mtmd: use sha256 for input hashing (#27274)

* mtmd: use sha256 for input hashing

* void conflict with boringssl

vendor/hash/sha1/sha1.c

@@ -25,6 +25,8 @@ A million repetitions of "a"
 
 #include "sha1.h"
 
+namespace vendor_hash {
+
 
 #define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))
 
@@ -293,3 +295,5 @@ void SHA1(
     SHA1Final((unsigned char *)hash_out, &ctx);
 }
 
+} // namespace vendor_hash
+

vendor/hash/sha1/sha1.h

@@ -9,9 +9,7 @@
 
 #include "stdint.h"
 
-#if defined(__cplusplus)
-extern "C" {
-#endif
+namespace vendor_hash {
 
 typedef struct
 {
@@ -45,8 +43,6 @@ void SHA1(
     const char *str,
     uint32_t len);
 
-#if defined(__cplusplus)
-}
-#endif
+} // namespace vendor_hash
 
 #endif /* SHA1_H */