Merge pull request #3451 from ThomasWaldmann/blake2-ext-building

crypto.low_level ext building (blake2 part)

setup.py

@@ -14,6 +14,7 @@ import textwrap
 
 import setup_lz4
 import setup_zstd
+import setup_b2
 
 # True: use the shared liblz4 (>= 1.7.0 / r129) from the system, False: use the bundled lz4 code
 prefer_system_liblz4 = True
@@ -21,6 +22,9 @@ prefer_system_liblz4 = True
 # True: use the shared libzstd (>= 1.3.0) from the system, False: use the bundled zstd code
 prefer_system_libzstd = True
 
+# True: use the shared libb2 from the system, False: use the bundled blake2 code
+prefer_system_libb2 = True
+
 min_python = (3, 5)
 my_python = sys.version_info
 
@@ -150,19 +154,9 @@ def detect_openssl(prefixes):
                     return prefix
 
 
-def detect_libb2(prefixes):
-    for prefix in prefixes:
-        filename = os.path.join(prefix, 'include', 'blake2.h')
-        if os.path.exists(filename):
-            with open(filename, 'r') as fd:
-                if 'blake2b_init' in fd.read():
-                    return prefix
-
-
 include_dirs = []
 library_dirs = []
 define_macros = []
-crypto_libraries = ['crypto']
 
 possible_openssl_prefixes = ['/usr', '/usr/local', '/usr/local/opt/openssl', '/usr/local/ssl', '/usr/local/openssl',
                              '/usr/local/borg', '/opt/local', '/opt/pkg', ]
@@ -191,13 +185,13 @@ possible_libb2_prefixes = ['/usr', '/usr/local', '/usr/local/opt/libb2', '/usr/l
                            '/usr/local/borg', '/opt/local', '/opt/pkg', ]
 if os.environ.get('BORG_LIBB2_PREFIX'):
     possible_libb2_prefixes.insert(0, os.environ.get('BORG_LIBB2_PREFIX'))
-libb2_prefix = detect_libb2(possible_libb2_prefixes)
-if libb2_prefix:
+libb2_prefix = setup_b2.b2_system_prefix(possible_libb2_prefixes)
+if prefer_system_libb2 and libb2_prefix:
     print('Detected and preferring libb2 over bundled BLAKE2')
-    include_dirs.append(os.path.join(libb2_prefix, 'include'))
-    library_dirs.append(os.path.join(libb2_prefix, 'lib'))
-    crypto_libraries.append('b2')
     define_macros.append(('BORG_USE_LIBB2', 'YES'))
+    libb2_system = True
+else:
+    libb2_system = False
 
 possible_libzstd_prefixes = ['/usr', '/usr/local', '/usr/local/opt/libzstd', '/usr/local/libzstd',
                              '/usr/local/borg', '/opt/local', '/opt/pkg', ]
@@ -778,10 +772,14 @@ if not on_rtd:
     compress_ext_kwargs = setup_zstd.zstd_ext_kwargs(bundled_path='src/borg/algorithms/zstd',
                                                      system_prefix=libzstd_prefix, system=libzstd_system,
                                                      multithreaded=False, legacy=False, **compress_ext_kwargs)
+    crypto_ext_kwargs = dict(sources=[crypto_ll_source, crypto_helpers], libraries=['crypto'],
+                             include_dirs=include_dirs, library_dirs=library_dirs, define_macros=define_macros)
+    crypto_ext_kwargs = setup_b2.b2_ext_kwargs(bundled_path='src/borg/algorithms/blake2',
+                                               system_prefix=libb2_prefix, system=libb2_system,
+                                               **crypto_ext_kwargs)
     ext_modules += [
         Extension('borg.compress', **compress_ext_kwargs),
-        Extension('borg.crypto.low_level', [crypto_ll_source, crypto_helpers], libraries=crypto_libraries,
-                  include_dirs=include_dirs, library_dirs=library_dirs, define_macros=define_macros),
+        Extension('borg.crypto.low_level', **crypto_ext_kwargs),
         Extension('borg.hashindex', [hashindex_source]),
         Extension('borg.item', [item_source]),
         Extension('borg.chunker', [chunker_source]),

