diff --git a/libziparchive/include/ziparchive/zip_archive.h b/libziparchive/include/ziparchive/zip_archive.h
index 047af90..098a9cb 100644
--- a/libziparchive/include/ziparchive/zip_archive.h
+++ b/libziparchive/include/ziparchive/zip_archive.h
@@ -126,6 +126,9 @@
 int32_t OpenArchiveFd(const int fd, const char* debugFileName, ZipArchiveHandle* handle,
                       bool assume_ownership = true);
 
+int32_t OpenArchiveFdRange(const int fd, const char* debugFileName, ZipArchiveHandle* handle,
+                           off64_t length, off64_t offset, bool assume_ownership = true);
+
 int32_t OpenArchiveFromMemory(const void* address, size_t length, const char* debugFileName,
                               ZipArchiveHandle* handle);
 /*
@@ -222,6 +225,12 @@
 
 int GetFileDescriptor(const ZipArchiveHandle archive);
 
+/**
+ * Returns the offset of the zip archive in the backing file descriptor, or 0 if the zip archive is
+ * not backed by a file descriptor.
+ */
+off64_t GetFileDescriptorOffset(const ZipArchiveHandle archive);
+
 const char* ErrorCodeString(int32_t error_code);
 
 #if !defined(_WIN32)
diff --git a/libziparchive/zip_archive.cc b/libziparchive/zip_archive.cc
index b5a855a..aa8bafc 100644
--- a/libziparchive/zip_archive.cc
+++ b/libziparchive/zip_archive.cc
@@ -92,8 +92,8 @@
 }
 #endif
 
-ZipArchive::ZipArchive(const int fd, bool assume_ownership)
-    : mapped_zip(fd),
+ZipArchive::ZipArchive(MappedZipFile&& map, bool assume_ownership)
+    : mapped_zip(map),
       close_file(assume_ownership),
       directory_offset(0),
       central_directory(),
@@ -101,7 +101,8 @@
       num_entries(0) {
 #if defined(__BIONIC__)
   if (assume_ownership) {
-    android_fdsan_exchange_owner_tag(fd, 0, GetOwnerTag(this));
+    CHECK(mapped_zip.HasFd());
+    android_fdsan_exchange_owner_tag(mapped_zip.GetFileDescriptor(), 0, GetOwnerTag(this));
   }
 #endif
 }
@@ -362,14 +363,32 @@
 
 int32_t OpenArchiveFd(int fd, const char* debug_file_name, ZipArchiveHandle* handle,
                       bool assume_ownership) {
-  ZipArchive* archive = new ZipArchive(fd, assume_ownership);
+  ZipArchive* archive = new ZipArchive(MappedZipFile(fd), assume_ownership);
   *handle = archive;
   return OpenArchiveInternal(archive, debug_file_name);
 }
 
+int32_t OpenArchiveFdRange(int fd, const char* debug_file_name, ZipArchiveHandle* handle,
+                           off64_t length, off64_t offset, bool assume_ownership) {
+  ZipArchive* archive = new ZipArchive(MappedZipFile(fd, length, offset), assume_ownership);
+  *handle = archive;
+
+  if (length < 0) {
+    ALOGW("Invalid zip length %" PRId64, length);
+    return kIoError;
+  }
+
+  if (offset < 0) {
+    ALOGW("Invalid zip offset %" PRId64, offset);
+    return kIoError;
+  }
+
+  return OpenArchiveInternal(archive, debug_file_name);
+}
+
 int32_t OpenArchive(const char* fileName, ZipArchiveHandle* handle) {
   const int fd = ::android::base::utf8::open(fileName, O_RDONLY | O_BINARY | O_CLOEXEC, 0);
-  ZipArchive* archive = new ZipArchive(fd, true);
+  ZipArchive* archive = new ZipArchive(MappedZipFile(fd), true);
   *handle = archive;
 
   if (fd < 0) {
@@ -1030,6 +1049,10 @@
   return archive->mapped_zip.GetFileDescriptor();
 }
 
+off64_t GetFileDescriptorOffset(const ZipArchiveHandle archive) {
+  return archive->mapped_zip.GetFileOffset();
+}
+
 #if !defined(_WIN32)
 class ProcessWriter : public zip_archive::Writer {
  public:
@@ -1069,31 +1092,65 @@
   return base_ptr_;
 }
 
+off64_t MappedZipFile::GetFileOffset() const {
+  return fd_offset_;
+}
+
 off64_t MappedZipFile::GetFileLength() const {
   if (has_fd_) {
-    off64_t result = lseek64(fd_, 0, SEEK_END);
-    if (result == -1) {
+    if (data_length_ != -1) {
+      return data_length_;
+    }
+    data_length_ = lseek64(fd_, 0, SEEK_END);
+    if (data_length_ == -1) {
       ALOGE("Zip: lseek on fd %d failed: %s", fd_, strerror(errno));
     }
-    return result;
+    return data_length_;
   } else {
     if (base_ptr_ == nullptr) {
       ALOGE("Zip: invalid file map");
       return -1;
     }
-    return static_cast<off64_t>(data_length_);
+    return data_length_;
   }
 }
 
