1 /* -*- C++ -*-
2  * This code is derived from (original license follows):
3  *
4  * This is an OpenSSL-compatible implementation of the RSA Data Security, Inc.
5  * MD5 Message-Digest Algorithm (RFC 1321).
6  *
7  * Homepage:
8  * http://openwall.info/wiki/people/solar/software/public-domain-source-code/md5
9  *
10  * Author:
11  * Alexander Peslyak, better known as Solar Designer <solar at openwall.com>
12  *
13  * This software was written by Alexander Peslyak in 2001.  No copyright is
14  * claimed, and the software is hereby placed in the public domain.
15  * In case this attempt to disclaim copyright and place the software in the
16  * public domain is deemed null and void, then the software is
17  * Copyright (c) 2001 Alexander Peslyak and it is hereby released to the
18  * general public under the following terms:
19  *
20  * Redistribution and use in source and binary forms, with or without
21  * modification, are permitted.
22  *
23  * There's ABSOLUTELY NO WARRANTY, express or implied.
24  *
25  * See md5.c for more information.
26  */
27 
28 #ifndef LLVM_SUPPORT_MD5_H
29 #define LLVM_SUPPORT_MD5_H
30 
31 #include "llvm/ADT/StringRef.h"
32 #include "llvm/Support/Endian.h"
33 #include <array>
34 #include <cstdint>
35 
36 namespace llvm {
37 
38 template <unsigned N> class SmallString;
39 template <typename T> class ArrayRef;
40 
41 class MD5 {
42   // Any 32-bit or wider unsigned integer data type will do.
43   typedef uint32_t MD5_u32plus;
44 
45   MD5_u32plus a = 0x67452301;
46   MD5_u32plus b = 0xefcdab89;
47   MD5_u32plus c = 0x98badcfe;
48   MD5_u32plus d = 0x10325476;
49   MD5_u32plus hi = 0;
50   MD5_u32plus lo = 0;
51   uint8_t buffer[64];
52   MD5_u32plus block[16];
53 
54 public:
55   struct MD5Result {
56     std::array<uint8_t, 16> Bytes;
57 
58     operator std::array<uint8_t, 16>() const { return Bytes; }
59 
60     const uint8_t &operator[](size_t I) const { return Bytes[I]; }
61     uint8_t &operator[](size_t I) { return Bytes[I]; }
62 
63     SmallString<32> digest() const;
64 
65     uint64_t low() const {
66       // Our MD5 implementation returns the result in little endian, so the low
67       // word is first.
68       using namespace support;
69       return endian::read<uint64_t, little, unaligned>(Bytes.data());
70     }
71 
72     uint64_t high() const {
73       using namespace support;
74       return endian::read<uint64_t, little, unaligned>(Bytes.data() + 8);
75     }
76     std::pair<uint64_t, uint64_t> words() const {
77       using namespace support;
78       return std::make_pair(high(), low());
79     }
80   };
81 
82   MD5();
83 
84   /// Updates the hash for the byte stream provided.
85   void update(ArrayRef<uint8_t> Data);
86 
87   /// Updates the hash for the StringRef provided.
88   void update(StringRef Str);
89 
90   /// Finishes off the hash and puts the result in result.
91   void final(MD5Result &Result);
92 
93   /// Translates the bytes in \p Res to a hex string that is
94   /// deposited into \p Str. The result will be of length 32.
95   static void stringifyResult(MD5Result &Result, SmallString<32> &Str);
96 
97   /// Computes the hash for a given bytes.
98   static std::array<uint8_t, 16> hash(ArrayRef<uint8_t> Data);
99 
100 private:
101   const uint8_t *body(ArrayRef<uint8_t> Data);
102 };
103 
104 inline bool operator==(const MD5::MD5Result &LHS, const MD5::MD5Result &RHS) {
105   return LHS.Bytes == RHS.Bytes;
106 }
107 
108 /// Helper to compute and return lower 64 bits of the given string's MD5 hash.
109 inline uint64_t MD5Hash(StringRef Str) {
110   using namespace support;
111 
112   MD5 Hash;
113   Hash.update(Str);
114   MD5::MD5Result Result;
115   Hash.final(Result);
116   // Return the least significant word.
117   return Result.low();
118 }
119 
120 } // end namespace llvm
121 
122 #endif // LLVM_SUPPORT_MD5_H
123