lix/src/nix/hash.cc
Eelco Dolstra c0015e87af
Support base-64 hashes
Also simplify the Hash API.

Fixes #1437.
2017-07-04 15:07:41 +02:00

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#include "command.hh"
#include "hash.hh"
#include "legacy.hh"
#include "shared.hh"
using namespace nix;
struct CmdHash : Command
{
enum Mode { mFile, mPath };
Mode mode;
Base base = Base16;
bool truncate = false;
HashType ht = htSHA512;
Strings paths;
CmdHash(Mode mode) : mode(mode)
{
mkFlag(0, "base64", "print hash in base-64", &base, Base64);
mkFlag(0, "base32", "print hash in base-32 (Nix-specific)", &base, Base32);
mkFlag(0, "base16", "print hash in base-16", &base, Base16);
mkHashTypeFlag("type", &ht);
expectArgs("paths", &paths);
}
std::string name() override
{
return mode == mFile ? "hash-file" : "hash-path";
}
std::string description() override
{
return mode == mFile
? "print cryptographic hash of a regular file"
: "print cryptographic hash of the NAR serialisation of a path";
}
void run() override
{
for (auto path : paths) {
Hash h = mode == mFile ? hashFile(ht, path) : hashPath(ht, path).first;
if (truncate && h.hashSize > 20) h = compressHash(h, 20);
std::cout << format("%1%\n") %
h.to_string(base, false);
}
}
};
static RegisterCommand r1(make_ref<CmdHash>(CmdHash::mFile));
static RegisterCommand r2(make_ref<CmdHash>(CmdHash::mPath));
struct CmdToBase : Command
{
Base base;
HashType ht = htSHA512;
Strings args;
CmdToBase(Base base) : base(base)
{
mkHashTypeFlag("type", &ht);
expectArgs("strings", &args);
}
std::string name() override
{
return
base == Base16 ? "to-base16" :
base == Base32 ? "to-base32" :
"to-base64";
}
std::string description() override
{
return fmt("convert a hash to base-%d representation",
base == Base16 ? 16 :
base == Base32 ? 32 : 64);
}
void run() override
{
for (auto s : args)
std::cout << fmt("%s\n", Hash(s, ht).to_string(base, false));
}
};
static RegisterCommand r3(make_ref<CmdToBase>(Base16));
static RegisterCommand r4(make_ref<CmdToBase>(Base32));
static RegisterCommand r5(make_ref<CmdToBase>(Base64));
/* Legacy nix-hash command. */
static int compatNixHash(int argc, char * * argv)
{
HashType ht = htMD5;
bool flat = false;
bool base32 = false;
bool truncate = false;
enum { opHash, opTo32, opTo16 } op = opHash;
Strings 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);
if (ht == htUnknown)
throw UsageError(format("unknown hash type %1%") % 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 ? CmdHash::mFile : CmdHash::mPath);
cmd.ht = ht;
cmd.base = base32 ? Base32 : Base16;
cmd.truncate = truncate;
cmd.paths = ss;
cmd.run();
}
else {
CmdToBase cmd(op == opTo32 ? Base32 : Base16);
cmd.args = ss;
cmd.ht = ht;
cmd.run();
}
return 0;
}
static RegisterLegacyCommand s1("nix-hash", compatNixHash);