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什么是对称加密和非对称加密？
对称加密是指：有一个密钥，加密用它来加密，解密也需要用到它。因为加密解密都是用同一个密钥所以叫对称加密。
非对称加密是指：就是有 2 个密钥，一个是公钥，一个是私钥。私钥是自己的，不能随便给人，公钥随便给，无所谓。一般是别人用你的公钥加密，然后把密文给你，你用你的私钥解密，这样一样加密和解密不是同一个密钥，所以叫非对称。
对称和非对称的优劣？
对称加密有一个坏处只要拥有密钥的人都可以解密。
非对称的好处是假如没有私钥，别人是无法解密的，就算加密的那个人他把数据加密了他也无法解密，加密者把密文和公钥随便给那个人都无法解密。
什么是数字签名？
数字签名是指：用一段密码与原文进行加密，检测原文有没有被 篡改。意义就是这些数据与原文数据比对是否修改过，这个解释有点麻烦，一般是用自己的私钥对数据进行签名，然后用公钥去验证这个数据是否修改过
1、用 RSACryptoServiceProvider 加密解密
'要加密的数据
Dim messageBytes As Byte() = Text.Encoding.UTF8.GetBytes('激情燃烧的木炭[http://www.woodcoal.cn/]')
'1. 产生公匙和私匙,两个数据都要保存
Dim oRsa As New Security.Cryptography.RSACryptoServiceProvider
Dim privateKey As String = oRsa.ToXmlString(True)
Dim publicKey As String = oRsa.ToXmlString(False)
'2. 用公匙加密数据
Dim oRsaEncode As New Security.Cryptography.RSACryptoServiceProvider
'导入公匙
oRsaEncode.FromXmlString(publicKey)
'输出加密后的数据
Dim resultByte As Byte() = oRsaEncode.Encrypt(messageBytes,
False)
'3. 用私匙解密数据
Dim oRsaDecode As New Security.Cryptography.RSACryptoServiceProvider
'导入私匙
oRsaDecode.FromXmlString(privateKey)
'输出解密后的数据
messageBytes = oRsaDecode.Decrypt(resultByte,
False)
'结果
Return Text.Encoding.UTF8.GetString(messageBytes)
2、用 RSACryptoServiceProvider 签名验签
'要加密的数据
Dim messageBytes As Byte() = Text.Encoding.UTF8.GetBytes('激情燃烧的木炭[http://www.woodcoal.cn/]')
'1. 产生公匙和私匙,两个数据都要保存
Dim oRsa As New Security.Cryptography.RSACryptoServiceProvider
Dim privateKey As String = oRsa.ToXmlString(True)
Dim publicKey As String = oRsa.ToXmlString(False)
'2. 用私钥匙签名数据
Dim oRsaEncode As New Security.Cryptography.RSACryptoServiceProvider
'导入私钥
oRsaEncode.FromXmlString(privateKey)
'输出签名后的数据
Dim resultByte As Byte() = oRsaEncode.SignData(messageBytes,
'SHA1')
'3. 用公钥验证数据
Dim oRsaDecode As New Security.Cryptography.RSACryptoServiceProvider
'导入公钥
oRsaDecode.FromXmlString(publicKey)
'输出验证后的结果，是否验证成功
Return oRsaDecode.VerifyData(resultByte,
'SHA1', messageBytes)
3、用证书进行签名
因为一般证书的私钥是不可以导出的，所以用第 2 种方法导入私钥的来进行签名行不通。
'要加密的数据
Dim messageBytes As Byte() = Text.Encoding.UTF8.GetBytes('激情燃烧的木炭[http://www.woodcoal.cn/]')
Dim certificatePath As String = 'E:\Certificate.P12'
'导入证书
Dim x509 As New Security.Cryptography.X509Certificates.X509Certificate2(certificatePath,
'Import Password')
Dim privateKey As Security.Cryptography.RSACryptoServiceProvider
= x509.PrivateKey
Dim publicKey As String = x509.PublicKey.Key.ToXmlString(False)
'对要签名的数据进行哈希
Dim sha1 As New Security.Cryptography.SHA1CryptoServiceProvider
Dim hashBytes As Byte() = sha1.ComputeHash(messageBytes)
'签名对象
Dim signe As New Security.Cryptography.RSAPKCS1SignatureFormatter
'设置签名用到的私钥
signe.SetKey(privateKey)
'设置签名算法
signe.SetHashAlgorithm('SHA1')
'返回结果
Dim reslutBytes As Byte() = signe.CreateSignature(hashBytes)
'3. 用公钥验证数据,与第2方法相同
Dim oRsaDecode As New Security.Cryptography.RSACryptoServiceProvider
'导入公钥
oRsaDecode.FromXmlString(publicKey)
'输出验证后的结果，是否验证成功
Return oRsaDecode.VerifyData(resultByte,
'SHA1', messageBytes)
4、用证书加密解密
'要加密的数据
Dim messageBytes As Byte() = Text.Encoding.UTF8.GetBytes('激情燃烧的木炭[http://www.woodcoal.cn/]')
Dim certificatePath As String = 'E:\Certificate.P12'
'导入证书
Dim x509 As New Security.Cryptography.X509Certificates.X509Certificate2(certificatePath,
'Import Password')
