remove libressl support

currently it does not have what we need, so we can simplify our code.

setup.py

@@ -49,7 +49,6 @@ cflags = [
 
 compress_source = 'src/borg/compress.pyx'
 crypto_ll_source = 'src/borg/crypto/low_level.pyx'
-crypto_helpers = 'src/borg/crypto/_crypto_helpers.c'
 chunker_source = 'src/borg/chunker.pyx'
 hashindex_source = 'src/borg/hashindex.pyx'
 item_source = 'src/borg/item.pyx'
@@ -171,7 +170,7 @@ if not on_rtd:
             pc, 'BORG_OPENSSL_PREFIX', 'crypto', 'libcrypto', '>=1.1.1')
 
     crypto_ext_kwargs = members_appended(
-        dict(sources=[crypto_ll_source, crypto_helpers]),
+        dict(sources=[crypto_ll_source]),
         crypto_ext_lib,
         dict(extra_compile_args=cflags),
         dict(extra_link_args=crypto_ldflags),

src/borg/archiver.py

@@ -602,7 +602,6 @@ class Archiver:
 
         from borg.crypto.low_level import AES256_CTR_BLAKE2b, AES256_CTR_HMAC_SHA256
         from borg.crypto.low_level import AES256_OCB, CHACHA20_POLY1305
-        from borg.crypto.low_level import is_libressl
         print("Encryption =====================================================")
         size = "1GB"
 
@@ -611,14 +610,11 @@ class Archiver:
                 key_256, key_256, iv=key_128, header_len=1, aad_offset=1).encrypt(random_10M, header=b'X')),
             ("aes-256-ctr-blake2b", lambda: AES256_CTR_BLAKE2b(
                 key_256*4, key_256, iv=key_128, header_len=1, aad_offset=1).encrypt(random_10M, header=b'X')),
+            ("aes-256-ocb", lambda: AES256_OCB(
+                key_256, iv=key_96, header_len=1, aad_offset=1).encrypt(random_10M, header=b'X')),
+            ("chacha20-poly1305", lambda: CHACHA20_POLY1305(
+                key_256, iv=key_96, header_len=1, aad_offset=1).encrypt(random_10M, header=b'X')),
         ]
-        if not is_libressl:
-            tests.extend([
-                ("aes-256-ocb", lambda: AES256_OCB(
-                    key_256, iv=key_96, header_len=1, aad_offset=1).encrypt(random_10M, header=b'X')),
-                ("chacha20-poly1305", lambda: CHACHA20_POLY1305(
-                    key_256, iv=key_96, header_len=1, aad_offset=1).encrypt(random_10M, header=b'X')),
-            ])
         for spec, func in tests:
             print(f"{spec:<24} {size:<10} {timeit(func, number=100):.3f}s")
 

src/borg/crypto/_crypto_helpers.c

@@ -1,14 +0,0 @@
-/* some helpers, so our code also works with LibreSSL */
-
-#include <openssl/opensslv.h>
-#include <openssl/evp.h>
-
-#if defined(LIBRESSL_VERSION_NUMBER)
-const EVP_CIPHER *EVP_aes_256_ocb(void){  /* dummy, so that code compiles */
-    return NULL;
-}
-
-const EVP_CIPHER *EVP_chacha20_poly1305(void){  /* dummy, so that code compiles */
-    return NULL;
-}
-#endif

src/borg/crypto/_crypto_helpers.h

@@ -1,13 +0,0 @@
-/* some helpers, so our code also works with LibreSSL */
-
-#include <openssl/opensslv.h>
-#include <openssl/evp.h>
-
-#if defined(LIBRESSL_VERSION_NUMBER)
-const EVP_CIPHER *EVP_aes_256_ocb(void);  /* dummy, so that code compiles */
-const EVP_CIPHER *EVP_chacha20_poly1305(void);  /* dummy, so that code compiles */
-#endif
-
-#if !defined(LIBRESSL_VERSION_NUMBER)
-#define LIBRESSL_VERSION_NUMBER 0
-#endif

src/borg/crypto/low_level.pyx

@@ -47,6 +47,8 @@ API_VERSION = '1.3_01'
 cdef extern from "openssl/crypto.h":
     int CRYPTO_memcmp(const void *a, const void *b, size_t len)
 
+cdef extern from "openssl/opensslv.h":
+    long OPENSSL_VERSION_NUMBER
 
 cdef extern from "openssl/evp.h":
     ctypedef struct EVP_MD:
@@ -92,16 +94,6 @@ cdef extern from "openssl/hmac.h":
                     const unsigned char *data, int data_len,
                     unsigned char *md, unsigned int *md_len) nogil
 
