diff --git a/.ci/scripts/linux/docker.sh b/.ci/scripts/linux/docker.sh
index 090ca75f16..5559a527c3 100644
--- a/.ci/scripts/linux/docker.sh
+++ b/.ci/scripts/linux/docker.sh
@@ -11,5 +11,4 @@ ninja
 
 ccache -s
 
-# Ignore zlib's tests, since they aren't gated behind a CMake option.
-ctest -VV -E "(example|example64)" -C Release
+ctest -VV -C Release
diff --git a/.gitmodules b/.gitmodules
index ee0dc6c19d..63bf2cda04 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -47,8 +47,8 @@
     path = externals/sirit
     url = https://github.com/ReinUsesLisp/sirit
 [submodule "libzip"]
-    path = externals/libzip
-    url = https://github.com/DarkLordZach/libzip
+    path = externals/libzip/libzip
+    url = https://github.com/nih-at/libzip.git
 [submodule "zlib"]
-    path = externals/zlib
-    url = https://github.com/madler/zlib
+    path = externals/zlib/zlib
+    url = https://github.com/madler/zlib.git
diff --git a/externals/CMakeLists.txt b/externals/CMakeLists.txt
index ac7529edd1..61ad3487a8 100644
--- a/externals/CMakeLists.txt
+++ b/externals/CMakeLists.txt
@@ -76,6 +76,7 @@ endif()
 
 # zlib
 add_subdirectory(zlib EXCLUDE_FROM_ALL)
+set(ZLIB_LIBRARIES z)
 
 # libzip
 add_subdirectory(libzip EXCLUDE_FROM_ALL)
diff --git a/externals/libzip b/externals/libzip
deleted file mode 160000
index bd7a8103e9..0000000000
--- a/externals/libzip
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit bd7a8103e96bc6d50164447f6b7b57bb786d8e2a
diff --git a/externals/libzip/CMakeLists.txt b/externals/libzip/CMakeLists.txt
new file mode 100644
index 0000000000..ea5329fa01
--- /dev/null
+++ b/externals/libzip/CMakeLists.txt
@@ -0,0 +1,564 @@
+# TODO:
+# create usable libtool .la file
+
+CMAKE_MINIMUM_REQUIRED(VERSION 3.0.2)
+
+LIST(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/libzip")
+
+PROJECT(libzip C)
+
+OPTION(ENABLE_COMMONCRYPTO "Enable use of CommonCrypto" ON)
+OPTION(ENABLE_GNUTLS "Enable use of GnuTLS" ON)
+OPTION(ENABLE_MBEDTLS "Enable use of mbed TLS" ON)
+OPTION(ENABLE_OPENSSL "Enable use of OpenSSL" ON)
+OPTION(ENABLE_WINDOWS_CRYPTO "Enable use of Windows cryptography libraries" ON)
+
+OPTION(ENABLE_BZIP2 "Enable use of BZip2" OFF)
+OPTION(ENABLE_LZMA "Enable use of LZMA" OFF)
+
+INCLUDE(CheckFunctionExists)
+INCLUDE(CheckIncludeFiles)
+INCLUDE(CheckSymbolExists)
+INCLUDE(CheckTypeSize)
+INCLUDE(CheckCSourceRuns)
+INCLUDE(CheckCSourceCompiles)
+INCLUDE(CheckStructHasMember)
+INCLUDE(TestBigEndian)
+INCLUDE(GNUInstallDirs)
+IF(ENABLE_COMMONCRYPTO)
+  CHECK_INCLUDE_FILES(CommonCrypto/CommonCrypto.h COMMONCRYPTO_FOUND)
+ELSE()
+  SET(COMMONCRYPTO_FOUND FALSE)
+ENDIF()
+IF(ENABLE_GNUTLS)
+  INCLUDE(FindNettle)
