digest_auth: fix Makefile detection of SHA256 and SHA512t256

(cherry picked from commit 3c11d3c)
(cherry picked from commit d92607f)
(cherry picked from commit d1c8a47)
(cherry picked from commit 8fccc49)

lib/digest_auth/Makefile

@@ -6,12 +6,12 @@ LIBS=
 
 CPP_CMD?=cpp
 
-SHA_256_SUPPORT:= $(shell printf '\#define SHA256_Init(x) \
-	_TEST_P_A_S_S_E_D_()\n\#include <openssl/sha.h>\n' \
+SHA_256_SUPPORT:= $(shell bash -c "echo -e '\x23define SHA256_Init(x) \
+	_TEST_P_A_S_S_E_D_()\n\x23include <openssl/sha.h>\n'" \
 	| $(CPP_CMD) $(DEFS) 2>/dev/null | grep -q _TEST_P_A_S_S_E_D_ && echo yes)
 
-SHA_512_256_SUPPORT:= $(shell printf '\#define EVP_sha512_256(x) \
-	_TEST_P_A_S_S_E_D_()\n\#include <openssl/evp.h>\n' \
+SHA_512_256_SUPPORT:= $(shell bash -c "echo -e '\x23define EVP_sha512_256(x) \
+       _TEST_P_A_S_S_E_D_()\n\x23include <openssl/evp.h>\n'" \
 	| $(CPP_CMD) $(DEFS) 2>/dev/null | grep -q _TEST_P_A_S_S_E_D_ && echo yes)
 
 ifeq ($(SHA_256_SUPPORT),yes)