#include "config.h" #include <iostream> #ifdef HAVE_OPENSSL #include <openssl/md5.h> #include <openssl/sha.h> #else extern "C" { #include "md5.h" #include "sha1.h" #include "sha256.h" } #endif #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 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; } static unsigned char divMod(unsigned char * bytes, unsigned char y) { unsigned int borrow = 0; int pos = Hash::maxHashSize - 1; while (pos >= 0 && !bytes[pos]) --pos; for ( ; pos >= 0; --pos) { unsigned int s = bytes[pos] + (borrow << 8); unsigned int d = s / y; borrow = s % y; bytes[pos] = d; } return borrow; } unsigned int hashLength32(const Hash & hash) { return (hash.hashSize * 8 - 1) / 5 + 1; } // omitted: E O U T const string base32Chars = "0123456789abcdfghijklmnpqrsvwxyz"; string printHash32(const Hash & hash) { Hash hash2(hash); unsigned int len = hashLength32(hash); const char * chars = base32Chars.c_str(); string s(len, '0'); int pos = len - 1; while (pos >= 0) { unsigned char digit = divMod(hash2.hash, 32); s[pos--] = chars[digit]; } for (unsigned int i = 0; i < hash2.maxHashSize; ++i) assert(hash2.hash[i] == 0); return s; } static bool mul(unsigned char * bytes, unsigned char y, int maxSize) { unsigned char carry = 0; for (int pos = 0; pos < maxSize; ++pos) { unsigned int m = bytes[pos] * y + carry; bytes[pos] = m & 0xff; carry = m >> 8; } return carry; } static bool add(unsigned char * bytes, unsigned char y, int maxSize) { unsigned char carry = y; for (int pos = 0; pos < maxSize; ++pos) { unsigned int m = bytes[pos] + carry; bytes[pos] = m & 0xff; carry = m >> 8; if (carry == 0) break; } return carry; } Hash parseHash32(HashType ht, const string & s) { Hash hash(ht); const char * chars = base32Chars.c_str(); for (unsigned int i = 0; i < s.length(); ++i) { char c = s[i]; unsigned char digit; for (digit = 0; digit < base32Chars.size(); ++digit) /* !!! slow */ if (chars[digit] == c) break; if (digit >= 32) throw Error(format("invalid base-32 hash `%1%'") % s); if (mul(hash.hash, 32, hash.hashSize) || add(hash.hash, digit, hash.hashSize)) throw Error(format("base-32 hash `%1%' is too large") % s); } 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; }; 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); } 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); } 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); } Hash hashString(HashType ht, const string & s) { Ctx ctx; Hash hash(ht); start(ht, ctx); update(ht, ctx, (const unsigned char *) s.c_str(), 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; } struct HashSink : Sink { HashType ht; Ctx ctx; virtual void operator () (const unsigned char * data, unsigned int len) { update(ht, ctx, data, len); } }; Hash hashPath(HashType ht, const Path & path) { HashSink sink; sink.ht = ht; Hash hash(ht); start(ht, sink.ctx); dumpPath(path, sink); finish(ht, sink.ctx, hash.hash); return hash; } 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 return htUnknown; } }