1 //==- SHA1.h - SHA1 implementation for LLVM --*- C++ -*-==// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // This code is taken from public domain 10 // (http://oauth.googlecode.com/svn/code/c/liboauth/src/sha1.c) 11 // and modified by wrapping it in a C++ interface for LLVM, 12 // and removing unnecessary code. 13 // 14 //===----------------------------------------------------------------------===// 15 16 #ifndef LLVM_SUPPORT_SHA1_H 17 #define LLVM_SUPPORT_SHA1_H 18 19 #include "llvm/ADT/ArrayRef.h" 20 21 #include <array> 22 #include <cstdint> 23 24 namespace llvm { 25 template <typename T> class ArrayRef; 26 class StringRef; 27 28 /// A class that wrap the SHA1 algorithm. 29 class SHA1 { 30 public: 31 SHA1() { init(); } 32 33 /// Reinitialize the internal state 34 void init(); 35 36 /// Digest more data. 37 void update(ArrayRef<uint8_t> Data); 38 39 /// Digest more data. 40 void update(StringRef Str) { 41 update(ArrayRef<uint8_t>((uint8_t *)const_cast<char *>(Str.data()), 42 Str.size())); 43 } 44 45 /// Return a reference to the current raw 160-bits SHA1 for the digested data 46 /// since the last call to init(). This call will add data to the internal 47 /// state and as such is not suited for getting an intermediate result 48 /// (see result()). 49 StringRef final(); 50 51 /// Return a reference to the current raw 160-bits SHA1 for the digested data 52 /// since the last call to init(). This is suitable for getting the SHA1 at 53 /// any time without invalidating the internal state so that more calls can be 54 /// made into update. 55 StringRef result(); 56 57 /// Returns a raw 160-bit SHA1 hash for the given data. 58 static std::array<uint8_t, 20> hash(ArrayRef<uint8_t> Data); 59 60 private: 61 /// Define some constants. 62 /// "static constexpr" would be cleaner but MSVC does not support it yet. 63 enum { BLOCK_LENGTH = 64 }; 64 enum { HASH_LENGTH = 20 }; 65 66 // Internal State 67 struct { 68 union { 69 uint8_t C[BLOCK_LENGTH]; 70 uint32_t L[BLOCK_LENGTH / 4]; 71 } Buffer; 72 uint32_t State[HASH_LENGTH / 4]; 73 uint32_t ByteCount; 74 uint8_t BufferOffset; 75 } InternalState; 76 77 // Internal copy of the hash, populated and accessed on calls to result() 78 uint32_t HashResult[HASH_LENGTH / 4]; 79 80 // Helper 81 void writebyte(uint8_t data); 82 void hashBlock(); 83 void addUncounted(uint8_t data); 84 void pad(); 85 }; 86 87 } // end llvm namespace 88 89 #endif 90