+  INCLUDE(FindGnuTLS)
+ELSE()
+  SET(GNUTLS_FOUND FALSE)
+ENDIF()
+IF(ENABLE_MBEDTLS)
+  FIND_PATH(MBEDTLS_INCLUDE_DIR mbedtls/aes.h)
+  FIND_LIBRARY(MBEDTLS_LIBRARIES NAMES mbedcrypto)
+ELSE()
+  SET(MBEDTLS_LIBRARIES FALSE)
+ENDIF()
+IF(ENABLE_OPENSSL)
+  INCLUDE(FindOpenSSL)
+ELSE()
+  SET(OPENSSL_FOUND FALSE)
+ENDIF()
+IF(WIN32)
+  IF(ENABLE_WINDOWS_CRYPTO)
+    SET(WINDOWS_CRYPTO_FOUND TRUE)
+  ENDIF()
+ELSE()
+  SET(WINDOWS_CRYPTO_FOUND FALSE)
+ENDIF()
+
+OPTION(BUILD_SHARED_LIBS "Build shared libraries" ON)
+OPTION(SHARED_LIB_VERSIONNING "Add SO version in .so build" ON)
+
+SET(PACKAGE "libzip")
+SET(PACKAGE_NAME ${PACKAGE})
+SET(PACKAGE_VERSION_MAJOR "1")
+SET(PACKAGE_VERSION_MINOR "5")
+SET(PACKAGE_VERSION_MICRO "2a")
+#SET(VERSION "${PACKAGE_VERSION_MAJOR}.${PACKAGE_VERSION_MINOR}")
+SET(VERSION "${PACKAGE_VERSION_MAJOR}.${PACKAGE_VERSION_MINOR}.${PACKAGE_VERSION_MICRO}")
+SET(PACKAGE_VERSION ${VERSION})
+SET(LIBZIP_VERSION ${PACKAGE_VERSION})
+SET(LIBZIP_VERSION_MAJOR ${PACKAGE_VERSION_MAJOR})
+SET(LIBZIP_VERSION_MINOR ${PACKAGE_VERSION_MINOR})
+SET(LIBZIP_VERSION_MICRO ${PACKAGE_VERSION_MICRO})
+SET(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
+
+SET(ARCHIVE_NAME ${PACKAGE_NAME}-${PACKAGE_VERSION})
+IF(NOT TARGET dist)
+ADD_CUSTOM_TARGET(dist
+  COMMAND git config tar.tar.xz.command "xz -c"
+  COMMAND git archive --prefix=${ARCHIVE_NAME}/ -o ${ARCHIVE_NAME}.tar.gz HEAD
+  COMMAND git archive --prefix=${ARCHIVE_NAME}/ -o ${ARCHIVE_NAME}.tar.xz HEAD
+  WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
+  )
+ADD_CUSTOM_TARGET(distcheck
+  COMMAND chmod -R u+w ${ARCHIVE_NAME} ${ARCHIVE_NAME}-build ${ARCHIVE_NAME}-dest 2>/dev/null || true
+  COMMAND rm -rf ${ARCHIVE_NAME} ${ARCHIVE_NAME}-build ${ARCHIVE_NAME}-dest
+  COMMAND cmake -E tar xf ${ARCHIVE_NAME}.tar.gz
+  COMMAND chmod -R u-w ${ARCHIVE_NAME}
+  COMMAND mkdir ${ARCHIVE_NAME}-build
+  COMMAND mkdir ${ARCHIVE_NAME}-dest
+  COMMAND cd ${ARCHIVE_NAME}-build && cmake -DCMAKE_INSTALL_PREFIX=../${ARCHIVE_NAME}-dest ../${ARCHIVE_NAME}
+  COMMAND cd ${ARCHIVE_NAME}-build && make -j4
+  COMMAND cd ${ARCHIVE_NAME}-build && make test
+  COMMAND cd ${ARCHIVE_NAME}-build && make install
+#  COMMAND cd ${ARCHIVE_NAME}-build && make uninstall
+#  COMMAND if [ `find ${ARCHIVE_NAME}-dest ! -type d | wc -l` -ne 0 ]; then echo leftover files in ${ARCHIVE_NAME}-dest; false; fi
+  COMMAND cd ${ARCHIVE_NAME}-build && make clean
+  COMMAND chmod -R u+w ${ARCHIVE_NAME} ${ARCHIVE_NAME}-build ${ARCHIVE_NAME}-dest
+  COMMAND rm -rf ${ARCHIVE_NAME} ${ARCHIVE_NAME}-build ${ARCHIVE_NAME}-dest
+  COMMAND echo "${ARCHIVE_NAME}.tar.gz is ready for distribution."
