简单讲解iOS应用开发中的MD5加密的使用(免费md5加密)
简单讲解iOS应用开发中的MD5加密的使用(免费md5加密)
一、简单说明
1.说明
在开发应用的时候，数据的安全性至关重要，而仅仅用POST请求提交用户的隐私数据，还是不能完全解决安全问题。
如：可以利用软件（比如Charles）设置代理服务器，拦截查看手机的请求数据
“青花瓷”软件
因此：提交用户的隐私数据时，一定不要明文提交，要加密处理后再提交
2.常见的加密算法
MD5 SHA DES 3DES RC2和RC4 RSA IDEA DSA AES
3.加密算法的选择
一般公司都会有一套自己的加密方案，按照公司接口文档的规定去加密
二、MD5
1.简单说明
MD5:全称是Message Digest Algorithm 5，译为“消息摘要算法第5版”
效果：对输入信息生成唯一的.128位散列值（32个字符）
2.MD5的特点
（1）输入两个不同的明文不会得到相同的输出值
（2）根据输出值，不能得到原始的明文，即其过程不可逆
3.MD5的应用
由于MD5加密算法具有较好的安全性，而且免费，因此该加密算法被广泛使用
主要运用在数字签名、文件完整性验证以及口令加密等方面
4.MD5破解
MD5解密网站：
5.MD5改进
现在的MD5已不再是绝对安全，对此，可以对MD5稍作改进，以增加解密的难度
加盐（Salt）：在明文的固定位置插入随机串，然后再进行MD5
先加密，后乱序：先对明文进行MD5，然后对加密得到的MD5串的字符进行乱序
总之宗旨就是：黑客就算攻破了数据库，也无法解密出正确的明文
代码示例：
复制代码 代码如下:
#import "HMViewController.h"
#import "NSString+Hash.h"
#define Salt @"fsdhjkfhjksdhjkfjhkd546783765"
@interface HMViewController ()
@end
@implementation HMViewController
- (void)viewDidLoad
{
[super viewDidLoad];
[self digest:@"123"]; //
[self digest:@"abc"];
[self digest:@"456"];
}
/**
* 直接用MD5加密
*/
- (NSString *)digest:(NSString *)str
{
NSString *anwen = [str md5String];
NSLog(@"%@ - %@", str, anwen);
return anwen;
}
/**
* 加盐
*/
- (NSString *)digest2:(NSString *)str
{
str = [str stringByAppendingString:Salt];
NSString *anwen = [str md5String];
NSLog(@"%@ - %@", str, anwen);
return anwen;
}
/**
* 多次MD5
*/
- (NSString *)digest3:(NSString *)str
{
NSString *anwen = [str md5String];
anwen = [anwen md5String];
NSLog(@"%@ - %@", str, anwen);
return anwen;
}
/**
* 先加密, 后乱序
*/
- (NSString *)digest4:(NSString *)str
{
NSString *anwen = [str md5String];
// 注册: 123 ---- 2CB962AC59075B964B07152D234B7020
// 登录: 123 --- 202CB962AC59075B964B07152D234B70
NSString *header = [anwen substringToIndex:2];
NSString *footer = [anwen substringFromIndex:2];
anwen = [footer stringByAppendingString:header];
NSLog(@"%@ - %@", str, anwen);
return anwen;
}
@end
（1）直接使用MD5加密（去MD5解密网站即可破解）
（2）使用加盐（通过MD5解密之后，很容易发现规律）
（3）多次MD5加密（使用MD5解密之后，发现还是密文，那就接着MD5解密）
（4）先加密，后乱序（破解难度增加）
三、注册和验证的数据处理过程
1.提交隐私数据的安全过程 – 注册
2.提交隐私数据的安全过程 – 登录
md5加密，不知道你是想在客户端加密还是在服务端加密。若是在客户端加密，建议你用js的md5加密。若是你想用服务端加密，你就讲自己的信息直接传到你建好的md5.asp，在调用md5方法加密就好了。
Private Const BITS_TO_A_BYTE = 8
Private Const BYTES_TO_A_WORD = 4
Private Const BITS_TO_A_WORD = 32
Private m_lOnBits(30)
Private m_l2Power(30)
Private Function LShift(lValue, iShiftBits)
If iShiftBits = 0 Then
LShift = lValue
Exit Function
ElseIf iShiftBits = 31 Then
If lValue And 1 Then
LShift = H80000000
Else
LShift = 0
End If
Exit Function
ElseIf iShiftBits 0 Or iShiftBits 31 Then
Err.Raise 6
End If
If (lValue And m_l2Power(31 - iShiftBits)) Then
LShift = ((lValue And m_lOnBits(31 - (iShiftBits + 1))) * m_l2Power(iShiftBits)) Or H80000000
Else
LShift = ((lValue And m_lOnBits(31 - iShiftBits)) * m_l2Power(iShiftBits))
End If
End Function
Private Function RShift(lValue, iShiftBits)
