Only check the actual used lenght of the hash. (esp8266#8709)

seism0saurus · hasenradball · commit e3c72fb3ae01 · 2024-11-18T17:40:55.000+01:00
diff --git a/libraries/ESP8266WiFi/src/BearSSLHelpers.cpp b/libraries/ESP8266WiFi/src/BearSSLHelpers.cpp
@@ -945,7 +945,7 @@ extern "C" bool SigningVerifier_verify(PublicKey *_pubKey, UpdaterHashClass *has
     }
     br_rsa_pkcs1_vrfy vrfy = br_rsa_pkcs1_vrfy_get_default();
     bool ret = vrfy((const unsigned char *)signature, signatureLen, hash->oid(), hash->len(), _pubKey->getRSA(), vrf);
-    if (!ret || memcmp(vrf, hash->hash(), sizeof(vrf)) ) {
+    if (!ret || memcmp(vrf, hash->hash(), std::min(HashLengthMax, hash->len())) ) {
       return false;
     } else {
       return true;

Original file line number	Diff line number	Diff line change
`@@ -945,7 +945,7 @@ extern "C" bool SigningVerifier_verify(PublicKey _pubKey, UpdaterHashClass has`
`945`	`945`	`}`
`946`	`946`	`br_rsa_pkcs1_vrfy vrfy = br_rsa_pkcs1_vrfy_get_default();`
`947`	`947`	`bool ret = vrfy((const unsigned char *)signature, signatureLen, hash->oid(), hash->len(), _pubKey->getRSA(), vrf);`
`948`		`- if (!ret \|\| memcmp(vrf, hash->hash(), sizeof(vrf)) ) {`
	`948`	`+ if (!ret \|\| memcmp(vrf, hash->hash(), std::min(HashLengthMax, hash->len())) ) {`
`949`	`949`	`return false;`
`950`	`950`	`} else {`
`951`	`951`	`return true;`