+  WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
+  )
+ADD_DEPENDENCIES(distcheck dist)
+ENDIF(NOT TARGET dist)
+
+IF(BUILD_SHARED_LIBS)
+  SET(HAVE_SHARED TRUE)
+ELSE()
+  SET(ZIP_STATIC TRUE)
+ENDIF()
+
+# Checks
+
+CHECK_FUNCTION_EXISTS(_chmod HAVE__CHMOD)
+CHECK_FUNCTION_EXISTS(_close HAVE__CLOSE)
+CHECK_FUNCTION_EXISTS(_dup HAVE__DUP)
+CHECK_FUNCTION_EXISTS(_fdopen HAVE__FDOPEN)
+CHECK_FUNCTION_EXISTS(_fileno HAVE__FILENO)
+CHECK_FUNCTION_EXISTS(_open HAVE__OPEN)
+CHECK_FUNCTION_EXISTS(_setmode HAVE__SETMODE)
+CHECK_FUNCTION_EXISTS(_snprintf HAVE__SNPRINTF)
+CHECK_FUNCTION_EXISTS(_strdup HAVE__STRDUP)
+CHECK_FUNCTION_EXISTS(_stricmp HAVE__STRICMP)
+CHECK_FUNCTION_EXISTS(_strtoi64 HAVE__STRTOI64)
+CHECK_FUNCTION_EXISTS(_strtoui64 HAVE__STRTOUI64)
+CHECK_FUNCTION_EXISTS(_unlink HAVE__UNLINK)
+CHECK_FUNCTION_EXISTS(arc4random HAVE_ARC4RANDOM)
+CHECK_FUNCTION_EXISTS(clonefile HAVE_CLONEFILE)
+CHECK_FUNCTION_EXISTS(explicit_bzero HAVE_EXPLICIT_BZERO)
+CHECK_FUNCTION_EXISTS(explicit_memset HAVE_EXPLICIT_MEMSET)
+CHECK_FUNCTION_EXISTS(fileno HAVE_FILENO)
+CHECK_FUNCTION_EXISTS(fseeko HAVE_FSEEKO)
+CHECK_FUNCTION_EXISTS(ftello HAVE_FTELLO)
+CHECK_FUNCTION_EXISTS(getprogname HAVE_GETPROGNAME)
+CHECK_FUNCTION_EXISTS(localtime_r HAVE_LOCALTIME_R)
+CHECK_FUNCTION_EXISTS(open HAVE_OPEN)
+CHECK_FUNCTION_EXISTS(setmode HAVE_SETMODE)
+CHECK_FUNCTION_EXISTS(snprintf HAVE_SNPRINTF)
+CHECK_FUNCTION_EXISTS(strcasecmp HAVE_STRCASECMP)
+CHECK_FUNCTION_EXISTS(strdup HAVE_STRDUP)
+CHECK_FUNCTION_EXISTS(stricmp HAVE_STRICMP)
+CHECK_FUNCTION_EXISTS(strtoll HAVE_STRTOLL)
+CHECK_FUNCTION_EXISTS(strtoull HAVE_STRTOULL)
+
+CHECK_INCLUDE_FILES("sys/types.h;sys/stat.h;fts.h" HAVE_FTS_H)
+CHECK_INCLUDE_FILES(stdbool.h HAVE_STDBOOL_H)
+CHECK_INCLUDE_FILES(strings.h HAVE_STRINGS_H)
+CHECK_INCLUDE_FILES(unistd.h HAVE_UNISTD_H)
+
+CHECK_INCLUDE_FILES(inttypes.h HAVE_INTTYPES_H_LIBZIP)
+CHECK_INCLUDE_FILES(stdint.h HAVE_STDINT_H_LIBZIP)
+CHECK_INCLUDE_FILES(sys/types.h HAVE_SYS_TYPES_H_LIBZIP)
+
+# TODO: fix test
+# this test does not find __progname even when it exists
+#CHECK_SYMBOL_EXISTS(__progname stdlib.h HAVE___PROGNAME)
+
+CHECK_TYPE_SIZE(__int8 __INT8_LIBZIP)
+CHECK_TYPE_SIZE(int8_t INT8_T_LIBZIP)
+CHECK_TYPE_SIZE(uint8_t UINT8_T_LIBZIP)
+CHECK_TYPE_SIZE(__int16 __INT16_LIBZIP)
+CHECK_TYPE_SIZE(int16_t INT16_T_LIBZIP)
+CHECK_TYPE_SIZE(uint16_t UINT16_T_LIBZIP)
+CHECK_TYPE_SIZE(__int32 __INT32_LIBZIP)
+CHECK_TYPE_SIZE(int32_t INT32_T_LIBZIP)
+CHECK_TYPE_SIZE(uint32_t UINT32_T_LIBZIP)
+CHECK_TYPE_SIZE(__int64 __INT64_LIBZIP)
+CHECK_TYPE_SIZE(int64_t INT64_T_LIBZIP)
+CHECK_TYPE_SIZE(uint64_t UINT64_T_LIBZIP)
+CHECK_TYPE_SIZE("short" SHORT_LIBZIP)
+CHECK_TYPE_SIZE("int" INT_LIBZIP)
+CHECK_TYPE_SIZE("long" LONG_LIBZIP)
+CHECK_TYPE_SIZE("long long" LONG_LONG_LIBZIP)
+CHECK_TYPE_SIZE("off_t" SIZEOF_OFF_T)
+CHECK_TYPE_SIZE("size_t" SIZE_T_LIBZIP)
+CHECK_TYPE_SIZE("ssize_t" SSIZE_T_LIBZIP)
+
