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-rw-r--r--third_party/nix/src/libutil/hash.cc484
1 files changed, 484 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..ba61254392e0
--- /dev/null
+++ b/third_party/nix/src/libutil/hash.cc
@@ -0,0 +1,484 @@
+#include "libutil/hash.hh"
+
+#include <cstring>
+#include <iostream>
+
+#include <absl/strings/escaping.h>
+#include <absl/strings/str_format.h>
+#include <fcntl.h>
+#include <glog/logging.h>
+#include <openssl/md5.h>
+#include <openssl/sha.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include "libutil/archive.hh"
+#include "libutil/istringstream_nocopy.hh"
+#include "libutil/util.hh"
+
+namespace nix {
+
+std::optional<HashType> hash_type_from(nix::proto::HashType hash_type) {
+  switch (hash_type) {
+    case nix::proto::HashType::UNKNOWN:
+      return HashType::htUnknown;
+    case nix::proto::HashType::MD5:
+      return HashType::htMD5;
+    case nix::proto::HashType::SHA1:
+      return HashType::htSHA1;
+    case nix::proto::HashType::SHA256:
+      return HashType::htSHA256;
+    case nix::proto::HashType::SHA512:
+      return HashType::htSHA512;
+    default:
+      return {};
+  }
+}
+
+nix::proto::HashType HashTypeToProto(HashType hash_type) {
+  switch (hash_type) {
+    case HashType::htMD5:
+      return nix::proto::HashType::MD5;
+    case HashType::htSHA1:
+      return nix::proto::HashType::SHA1;
+    case HashType::htSHA256:
+      return nix::proto::HashType::SHA256;
+    case HashType::htSHA512:
+      return nix::proto::HashType::SHA512;
+    default:
+      return nix::proto::HashType::UNKNOWN;
+  }
+}
+
+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 std::string base16Chars = "0123456789abcdef";
+
+static std::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 std::string(buf, hash.hashSize * 2);
+}
+
+bool Hash::IsValidBase16(absl::string_view s) {
+  for (char c : s) {
+    if ('0' <= c && c <= '9') {
+      continue;
+    }
+    if ('a' <= c && c <= 'f') {
+      continue;
+    }
+    if ('A' <= c && c <= 'F') {
+      continue;
+    }
+    return false;
+  }
+  return true;
+}
+
+constexpr signed char kUnBase32[] = {
+    -1, -1, -1, -1, -1, -1, -1, -1, /* unprintables */
+    -1, -1, -1, -1, -1, -1, -1, -1, /* unprintables */
+    -1, -1, -1, -1, -1, -1, -1, -1, /* unprintables */
+    -1, -1, -1, -1, -1, -1, -1, -1, /* unprintables */
+    -1, -1, -1, -1, -1, -1, -1, -1, /* SP..' */
+    -1, -1, -1, -1, -1, -1, -1, -1, /* (../ */
+    0,  1,  2,  3,  4,  5,  6,  7,  /* 0..7 */
+    8,  9,  -1, -1, -1, -1, -1, -1, /* 8..? */
+    -1, -1, -1, -1, -1, -1, -1, -1, /* @..G */
+    -1, -1, -1, -1, -1, -1, -1, -1, /* H..O */
+    -1, -1, -1, -1, -1, -1, -1, -1, /* P..W */
+    -1, -1, -1, -1, -1, -1, -1, -1, /* X.._ */
+    -1, 10, 11, 12, 13, -1, 14, 15, /* `..g */
+    16, 17, 18, 19, 20, 21, 22, -1, /* h..o */
+    23, 24, 25, 26, -1, -1, 27, 28, /* p..w */
+    29, 30, 31, -1, -1, -1, -1, -1, /* x..DEL */
+
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* high */
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* high */
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* high */
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* high */
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* high */
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* high */
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* high */
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* high */
+};
+
+bool Hash::IsValidBase32(absl::string_view s) {
+  static_assert(sizeof(kUnBase32) == 256);
+
+  for (char c : s) {
+    if (kUnBase32[static_cast<unsigned char>(c)] == -1) {
+      return false;
+    }
+  }
+  return true;
+}
+
+std::string Hash::ToStorePathHash() const {
+  return compressHash(*this, kStorePathHashSize).to_string(Base32, false);
+}
+
+static std::string printHash32(const Hash& hash) {
+  assert(hash.hashSize);
+  size_t len = hash.base32Len();
+  assert(len);
+
+  std::string s;
+  s.reserve(len);
+
+  for (int n = static_cast<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;
+}
+
+std::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:
+      std::string b64;
+      absl::Base64Escape(
+          std::string(reinterpret_cast<const char*>(hash), hashSize), &b64);
+      s += b64;
+      break;
+  }
+  return s;
+}
+
+Hash::Hash(std::string_view s, HashType type) : type(type) {
+  absl::StatusOr<Hash> result = deserialize(s, type);
+  *this = unwrap_throw(result);
+}
+
+// TODO(riking): change ht to an optional
