#include "config.h" #include <iostream> #include <cstring> #include <openssl/md5.h> #include <openssl/sha.h> #include "hash.hh" #include "archive.hh" #include "util.hh" #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> namespace nix { Hash::Hash() { type = htUnknown; hashSize = 0; memset(hash, 0, maxHashSize); } Hash::Hash(HashType type) { this->type = type; if (type == htMD5) hashSize = md5HashSize; else if (type == htSHA1) hashSize = sha1HashSize; else if (type == htSHA256) hashSize = sha256HashSize; else if (type == htSHA512) hashSize = sha512HashSize; else throw Error("unknown hash type"); assert(hashSize <= maxHashSize); memset(hash, 0, maxHashSize); } bool Hash::operator == (const Hash & h2) const { if (hashSize != h2.hashSize) return false; for (unsigned int i = 0; i < hashSize; i++) if (hash[i] != h2.hash[i]) return false; return true; } bool Hash::operator != (const Hash & h2) const { return !(*this == h2); } bool Hash::operator < (const Hash & h) const { for (unsigned int i = 0; i < hashSize; i++) { if (hash[i] < h.hash[i]) return true; if (hash[i] > h.hash[i]) return false; } return false; } const string base16Chars = "0123456789abcdef"; string printHash(const Hash & hash) { char buf[hash.hashSize * 2]; for (unsigned int i = 0; i < hash.hashSize; i++) { buf[i * 2] = base16Chars[hash.hash[i] >> 4]; buf[i * 2 + 1] = base16Chars[hash.hash[i] & 0x0f]; } return string(buf, hash.hashSize * 2); } Hash parseHash(HashType ht, const string & s) { Hash hash(ht); if (s.length() != hash.hashSize * 2) throw Error(format("invalid hash ‘%1%’") % s); for (unsigned int i = 0; i < hash.hashSize; i++) { string s2(s, i * 2, 2); if (!isxdigit(s2[0]) || !isxdigit(s2[1])) throw Error(format("invalid hash ‘%1%’") % s); std::istringstream str(s2); int n; str >> std::hex >> n; hash.hash[i] = n; } return hash; } // omitted: E O U T const string base32Chars = "0123456789abcdfghijklmnpqrsvwxyz"; string printHash32(const Hash & hash) { size_t len = hash.base32Len(); string s; s.reserve(len); for (int n = len - 1; n >= 0; n--) { unsigned int b = n * 5; unsigned int i = b / 8; unsigned int j = b % 8; unsigned char c = (hash.hash[i] >> j) | (i >= hash.hashSize - 1 ? 0 : hash.hash[i + 1] << (8 - j)); s.push_back(base32Chars[c & 0x1f]); } return s; } string printHash16or32(const Hash & hash) { return hash.type == htMD5 ? printHash(hash) : printHash32(hash); } Hash parseHash32(HashType ht, const string & s) { Hash hash(ht); size_t len = hash.base32Len(); assert(s.size() == len); for (unsigned int n = 0; n < len; ++n) { char c = s[len - n - 1]; unsigned char digit; for (digit = 0; digit < base32Chars.size(); ++digit) /* !!! slow */ if (base32Chars[digit] == c) break; if (digit >= 32) throw Error(format("invalid base-32 hash ‘%1%’") % s); unsigned int b = n * 5; unsigned int i = b / 8; unsigned int j = b % 8; hash.hash[i] |= digit << j; if (i < hash.hashSize - 1) hash.hash[i + 1] |= digit >> (8 - j); } return hash; } Hash parseHash16or32(HashType ht, const string & s) { Hash hash(ht); if (s.size() == hash.hashSize * 2) /* hexadecimal representation */ hash = parseHash(ht, s); else if (s.size() == hash.base32Len()) /* base-32 representation */ hash = parseHash32(ht, s); else throw Error(format("hash ‘%1%’ has wrong length for hash type ‘%2%’") % s % printHashType(ht)); return hash; } bool isHash(const string & s) { if (s.length() != 32) return false; for (int i = 0; i < 32; i++) { char c = s[i]; if (!