-cdef extern from "_crypto_helpers.h":
-    long OPENSSL_VERSION_NUMBER
-    long LIBRESSL_VERSION_NUMBER
-
-    const EVP_CIPHER *EVP_aes_256_ocb()  # dummy
-    const EVP_CIPHER *EVP_chacha20_poly1305()  # dummy
-
-
-is_libressl = bool(LIBRESSL_VERSION_NUMBER)
-
 
 import struct
 
@@ -600,8 +592,7 @@ cdef class _AEAD_BASE:
 cdef class AES256_OCB(_AEAD_BASE):
     @classmethod
     def requirements_check(cls):
-        if is_libressl:
-            raise ValueError('AES OCB is not implemented by LibreSSL (yet?).')
+        pass
 
     def __init__(self, key, iv=None, header_len=0, aad_offset=0):
         self.requirements_check()
@@ -613,8 +604,7 @@ cdef class AES256_OCB(_AEAD_BASE):
 cdef class CHACHA20_POLY1305(_AEAD_BASE):
     @classmethod
     def requirements_check(cls):
-        if is_libressl:
-            raise ValueError('CHACHA20-POLY1305 is not implemented by LibreSSL (yet?).')
+        pass
 
     def __init__(self, key, iv=None, header_len=0, aad_offset=0):
         self.requirements_check()

src/borg/testsuite/crypto.py

@@ -3,8 +3,7 @@ from unittest.mock import MagicMock
 import unittest
 
 
-from ..crypto.low_level import AES256_CTR_HMAC_SHA256, AES256_OCB, CHACHA20_POLY1305, UNENCRYPTED, \
-                               IntegrityError, is_libressl
+from ..crypto.low_level import AES256_CTR_HMAC_SHA256, AES256_OCB, CHACHA20_POLY1305, UNENCRYPTED, IntegrityError
 from ..crypto.low_level import bytes_to_long, bytes_to_int, long_to_bytes
 from ..crypto.low_level import hkdf_hmac_sha512
 from ..crypto.low_level import AES, hmac_sha256
@@ -103,16 +102,13 @@ class CryptoTestCase(BaseTestCase):
         header = b'\x23' + iv_int.to_bytes(12, 'big')
         tests = [
             # (ciphersuite class, exp_mac, exp_cdata)
+            (AES256_OCB,
+             b'b6909c23c9aaebd9abbe1ff42097652d',
+             b'877ce46d2f62dee54699cebc3ba41d9ab613f7c486778c1b3636664b1493', ),
+            (CHACHA20_POLY1305,
+             b'fd08594796e0706cde1e8b461e3e0555',
+             b'a093e4b0387526f085d3c40cca84a35230a5c0dd766453b77ba38bcff775', )
         ]
-        if not is_libressl:
-            tests += [
-                (AES256_OCB,
-                 b'b6909c23c9aaebd9abbe1ff42097652d',
-                 b'877ce46d2f62dee54699cebc3ba41d9ab613f7c486778c1b3636664b1493', ),
-                (CHACHA20_POLY1305,
-                 b'fd08594796e0706cde1e8b461e3e0555',
-                 b'a093e4b0387526f085d3c40cca84a35230a5c0dd766453b77ba38bcff775', )
-            ]
         for cs_cls, exp_mac, exp_cdata in tests:
             # print(repr(cs_cls))
             # encrypt/mac
@@ -146,16 +142,13 @@ class CryptoTestCase(BaseTestCase):
         header = b'\x12\x34\x56' + iv_int.to_bytes(12, 'big')
         tests = [
             # (ciphersuite class, exp_mac, exp_cdata)
+            (AES256_OCB,
+             b'f2748c412af1c7ead81863a18c2c1893',
+             b'877ce46d2f62dee54699cebc3ba41d9ab613f7c486778c1b3636664b1493', ),
+            (CHACHA20_POLY1305,
+             b'b7e7c9a79f2404e14f9aad156bf091dd',
+             b'a093e4b0387526f085d3c40cca84a35230a5c0dd766453b77ba38bcff775', )
         ]
-        if not is_libressl:
-            tests += [
-                (AES256_OCB,
-                 b'f2748c412af1c7ead81863a18c2c1893',
-                 b'877ce46d2f62dee54699cebc3ba41d9ab613f7c486778c1b3636664b1493', ),
-                (CHACHA20_POLY1305,
-                 b'b7e7c9a79f2404e14f9aad156bf091dd',
-                 b'a093e4b0387526f085d3c40cca84a35230a5c0dd766453b77ba38bcff775', )
-            ]
         for cs_cls, exp_mac, exp_cdata in tests:
             # print(repr(cs_cls))
             # encrypt/mac
@@ -187,9 +180,7 @@ class CryptoTestCase(BaseTestCase):
         iv_int = 0
         data = b'foo' * 10
         header = b'\x12\x34'
-        tests = []
-        if not is_libressl:
-            tests += [AES256_OCB, CHACHA20_POLY1305]
+        tests = [AES256_OCB, CHACHA20_POLY1305]
         for cs_cls in tests:
             # encrypt/mac
             cs = cs_cls(key, iv_int, header_len=len(header), aad_offset=0)