#pragma once #include "types.hh" #include "serialise.hh" namespace nix { MakeError(BadHash, Error); enum HashType : char { htUnknown, htMD5, htSHA1, htSHA256, htSHA512 }; const int md5HashSize = 16; const int sha1HashSize = 20; const int sha256HashSize = 32; const int sha512HashSize = 64; extern const string base32Chars; struct Hash { static const unsigned int maxHashSize = 64; unsigned int hashSize; unsigned char hash[maxHashSize]; HashType type; /* Create an unset hash object. */ Hash(); /* Create a zero-filled hash object. */ Hash(HashType type); /* Check whether a hash is set. */ operator bool () const { return type != htUnknown; } /* Check whether two hash are equal. */ bool operator == (const Hash & h2) const; /* Check whether two hash are not equal. */ bool operator != (const Hash & h2) const; /* For sorting. */ bool operator < (const Hash & h) const; /* Returns the length of a base-16 representation of this hash. */ size_t base16Len() const { return hashSize * 2; } /* Returns the length of a base-32 representation of this hash. */ size_t base32Len() const { return (hashSize * 8 - 1) / 5 + 1; } std::string to_string(bool base32 = true) const; }; /* Convert a hash to a hexadecimal representation. */ string printHash(const Hash & hash); Hash parseHash(const string & s); /* Parse a hexadecimal representation of a hash code. */ Hash parseHash(HashType ht, const string & s); /* Convert a hash to a base-32 representation. */ string printHash32(const Hash & hash); /* Print a hash in base-16 if it's MD5, or base-32 otherwise. */ string printHash16or32(const Hash & hash); /* Parse a base-32 representation of a hash code. */ Hash parseHash32(HashType ht, const string & s); /* Parse a base-16 or base-32 representation of a hash code. */ Hash parseHash16or32(HashType ht, const string & s); /* Verify that the given string is a valid hash code. */ bool isHash(const string & s); /* Compute the hash of the given string. */ Hash hashString(HashType ht, const string & s); /* Compute the hash of the given file. */ Hash hashFile(HashType ht, const Path & path); /* Compute the hash of the given path. The hash is defined as (essentially) hashString(ht, dumpPath(path)). */ struct PathFilter; extern PathFilter defaultPathFilter; typedef std::pair<Hash, unsigned long long> HashResult; HashResult hashPath(HashType ht, const Path & path, PathFilter & filter = defaultPathFilter); /* Compress a hash to the specified number of bytes by cyclically XORing bytes together. */ Hash compressHash(const Hash & hash, unsigned int newSize); /* Parse a string representing a hash type. */ HashType parseHashType(const string & s); /* And the reverse. */ string printHashType(HashType ht); union Ctx; class HashSink : public BufferedSink { private: HashType ht; Ctx * ctx; unsigned long long bytes; public: HashSink(HashType ht); HashSink(const HashSink & h); ~HashSink(); void write(const unsigned char * data, size_t len); HashResult finish(); HashResult currentHash(); }; }