If iShiftBits = 0 Then
RShift = lValue
Exit Function
ElseIf iShiftBits = 31 Then
If lValue And H80000000 Then
RShift = 1
Else
RShift = 0
End If
Exit Function
ElseIf iShiftBits 0 Or iShiftBits 31 Then
Err.Raise 6
End If
RShift = (lValue And H7FFFFFFE) \ m_l2Power(iShiftBits)
If (lValue And H80000000) Then
RShift = (RShift Or (H40000000 \ m_l2Power(iShiftBits - 1)))
End If
End Function
Private Function RotateLeft(lValue, iShiftBits)
RotateLeft = LShift(lValue, iShiftBits) Or RShift(lValue, (32 - iShiftBits))
End Function
Private Function AddUnsigned(lX, lY)
Dim lX4
Dim lY4
Dim lX8
Dim lY8
Dim lResult
lX8 = lX And H80000000
lY8 = lY And H80000000
lX4 = lX And H40000000
lY4 = lY And H40000000
lResult = (lX And H3FFFFFFF) + (lY And H3FFFFFFF)
If lX4 And lY4 Then
lResult = lResult Xor H80000000 Xor lX8 Xor lY8
ElseIf lX4 Or lY4 Then
If lResult And H40000000 Then
lResult = lResult Xor HC0000000 Xor lX8 Xor lY8
Else
lResult = lResult Xor H40000000 Xor lX8 Xor lY8
End If
Else
lResult = lResult Xor lX8 Xor lY8
End If
AddUnsigned = lResult
End Function
Private Function md5_F(X, Y, z)
md5_F = (X And Y) Or ((Not X) And z)
End Function
Private Function md5_G(X, Y, z)
md5_G = (X And z) Or (Y And (Not z))
End Function
Private Function md5_H(X, Y, z)
md5_H = (X Xor Y Xor z)
End Function
Private Function md5_I(X, Y, z)
md5_I = (Y Xor (X Or (Not z)))
End Function
Private Sub md5_FF(a, b, c, d, X, s, ac)
a = AddUnsigned(a, AddUnsigned(AddUnsigned(md5_F(b, c, d), X), ac))
a = RotateLeft(a, s)
a = AddUnsigned(a, b)
End Sub
Private Sub md5_GG(a, b, c, d, X, s, ac)
a = AddUnsigned(a, AddUnsigned(AddUnsigned(md5_G(b, c, d), X), ac))
a = RotateLeft(a, s)
a = AddUnsigned(a, b)
End Sub
Private Sub md5_HH(a, b, c, d, X, s, ac)
a = AddUnsigned(a, AddUnsigned(AddUnsigned(md5_H(b, c, d), X), ac))
a = RotateLeft(a, s)
a = AddUnsigned(a, b)
End Sub
Private Sub md5_II(a, b, c, d, X, s, ac)
a = AddUnsigned(a, AddUnsigned(AddUnsigned(md5_I(b, c, d), X), ac))
a = RotateLeft(a, s)
a = AddUnsigned(a, b)
End Sub
Private Function ConvertToWordArray(sMessage)
Dim lMessageLength
Dim lNumberOfWords
Dim lWordArray()
Dim lBytePosition
Dim lByteCount
Dim lWordCount
Const MODULUS_BITS = 512
Const CONGRUENT_BITS = 448
lMessageLength = Len(sMessage)
lNumberOfWords = (((lMessageLength + ((MODULUS_BITS - CONGRUENT_BITS) \ BITS_TO_A_BYTE)) \ (MODULUS_BITS \ BITS_TO_A_BYTE)) + 1) * (MODULUS_BITS \ BITS_TO_A_WORD)
ReDim lWordArray(lNumberOfWords - 1)
lBytePosition = 0
lByteCount = 0
Do Until lByteCount = lMessageLength
lWordCount = lByteCount \ BYTES_TO_A_WORD
lBytePosition = (lByteCount Mod BYTES_TO_A_WORD) * BITS_TO_A_BYTE
lWordArray(lWordCount) = lWordArray(lWordCount) Or LShift(Asc(Mid(sMessage, lByteCount + 1, 1)), lBytePosition)
lByteCount = lByteCount + 1
Loop