+CHECK_C_SOURCE_COMPILES("#include <sys/ioctl.h>
+#include <linux/fs.h>
+int main(int argc, char *argv[]) { unsigned long x = FICLONERANGE; }" HAVE_FICLONERANGE)
+
+CHECK_C_SOURCE_COMPILES("
+int foo(char * _Nullable bar);
+int main(int argc, char *argv[]) { }" HAVE_NULLABLE)
+
+TEST_BIG_ENDIAN(WORDS_BIGENDIAN)
+
+#FIND_PACKAGE(ZLIB 1.1.2 REQUIRED)
+INCLUDE_DIRECTORIES(../zlib/zlib)
+SET(CMAKE_REQUIRED_INCLUDES ../zlib/zlib)
+
+IF(ENABLE_BZIP2)
+  FIND_PACKAGE(BZip2)
+  IF(BZIP2_FOUND)
+    SET (HAVE_LIBBZ2 1)
+
+    INCLUDE_DIRECTORIES(${BZIP2_INCLUDE_DIR})
+    SET (OPTIONAL_LIBRARY ${OPTIONAL_LIBRARY} ${BZIP2_LIBRARIES})
+  ELSE()
+    MESSAGE(WARNING "-- bzip2 library not found; bzip2 support disabled")
+  ENDIF(BZIP2_FOUND)
+ENDIF(ENABLE_BZIP2)
+
+IF(ENABLE_LZMA)
+  FIND_PACKAGE(LibLZMA)
+  IF(LIBLZMA_FOUND)
+    SET (HAVE_LIBLZMA 1)
+
+    INCLUDE_DIRECTORIES(${LIBLZMA_INCLUDE_DIR})
+    SET (OPTIONAL_LIBRARY ${OPTIONAL_LIBRARY} ${LIBLZMA_LIBRARY})
+  ELSE()
+    MESSAGE(WARNING "-- lzma library not found; lzma support disabled")
+  ENDIF(LIBLZMA_FOUND)
+ENDIF(ENABLE_LZMA)
+
+
+IF (COMMONCRYPTO_FOUND)
+  SET (HAVE_CRYPTO 1)
+  SET (HAVE_COMMONCRYPTO 1)
+ELSEIF (WINDOWS_CRYPTO_FOUND)
+  SET (HAVE_CRYPTO 1)
+  SET (HAVE_WINDOWS_CRYPTO 1)
+ELSEIF (GNUTLS_FOUND AND NETTLE_FOUND)
+  SET (HAVE_CRYPTO 1)
+  SET (HAVE_GNUTLS 1)
+  INCLUDE_DIRECTORIES(${GNUTLS_INCLUDE_DIR} ${NETTLE_INCLUDE_DIR})
+  SET (OPTIONAL_LIBRARY ${OPTIONAL_LIBRARY} ${GNUTLS_LIBRARY} ${NETTLE_LIBRARY})
+ELSEIF (OPENSSL_FOUND)
+  SET (HAVE_CRYPTO 1)
+  SET (HAVE_OPENSSL 1)
+  INCLUDE_DIRECTORIES(${OPENSSL_INCLUDE_DIR})
+  SET (OPTIONAL_LIBRARY ${OPTIONAL_LIBRARY} ${OPENSSL_LIBRARIES})
+ELSEIF (MBEDTLS_LIBRARIES)
+  SET (HAVE_CRYPTO 1)
+  SET (HAVE_MBEDTLS 1)
+  INCLUDE_DIRECTORIES(${MBEDTLS_INCLUDE_DIR})
+  SET (OPTIONAL_LIBRARY ${OPTIONAL_LIBRARY} ${MBEDTLS_LIBRARIES})
+ENDIF()
+
+IF (NOT HAVE_CRYPTO)
+  MESSAGE(WARNING "-- neither Common Crypto, GnuTLS, mbed TLS, OpenSSL, nor Windows Cryptography found; AES support disabled")
+ENDIF()
+
+IF(MSVC)
+ADD_DEFINITIONS("-D_CRT_SECURE_NO_WARNINGS")
+ADD_DEFINITIONS("-D_CRT_NONSTDC_NO_DEPRECATE")
+ENDIF(MSVC)
+
+if(WIN32)
+  if(HAVE_WINDOWS_CRYPTO)
+    SET (OPTIONAL_LIBRARY ${OPTIONAL_LIBRARY} bcrypt)
+  endif()
+  if(CMAKE_SYSTEM_NAME MATCHES WindowsPhone OR CMAKE_SYSTEM_NAME MATCHES WindowsStore)
+    ADD_DEFINITIONS(-DMS_UWP)
+  else(CMAKE_SYSTEM_NAME MATCHES WindowsPhone OR CMAKE_SYSTEM_NAME MATCHES WindowsStore)
+    SET (OPTIONAL_LIBRARY ${OPTIONAL_LIBRARY} advapi32)
+  endif(CMAKE_SYSTEM_NAME MATCHES WindowsPhone OR CMAKE_SYSTEM_NAME MATCHES WindowsStore)
+endif(WIN32)
+
+ADD_DEFINITIONS("-DHAVE_CONFIG_H")
+
+# rpath handling: use rpath in installed binaries
+IF(NOT CMAKE_SYSTEM_NAME MATCHES Linux)
+	SET(CMAKE_INSTALL_RPATH "${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR}")
+	SET(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)
+ENDIF()
+