 // Attempts to read |len| bytes into |buf| at offset |off|.
 bool MappedZipFile::ReadAtOffset(uint8_t* buf, size_t len, off64_t off) const {
   if (has_fd_) {
-    if (!android::base::ReadFullyAtOffset(fd_, buf, len, off)) {
+    if (off < 0) {
+      ALOGE("Zip: invalid offset %" PRId64, off);
+      return false;
+    }
+
+    off64_t read_offset;
+    if (__builtin_add_overflow(fd_offset_, off, &read_offset)) {
+      ALOGE("Zip: invalid read offset %" PRId64 " overflows, fd offset %" PRId64, off, fd_offset_);
+      return false;
+    }
+
+    if (data_length_ != -1) {
+      off64_t read_end;
+      if (len > std::numeric_limits<off64_t>::max() ||
+          __builtin_add_overflow(off, static_cast<off64_t>(len), &read_end)) {
+        ALOGE("Zip: invalid read length %" PRId64 " overflows, offset %" PRId64,
+              static_cast<off64_t>(len), off);
+        return false;
+      }
+
+      if (read_end > data_length_) {
+        ALOGE("Zip: invalid read length %" PRId64 " exceeds data length %" PRId64 ", offset %"
+              PRId64, static_cast<off64_t>(len), data_length_, off);
+        return false;
+      }
+    }
+
+    if (!android::base::ReadFullyAtOffset(fd_, buf, len, read_offset)) {
       ALOGE("Zip: failed to read at offset %" PRId64, off);
       return false;
     }
   } else {
-    if (off < 0 || off > static_cast<off64_t>(data_length_)) {
+    if (off < 0 || off > data_length_) {
       ALOGE("Zip: invalid offset: %" PRId64 ", data length: %" PRId64, off, data_length_);
       return false;
     }
@@ -1111,7 +1168,8 @@
 bool ZipArchive::InitializeCentralDirectory(off64_t cd_start_offset, size_t cd_size) {
   if (mapped_zip.HasFd()) {
     directory_map = android::base::MappedFile::FromFd(mapped_zip.GetFileDescriptor(),
-                                                      cd_start_offset, cd_size, PROT_READ);
+                                                      mapped_zip.GetFileOffset() + cd_start_offset,
+                                                      cd_size, PROT_READ);
     if (!directory_map) {
       ALOGE("Zip: failed to map central directory (offset %" PRId64 ", size %zu): %s",
             cd_start_offset, cd_size, strerror(errno));
diff --git a/libziparchive/zip_archive_private.h b/libziparchive/zip_archive_private.h
index 536894c..3509b89 100644
--- a/libziparchive/zip_archive_private.h
+++ b/libziparchive/zip_archive_private.h
@@ -34,10 +34,14 @@
 class MappedZipFile {
  public:
   explicit MappedZipFile(const int fd)
-      : has_fd_(true), fd_(fd), base_ptr_(nullptr), data_length_(0) {}
+      : has_fd_(true), fd_(fd), fd_offset_(0), base_ptr_(nullptr), data_length_(-1) {}
+
+  explicit MappedZipFile(const int fd, off64_t length, off64_t offset)
+      : has_fd_(true), fd_(fd), fd_offset_(offset), base_ptr_(nullptr), data_length_(length) {}
 
   explicit MappedZipFile(const void* address, size_t length)
-      : has_fd_(false), fd_(-1), base_ptr_(address), data_length_(static_cast<off64_t>(length)) {}
+      : has_fd_(false), fd_(-1), fd_offset_(0), base_ptr_(address),
+        data_length_(static_cast<off64_t>(length)) {}
 
   bool HasFd() const { return has_fd_; }
 
@@ -45,6 +49,8 @@
 
   const void* GetBasePtr() const;
 
+  off64_t GetFileOffset() const;
+
   off64_t GetFileLength() const;
 
   bool ReadAtOffset(uint8_t* buf, size_t len, off64_t off) const;
@@ -57,9 +63,10 @@
   const bool has_fd_;
 
   const int fd_;
+  const off64_t fd_offset_;
 
   const void* const base_ptr_;
-  const off64_t data_length_;
+  mutable off64_t data_length_;
 };
 
 class CentralDirectory {
@@ -91,7 +98,7 @@
   uint16_t num_entries;
   std::unique_ptr<CdEntryMapInterface> cd_entry_map;
 