((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f'))) return false; } return true; } union Ctx { MD5_CTX md5; SHA_CTX sha1; SHA256_CTX sha256; SHA512_CTX sha512; }; static void start(HashType ht, Ctx & ctx) { if (ht == htMD5) MD5_Init(&ctx.md5); else if (ht == htSHA1) SHA1_Init(&ctx.sha1); else if (ht == htSHA256) SHA256_Init(&ctx.sha256); else if (ht == htSHA512) SHA512_Init(&ctx.sha512); } static void update(HashType ht, Ctx & ctx, const unsigned char * bytes, unsigned int len) { if (ht == htMD5) MD5_Update(&ctx.md5, bytes, len); else if (ht == htSHA1) SHA1_Update(&ctx.sha1, bytes, len); else if (ht == htSHA256) SHA256_Update(&ctx.sha256, bytes, len); else if (ht == htSHA512) SHA512_Update(&ctx.sha512, bytes, len); } static void finish(HashType ht, Ctx & ctx, unsigned char * hash) { if (ht == htMD5) MD5_Final(hash, &ctx.md5); else if (ht == htSHA1) SHA1_Final(hash, &ctx.sha1); else if (ht == htSHA256) SHA256_Final(hash, &ctx.sha256); else if (ht == htSHA512) SHA512_Final(hash, &ctx.sha512); } Hash hashString(HashType ht, const string & s) { Ctx ctx; Hash hash(ht); start(ht, ctx); update(ht, ctx, (const unsigned char *) s.data(), s.length()); finish(ht, ctx, hash.hash); return hash; } Hash hashFile(HashType ht, const Path & path) { Ctx ctx; Hash hash(ht); start(ht, ctx); AutoCloseFD fd = open(path.c_str(), O_RDONLY); if (fd == -1) throw SysError(format("opening file ‘%1%’") % path); unsigned char buf[8192]; ssize_t n; while ((n = read(fd, buf, sizeof(buf)))) { checkInterrupt(); if (n == -1) throw SysError(format("reading file ‘%1%’") % path); update(ht, ctx, buf, n); } finish(ht, ctx, hash.hash); return hash; } HashSink::HashSink(HashType ht) : ht(ht) { ctx = new Ctx; bytes = 0; start(ht, *ctx); } HashSink::~HashSink() { bufPos = 0; delete ctx; } void HashSink::write(const unsigned char * data, size_t len) { bytes += len; update(ht, *ctx, data, len); } HashResult HashSink::finish() { flush(); Hash hash(ht); nix::finish(ht, *ctx, hash.hash); return HashResult(hash, bytes); } HashResult HashSink::currentHash() { flush(); Ctx ctx2 = *ctx; Hash hash(ht); nix::finish(ht, ctx2, hash.hash); return HashResult(hash, bytes); } HashResult hashPath( HashType ht, const Path & path, PathFilter & filter) { HashSink sink(ht); dumpPath(path, sink, filter); return sink.finish(); } Hash compressHash(const Hash & hash, unsigned int newSize) { Hash h; h.hashSize = newSize; for (unsigned int i = 0; i < hash.hashSize; ++i) h.hash[i % newSize] ^= hash.hash[i]; return h; } HashType parseHashType(const string & s) { if (s == "md5") return htMD5; else if (s == "sha1") return htSHA1; else if (s == "sha256") return htSHA256; else if (s == "sha512") return htSHA512; else return htUnknown; } string printHashType(HashType ht) { if (ht == htMD5) return "md5"; else if (ht == htSHA1) return "sha1"; else if (ht == htSHA256) return "sha256"; else if (ht == htSHA512) return "sha512"; else throw Error("cannot print unknown hash type"); } }