From 5ae0e79b6239c3bdb024707a2c9ab35d8dfa329d Mon Sep 17 00:00:00 2001
From: wbond <will@wbond.net>
Date: Wed, 9 Mar 2022 12:56:44 +0000
Subject: [PATCH] Enable legacy provider with OpenSSL 3 so older algos are
 supported

---
 oscrypto/_openssl/_libcrypto_ctypes.py | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/oscrypto/_openssl/_libcrypto_ctypes.py b/oscrypto/_openssl/_libcrypto_ctypes.py
index f783663..79f1af8 100644
--- a/oscrypto/_openssl/_libcrypto_ctypes.py
+++ b/oscrypto/_openssl/_libcrypto_ctypes.py
@@ -73,6 +73,8 @@
 P_EVP_MD = c_void_p
 
 P_ENGINE = c_void_p
+OSSL_PROVIDER = c_void_p
+OSSL_LIB_CTX = c_void_p
 
 P_EVP_PKEY = c_void_p
 EVP_PKEY_CTX = c_void_p
@@ -97,6 +99,12 @@
         libcrypto.ERR_free_strings.argtypes = []
         libcrypto.ERR_free_strings.restype = None
 
+    if version_info >= (3, 0):
+        libcrypto.OSSL_PROVIDER_load.argtypes = [OSSL_LIB_CTX, c_char_p]
+        libcrypto.OSSL_PROVIDER_load.restype = POINTER(OSSL_PROVIDER)
+
+        libcrypto.OSSL_PROVIDER_load(None, "legacy".encode("ascii"))
+
     libcrypto.ERR_get_error.argtypes = []
     libcrypto.ERR_get_error.restype = c_ulong
 
@@ -301,10 +309,17 @@
     libcrypto.EVP_sha512.argtypes = []
     libcrypto.EVP_sha512.restype = P_EVP_MD
 
-    libcrypto.EVP_PKEY_size.argtypes = [
-        P_EVP_PKEY
-    ]
-    libcrypto.EVP_PKEY_size.restype = c_int
+    if version_info < (3, 0):
+        libcrypto.EVP_PKEY_size.argtypes = [
+            P_EVP_PKEY
+        ]
+        libcrypto.EVP_PKEY_size.restype = c_int
+    else:
+        libcrypto.EVP_PKEY_get_size.argtypes = [
+            P_EVP_PKEY
+        ]
+        libcrypto.EVP_PKEY_get_size.restype = c_int
+        libcrypto.EVP_PKEY_size = libcrypto.EVP_PKEY_get_size
 
     libcrypto.EVP_PKEY_get1_RSA.argtypes = [
         P_EVP_PKEY