Ⅰ 求一段VB登陆代码~需要MD5加密密码框的
Private Sub Command1_Click()
Dim md5Pwd As String
Dim rs As Recordset
Dim con As Connection
md5Pwd = Md5_String_Calc(Text2)
Set rs = con.Execute("select count(*) from user where username = '" & Text1.Text & "' and userpwd = '" & md5Pwd & "'")
If rs.RecordCount = 0 Then
MsgBox "用户名或者密码错误"
Else
MsgBox "登录成功"
End If
End Sub
'模块中
Option Explicit
Private Const OFFSET_4 = 4294967296#
Private Const MAXINT_4 = 2147483647
Private State(4) As Long
Private ByteCounter As Long
Private ByteBuffer(63) As Byte
Private Const S11 = 7
Private Const S12 = 12
Private Const S13 = 17
Private Const S14 = 22
Private Const S21 = 5
Private Const S22 = 9
Private Const S23 = 14
Private Const S24 = 20
Private Const S31 = 4
Private Const S32 = 11
Private Const S33 = 16
Private Const S34 = 23
Private Const S41 = 6
Private Const S42 = 10
Private Const S43 = 15
Private Const S44 = 21
Public Function GetValues() As String
GetValues = LongToString(State(1)) & LongToString(State(2)) & LongToString(State(3)) & LongToString(State(4))
End Function
Function LongLeftRotate(value As Long, Bits As Long) As Long
Dim lngSign As Long, lngI As Long
Bits = Bits Mod 32
If Bits = 0 Then LongLeftRotate = value: Exit Function
For lngI = 1 To Bits
lngSign = value And &HC0000000
value = (value And &H3FFFFFFF) * 2
value = value Or ((lngSign < 0) And 1) Or (CBool(lngSign And &H40000000) And &H80000000)
Next
LongLeftRotate = value
End Function
Public Function Md5_File_Calc(InFile As String) As String
On Error GoTo errorhandler
GoSub begin
errorhandler:
Md5_File_Calc = ""
Exit Function
begin:
Dim FileO As Integer
FileO = FreeFile
Call FileLen(InFile)
Open InFile For Binary Access Read As #FileO
MD5Init
Do While Not EOF(FileO)
Get #FileO, , ByteBuffer
If Loc(FileO) < LOF(FileO) Then
ByteCounter = ByteCounter + 64
MD5Transform ByteBuffer
End If
Loop
ByteCounter = ByteCounter + (LOF(FileO) Mod 64)
Close #FileO
MD5Final
Md5_File_Calc = GetValues
End Function
Public Function Md5_String_Calc(SourceString As String) As String
MD5Init
MD5Update LenB(StrConv(SourceString, vbFromUnicode)), StringToArray(SourceString)
MD5Final
Md5_String_Calc = GetValues
End Function
Public Sub MD5Final()
Dim dblBits As Double, padding(72) As Byte, lngBytesBuffered As Long
padding(0) = &H80
dblBits = ByteCounter * 8
lngBytesBuffered = ByteCounter Mod 64
If lngBytesBuffered <= 56 Then MD5Update 56 - lngBytesBuffered, padding Else MD5Update 120 - ByteCounter, padding
padding(0) = UnsignedToLong(dblBits) And &HFF&
padding(1) = UnsignedToLong(dblBits) \ 256 And &HFF&
padding(2) = UnsignedToLong(dblBits) \ 65536 And &HFF&
padding(3) = UnsignedToLong(dblBits) \ 16777216 And &HFF&
padding(4) = 0
padding(5) = 0
padding(6) = 0
padding(7) = 0
MD5Update 8, padding
End Sub
Public Sub MD5Init()
ByteCounter = 0