+# fixed size integral types
+
+IF(HAVE_INTTYPES_H_LIBZIP)
+  SET(LIBZIP_TYPES_INCLUDE "#define __STDC_FORMAT_MACROS 1
+#include <inttypes.h>")
+ELSEIF(HAVE_STDINT_H_LIBZIP)
+  SET(LIBZIP_TYPES_INCLUDE "#include <stdint.h>")
+ELSEIF(HAVE_SYS_TYPES_H_LIBZIP)
+  SET(LIBZIP_TYPES_INCLUDE "#include <sys/types.h>")
+ENDIF()
+
+IF(HAVE_INT8_T_LIBZIP)
+  SET(ZIP_INT8_T int8_t)
+ELSEIF(HAVE___INT8_LIBZIP)
+  SET(ZIP_INT8_T __int8)
+ELSE()
+  SET(ZIP_INT8_T "signed char")
+ENDIF()
+
+IF(HAVE_UINT8_T_LIBZIP)
+  SET(ZIP_UINT8_T uint8_t)
+ELSEIF(HAVE___INT8_LIBZIP)
+  SET(ZIP_UINT8_T "unsigned __int8")
+ELSE()
+  SET(ZIP_UINT8_T "unsigned char")
+ENDIF()
+
+IF(HAVE_INT16_T_LIBZIP)
+  SET(ZIP_INT16_T int16_t)
+ELSEIF(HAVE___INT16_LIBZIP)
+  SET(INT16_T_LIBZIP __int16)
+ELSEIF(SHORT_LIBZIP EQUAL 2)
+  SET(INT16_T_LIBZIP short)
+ENDIF()
+
+IF(HAVE_UINT16_T_LIBZIP)
+  SET(ZIP_UINT16_T uint16_t)
+ELSEIF(HAVE___INT16_LIBZIP)
+  SET(UINT16_T_LIBZIP "unsigned __int16")
+ELSEIF(SHORT_LIBZIP EQUAL 2)
+  SET(UINT16_T_LIBZIP "unsigned short")
+ENDIF()
+
+IF(HAVE_INT32_T_LIBZIP)
+  SET(ZIP_INT32_T int32_t)
+ELSEIF(HAVE___INT32_LIBZIP)
+  SET(ZIP_INT32_T __int32)
+ELSEIF(INT_LIBZIP EQUAL 4)
+  SET(ZIP_INT32_T int)
+ELSEIF(LONG_LIBZIP EQUAL 4)
+  SET(ZIP_INT32_T long)
+ENDIF()
+
+IF(HAVE_UINT32_T_LIBZIP)
+SET(ZIP_UINT32_T uint32_t)
+ELSEIF(HAVE___INT32_LIBZIP)
+SET(ZIP_UINT32_T "unsigned __int32")
+ELSEIF(INT_LIBZIP EQUAL 4)
+SET(ZIP_UINT32_T "unsigned int")
+ELSEIF(LONG_LIBZIP EQUAL 4)
+SET(ZIP_UINT32_T "unsigned long")
+ENDIF()
+
+IF(HAVE_INT64_T_LIBZIP)
+  SET(ZIP_INT64_T int64_t)
+ELSEIF(HAVE___INT64_LIBZIP)
+  SET(ZIP_INT64_T __int64)
+ELSEIF(LONG_LIBZIP EQUAL 8)
+  SET(ZIP_INT64_T long)
+ELSEIF(LONG_LONG_LIBZIP EQUAL 8)
+  SET(ZIP_INT64_T "long long")
+ENDIF()
+
+IF(HAVE_UINT64_T_LIBZIP)
+  SET(ZIP_UINT64_T uint64_t)
+ELSEIF(HAVE___INT64_LIBZIP)
+  SET(ZIP_UINT64_T "unsigned __int64")
+ELSEIF(LONG_LIBZIP EQUAL 8)
+  SET(ZIP_UINT64_T "unsigned long")
+ELSEIF(LONG_LONG_LIBZIP EQUAL 8)
+  SET(ZIP_UINT64_T "unsigned long long")
+ENDIF()
+
+IF(HAVE_NULLABLE)
+  SET(ZIP_NULLABLE_DEFINES)
+ELSE()
+  SET(ZIP_NULLABLE_DEFINES "#define _Nullable
+#define _Nonnull")
+ENDIF()
+
+# write out config file
+CONFIGURE_FILE(${CMAKE_CURRENT_SOURCE_DIR}/libzip/cmake-config.h.in ${CMAKE_CURRENT_BINARY_DIR}/libzip/config.h)
+CONFIGURE_FILE(${CMAKE_CURRENT_SOURCE_DIR}/libzip/cmake-zipconf.h.in ${CMAKE_CURRENT_BINARY_DIR}/libzip/zipconf.h)
+
+# installation
+INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/libzip/zipconf.h DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+INSTALL(FILES libzip/lib/zip.h DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+
+SET(CMAKE_C_VISIBILITY_PRESET hidden)
+
+ADD_LIBRARY(zip
+  libzip/lib/zip_add.c
+  libzip/lib/zip_add_dir.c
+  libzip/lib/zip_add_entry.c
+  libzip/lib/zip_algorithm_deflate.c
+  libzip/lib/zip_buffer.c
+  libzip/lib/zip_close.c
+  libzip/lib/zip_delete.c