Dim privateKey As Security.Cryptography.RSACryptoServiceProvider
= x509.PrivateKey
Dim publicKey As String = x509.PublicKey.Key.ToXmlString(False)
'证书公钥加密
Dim oRsaEncode As New Security.Cryptography.RSACryptoServiceProvider
oRsaEncode.FromXmlString(publicKey)
Dim resultBytes As Byte() = oRsaEncode.Encrypt(messageBytes,
False)
'证书私钥解密
Dim oRsaDecode As Security.Cryptography.RSACryptoServiceProvider
= DirectCast(privateKey, Security.Cryptography.RSACryptoServiceProvider)
messageBytes = oRsaDecode.Decrypt(resultBytes,
False)
'返回结果
Return Text.Encoding.UTF8.GetString(messageBytes)
5、用证书对文件加密解密
因为文件可能特别大 所以需要用流和 Buffer 的方式，如果把文件全部读到
Byte() 里进行加密，当文件很大，比如 5G，那全部读到 Byte() 里崩溃掉
''' 用证书加密文件
''' 证书路径
''' 证书导入密码
''' 需要加密的文件路径
''' 加密后的文件路径
'''
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Public Sub Encrypt(ByVal certificatePath As String, ByVal certificatePassword As String,
ByVal sourcePath As String, ByVal targetPath As String)
'导入证书
Dim x509 As New Security.Cryptography.X509Certificates.X509Certificate2(certificatePath,
certificatePassword)
'Dim privateKey As Security.Cryptography.RSACryptoServiceProvider = x509.PrivateKey
Dim publicKey As String = x509.PublicKey.Key.ToXmlString(False)
Dim oRsa As New Security.Cryptography.RSACryptoServiceProvider()
oRsa.FromXmlString(publicKey)
Dim sourceStream As New System.IO.FileStream(sourcePath, System.IO.FileMode.Open)
Dim targetStream As New System.IO.FileStream(targetPath, System.IO.FileMode.OpenOrCreate)
Dim blockSize As Integer = 0
If oRsa.KeySize = 1024 Then
blockSize = 16
Else
blockSize = 8
End If
Dim K As Integer = 1
While K > 0
Dim buffer As Byte() = New Byte(blockSize - 1) {}
K = sourceStream.Read(buffer, 0, buffer.Length)
If K > 0 Then
Dim buffer1 As Byte(), encryblock As Byte()
If blockSize = K Then
encryblock = oRsa.Encrypt(buffer, False)
targetStream.Write(encryblock, 0, encryblock.Length)
Else
buffer1 = New Byte(K - 1) {}
For i As Integer = 0 To K - 1
buffer1(i) = buffer(i)
Next
encryblock = oRsa.Encrypt(buffer1, False)
targetStream.Write(encryblock, 0, encryblock.Length)
End If
Else
sourceStream.Close()
targetStream.Close()
End If
End While
End Sub |
''' 用证书解密文件
''' 证书路径
''' 证书导入密码
''' 需要解密的文件路径
''' 解密后的文件路径
'''
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Public Sub Decrypt(ByVal certificatePath As String, ByVal certificatePassword As String,
ByVal sourcePath As String, ByVal targetPath As String)
'导入证书
Dim x509 As New Security.Cryptography.X509Certificates.X509Certificate2(certificatePath,
certificatePassword)
Dim privateKey As Security.Cryptography.RSACryptoServiceProvider = x509.PrivateKey
'Dim publicKey As String = x509.PublicKey.Key.ToXmlString(False)
Dim oRsa As Security.Cryptography.RSACryptoServiceProvider = DirectCast(privateKey,
Security.Cryptography.RSACryptoServiceProvider)
Dim sourceStream As New System.IO.FileStream(sourcePath, System.IO.FileMode.Open)
Dim targetStream As New System.IO.FileStream(targetPath, System.IO.FileMode.OpenOrCreate)
Dim blockSize As Integer = oRsa.KeySize / 8
Dim buffer1 As Byte(), encryblock As Byte()
Dim K As Integer = 1
While K > 0
Dim buffer As Byte() = New Byte(blockSize - 1) {}
K = sourceStream.Read(Buffer, 0, Buffer.Length)
If K > 0 Then
If blockSize = K Then
encryblock = oRsa.Decrypt(buffer, False)