State(1) = UnsignedToLong(1732584193#)
State(2) = UnsignedToLong(4023233417#)
State(3) = UnsignedToLong(2562383102#)
State(4) = UnsignedToLong(271733878#)
End Sub
Public Sub MD5Update(InputLen As Long, InputBuffer() As Byte)
Dim II As Integer, I As Integer, J As Integer, K As Integer, lngBufferedBytes As Long, lngBufferRemaining As Long, lngRem As Long
lngBufferedBytes = ByteCounter Mod 64
lngBufferRemaining = 64 - lngBufferedBytes
ByteCounter = ByteCounter + InputLen
If InputLen >= lngBufferRemaining Then
For II = 0 To lngBufferRemaining - 1
ByteBuffer(lngBufferedBytes + II) = InputBuffer(II)
Next II
MD5Transform ByteBuffer
lngRem = (InputLen) Mod 64
For I = lngBufferRemaining To InputLen - II - lngRem Step 64
For J = 0 To 63
ByteBuffer(J) = InputBuffer(I + J)
Next J
MD5Transform ByteBuffer
Next I
lngBufferedBytes = 0
Else
I = 0
End If
For K = 0 To InputLen - I - 1
ByteBuffer(lngBufferedBytes + K) = InputBuffer(I + K)
Next K
End Sub
Private Sub Decode(Length As Integer, OutputBuffer() As Long, InputBuffer() As Byte)
Dim intDblIndex As Integer, intByteIndex As Integer, dblSum As Double
For intByteIndex = 0 To Length - 1 Step 4
dblSum = InputBuffer(intByteIndex) + InputBuffer(intByteIndex + 1) * 256# + InputBuffer(intByteIndex + 2) * 65536# + InputBuffer(intByteIndex + 3) * 16777216#
OutputBuffer(intDblIndex) = UnsignedToLong(dblSum)
intDblIndex = intDblIndex + 1
Next intByteIndex
End Sub
Private Function FF(A As Long, B As Long, c As Long, d As Long, X As Long, S As Long, ac As Long) As Long
A = LongOverflowAdd4(A, (B And c) Or (Not (B) And d), X, ac)
A = LongLeftRotate(A, S)
A = LongOverflowAdd(A, B)
End Function
Private Function GG(A As Long, B As Long, c As Long, d As Long, X As Long, S As Long, ac As Long) As Long
A = LongOverflowAdd4(A, (B And d) Or (c And Not (d)), X, ac)
A = LongLeftRotate(A, S)
A = LongOverflowAdd(A, B)
End Function
Private Function HH(A As Long, B As Long, c As Long, d As Long, X As Long, S As Long, ac As Long) As Long
A = LongOverflowAdd4(A, B Xor c Xor d, X, ac)
A = LongLeftRotate(A, S)
A = LongOverflowAdd(A, B)
End Function
Private Function II(A As Long, B As Long, c As Long, d As Long, X As Long, S As Long, ac As Long) As Long
A = LongOverflowAdd4(A, c Xor (B Or Not (d)), X, ac)
A = LongLeftRotate(A, S)
A = LongOverflowAdd(A, B)
End Function
Private Function LongOverflowAdd(Val1 As Long, Val2 As Long) As Long
Dim lngHighWord As Long, lngLowWord As Long, lngOverflow As Long
lngLowWord = (Val1 And &HFFFF&) + (Val2 And &HFFFF&)
lngOverflow = lngLowWord \ 65536
lngHighWord = (((Val1 And &HFFFF0000) \ 65536) + ((Val2 And &HFFFF0000) \ 65536) + lngOverflow) And &HFFFF&
LongOverflowAdd = UnsignedToLong((lngHighWord * 65536#) + (lngLowWord And &HFFFF&))
End Function
Private Function LongOverflowAdd4(Val1 As Long, Val2 As Long, val3 As Long, val4 As Long) As Long