+  libzip/lib/zip_dir_add.c
+  libzip/lib/zip_dirent.c
+  libzip/lib/zip_discard.c
+  libzip/lib/zip_entry.c
+  libzip/lib/zip_err_str.c
+  libzip/lib/zip_error.c
+  libzip/lib/zip_error_clear.c
+  libzip/lib/zip_error_get.c
+  libzip/lib/zip_error_get_sys_type.c
+  libzip/lib/zip_error_strerror.c
+  libzip/lib/zip_error_to_str.c
+  libzip/lib/zip_extra_field.c
+  libzip/lib/zip_extra_field_api.c
+  libzip/lib/zip_fclose.c
+  libzip/lib/zip_fdopen.c
+  libzip/lib/zip_file_add.c
+  libzip/lib/zip_file_error_clear.c
+  libzip/lib/zip_file_error_get.c
+  libzip/lib/zip_file_get_comment.c
+  libzip/lib/zip_file_get_external_attributes.c
+  libzip/lib/zip_file_get_offset.c
+  libzip/lib/zip_file_rename.c
+  libzip/lib/zip_file_replace.c
+  libzip/lib/zip_file_set_comment.c
+  libzip/lib/zip_file_set_encryption.c
+  libzip/lib/zip_file_set_external_attributes.c
+  libzip/lib/zip_file_set_mtime.c
+  libzip/lib/zip_file_strerror.c
+  libzip/lib/zip_filerange_crc.c
+  libzip/lib/zip_fopen.c
+  libzip/lib/zip_fopen_encrypted.c
+  libzip/lib/zip_fopen_index.c
+  libzip/lib/zip_fopen_index_encrypted.c
+  libzip/lib/zip_fread.c
+  libzip/lib/zip_fseek.c
+  libzip/lib/zip_ftell.c
+  libzip/lib/zip_get_archive_comment.c
+  libzip/lib/zip_get_archive_flag.c
+  libzip/lib/zip_get_encryption_implementation.c
+  libzip/lib/zip_get_file_comment.c
+  libzip/lib/zip_get_name.c
+  libzip/lib/zip_get_num_entries.c
+  libzip/lib/zip_get_num_files.c
+  libzip/lib/zip_hash.c
+  libzip/lib/zip_io_util.c
+  libzip/lib/zip_libzip_version.c
+  libzip/lib/zip_memdup.c
+  libzip/lib/zip_name_locate.c
+  libzip/lib/zip_new.c
+  libzip/lib/zip_open.c
+  libzip/lib/zip_progress.c
+  libzip/lib/zip_rename.c
+  libzip/lib/zip_replace.c
+  libzip/lib/zip_set_archive_comment.c
+  libzip/lib/zip_set_archive_flag.c
+  libzip/lib/zip_set_default_password.c
+  libzip/lib/zip_set_file_comment.c
+  libzip/lib/zip_set_file_compression.c
+  libzip/lib/zip_set_name.c
+  libzip/lib/zip_source_accept_empty.c
+  libzip/lib/zip_source_begin_write.c
+  libzip/lib/zip_source_begin_write_cloning.c
+  libzip/lib/zip_source_buffer.c
+  libzip/lib/zip_source_call.c
+  libzip/lib/zip_source_close.c
+  libzip/lib/zip_source_commit_write.c
+  libzip/lib/zip_source_compress.c
+  libzip/lib/zip_source_crc.c
+  libzip/lib/zip_source_error.c
+  libzip/lib/zip_source_filep.c
+  libzip/lib/zip_source_free.c
+  libzip/lib/zip_source_function.c
+  libzip/lib/zip_source_get_compression_flags.c
+  libzip/lib/zip_source_is_deleted.c
+  libzip/lib/zip_source_layered.c
+  libzip/lib/zip_source_open.c
+  libzip/lib/zip_source_pkware.c
+  libzip/lib/zip_source_read.c
+  libzip/lib/zip_source_remove.c
+  libzip/lib/zip_source_rollback_write.c
+  libzip/lib/zip_source_seek.c
+  libzip/lib/zip_source_seek_write.c
+  libzip/lib/zip_source_stat.c
+  libzip/lib/zip_source_supports.c
+  libzip/lib/zip_source_tell.c
+  libzip/lib/zip_source_tell_write.c
