/o:p><\/span><\/span><\/p>\n

            <\/span><<\/span>asp<\/span>:<\/span>TextBox<\/span> Width<\/span>="100%"<\/span> ID<\/span>="TextBoxSifrelenmisMetin"<\/span> runat<\/span>="server"><\/<\/span>asp<\/span>:<\/span>TextBox<\/span>><\/o:p><\/span><\/span><\/p>\n

        <\/span><\/<\/span>td<\/span>><\/o:p><\/span><\/span><\/p>\n

    <\/span><\/<\/span>tr<\/span>><\/o:p><\/span><\/span><\/p>\n

<\/<\/span>table<\/span>><\/span><\/p>\n <\/td>\n <\/tr>\n <\/tbody>\n<\/table>\n

 <\/o:p><\/p>\n

Butona basinca asagidaki kodlari çalistiracagiz.<\/p>\n\n \n \n
\n

protected<\/span> void<\/span> ButtonSifrele_Click(object<\/span> sender, EventArgs<\/span> e)<\/o:p><\/span><\/p>\n

{<\/o:p><\/span><\/p>\n

    <\/span>Sifreleme<\/span> sifreleme = new<\/span> Sifreleme<\/span>();<\/o:p><\/span><\/p>\n

    <\/span>string<\/span> sifrelenmisMetin = sifreleme.TextSifrele(TextBoxSifrelenecekMetin.Text);<\/o:p><\/span><\/p>\n

    <\/span>TextBoxSifrelenmisMetin.Text = sifrelenmisMetin;<\/o:p><\/span><\/p>\n

}<\/span><\/p>\n <\/td>\n <\/tr>\n <\/tbody>\n<\/table>\n

 <\/o:p>.<\/a><\/p>\n

 <\/o:p><\/p>\n

\"\"<\/span><\/p>\n

Gördügünüz gibi “sabri” yazdigim zaman karsiliginda “Pu2bqt500v7QGHCDfp8Yfg==” degeri dönüyor. Bu sekilde istedigimiz bilgileri veritabanina atmadan önce rahatça sikistirabiliriz.<\/p>\n

Simdi sirada sifre çözme islemi var. Bunun için sayfamiza iki adet textbox ve bir buton daha ekleyelim<\/p>\n\n \n \n
\n

<<\/span>tr<\/span>><\/o:p><\/span><\/p>\n

                <\/span><<\/span>th<\/span>><\/o:p><\/span><\/span><\/p>\n

                    <\/span>Sifre Çözme Islemi<\/o:p><\/span><\/p>\n

                <\/span><\/<\/span>th<\/span>><\/o:p><\/span><\/span><\/p>\n

            <\/span><\/<\/span>tr<\/span>><\/o:p><\/span><\/span><\/p>\n

 <\/span>           <\/span><<\/span>tr<\/span>><\/o:p><\/span><\/span><\/p>\n

                <\/span><<\/span>td<\/span>><\/o:p><\/span><\/span><\/p>\n

                    <\/span>Sifreli Metin<\/o:p><\/span><\/p>\n

                <\/span><\/<\/span>td<\/span>><\/o:p><\/span><\/span><\/p>\n

                <\/span><<\/span>td<\/span>><\/o:p><\/span><\/span><\/p>\n

                    <\/span><<\/span>asp<\/span>:<\/span>TextBox<\/span> Width<\/span>="200px"<\/span> ID<\/span>="TextBoxSifreliMetin"<\/span> runat<\/span>="server"><\/<\/span>asp<\/span>:<\/span>TextBox<\/span>><\/o:p><\/span><\/span><\/p>\n

                    <\/span><<\/span>asp<\/span>:<\/span>Button<\/span> ID<\/span>="ButtonSifreCoz"<\/span> runat<\/span>="server"<\/span> Text<\/span>="SifreÇöz"<\/span> OnClick<\/span>="ButtonSifreCoz_Click"<\/span> \/><\/o:p><\/span><\/span><\/p>\n