Dim lngHighWord As Long, lngLowWord As Long, lngOverflow As Long
lngLowWord = (Val1 And &HFFFF&) + (Val2 And &HFFFF&) + (val3 And &HFFFF&) + (val4 And &HFFFF&)
lngOverflow = lngLowWord \ 65536
lngHighWord = (((Val1 And &HFFFF0000) \ 65536) + ((Val2 And &HFFFF0000) \ 65536) + ((val3 And &HFFFF0000) \ 65536) + ((val4 And &HFFFF0000) \ 65536) + lngOverflow) And &HFFFF&
LongOverflowAdd4 = UnsignedToLong((lngHighWord * 65536#) + (lngLowWord And &HFFFF&))
End Function
Private Function LongToString(Num As Long) As String
Dim A As Byte, B As Byte, c As Byte, d As Byte
A = Num And &HFF&
If A < 16 Then LongToString = "0" & Hex(A) Else LongToString = Hex(A)
B = (Num And &HFF00&) \ 256
If B < 16 Then LongToString = LongToString & "0" & Hex(B) Else LongToString = LongToString & Hex(B)
c = (Num And &HFF0000) \ 65536
If c < 16 Then LongToString = LongToString & "0" & Hex(c) Else LongToString = LongToString & Hex(c)
If Num < 0 Then d = ((Num And &H7F000000) \ 16777216) Or &H80& Else d = (Num And &HFF000000) \ 16777216
If d < 16 Then LongToString = LongToString & "0" & Hex(d) Else LongToString = LongToString & Hex(d)
End Function
Private Function LongToUnsigned(value As Long) As Double
If value < 0 Then LongToUnsigned = value + OFFSET_4 Else LongToUnsigned = value
End Function
Private Sub MD5Transform(Buffer() As Byte)
Dim X(16) As Long, A As Long, B As Long, c As Long, d As Long
A = State(1)
B = State(2)
c = State(3)
d = State(4)
Decode 64, X, Buffer
FF A, B, c, d, X(0), S11, -680876936
FF d, A, B, c, X(1), S12, -389564586
FF c, d, A, B, X(2), S13, 606105819
FF B, c, d, A, X(3), S14, -1044525330
FF A, B, c, d, X(4), S11, -176418897
FF d, A, B, c, X(5), S12, 1200080426
FF c, d, A, B, X(6), S13, -1473231341
FF B, c, d, A, X(7), S14, -45705983
FF A, B, c, d, X(8), S11, 1770035416
FF d, A, B, c, X(9), S12, -1958414417
FF c, d, A, B, X(10), S13, -42063
FF B, c, d, A, X(11), S14, -1990404162
FF A, B, c, d, X(12), S11, 1804603682
FF d, A, B, c, X(13), S12, -40341101
FF c, d, A, B, X(14), S13, -1502002290
FF B, c, d, A, X(15), S14, 1236535329
GG A, B, c, d, X(1), S21, -165796510
GG d, A, B, c, X(6), S22, -1069501632
GG c, d, A, B, X(11), S23, 643717713
GG B, c, d, A, X(0), S24, -373897302
GG A, B, c, d, X(5), S21, -701558691
GG d, A, B, c, X(10), S22, 38016083
GG c, d, A, B, X(15), S23, -660478335
GG B, c, d, A, X(4), S24, -405537848
GG A, B, c, d, X(9), S21, 568446438
GG d, A, B, c, X(14), S22, -1019803690
GG c, d, A, B, X(3), S23, -187363961
GG B, c, d, A, X(8), S24, 1163531501
GG A, B, c, d, X(13), S21, -1444681467
GG d, A, B, c, X(2), S22, -51403784
GG c, d, A, B, X(7), S23, 1735328473
GG B, c, d, A, X(12), S24, -1926607734
HH A, B, c, d, X(5), S31, -378558
HH d, A, B, c, X(8), S32, -2022574463
HH c, d, A, B, X(11), S33, 1839030562