+  libzip/lib/zip_source_window.c
+  libzip/lib/zip_source_write.c
+  libzip/lib/zip_source_zip.c
+  libzip/lib/zip_source_zip_new.c
+  libzip/lib/zip_stat.c
+  libzip/lib/zip_stat_index.c
+  libzip/lib/zip_stat_init.c
+  libzip/lib/zip_strerror.c
+  libzip/lib/zip_string.c
+  libzip/lib/zip_unchange.c
+  libzip/lib/zip_unchange_all.c
+  libzip/lib/zip_unchange_archive.c
+  libzip/lib/zip_unchange_data.c
+  libzip/lib/zip_utf-8.c
+)
+
+IF(WIN32)
+  target_sources(zip PRIVATE
+    libzip/lib/zip_source_win32handle.c
+    libzip/lib/zip_source_win32utf8.c
+    libzip/lib/zip_source_win32w.c
+  )
+  IF(CMAKE_SYSTEM_NAME MATCHES WindowsPhone OR CMAKE_SYSTEM_NAME MATCHES WindowsStore)
+  ELSE()
+    target_sources(zip PRIVATE libzip/lib/zip_source_win32a.c)
+  ENDIF()
+ELSE()
+  target_sources(zip PRIVATE
+    libzip/lib/zip_mkstempm.c
+    libzip/lib/zip_source_file.c
+    libzip/lib/zip_random_unix.c
+  )
+ENDIF()
+
+IF(HAVE_LIBBZ2)
+  target_sources(zip PRIVATE libzip/lib/zip_algorithm_bzip2.c)
+ENDIF()
+
+IF(HAVE_LIBLZMA)
+  target_sources(zip PRIVATE libzip/lib/zip_algorithm_xz.c)
+ENDIF()
+
+IF(HAVE_COMMONCRYPTO)
+  target_sources(zip PRIVATE libzip/lib/zip_crypto_commoncrypto.c)
+ELSEIF(HAVE_WINDOWS_CRYPTO)
+  target_sources(zip PRIVATE libzip/lib/zip_crypto_win.c)
+ELSEIF(HAVE_GNUTLS)
+  target_sources(zip PRIVATE libzip/lib/zip_crypto_gnutls.c)
+ELSEIF(HAVE_OPENSSL)
+  target_sources(zip PRIVATE libzip/lib/zip_crypto_openssl.c)
+ELSEIF(HAVE_MBEDTLS)
+  target_sources(zip PRIVATE libzip/lib/zip_crypto_mbedtls.c)
+ENDIF()
+
+IF(HAVE_CRYPTO)
+  target_sources(zip PRIVATE
+    libzip/lib/zip_winzip_aes.c
+    libzip/lib/zip_source_winzip_aes_decode.c
+    libzip/lib/zip_source_winzip_aes_encode.c
+  )
+ENDIF()
+
+target_include_directories(zip
+PUBLIC
+  libzip/lib
+  ${CMAKE_CURRENT_BINARY_DIR}/libzip
+)
+
+# pkgconfig file
+SET(prefix ${CMAKE_INSTALL_PREFIX})
+SET(exec_prefix \${prefix})
+SET(bindir \${exec_prefix}/${CMAKE_INSTALL_BINDIR})
+SET(libdir \${exec_prefix}/${CMAKE_INSTALL_LIBDIR})
+SET(includedir \${prefix}/${CMAKE_INSTALL_INCLUDEDIR})
+IF(CMAKE_SYSTEM_NAME MATCHES BSD)
+  SET(PKG_CONFIG_RPATH "-Wl,-R\${libdir}")
+ENDIF(CMAKE_SYSTEM_NAME MATCHES BSD)
+get_target_property(LIBS_PRIVATE zip LINK_LIBRARIES)
+foreach(LIB ${LIBS_PRIVATE})
+  if(LIB MATCHES "^/")
+    get_filename_component(LIB ${LIB} NAME_WE)
+    string(REGEX REPLACE "^lib" "" LIB ${LIB})
+  endif()
+  set(LIBS "${LIBS} -l${LIB}")
+endforeach()
+CONFIGURE_FILE(libzip/libzip.pc.in libzip/libzip.pc @ONLY)
+INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/libzip.pc DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
+
+ADD_CUSTOM_TARGET(update_zip_err_str
+  COMMAND sh ${CMAKE_CURRENT_SOURCE_DIR}/libzip/lib/make_zip_err_str.sh ${CMAKE_CURRENT_SOURCE_DIR}/libzip/lib/zip.h ${CMAKE_CURRENT_SOURCE_DIR}/libzip/lib/zip_err_str.c
+  DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/libzip/lib/zip.h ${CMAKE_CURRENT_SOURCE_DIR}/libzip/lib/make_zip_err_str.sh