-  ZipArchive(const int fd, bool assume_ownership);
+  ZipArchive(MappedZipFile&& map, bool assume_ownership);
   ZipArchive(const void* address, size_t length);
   ~ZipArchive();
 
diff --git a/libziparchive/zip_archive_test.cc b/libziparchive/zip_archive_test.cc
index 523d4c5..5caca8a 100644
--- a/libziparchive/zip_archive_test.cc
+++ b/libziparchive/zip_archive_test.cc
@@ -181,6 +181,32 @@
   close(fd);
 }
 
+TEST(ziparchive, OpenAssumeFdRangeOwnership) {
+  int fd = open((test_data_dir + "/" + kValidZip).c_str(), O_RDONLY | O_BINARY);
+  ASSERT_NE(-1, fd);
+  const off64_t length = lseek64(fd, 0, SEEK_END);
+  ASSERT_NE(-1, length);
+  ZipArchiveHandle handle;
+  ASSERT_EQ(0, OpenArchiveFdRange(fd, "OpenWithAssumeFdOwnership", &handle,
+                                  static_cast<size_t>(length), 0));
+  CloseArchive(handle);
+  ASSERT_EQ(-1, lseek(fd, 0, SEEK_SET));
+  ASSERT_EQ(EBADF, errno);
+}
+
+TEST(ziparchive, OpenDoNotAssumeFdRangeOwnership) {
+  int fd = open((test_data_dir + "/" + kValidZip).c_str(), O_RDONLY | O_BINARY);
+  ASSERT_NE(-1, fd);
+  const off64_t length = lseek(fd, 0, SEEK_END);
+  ASSERT_NE(-1, length);
+  ZipArchiveHandle handle;
+  ASSERT_EQ(0, OpenArchiveFdRange(fd, "OpenWithAssumeFdOwnership", &handle,
+                                  static_cast<size_t>(length), 0, false));
+  CloseArchive(handle);
+  ASSERT_EQ(0, lseek(fd, 0, SEEK_SET));
+  close(fd);
+}
+
 TEST(ziparchive, Iteration_std_string_view) {
   ZipArchiveHandle handle;
   ASSERT_EQ(0, OpenArchiveWrapper(kValidZip, &handle));
@@ -327,6 +353,48 @@
   CloseArchive(handle);
 }
 
+TEST(ziparchive, OpenArchiveFdRange) {
+  TemporaryFile tmp_file;
+  ASSERT_NE(-1, tmp_file.fd);
+
+  const std::string leading_garbage(21, 'x');
+  ASSERT_TRUE(android::base::WriteFully(tmp_file.fd, leading_garbage.c_str(),
+                                        leading_garbage.size()));
+
+  std::string valid_content;
+  ASSERT_TRUE(android::base::ReadFileToString(test_data_dir + "/" + kValidZip, &valid_content));
+  ASSERT_TRUE(android::base::WriteFully(tmp_file.fd, valid_content.c_str(), valid_content.size()));
+
+  const std::string ending_garbage(42, 'x');
+  ASSERT_TRUE(android::base::WriteFully(tmp_file.fd, ending_garbage.c_str(),
+                                        ending_garbage.size()));
+
+  ZipArchiveHandle handle;
+  ASSERT_EQ(0, lseek(tmp_file.fd, 0, SEEK_SET));
+  ASSERT_EQ(0, OpenArchiveFdRange(tmp_file.fd, "OpenArchiveFdRange", &handle,
+                                  valid_content.size(),
+                                  static_cast<off64_t>(leading_garbage.size())));
+
+  // An entry that's deflated.
+  ZipEntry data;
+  ASSERT_EQ(0, FindEntry(handle, "a.txt", &data));
+  const uint32_t a_size = data.uncompressed_length;
+  ASSERT_EQ(a_size, kATxtContents.size());
+  auto buffer = std::unique_ptr<uint8_t[]>(new uint8_t[a_size]);
+  ASSERT_EQ(0, ExtractToMemory(handle, &data, buffer.get(), a_size));
+  ASSERT_EQ(0, memcmp(buffer.get(), kATxtContents.data(), a_size));
+
+  // An entry that's stored.
+  ASSERT_EQ(0, FindEntry(handle, "b.txt", &data));
+  const uint32_t b_size = data.uncompressed_length;
+  ASSERT_EQ(b_size, kBTxtContents.size());
+  buffer = std::unique_ptr<uint8_t[]>(new uint8_t[b_size]);
+  ASSERT_EQ(0, ExtractToMemory(handle, &data, buffer.get(), b_size));
+  ASSERT_EQ(0, memcmp(buffer.get(), kBTxtContents.data(), b_size));
+
+  CloseArchive(handle);
+}
+
 TEST(ziparchive, ExtractToMemory) {
   ZipArchiveHandle handle;
   ASSERT_EQ(0, OpenArchiveWrapper(kValidZip, &handle));