HH B, c, d, A, X(14), S34, -35309556
HH A, B, c, d, X(1), S31, -1530992060
HH d, A, B, c, X(4), S32, 1272893353
HH c, d, A, B, X(7), S33, -155497632
HH B, c, d, A, X(10), S34, -1094730640
HH A, B, c, d, X(13), S31, 681279174
HH d, A, B, c, X(0), S32, -358537222
HH c, d, A, B, X(3), S33, -722521979
HH B, c, d, A, X(6), S34, 76029189
HH A, B, c, d, X(9), S31, -640364487
HH d, A, B, c, X(12), S32, -421815835
HH c, d, A, B, X(15), S33, 530742520
HH B, c, d, A, X(2), S34, -995338651
II A, B, c, d, X(0), S41, -198630844
II d, A, B, c, X(7), S42, 1126891415
II c, d, A, B, X(14), S43, -1416354905
II B, c, d, A, X(5), S44, -57434055
II A, B, c, d, X(12), S41, 1700485571
II d, A, B, c, X(3), S42, -1894986606
II c, d, A, B, X(10), S43, -1051523
II B, c, d, A, X(1), S44, -2054922799
II A, B, c, d, X(8), S41, 1873313359
II d, A, B, c, X(15), S42, -30611744
II c, d, A, B, X(6), S43, -1560198380
II B, c, d, A, X(13), S44, 1309151649
II A, B, c, d, X(4), S41, -145523070
II d, A, B, c, X(11), S42, -1120210379
II c, d, A, B, X(2), S43, 718787259
II B, c, d, A, X(9), S44, -343485551
State(1) = LongOverflowAdd(State(1), A)
State(2) = LongOverflowAdd(State(2), B)
State(3) = LongOverflowAdd(State(3), c)
State(4) = LongOverflowAdd(State(4), d)
End Sub
Private Function StringToArray(InString As String) As Byte()
Dim I As Integer, bytBuffer() As Byte
ReDim bytBuffer(LenB(StrConv(InString, vbFromUnicode)))
bytBuffer = StrConv(InString, vbFromUnicode)
StringToArray = bytBuffer
End Function
Private Function UnsignedToLong(value As Double) As Long
If value < 0 Or value >= OFFSET_4 Then Error 6
If value <= MAXINT_4 Then UnsignedToLong = value Else UnsignedToLong = value - OFFSET_4
End Function
Property Get RegisterA() As String
RegisterA = State(1)
End Property
Property Get RegisterB() As String
RegisterB = State(2)
End Property
Property Get RegisterC() As String
RegisterC = State(3)
End Property
Property Get RegisterD() As String
RegisterD = State(4)
End Property
Ⅱ 求一个简单短小的VB加密算法,每段要有解释
Public Function StringEnDeCodecn(strSource As String, MA) As String '该函数只对中西文起到加密作用 '参数为：源文件，密码 On Error GoTo ErrEnDeCode Dim X As Single Dim CHARNUM As Long, RANDOMINTEGER As Integer Dim SINGLECHAR As String * 1 Dim strTmp As String If MA < 0 Then MA = MA * (-1) End If X = Rnd(-MA) For i = 1 To Len(strSource) Step 1 '取单字节内容 SINGLECHAR = Mid(strSource, i, 1) CHARNUM = Asc(SINGLECHAR) g: RANDOMINTEGER = Int(127 * Rnd) If RANDOMINTEGER < 30 Or RANDOMINTEGER > 100 Then GoTo g CHARNUM = CHARNUM Xor RANDOMINTEGER strTmp = strTmp & Chr(CHARNUM) Next i StringEnDeCodecn = strTmp Exit Function ErrEnDeCode: StringEnDeCodecn = "" MsgBox Err.Number & "\" & Err.Description End Function Private Sub Command1_Click() tmp1 = StringEnDeCodecn(Text1.Text, 75) Text2.Text = tmp1 End Sub 窗体放两个文本框Text1,Text2和一个按钮Command1。 使用上面代码可以把Text1中的内容加密，显示在Text2中。 要解密直接把Text2的内容复制到Text1中，再次点击按钮Command1，解密后的内容会显示在Text2中。
