lix/src/nix/hash.cc
John Ericson 450dcf2c1b Remove HashType::Unknown
Instead, `Hash` uses `std::optional<HashType>`. In the future, we may
also make `Hash` itself require a known hash type, encoraging people to
use `std::optional<Hash>` instead.
2020-06-02 15:52:13 +00:00

165 lines
4.9 KiB
C++

#include "command.hh"
#include "hash.hh"
#include "legacy.hh"
#include "shared.hh"
#include "references.hh"
#include "archive.hh"
using namespace nix;
struct CmdHash : Command
{
FileIngestionMethod mode;
Base base = Base::SRI;
bool truncate = false;
HashType ht = HashType::SHA256;
std::vector<std::string> paths;
std::optional<std::string> modulus;
CmdHash(FileIngestionMethod mode) : mode(mode)
{
mkFlag(0, "sri", "print hash in Base::SRI format", &base, Base::SRI);
mkFlag(0, "base64", "print hash in base-64", &base, Base::Base64);
mkFlag(0, "base32", "print hash in base-32 (Nix-specific)", &base, Base::Base32);
mkFlag(0, "base16", "print hash in base-16", &base, Base::Base16);
addFlag(Flag::mkHashTypeFlag("type", &ht));
#if 0
mkFlag()
.longName("modulo")
.description("compute hash modulo specified string")
.labels({"modulus"})
.dest(&modulus);
#endif
expectArgs("paths", &paths);
}
std::string description() override
{
const char* d;
switch (mode) {
case FileIngestionMethod::Flat:
d = "print cryptographic hash of a regular file";
case FileIngestionMethod::Recursive:
d = "print cryptographic hash of the NAR serialisation of a path";
};
return d;
}
Category category() override { return catUtility; }
void run() override
{
for (auto path : paths) {
std::unique_ptr<AbstractHashSink> hashSink;
if (modulus)
hashSink = std::make_unique<HashModuloSink>(ht, *modulus);
else
hashSink = std::make_unique<HashSink>(ht);
switch (mode) {
case FileIngestionMethod::Flat:
readFile(path, *hashSink);
break;
case FileIngestionMethod::Recursive:
dumpPath(path, *hashSink);
break;
}
Hash h = hashSink->finish().first;
if (truncate && h.hashSize > 20) h = compressHash(h, 20);
logger->stdout(h.to_string(base, base == Base::SRI));
}
}
};
static RegisterCommand r1("hash-file", [](){ return make_ref<CmdHash>(FileIngestionMethod::Flat); });
static RegisterCommand r2("hash-path", [](){ return make_ref<CmdHash>(FileIngestionMethod::Recursive); });
struct CmdToBase : Command
{
Base base;
HashType ht;
std::vector<std::string> args;
CmdToBase(Base base) : base(base)
{
addFlag(Flag::mkHashTypeFlag("type", &ht));
expectArgs("strings", &args);
}
std::string description() override
{
return fmt("convert a hash to %s representation",
base == Base::Base16 ? "base-16" :
base == Base::Base32 ? "base-32" :
base == Base::Base64 ? "base-64" :
"Base::SRI");
}
Category category() override { return catUtility; }
void run() override
{
for (auto s : args)
logger->stdout(Hash(s, ht).to_string(base, base == Base::SRI));
}
};
static RegisterCommand r3("to-base16", [](){ return make_ref<CmdToBase>(Base::Base16); });
static RegisterCommand r4("to-base32", [](){ return make_ref<CmdToBase>(Base::Base32); });
static RegisterCommand r5("to-base64", [](){ return make_ref<CmdToBase>(Base::Base64); });
static RegisterCommand r6("to-sri", [](){ return make_ref<CmdToBase>(Base::SRI); });
/* Legacy nix-hash command. */
static int compatNixHash(int argc, char * * argv)
{
HashType ht = HashType::MD5;
bool flat = false;
bool base32 = false;
bool truncate = false;
enum { opHash, opTo32, opTo16 } op = opHash;
std::vector<std::string> ss;
parseCmdLine(argc, argv, [&](Strings::iterator & arg, const Strings::iterator & end) {
if (*arg == "--help")
showManPage("nix-hash");
else if (*arg == "--version")
printVersion("nix-hash");
else if (*arg == "--flat") flat = true;
else if (*arg == "--base32") base32 = true;
else if (*arg == "--truncate") truncate = true;
else if (*arg == "--type") {
string s = getArg(*arg, arg, end);
ht = parseHashType(s);
}
else if (*arg == "--to-base16") op = opTo16;
else if (*arg == "--to-base32") op = opTo32;
else if (*arg != "" && arg->at(0) == '-')
return false;
else
ss.push_back(*arg);
return true;
});
if (op == opHash) {
CmdHash cmd(flat ? FileIngestionMethod::Flat : FileIngestionMethod::Recursive);
cmd.ht = ht;
cmd.base = base32 ? Base::Base32 : Base::Base16;
cmd.truncate = truncate;
cmd.paths = ss;
cmd.run();
}
else {
CmdToBase cmd(op == opTo32 ? Base::Base32 : Base::Base16);
cmd.args = ss;
cmd.ht = ht;
cmd.run();
}
return 0;
}
static RegisterLegacyCommand s1("nix-hash", compatNixHash);