                <\/span><\/<\/span>td<\/span>><\/o:p><\/span><\/span><\/p>\n

            <\/span><\/<\/span>tr<\/span>><\/o:p><\/span><\/span><\/p>\n

            <\/span><<\/span>tr<\/span>><\/o:p><\/span><\/span><\/p>\n

                <\/span><<\/span>td<\/span>><\/o:p><\/span><\/span><\/p>\n

                    <\/span>Sifresi Çözülmüs Metin<\/o:p><\/span><\/p>\n

                <\/span><\/<\/span>td<\/span>><\/o:p><\/span><\/span><\/p>\n

                <\/span><<\/span>td<\/span>><\/o:p><\/span><\/span><\/p>\n

                    <\/span><<\/span>asp<\/span>:<\/span>TextBox<\/span> Width<\/span>="100%"<\/span> ID<\/span>="TextBoxCozulmusMetin"<\/span> runat<\/span>="server"><\/<\/span>asp<\/span>:<\/span>TextBox<\/span>><\/o:p><\/span><\/span><\/p>\n

                <\/span><\/<\/span>td<\/span>><\/o:p><\/span><\/span><\/p>\n

<\/<\/span>tr<\/span>><\/span><\/p>\n <\/td>\n <\/tr>\n <\/tbody>\n<\/table>\n


\nIlk islemin tersine bu sefer<\/p>\n

Sifre Çöz metodunu kullanacagiz.<\/p>\n\n \n \n
\n

protected<\/span> void<\/span> ButtonSifreCoz_Click(object<\/span> sender, EventArgs<\/span> e)<\/o:p><\/span><\/p>\n

{<\/o:p><\/span><\/p>\n

    <\/span>Sifreleme<\/span> sifreleme = new<\/span> Sifreleme<\/span>();<\/o:p><\/span><\/p>\n

    <\/span>string<\/span> sifresiCozulmusMetin = sifreleme.TextSifreCoz(TextBoxSifreliMetin.Text);<\/o:p><\/span><\/p>\n

    <\/span>TextBoxCozulmusMetin.Text = sifresiCozulmusMetin;<\/o:p><\/span><\/p>\n

}<\/span><\/p>\n <\/td>\n <\/tr>\n <\/tbody>\n<\/table>\n

 <\/o:p><\/p>\n

\"\"<\/span><\/p>\n

Kullanicilara ait sifreleri veritabaninda saklamak için kullanilan yöntemlerden birini anlatmis olduk, diger bir yöntem ise kullanici sifresinin hash bilgisini almak ve bunu veritabanina kaydetmektir. Iki yöntem arasinda bariz bir fark vardir. Bizim anlattigimiz yöntemde kullanicinin sifresi veritabaninda sifreli olarak  <\/span>da olsa vardir fakat hash metodunda kullanicinin sifresine artik ulasamayiz sadece hash bilgisine ulasabiliriz. Kullanici giris yapacagi zaman girdigi sifrenin hashini alip veritabani ile karsilastirarak dogru girilip girilmedigine karar veririz. Tabiki hash kullanilan yöntemlerde kullanici sifre hatirlatma fonksiyonu olmaz sadece sifre sifirlama yapilabilir. Bu konuyuda bir baska makalemizde bahsederiz.<\/p>\n

Yukarida anlattigimiz konuya ait örnek projeyi buradan indirebilirsiniz<\/a><\/p>","protected":false},"excerpt":{"rendered":"

Bazen Text olarak girilen verileri sifreli olarak kaydetmemiz gerekebilir. Genel olarak kullanici sifreleri veritabaninda sifrelenmis olarak tutulur, bu sayede veritabanina erisebilen birisi dahi kullanicilara ait sifreleri göremez. Peki girilen verileri nasil sifreleriz. Bu makalemizde bu islemi nasil yapacagimiz ögrenecegiz.<\/p>\n","protected":false},"author":517,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[407],"tags":[5688,5737,5169,5100,4349,4426],"_links":{"self":[{"href":"https:\/\/www.yazilimmutfagi.com\/index.php\/wp-json\/wp\/v2\/posts\/162"}],"collection":[{"href":"https:\/\/www.yazilimmutfagi.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.yazilimmutfagi.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.yazilimmutfagi.com\/index.php\/wp-json\/wp\/v2\/users\/517"}],"replies":[{"embeddable":true,"href":"https:\/\/www.yazilimmutfagi.com\/index.php\/wp-json\/wp\/v2\/comments?post=162"}],"version-history":[{"count":0,"href":"https:\/\/www.yazilimmutfagi.com\/index.php\/wp-json\/wp\/v2\/posts\/162\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.yazilimmutfagi.com\/index.php\/wp-json\/wp\/v2\/media?parent=162"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.yazilimmutfagi.com\/index.php\/wp-json\/wp\/v2\/categories?post=162"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.yazilimmutfagi.com\/index.php\/wp-json\/wp\/v2\/tags?post=162"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}