Ⅲ VB中如何编写一个加密程序
编写一个加密软件，要求将源文件按字节逐位倒排序加密法加密。
字节逐位倒排序加密法是以比特为单位的换位加密方法，用vb实现的具体算法是：
(1) 以二进制模式打开源文件；
(2) 从源文件第i位读取一个字节，假设为字母“a”，得到“a”的ascii值为65；
(3) 将65转换成八位二进制串为“01000001”；
(4) 将“01000001”按字节逐位倒排序得另一个八位二进制串“10000010”；
(5) 将“10000010”转换成十进制再写回源文件第i位置，完成一个字节的加密；
(6) 重复(2)、(3)、(4)和(5)，直到所有字节加密结束。
为了使程序模块化，我们用函数过程bytetobin完成将字节型数据转换成二进制串（其实质就是将十进制数转换成八位二进制串）；用函数过程bintobyte将二进制串转换成字节型数据（实质是将八位二进制串转换成十进制数）：用函数过程reverse将八位二进制串逐位倒排序。具体程序如下：
function bytetobin(m as byte) as string ' 将字节型数据转换成八位二进制字符串
dim c$
c$ = ""
do while m <> 0
r = m mod 2
m = m \ 2
c$ = r & c$
loop
c$ = right("00000000" & c$, 8)
bytetobin = c$
end function
function reverse(m as string) as string ' 将八位二进制字符串颠倒顺序
dim i%, x$
x = ""
for i = 1 to 8
x = mid(m, i, 1) & x
next i
reverse = x
end function
function bintobyte(m as string) as byte ' 将八位二进制串转换成十进制
dim x as string * 1, y%, z%
z = 0
for i = 1 to 8
x = mid(m, i, 1)
y = x * 2 ^ (8 - i)
z = z + y
next i
bintobyte = z
end function
private sub command1_click()
dim x as byte, i%, fname$
fname = inputbox("请输入要加密的文件名！注意加上路径名：")
if dir(fname) = "" then
msgbox "文件不存在！"
exit sub
end if
open fname for binary as #1 ' 以二进制访问模式打开待加密文件
for i = 1 to lof(1) ' lof函数是求文件长度的内部函数
get #1, i, x ' 取出第i个字节
x = bintobyte(reverse(bytetobin(x))) ' 这里调用了三个自定义函数
put #1, i, x ' 将加密后的这个字节写回到文件原位置
next i
close
msgbox "任务完成！"
end sub
Ⅳ vb字串加密算法（支持中文）
就按你的要求写一个例子吧，你可以在这个基础上改进算法：（例子里XOR的加密因子是固定的12345，正式的产品里应是动态的，并且长度更长、带有校验和防破解机制）
'简单字符串加密（参数为正常文本，返回加密文本，同时支持中文和英文）
private function StrEncrypt(byval sStr as string) as string
dim i as long
dim sRtn as string
for i=1 to len(sStr)
sRtn=sRtn & hex(asc(mid(sStr,i,1)) xor 12345) & " "
next i
StrEncrypt=sRtn
end function
'简单字符串解密（参数为被加密的文本，返回解密后的文本，同时支持中文和英文）
private function StrDecryption(byval sStr as string) as string
dim i as long
dim sChr as string
dim sCode as string
dim sRtn as string
for i=1 to len(sStr)
sChr=mid(sStr,i,1)
if sChr=" " then
sRtn=sRtn & chr(val("&H" & sCode) xor 12345)
sCode=""
else
sCode=sCode & sChr
end if
next i
StrDecryption=sRtn
end function
把这段代码复制到VB6里的调试结果：
? StrEncrypt("中国AB C")
E6E9 89C3 3078 307B 3019 307A
? StrDecryption("E6E9 89C3 3078 307B 3019 307A ")
中国AB C
Ⅳ VB加密算法
首先程序定义两个字符串k1和k2；
这里他给出了一个Text1变量，应该是一个全局变量，在程序之前已经定义了。
首先定义code为一个字符串，将Text1里面的文字用LCase()函数将大写字母转换成小写字母。
加密的过程开始，为那一个循环过程。
在这个循环里 设定i的区间是1到code的长度
每个循环开始时候，将code中每一个字母取出来，赋值到s变量里面。
然后判断如果s不是空字符时候，将n赋值为s中的字母与字母a的一个"距离"(这里说不知道你明白不，你好好理解一下吧)。
假如i，即s里面的那个字母在code中是第几位的位数，不是2的倍数，那么就将在decode里面加入k1字符串中的第n个字母。假如i是2的倍数的话，就在decode加入k2字符串里面的第n个字母。
在刚才判断s是否为空字符时候，假如得到的s是为空字符，即跳入以下过程、。
假如i不是2的倍数，空格那个字母变为k1的第27个字母即p，就加入k2的第27个字母即z。
最后将decode赋值给text2。
其实这个程序很简单，定义两个字符串，分别是27个字母，等于是26个字母加空格，再把顺序掉乱。然后根据需要加密的字符串来分别去每一个字母，根据字母的位置来确定取k1或者k2对应的那个掩码字母。