Make certain hash bits constant

Author: earlephilhower

cores/esp8266/Updater.h

@@ -36,14 +36,14 @@ class UpdaterHashClass {
     virtual void add(const void *data, uint32_t len) = 0;
     virtual void end() = 0;
     virtual int len() = 0;
-    virtual void *hash() = 0;
+    virtual const void *hash() = 0;
 };
 
 // Abstract class to implement a signature verifier
 class UpdaterVerifyClass {
   public:
     virtual uint32_t length() = 0; // How many bytes of signature are expected
-    virtual bool verify(UpdaterHashClass *hash, void *signature, uint32_t signatureLen) = 0; // Verify, return "true" on success
+    virtual bool verify(UpdaterHashClass *hash, const void *signature, uint32_t signatureLen) = 0; // Verify, return "true" on success
 };
 
 class UpdaterClass {

libraries/ESP8266WiFi/src/BearSSLHelpers.cpp

@@ -839,8 +839,8 @@ int BearSSLHashSHA256::len() {
   return sizeof(_sha256);
 }
 
-void *BearSSLHashSHA256::hash() {
-  return (void*) _sha256;
+const void *BearSSLHashSHA256::hash() {
+  return (const void*) _sha256;
 }
 
 // SHA256 verifier
@@ -857,7 +857,7 @@ uint32_t BearSSLSigningVerifier::length()
   }
 }
 
-bool BearSSLSigningVerifier::verify(UpdaterHashClass *hash, void *signature, uint32_t signatureLen) {
+bool BearSSLSigningVerifier::verify(UpdaterHashClass *hash, const void *signature, uint32_t signatureLen) {
   if (!_pubKey || !hash || !signature || signatureLen != length()) return false;
 
   if (_pubKey->isRSA()) {

libraries/ESP8266WiFi/src/BearSSLHelpers.h

@@ -146,7 +146,7 @@ class BearSSLHashSHA256 : public UpdaterHashClass {
     virtual void add(const void *data, uint32_t len) override;
     virtual void end() override;
     virtual int len() override;
-    virtual void *hash() override;
+    virtual const void *hash() override;
   private:
     br_sha256_context _cc;
     unsigned char _sha256[32];
@@ -155,7 +155,7 @@ class BearSSLHashSHA256 : public UpdaterHashClass {
 class BearSSLSigningVerifier : public UpdaterVerifyClass {
   public:
     virtual uint32_t length() override;
-    virtual bool verify(UpdaterHashClass *hash, void *signature, uint32_t signatureLen) override;
+    virtual bool verify(UpdaterHashClass *hash, const void *signature, uint32_t signatureLen) override;
 
   public:
     BearSSLSigningVerifier(BearSSLPublicKey *pubKey) { _pubKey = pubKey; }