lWordCount = lByteCount \ BYTES_TO_A_WORD
lBytePosition = (lByteCount Mod BYTES_TO_A_WORD) * BITS_TO_A_BYTE
lWordArray(lWordCount) = lWordArray(lWordCount) Or LShift(H80, lBytePosition)
lWordArray(lNumberOfWords - 2) = LShift(lMessageLength, 3)
lWordArray(lNumberOfWords - 1) = RShift(lMessageLength, 29)
ConvertToWordArray = lWordArray
End Function
Private Function WordToHex(lValue)
Dim lByte
Dim lCount
For lCount = 0 To 3
lByte = RShift(lValue, lCount * BITS_TO_A_BYTE) And m_lOnBits(BITS_TO_A_BYTE - 1)
WordToHex = WordToHex Right("0" Hex(lByte), 2)
Next
End Function
Public Function MD5(sMessage)
m_lOnBits(0) = CLng(1)
m_lOnBits(1) = CLng(3)
m_lOnBits(2) = CLng(7)
m_lOnBits(3) = CLng(15)
m_lOnBits(4) = CLng(31)
m_lOnBits(5) = CLng(63)
m_lOnBits(6) = CLng(127)
m_lOnBits(7) = CLng(255)
m_lOnBits(8) = CLng(511)
m_lOnBits(9) = CLng(1023)
m_lOnBits(10) = CLng(2047)
m_lOnBits(11) = CLng(4095)
m_lOnBits(12) = CLng(8191)
m_lOnBits(13) = CLng(16383)
m_lOnBits(14) = CLng(32767)
m_lOnBits(15) = CLng(65535)
m_lOnBits(16) = CLng(131071)
m_lOnBits(17) = CLng(262143)
m_lOnBits(18) = CLng(524287)
m_lOnBits(19) = CLng(1048575)
m_lOnBits(20) = CLng(2097151)
m_lOnBits(21) = CLng(4194303)
m_lOnBits(22) = CLng(8388607)
m_lOnBits(23) = CLng(16777215)
m_lOnBits(24) = CLng(33554431)
m_lOnBits(25) = CLng(67108863)
m_lOnBits(26) = CLng(134217727)
m_lOnBits(27) = CLng(268435455)
m_lOnBits(28) = CLng(536870911)
m_lOnBits(29) = CLng(1073741823)
m_lOnBits(30) = CLng(2147483647)
m_l2Power(0) = CLng(1)
m_l2Power(1) = CLng(2)
m_l2Power(2) = CLng(4)
m_l2Power(3) = CLng(8)
m_l2Power(4) = CLng(16)
m_l2Power(5) = CLng(32)
m_l2Power(6) = CLng(64)
m_l2Power(7) = CLng(128)
m_l2Power(8) = CLng(256)
m_l2Power(9) = CLng(512)
m_l2Power(10) = CLng(1024)
m_l2Power(11) = CLng(2048)
m_l2Power(12) = CLng(4096)
m_l2Power(13) = CLng(8192)
m_l2Power(14) = CLng(16384)
m_l2Power(15) = CLng(32768)
m_l2Power(16) = CLng(65536)
m_l2Power(17) = CLng(131072)
m_l2Power(18) = CLng(262144)
m_l2Power(19) = CLng(524288)
m_l2Power(20) = CLng(1048576)
m_l2Power(21) = CLng(2097152)
m_l2Power(22) = CLng(4194304)
m_l2Power(23) = CLng(8388608)
m_l2Power(24) = CLng(16777216)
m_l2Power(25) = CLng(33554432)
m_l2Power(26) = CLng(67108864)
m_l2Power(27) = CLng(134217728)
m_l2Power(28) = CLng(268435456)
m_l2Power(29) = CLng(536870912)
m_l2Power(30) = CLng(1073741824)
Dim X
Dim k
Dim AA
Dim BB
Dim CC
Dim DD
Dim a
Dim b
Dim c
Dim d
Const S11 = 7
Const S12 = 12
Const S13 = 17
Const S14 = 22
Const S21 = 5
Const S22 = 9
Const S23 = 14
Const S24 = 20
Const S31 = 4
Const S32 = 11
Const S33 = 16
Const S34 = 23
Const S41 = 6
Const S42 = 10
Const S43 = 15
Const S44 = 21
X = ConvertToWordArray(sMessage)
a = H67452301
b = HEFCDAB89
c = H98BADCFE
d = H10325476
For k = 0 To UBound(X) Step 16
AA = a
BB = b
CC = c
DD = d
