diff --git a/src/borg/crypto/low_level.pyx b/src/borg/crypto/low_level.pyx
index c5b8c7c3f..aa28aa143 100644
--- a/src/borg/crypto/low_level.pyx
+++ b/src/borg/crypto/low_level.pyx
@@ -63,6 +63,8 @@ cdef extern from "openssl/evp.h":
     const EVP_CIPHER *EVP_aes_256_ocb()
     const EVP_CIPHER *EVP_chacha20_poly1305()
 
+    EVP_CIPHER_CTX *EVP_CIPHER_CTX_new()
+    void EVP_CIPHER_CTX_free(EVP_CIPHER_CTX *a)
     void EVP_CIPHER_CTX_init(EVP_CIPHER_CTX *a)
     void EVP_CIPHER_CTX_cleanup(EVP_CIPHER_CTX *a)
 
@@ -82,17 +84,6 @@ cdef extern from "openssl/evp.h":
     int EVP_CTRL_AEAD_SET_TAG
     int EVP_CTRL_AEAD_SET_IVLEN
 
-    const EVP_MD *EVP_sha256() nogil
-
-    EVP_CIPHER_CTX *EVP_CIPHER_CTX_new()
-    void EVP_CIPHER_CTX_free(EVP_CIPHER_CTX *a)
-
-cdef extern from "openssl/hmac.h":
-    unsigned char *HMAC(const EVP_MD *evp_md,
-                    const void *key, int key_len,
-                    const unsigned char *data, int data_len,
-                    unsigned char *md, unsigned int *md_len) nogil
-
 
 import struct
 
@@ -175,7 +166,7 @@ class UNENCRYPTED:
 
 
 cdef class AES256_CTR_BASE:
-    # Layout: HEADER + MAC 32 + IV 8 + CT (same as attic / borg < 1.3 IF HEADER = TYPE_BYTE, no AAD)
+    # Layout: HEADER + MAC 32 + IV 8 + CT (same as attic / borg < 2.0 IF HEADER = TYPE_BYTE, no AAD)
 
     cdef EVP_CIPHER_CTX *ctx
     cdef unsigned char enc_key[32]
@@ -407,7 +398,7 @@ ctypedef const EVP_CIPHER * (* CIPHER)()
 
 
 cdef class _AEAD_BASE:
-    # new crypto used in borg >= 1.3
+    # new crypto used in borg >= 2.0
     # Layout: HEADER + MAC 16 + CT
 
     cdef CIPHER cipher