+)
+
+IF(SHARED_LIB_VERSIONNING)
+SET_TARGET_PROPERTIES(zip PROPERTIES VERSION 5.0 SOVERSION 5)
+ENDIF()
+
+TARGET_LINK_LIBRARIES(zip ${ZLIB_LIBRARIES} ${OPTIONAL_LIBRARY})
+INSTALL(TARGETS zip
+  RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+  ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+  LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+)
+
diff --git a/externals/libzip/libzip b/externals/libzip/libzip
new file mode 160000
index 0000000000..89bd6d63bd
--- /dev/null
+++ b/externals/libzip/libzip
@@ -0,0 +1 @@
+Subproject commit 89bd6d63bdea9da7627695f6c82e54f16d368b51
diff --git a/externals/zlib/CMakeLists.txt b/externals/zlib/CMakeLists.txt
new file mode 100644
index 0000000000..0ca32aae46
--- /dev/null
+++ b/externals/zlib/CMakeLists.txt
@@ -0,0 +1,81 @@
+project(zlib C)
+
+include(CheckTypeSize)
+include(CheckFunctionExists)
+include(CheckIncludeFile)
+
+check_include_file(sys/types.h HAVE_SYS_TYPES_H)
+check_include_file(stdint.h    HAVE_STDINT_H)
+check_include_file(stddef.h    HAVE_STDDEF_H)
+
+# Check to see if we have large file support
+set(CMAKE_REQUIRED_DEFINITIONS -D_LARGEFILE64_SOURCE=1)
+# We add these other definitions here because CheckTypeSize.cmake
+# in CMake 2.4.x does not automatically do so and we want
+# compatibility with CMake 2.4.x.
+if(HAVE_SYS_TYPES_H)
+    list(APPEND CMAKE_REQUIRED_DEFINITIONS -DHAVE_SYS_TYPES_H)
+endif()
+if(HAVE_STDINT_H)
+    list(APPEND CMAKE_REQUIRED_DEFINITIONS -DHAVE_STDINT_H)
+endif()
+if(HAVE_STDDEF_H)
+    list(APPEND CMAKE_REQUIRED_DEFINITIONS -DHAVE_STDDEF_H)
+endif()
+check_type_size(off64_t OFF64_T)
+if(HAVE_OFF64_T)
+   add_definitions(-D_LARGEFILE64_SOURCE=1)
+endif()
+set(CMAKE_REQUIRED_DEFINITIONS) # clear variable
+
+# Check for fseeko
+check_function_exists(fseeko HAVE_FSEEKO)
+if(NOT HAVE_FSEEKO)
+    add_definitions(-DNO_FSEEKO)
+endif()
+
+# Check for unistd.h
+check_include_file(unistd.h HAVE_UNISTD_H)
+if(HAVE_UNISTD_H)
+    add_definitions(-DHAVE_UNISTD_H)
+endif()
+
+if(MSVC)
+    add_definitions(-D_CRT_SECURE_NO_DEPRECATE)
+    add_definitions(-D_CRT_NONSTDC_NO_DEPRECATE)
+endif()
+
+add_library(z STATIC
+    zlib/adler32.c
+    zlib/compress.c
+    zlib/crc32.c
+    zlib/crc32.h
+    zlib/deflate.c
+    zlib/deflate.h
+    zlib/gzclose.c
+    zlib/gzguts.h
+    zlib/gzlib.c
+    zlib/gzread.c
+    zlib/gzwrite.c
+    zlib/inffast.h
+    zlib/inffixed.h
+    zlib/inflate.c
+    zlib/inflate.h
+    zlib/infback.c
+    zlib/inftrees.c
+    zlib/inftrees.h
+    zlib/inffast.c
+    zlib/trees.c
+    zlib/trees.h
+    zlib/uncompr.c
+    zlib/zconf.h
+    zlib/zlib.h
+    zlib/zutil.c
+    zlib/zutil.h
+)
+add_library(ZLIB::ZLIB ALIAS z)
+
+target_include_directories(z
+PUBLIC
+    zlib/
+)
diff --git a/externals/zlib b/externals/zlib/zlib
similarity index 100%
rename from externals/zlib
rename to externals/zlib/zlib