Skip to content

Fix/constant time compare #1212

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
naveedqadir wants to merge 2 commits into
base: master
Choose a base branch
from
+13 −1
Open

Fix/constant time compare #1212

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
df03643
CompareStrings: constant-time comparison to mitigate timing attack
naveedqadir Dec 24, 2025
b0bf2ce
Update .npmignore
naveedqadir Dec 24, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
14 changes: 13 additions & 1 deletion src/bcrypt_node.cc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -195,8 +195,20 @@ namespace {
}

/* COMPARATOR */
/* COMPARATOR - constant-time to avoid timing attacks */
inline bool CompareStrings(const char* s1, const char* s2) {
return strcmp(s1, s2) == 0;
if (!s1 || !s2) return false;
size_t len1 = strlen(s1);
size_t len2 = strlen(s2);
size_t maxlen = len1 > len2 ? len1 : len2;
unsigned char diff = 0;
for (size_t i = 0; i < maxlen; i++) {
unsigned char c1 = i < len1 ? (unsigned char)s1[i] : 0;
unsigned char c2 = i < len2 ? (unsigned char)s2[i] : 0;
diff |= c1 ^ c2;
}
diff |= (unsigned char)(len1 ^ len2);
return diff == 0;
}

class CompareAsyncWorker : public Napi::AsyncWorker {
Expand Down