targetStream.Write(encryblock, 0, encryblock.Length)
Else
buffer1 = New Byte(K - 1) {}
For i As Integer = 0 To K - 1
buffer1(i) = buffer(i)
Next
encryblock = oRsa.Decrypt(buffer1, False)
targetStream.Write(encryblock, 0, encryblock.Length)
End If
Else
sourceStream.Close()
targetStream.Close()
End If
End While
End Sub |
6、用证书对文件进行签名验签
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Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs)
x509 = New X509Certificate2(Path, '12345678')
SignFile('1.txt', '11.txt')
VerifyFile('1.txt', '11.txt')
End Sub
Private Function VerifyFile(ByVal FileName As String, ByVal SignedFileName As String) As Boolean
Dim reslut As Boolean = True
Dim objread As New System.IO.StreamReader(FileName)
Dim objreadSigned As New System.IO.StreamReader(SignedFileName)
Dim VeryRsa As New RSACryptoServiceProvider()
VeryRsa.FromXmlString(x509.PublicKey.Key.ToXmlString(False))
Dim Inblocksize As Integer = 0
Dim Signedblocksize As Integer = 0
If VeryRsa.KeySize = 1024 Then
Inblocksize = 16
Else
Inblocksize = 8
End If
Signedblocksize = VeryRsa.KeySize / 8
Dim Closed As Boolean = True
Dim Buffer As Byte()
'原文缓存区
Dim InBuffer As Byte()
'原文缓存区
Dim Buffer1 As Byte()
'签名文件缓存区
While Closed
Buffer = Nothing
Buffer = New Byte(Inblocksize - 1) {}
Dim k As Integer = objread.BaseStream.Read(Buffer, 0, Buffer.Length)
If k > 0 Then
If Inblocksize = k Then
'读出来的长度和缓存区一样大
Buffer1 = New Byte(Signedblocksize - 1) {}
objreadSigned.BaseStream.Read(Buffer1, 0, Buffer1.Length)
reslut = VeryRsa.VerifyData(Buffer, 'SHA1', Buffer1)
If Not reslut Then
Closed = False
End If
Else
'意思是Buffer没满，只有k个字节，k字节后面全是空所以不需要验签
InBuffer = New Byte(k - 1) {}
For i As Integer = 0 To k - 1
InBuffer(i) = Buffer(i)
Next
Buffer1 = New Byte(Signedblocksize - 1) {}
objreadSigned.BaseStream.Read(Buffer1, 0, Buffer1.Length)
reslut = VeryRsa.VerifyData(InBuffer, 'SHA1', Buffer1)
If Not reslut Then
Closed = False
End If
End If
Else
'这里的意思是原文已经读完毕了，并且已经和签名文件对应验签成功，那么
'签名文件也必须读完毕了。
If objreadSigned.BaseStream.Position <> objreadSigned.BaseStream.Length Then
reslut = False
End If
objreadSigned.Close()
objread.Close()
Closed = False
End If
End While
Return reslut
End Function
Private Sub SignFile(ByVal InFileName As String, ByVal OutFileName As String)
Dim SignRsa As RSACryptoServiceProvider = DirectCast(x509.PrivateKey, RSACryptoServiceProvider)
Dim objread As New System.IO.StreamReader(InFileName)
Dim objwrite As New System.IO.StreamWriter(OutFileName, False)
Dim blocksize As Integer = 0
If SignRsa.KeySize = 1024 Then
blocksize = 16
Else
blocksize = 8
End If
Dim Closed As Boolean = True
Dim Buffer As Byte() = New Byte(blocksize - 1) {}
Dim buffer1 As Byte(), SignBytes As Byte()
While Closed
Dim k As Integer = objread.BaseStream.Read(Buffer, 0, Buffer.Length)
If k > 0 Then
If k = blocksize Then
SignBytes = SignRsa.SignData(Buffer, 'SHA1')
objwrite.BaseStream.Write(SignBytes, 0, SignBytes.Length)
Else
buffer1 = New Byte(k - 1) {}
For i As Integer = 0 To k - 1
buffer1(i) = Buffer(i)
Next
SignBytes = SignRsa.SignData(buffer1, 'SHA1')
objwrite.BaseStream.Write(SignBytes, 0, SignBytes.Length)
End If
Else
Closed = False
objread.Close()
objwrite.Close()
End If
End While
End Sub |
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