md5_FF a, b, c, d, X(k + 0), S11, HD76AA478
md5_FF d, a, b, c, X(k + 1), S12, HE8C7B756
md5_FF c, d, a, b, X(k + 2), S13, H242070DB
md5_FF b, c, d, a, X(k + 3), S14, HC1BDCEEE
md5_FF a, b, c, d, X(k + 4), S11, HF57C0FAF
md5_FF d, a, b, c, X(k + 5), S12, H4787C62A
md5_FF c, d, a, b, X(k + 6), S13, HA8304613
md5_FF b, c, d, a, X(k + 7), S14, HFD469501
md5_FF a, b, c, d, X(k + 8), S11, H698098D8
md5_FF d, a, b, c, X(k + 9), S12, H8B44F7AF
md5_FF c, d, a, b, X(k + 10), S13, HFFFF5BB1
md5_FF b, c, d, a, X(k + 11), S14, H895CD7BE
md5_FF a, b, c, d, X(k + 12), S11, H6B901122
md5_FF d, a, b, c, X(k + 13), S12, HFD987193
md5_FF c, d, a, b, X(k + 14), S13, HA679438E
md5_FF b, c, d, a, X(k + 15), S14, H49B40821
md5_GG a, b, c, d, X(k + 1), S21, HF61E2562
md5_GG d, a, b, c, X(k + 6), S22, HC040B340
md5_GG c, d, a, b, X(k + 11), S23, H265E5A51
md5_GG b, c, d, a, X(k + 0), S24, HE9B6C7AA
md5_GG a, b, c, d, X(k + 5), S21, HD62F105D
md5_GG d, a, b, c, X(k + 10), S22, H2441453
md5_GG c, d, a, b, X(k + 15), S23, HD8A1E681
md5_GG b, c, d, a, X(k + 4), S24, HE7D3FBC8
md5_GG a, b, c, d, X(k + 9), S21, H21E1CDE6
md5_GG d, a, b, c, X(k + 14), S22, HC33707D6
md5_GG c, d, a, b, X(k + 3), S23, HF4D50D87
md5_GG b, c, d, a, X(k + 8), S24, H455A14ED
md5_GG a, b, c, d, X(k + 13), S21, HA9E3E905
md5_GG d, a, b, c, X(k + 2), S22, HFCEFA3F8
md5_GG c, d, a, b, X(k + 7), S23, H676F02D9
md5_GG b, c, d, a, X(k + 12), S24, H8D2A4C8A
md5_HH a, b, c, d, X(k + 5), S31, HFFFA3942
md5_HH d, a, b, c, X(k + 8), S32, H8771F681
md5_HH c, d, a, b, X(k + 11), S33, H6D9D6122
md5_HH b, c, d, a, X(k + 14), S34, HFDE5380C
md5_HH a, b, c, d, X(k + 1), S31, HA4BEEA44
md5_HH d, a, b, c, X(k + 4), S32, H4BDECFA9
md5_HH c, d, a, b, X(k + 7), S33, HF6BB4B60
md5_HH b, c, d, a, X(k + 10), S34, HBEBFBC70
md5_HH a, b, c, d, X(k + 13), S31, H289B7EC6
md5_HH d, a, b, c, X(k + 0), S32, HEAA127FA
md5_HH c, d, a, b, X(k + 3), S33, HD4EF3085
md5_HH b, c, d, a, X(k + 6), S34, H4881D05
md5_HH a, b, c, d, X(k + 9), S31, HD9D4D039
md5_HH d, a, b, c, X(k + 12), S32, HE6DB99E5
md5_HH c, d, a, b, X(k + 15), S33, H1FA27CF8
md5_HH b, c, d, a, X(k + 2), S34, HC4AC5665
md5_II a, b, c, d, X(k + 0), S41, HF4292244
md5_II d, a, b, c, X(k + 7), S42, H432AFF97
md5_II c, d, a, b, X(k + 14), S43, HAB9423A7
md5_II b, c, d, a, X(k + 5), S44, HFC93A039
md5_II a, b, c, d, X(k + 12), S41, H655B59C3
md5_II d, a, b, c, X(k + 3), S42, H8F0CCC92
md5_II c, d, a, b, X(k + 10), S43, HFFEFF47D
md5_II b, c, d, a, X(k + 1), S44, H85845DD1
md5_II a, b, c, d, X(k + 8), S41, H6FA87E4F
md5_II d, a, b, c, X(k + 15), S42, HFE2CE6E0
md5_II c, d, a, b, X(k + 6), S43, HA3014314
md5_II b, c, d, a, X(k + 13), S44, H4E0811A1
md5_II a, b, c, d, X(k + 4), S41, HF7537E82
md5_II d, a, b, c, X(k + 11), S42, HBD3AF235
md5_II c, d, a, b, X(k + 2), S43, H2AD7D2BB
