guix-play/nix/libutil/hash.hh
Ludovic Courtès 3fb6b8f304
daemon: Map directly to gcrypt hash functions.
* nix/libutil/hash.hh (HashType): Map directly to GCRY_MD_ values.
(md5HashSize, sha1HashSize, sha256HashSize, sha512HashSize): Remove.
* nix/libutil/hash.cc (Hash::Hash): Use 'gcry_md_get_algo_dlen'.
2020-06-27 23:42:20 +02:00

116 lines
2.7 KiB
C++

#pragma once
#include <gcrypt.h>
#include "types.hh"
#include "serialise.hh"
namespace nix {
extern const string base32Chars;
typedef enum {
htUnknown = 0,
htMD5 = GCRY_MD_MD5,
htSHA1 = GCRY_MD_SHA1,
htSHA256 = GCRY_MD_SHA256,
htSHA512 = GCRY_MD_SHA512
} HashType;
struct Hash
{
static const unsigned int maxHashSize = 64;
unsigned int hashSize;
unsigned char hash[maxHashSize];
HashType type;
/* Create an unusable hash object. */
Hash();
/* Create a zero-filled hash object. */
Hash(HashType type);
/* 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;
};
/* Convert a hash to a hexadecimal representation. */
string printHash(const Hash & hash);
/* Parse a hexadecimal representation of a hash code. */
Hash parseHash(HashType ht, const string & s);
/* Returns the length of a base-32 hash representation. */
unsigned int hashLength32(const Hash & hash);
/* 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);
struct 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();
};
}