setup_b2.py

@@ -0,0 +1,72 @@
+# Support code for building a C extension with blake2 files
+#
+# Copyright (c) 2016-present, Gregory Szorc (original code for zstd)
+#               2017-present, Thomas Waldmann (mods to make it more generic, code for blake2)
+# All rights reserved.
+#
+# This software may be modified and distributed under the terms
+# of the BSD license. See the LICENSE file for details.
+
+import os
+
+# b2 files, structure as seen in BLAKE2 (reference implementation) project repository:
+
+b2_sources = [
+    'ref/blake2b-ref.c',
+]
+
+b2_includes = [
+    'ref',
+]
+
+
+def b2_system_prefix(prefixes):
+    for prefix in prefixes:
+        filename = os.path.join(prefix, 'include', 'blake2.h')
+        if os.path.exists(filename):
+            with open(filename, 'r') as fd:
+                if 'blake2b_init' in fd.read():
+                    return prefix
+
+
+def b2_ext_kwargs(bundled_path, system_prefix=None, system=False, **kwargs):
+    """amend kwargs with b2 stuff for a distutils.extension.Extension initialization.
+
+    bundled_path: relative (to this file) path to the bundled library source code files
+    system_prefix: where the system-installed library can be found
+    system: True: use the system-installed shared library, False: use the bundled library code
+    kwargs: distutils.extension.Extension kwargs that should be amended
+    returns: amended kwargs
+    """
+    def multi_join(paths, *path_segments):
+        """apply os.path.join on a list of paths"""
+        return [os.path.join(*(path_segments + (path, ))) for path in paths]
+
+    use_system = system and system_prefix is not None
+
+    sources = kwargs.get('sources', [])
+    if not use_system:
+        sources += multi_join(b2_sources, bundled_path)
+
+    include_dirs = kwargs.get('include_dirs', [])
+    if use_system:
+        include_dirs += multi_join(['include'], system_prefix)
+    else:
+        include_dirs += multi_join(b2_includes, bundled_path)
+
+    library_dirs = kwargs.get('library_dirs', [])
+    if use_system:
+        library_dirs += multi_join(['lib'], system_prefix)
+
+    libraries = kwargs.get('libraries', [])
+    if use_system:
+        libraries += ['b2', ]
+
+    extra_compile_args = kwargs.get('extra_compile_args', [])
+    if not use_system:
+        extra_compile_args += []  # not used yet
+
+    ret = dict(**kwargs)
+    ret.update(dict(sources=sources, extra_compile_args=extra_compile_args,
+                    include_dirs=include_dirs, library_dirs=library_dirs, libraries=libraries))
+    return ret

src/borg/algorithms/blake2-libselect.h

@@ -1,5 +1,5 @@
 #ifdef BORG_USE_LIBB2
 #include <blake2.h>
 #else
-#include "blake2/blake2b-ref.c"
+#include "blake2/ref/blake2.h"
 #endif

src/borg/algorithms/blake2/blake2-impl.h → src/borg/algorithms/blake2/ref/blake2-impl.h

@@ -1,14 +1,14 @@
 /*
    BLAKE2 reference source code package - reference C implementations
-  
+
    Copyright 2012, Samuel Neves <sneves@dei.uc.pt>.  You may use this under the
    terms of the CC0, the OpenSSL Licence, or the Apache Public License 2.0, at
    your option.  The terms of these licenses can be found at:
-  
+
    - CC0 1.0 Universal : http://creativecommons.org/publicdomain/zero/1.0
    - OpenSSL license   : https://www.openssl.org/source/license.html
    - Apache 2.0        : http://www.apache.org/licenses/LICENSE-2.0
-  
+
    More information about the BLAKE2 hash function can be found at
    https://blake2.net.
 */
@@ -158,4 +158,3 @@ static BLAKE2_INLINE void secure_zero_memory(void *v, size_t n)
 }
 
 #endif
-

src/borg/algorithms/blake2/blake2.h → src/borg/algorithms/blake2/ref/blake2.h

@@ -193,4 +193,3 @@ extern "C" {
 #endif
 
 #endif
-

src/borg/algorithms/blake2/blake2b-ref.c → src/borg/algorithms/blake2/ref/blake2b-ref.c

@@ -1,14 +1,14 @@
 /*
    BLAKE2 reference source code package - reference C implementations
-  
+
    Copyright 2012, Samuel Neves <sneves@dei.uc.pt>.  You may use this under the
    terms of the CC0, the OpenSSL Licence, or the Apache Public License 2.0, at
    your option.  The terms of these licenses can be found at:
-  
+
    - CC0 1.0 Universal : http://creativecommons.org/publicdomain/zero/1.0
    - OpenSSL license   : https://www.openssl.org/source/license.html
    - Apache 2.0        : http://www.apache.org/licenses/LICENSE-2.0
-  
+
    More information about the BLAKE2 hash function can be found at
    https://blake2.net.
 */
@@ -377,4 +377,3 @@ fail:
   return -1;
 }
 #endif
-