+absl::StatusOr<Hash> Hash::deserialize(std::string_view s, HashType type) {
+  size_t pos = 0;
+  bool isSRI = false;
+
+  auto sep = s.find(':');
+  if (sep == std::string::npos) {
+    sep = s.find('-');
+    if (sep != std::string::npos) {
+      isSRI = true;
+    } else if (type == htUnknown) {
+      return absl::InvalidArgumentError(
+          absl::StrCat("hash string '", s, " does not include a type"));
+    }
+  }
+
+  HashType parsedType = type;
+  if (sep != std::string::npos) {
+    std::string hts = std::string(s, 0, sep);
+    parsedType = parseHashType(hts);
+    if (type != htUnknown && parsedType != type) {
+      return absl::InvalidArgumentError(
+          absl::StrCat("hash '", s, "' should have type '", printHashType(type),
+                       "', found '", printHashType(parsedType), "'"));
+    }
+    pos = sep + 1;
+  }
+
+  Hash dest(parsedType);
+
+  size_t size = s.size() - pos;
+  absl::string_view sv(s.data() + pos, size);
+
+  if (!isSRI && size == dest.base16Len()) {
+    std::string bytes;
+    if (!IsValidBase16(sv)) {
+      return absl::InvalidArgumentError(
+          absl::StrCat("invalid base-16 hash: bad character in '", s, "'"));
+    }
+    bytes = absl::HexStringToBytes(sv);
+    if (bytes.size() != dest.hashSize) {
+      return absl::InvalidArgumentError(
+          absl::StrCat("hash '", s, "' has wrong length for base16 ",
+                       printHashType(dest.type)));
+    }
+    memcpy(dest.hash, bytes.data(), dest.hashSize);
+  }
+
+  else if (!isSRI && size == dest.base32Len()) {
+    for (unsigned int n = 0; n < size; ++n) {
+      char c = sv[size - n - 1];
+      // range: -1, 0..31
+      signed char digit = kUnBase32[static_cast<unsigned char>(c)];
+      if (digit < 0) {
+        return absl::InvalidArgumentError(
+            absl::StrCat("invalid base-32 hash: bad character ",
+                         absl::CEscape(absl::string_view(&c, 1))));
+      }
+      unsigned int b = n * 5;
+      unsigned int i = b / 8;
+      unsigned int j = b % 8;
+      dest.hash[i] |= digit << j;
+
+      if (i < dest.hashSize - 1) {
+        dest.hash[i + 1] |= digit >> (8 - j);
+      } else {
+        if ((digit >> (8 - j)) != 0) {
+          return absl::InvalidArgumentError(
+              absl::StrCat("invalid base-32 hash '", s, "'"));
+        }
+      }
+    }
+  }
+
+  else if (isSRI || size == dest.base64Len()) {
+    std::string decoded;
+    if (!absl::Base64Unescape(sv, &decoded)) {
+      return absl::InvalidArgumentError("invalid base-64 hash");
+    }
+    if (decoded.size() != dest.hashSize) {
+      return absl::InvalidArgumentError(
+          absl::StrCat("hash '", s, "' has wrong length for base64 ",
+                       printHashType(dest.type)));
+    }
+    memcpy(dest.hash, decoded.data(), dest.hashSize);
+  }
+
+  else {
+    return absl::InvalidArgumentError(absl::StrCat(
+        "hash '", s, "' has wrong length for ", printHashType(dest.type)));
+  }
+
+  return dest;
+}
+
+Hash Hash::unwrap_throw(absl::StatusOr<Hash> hash) {
+  if (hash.ok()) {
+    return *hash;
+  } else {
+    throw BadHash(hash.status().message());
+  }
+}
+
+namespace hash {
+
+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);
+  }
+}
+
+}  // namespace hash
+
+Hash hashString(HashType ht, const std::string& s) {
+  hash::Ctx ctx{};
+  Hash hash(ht);
+  start(ht, ctx);
+  update(ht, ctx, reinterpret_cast<const unsigned char*>(s.data()), s.length());
+  finish(ht, ctx, hash.hash);
+  return hash;
+}
+
+Hash hashFile(HashType ht, const Path& path) {
+  hash::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(std::make_unique<hash::Ctx>()), bytes(0) {
+  start(ht, *ctx);
+}
+
+HashSink::~HashSink() { bufPos = 0; }
+
+void HashSink::write(const unsigned char* data, size_t len) {
+  bytes += len;
+  nix::hash::update(ht, *ctx, data, len);
+}
+
+HashResult HashSink::finish() {
+  flush();
+  Hash hash(ht);
+  nix::hash::finish(ht, *ctx, hash.hash);
+  return HashResult(hash, bytes);
+}
+
+HashResult HashSink::currentHash() {
+  flush();
+  nix::hash::Ctx ctx2 = *ctx;
+  Hash hash(ht);
+  nix::hash::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 std::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;
+  }
+}
+
+std::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 if (ht == htUnknown) {
+    return "<unknown>";
+  } else {
+    LOG(FATAL) << "Unrecognized hash type: " << static_cast<int>(ht);
+    abort();
+  }
+}
+
+}  // namespace nix