md5_II b, c, d, a, X(k + 9), S44, HEB86D391
a = AddUnsigned(a, AA)
b = AddUnsigned(b, BB)
c = AddUnsigned(c, CC)
d = AddUnsigned(d, DD)
Next
MD5 = LCase(WordToHex(a) WordToHex(b) WordToHex(c) WordToHex(d)) '32位
'MD5 = LCase(WordToHex(b) WordToHex(c)) '16位
End Function
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
End Sub
前言
软件开发过程中，对数据进行加密是保证数据安全的重要手段，常见的加密有Base64加密和MD5加密。Base64加密是可逆的，MD5加密目前来说一般是不可逆的。
MD5生成的是固定的128bit，即128个0和1的二进制位，而在实际应用开发中，通常是以16进制输出的，所以正好就是32位的16进制，说白了也就是32个16进制的数字。
MD5主要特点是 不可逆，相同数据的MD5值肯定一样，不同数据的MD5值不一样（也不是绝对的，但基本是不能一样的）。
MD5算法还具有以下性质：
1、压缩性：任意长度的数据，算出的MD5值长度都是固定的。
2、容易计算：从原数据计算出MD5值很容易。
3、抗修改性：对原数据进行任何改动，哪怕只修改1个字节，所得到的MD5值都有很大区别。
4、弱抗碰撞：已知原数据和其MD5值，想找到一个具有相同MD5值的数据（即伪造数据）是非常困难的。
5、强抗碰撞：想找到两个不同的数据，使它们具有相同的MD5值，是非常困难的。
6、MD5加密是不可解密的，但是网上有一些解析MD5的，那个相当于一个大型的数据库，通过匹配MD5去找到原密码。所以，只要在要加密的字符串前面加上一些字母数字符号或者多次MD5加密，这样出来的结果一般是解析不出来的。
MD5的应用:
由于MD5加密算法具有较好的安全性，而且免费，因此该加密算法被广泛使用
大多数的'登录功能向后台提交密码时都会使用到这种算法
注意点:
（1）一定要和后台开发人员约定好，MD5加密的位数是16位还是32位(大多数都是32位的)，16位的可以通过32位的转换得到。
（2）MD5加密区分 大小写，使用时要和后台约定好。
MD5解密:
解密网站:
为了让MD5码更加安全 涌现了很多其他方法 如加盐。 盐要足够长足够乱 得到的MD5码就很难查到。
终端代码：$ echo -n abc|openssl md5 给字符串abc加密、
苹果包装了MD5加密的方法，使用起来十分的方便。
#import@interface MD5Encrypt : NSObject// MD5加密/**由于MD5加密是不可逆的,多用来进行验证*/// 32位小写+(NSString *)MD5ForLower32Bate:(NSString *)str;// 32位大写+(NSString *)MD5ForUpper32Bate:(NSString *)str;// 16为大写+(NSString *)MD5ForUpper16Bate:(NSString *)str;// 16位小写+(NSString *)MD5ForLower16Bate:(NSString *)str;@end
#import "MD5Encrypt.h"#import@implementation MD5Encrypt#pragma mark - 32位 小写+(NSString *)MD5ForLower32Bate:(NSString *)str{ //要进行UTF8的转码 const char* input = [str UTF8String]; unsigned char result[CC_MD5_DIGEST_LENGTH]; CC_MD5(input, (CC_LONG)strlen(input), result); NSMutableString *digest = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH * 2]; for (NSInteger i = 0; i CC_MD5_DIGEST_LENGTH; i++) { [digest appendFormat:@"%02x", result[i]]; } return digest;}#pragma mark - 32位 大写+(NSString *)MD5ForUpper32Bate:(NSString *)str{ //要进行UTF8的转码 const char* input = [str UTF8String]; unsigned char result[CC_MD5_DIGEST_LENGTH]; CC_MD5(input, (CC_LONG)strlen(input), result); NSMutableString *digest = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH * 2]; for (NSInteger i = 0; i CC_MD5_DIGEST_LENGTH; i++) { [digest appendFormat:@"%02X", result[i]]; } return digest;}#pragma mark - 16位 大写+(NSString *)MD5ForUpper16Bate:(NSString *)str{ NSString *md5Str = [self MD5ForUpper32Bate:str]; NSString *string; for (int i=0; i24; i++) { string=[md5Str substringWithRange:NSMakeRange(8, 16)]; } return string;}#pragma mark - 16位 小写+(NSString *)MD5ForLower16Bate:(NSString *)str{ NSString *md5Str = [self MD5ForLower32Bate:str]; NSString *string; for (int i=0; i24; i++) { string=[md5Str substringWithRange:NSMakeRange(8, 16)]; } return string;}@end
