forked from lix-project/lix
151 lines
3.7 KiB
C++
151 lines
3.7 KiB
C++
#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 std::set<std::string> hashTypes;
|
|
|
|
extern const string base32Chars;
|
|
|
|
enum Base : int { Base64, Base32, Base16, SRI };
|
|
|
|
|
|
struct Hash
|
|
{
|
|
static const unsigned int maxHashSize = 64;
|
|
unsigned int hashSize = 0;
|
|
unsigned char hash[maxHashSize] = {};
|
|
|
|
HashType type = htUnknown;
|
|
|
|
/* Create an unset hash object. */
|
|
Hash() { };
|
|
|
|
/* Create a zero-filled hash object. */
|
|
Hash(HashType type) : type(type) { init(); };
|
|
|
|
/* Initialize the hash from a string representation, in the format
|
|
"[<type>:]<base16|base32|base64>" or "<type>-<base64>" (a
|
|
Subresource Integrity hash expression). If the 'type' argument
|
|
is htUnknown, then the hash type must be specified in the
|
|
string. */
|
|
Hash(const std::string & s, HashType type = htUnknown);
|
|
|
|
void init();
|
|
|
|
/* 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;
|
|
}
|
|
|
|
/* Returns the length of a base-64 representation of this hash. */
|
|
size_t base64Len() const
|
|
{
|
|
return ((4 * hashSize / 3) + 3) & ~3;
|
|
}
|
|
|
|
/* Return a string representation of the hash, in base-16, base-32
|
|
or base-64. By default, this is prefixed by the hash type
|
|
(e.g. "sha256:"). */
|
|
std::string to_string(Base base = Base32, bool includeType = true) const;
|
|
|
|
std::string gitRev() const
|
|
{
|
|
assert(type == htSHA1);
|
|
return to_string(Base16, false);
|
|
}
|
|
|
|
std::string gitShortRev() const
|
|
{
|
|
assert(type == htSHA1);
|
|
return std::string(to_string(Base16, false), 0, 7);
|
|
}
|
|
};
|
|
|
|
|
|
/* Print a hash in base-16 if it's MD5, or base-32 otherwise. */
|
|
string printHash16or32(const Hash & hash);
|
|
|
|
/* 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)). */
|
|
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;
|
|
|
|
struct AbstractHashSink : virtual Sink
|
|
{
|
|
virtual HashResult finish() = 0;
|
|
};
|
|
|
|
class HashSink : public BufferedSink, public AbstractHashSink
|
|
{
|
|
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) override;
|
|
HashResult finish() override;
|
|
HashResult currentHash();
|
|
};
|
|
|
|
|
|
}
|