diff --git a/libraries/Crypto/ChaChaPoly.cpp b/libraries/Crypto/ChaChaPoly.cpp
index 3259cc81..c6cb3019 100644
--- a/libraries/Crypto/ChaChaPoly.cpp
+++ b/libraries/Crypto/ChaChaPoly.cpp
@@ -99,6 +99,7 @@ bool ChaChaPoly::setIV(const uint8_t *iv, size_t len)
     state.dataSize = 0;
     state.dataStarted = false;
     state.ivSize = len;
+    return true;
 }
 
 void ChaChaPoly::encrypt(uint8_t *output, const uint8_t *input, size_t len)
diff --git a/libraries/Crypto/Ed25519.cpp b/libraries/Crypto/Ed25519.cpp
index 004d225a..39c7e91a 100644
--- a/libraries/Crypto/Ed25519.cpp
+++ b/libraries/Crypto/Ed25519.cpp
@@ -256,7 +256,6 @@ void Ed25519::generatePrivateKey(uint8_t privateKey[32])
 void Ed25519::derivePublicKey(uint8_t publicKey[32], const uint8_t privateKey[32])
 {
     SHA512 hash;
-    uint8_t *buf = (uint8_t *)(hash.state.w);
     limb_t a[NUM_LIMBS_256BIT];
     Point ptA;
 
diff --git a/libraries/Crypto/GCM.cpp b/libraries/Crypto/GCM.cpp
index 537a25db..9550d801 100644
--- a/libraries/Crypto/GCM.cpp
+++ b/libraries/Crypto/GCM.cpp
@@ -122,6 +122,7 @@ bool GCMCommon::setIV(const uint8_t *iv, size_t len)
     // This value will be XOR'ed with the final authentication hash
     // value in computeTag().
     blockCipher->encryptBlock(state.nonce, state.counter);
+    return true;
 }
 
 /**
diff --git a/libraries/Crypto/Hash.cpp b/libraries/Crypto/Hash.cpp
index f49b9b6f..ef132572 100644
--- a/libraries/Crypto/Hash.cpp
+++ b/libraries/Crypto/Hash.cpp
@@ -171,8 +171,8 @@ void Hash::formatHMACKey(void *block, const void *key, size_t len, uint8_t pad)
         finalize(block, len);
         reset();
     }
-    memset(block + len, pad, size - len);
     uint8_t *b = (uint8_t *)block;
+    memset(b + len, pad, size - len);
     while (len > 0) {
         *b++ ^= pad;
         --len;