adjust digest hashing not to care about alignment; increase ValidatorPubKey alignment (#5296)

beacon_chain/spec/crypto.nim

@@ -57,12 +57,12 @@ type
     ##
     ## It must be 8-byte aligned because `hash(ValidatorPubKey)` just casts a
     ## ptr to one to a ptr to the other, so it needs a compatible alignment.
-    blob* {.align: sizeof(Hash).}: array[RawPubKeySize, byte]
+    blob* {.align: 16.}: array[RawPubKeySize, byte]
 
   UncompressedPubKey* = object
     ## Uncompressed variation of ValidatorPubKey - this type is faster to
     ## deserialize but doubles the storage footprint
-    blob*: array[UncompressedPubKeySize, byte]
+    blob* {.align: 16.}: array[UncompressedPubKeySize, byte]
 
   CookedPubKey* = distinct blscurve.PublicKey ## Valid deserialized key
 

beacon_chain/spec/digest.nim

@@ -130,7 +130,9 @@ template withEth2Hash*(body: untyped): Eth2Digest =
 template hash*(x: Eth2Digest): Hash =
   ## Hash for digests for Nim hash tables
   # digests are already good hashes
-  cast[ptr Hash](unsafeAddr x.data[0])[]
+  var h {.noinit.}: Hash
+  copyMem(addr h, unsafeAddr x.data[0], static(sizeof(Hash)))
+  h
 
 func `==`*(a, b: Eth2Digest): bool =
   when nimvm: