1 files changed, 371 insertions, 0 deletions
diff --git a/third_party/nix/src/libutil/hash.cc b/third_party/nix/src/libutil/hash.cc
new file mode 100644
index 000000000000..81d8628e972b
--- /dev/null
+++ b/third_party/nix/src/libutil/hash.cc
@@ -0,0 +1,371 @@
+#include "hash.hh"
+
+#include <cstring>
+#include <iostream>
+
+#include <fcntl.h>
+#include <openssl/md5.h>
+#include <openssl/sha.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include "archive.hh"
+#include "istringstream_nocopy.hh"
+#include "util.hh"
+
+namespace nix {
+
+void Hash::init() {
+  if (type == htMD5) {
+    hashSize = md5HashSize;
+  } else if (type == htSHA1) {
+    hashSize = sha1HashSize;
+  } else if (type == htSHA256) {
+    hashSize = sha256HashSize;
+  } else if (type == htSHA512) {
+    hashSize = sha512HashSize;
+  } else {
+    abort();
+  }
+  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 {
+  if (hashSize < h.hashSize) {
+    return true;
+  }
+  if (hashSize > h.hashSize) {
+    return false;
+  }
+  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";
+
+static string printHash16(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);
+}
+
+// omitted: E O U T
+const string base32Chars = "0123456789abcdfghijklmnpqrsvwxyz";
+
+static string printHash32(const Hash& hash) {
+  assert(hash.hashSize);
+  size_t len = hash.base32Len();
+  assert(len);
+
+  string s;
+  s.reserve(len);
+
+  for (int n = (int)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.to_string(hash.type == htMD5 ? Base16 : Base32, false);
+}
+
+std::string Hash::to_string(Base base, bool includeType) const {
+  std::string s;
+  if (base == SRI || includeType) {
+    s += printHashType(type);
+    s += base == SRI ? '-' : ':';
+  }
+  switch (base) {
+    case Base16:
+      s += printHash16(*this);
+      break;
+    case Base32:
+      s += printHash32(*this);
+      break;
+    case Base64:
+    case SRI:
+      s += base64Encode(std::string((const char*)hash, hashSize));
+      break;
+  }
+  return s;
+}
+
+Hash::Hash(const std::string& s, HashType type) : type(type) {
+  size_t pos = 0;
+  bool isSRI = false;
+
+  auto sep = s.find(':');
+  if (sep == string::npos) {
+    sep = s.find('-');
+    if (sep != string::npos) {
+      isSRI = true;
+    } else if (type == htUnknown) {
+      throw BadHash("hash '%s' does not include a type", s);
+    }
+  }
+
+  if (sep != string::npos) {
+    string hts = string(s, 0, sep);
+    this->type = parseHashType(hts);
+    if (this->type == htUnknown) {
+      throw BadHash("unknown hash type '%s'", hts);
+    }
+    if (type != htUnknown && type != this->type) {
+      throw BadHash("hash '%s' should have type '%s'", s, printHashType(type));
+    }
+    pos = sep + 1;
+  }
+
+  init();
+
+  size_t size = s.size() - pos;
+
+  if (!isSRI && size == base16Len()) {
+    auto parseHexDigit = [&](char c) {
+      if (c >= '0' && c <= '9') {
+        return c - '0';
+      }
+      if (c >= 'A' && c <= 'F') {
+        return c - 'A' + 10;
+      }
+      if (c >= 'a' && c <= 'f') {
+        return c - 'a' + 10;
+      }
+      throw BadHash("invalid base-16 hash '%s'", s);
+    };
+
+    for (unsigned int i = 0; i < hashSize; i++) {
+      hash[i] = parseHexDigit(s[pos + i * 2]) << 4 |
+                parseHexDigit(s[pos + i * 2 + 1]);
+    }
+  }
+
+  else if (!isSRI && size == base32Len()) {
+    for (unsigned int n = 0; n < size; ++n) {
+      char c = s[pos + size - n - 1];
+      unsigned char digit;
+      for (digit = 0; digit < base32Chars.size(); ++digit) { /* !!! slow */
+        if (base32Chars[digit] == c) {
+          break;
+        }
+      }
+      if (digit >= 32) {
+        throw BadHash("invalid base-32 hash '%s'", s);
+      }
+      unsigned int b = n * 5;
+      unsigned int i = b / 8;
+      unsigned int j = b % 8;
+      hash[i] |= digit << j;
+
+      if (i < hashSize - 1) {
+        hash[i + 1] |= digit >> (8 - j);
+      } else {
+        if ((digit >> (8 - j)) != 0) {
+          throw BadHash("invalid base-32 hash '%s'", s);
+        }
+      }
+    }
+  }
+
+  else if (isSRI || size == base64Len()) {
+    auto d = base64Decode(std::string(s, pos));
+    if (d.size() != hashSize) {
+      throw BadHash("invalid %s hash '%s'", isSRI ? "SRI" : "base-64", s);
+    }
+    assert(hashSize);
+    memcpy(hash, d.data(), hashSize);
+  }
+
+  else {
+    throw BadHash("hash '%s' has wrong length for hash type '%s'", s,
+                  printHashType(type));
+  }
+}
+
+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,
+                   size_t 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 | O_CLOEXEC);
+  if (!fd) {
+    throw SysError(format("opening file '%1%'") % path);
+  }
+
+  std::vector<unsigned char> buf(8192);
+  ssize_t n;
+  while ((n = read(fd.get(), buf.data(), buf.size())) != 0) {
+    checkInterrupt();
+    if (n == -1) {
+      throw SysError(format("reading file '%1%'") % path);
+    }
+    update(ht, ctx, buf.data(), 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;
+  }
+  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";
+  }
+  if (ht == htSHA1) {
+    return "sha1";
+  } else if (ht == htSHA256) {
+    return "sha256";
+  } else if (ht == htSHA512) {
+    return "sha512";
+  } else {
+    abort();
+  }
+}
+
+}  // namespace nix