util: Don't allow DecodeBase64(...) of strings with embedded NUL characters

practicalswift · practicalswift · commit 93cc18b0f6fa · 2019-12-16T09:04:36.000Z
diff --git a/src/util/strencodings.cpp b/src/util/strencodings.cpp
@@ -191,6 +191,12 @@ std::vector<unsigned char> DecodeBase64(const char* p, bool* pf_invalid)
 
 std::string DecodeBase64(const std::string& str, bool* pf_invalid)
 {
+    if (!ValidAsCString(str)) {
+        if (pf_invalid) {
+            *pf_invalid = true;
+        }
+        return {};
+    }
     std::vector<unsigned char> vchRet = DecodeBase64(str.c_str(), pf_invalid);
     return std::string((const char*)vchRet.data(), vchRet.size());
 }

Original file line number	Diff line number	Diff line change
`@@ -191,6 +191,12 @@ std::vector<unsigned char> DecodeBase64(const char* p, bool* pf_invalid)`
`191`	`191`
`192`	`192`	`std::string DecodeBase64(const std::string& str, bool* pf_invalid)`
`193`	`193`	`{`
	`194`	`+ if (!ValidAsCString(str)) {`
	`195`	`+ if (pf_invalid) {`
	`196`	`+ *pf_invalid = true;`
	`197`	`+ }`
	`198`	`+ return {};`
	`199`	`+ }`
`194`	`200`	`std::vector<unsigned char> vchRet = DecodeBase64(str.c_str(), pf_invalid);`
`195`	`201`	`return std::string((const char*)vchRet.data(), vchRet.size());`
`196`	`202`	`}`