From 1a8185828b70ed5f3bbf83846d4a05e6dc589b83 Mon Sep 17 00:00:00 2001
From: Jonathan Hawkes <jonathan@thoughtbuilt.com>
Date: Sun, 31 May 2020 22:48:09 -0400
Subject: [PATCH] Pass key_len to bcrypt(). Fix for issues #774, #776

---
 src/bcrypt.cc      | 8 +++-----
 src/bcrypt_node.cc | 8 ++++----
 src/node_blf.h     | 2 +-
 3 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/src/bcrypt.cc b/src/bcrypt.cc
index 898ef3ca..ec4b7d9f 100644
--- a/src/bcrypt.cc
+++ b/src/bcrypt.cc
@@ -146,12 +146,11 @@ bcrypt_gensalt(char minor, u_int8_t log_rounds, u_int8_t *seed, char *gsalt)
    i.e. $2$04$iwouldntknowwhattosayetKdJ6iFtacBqJdKe6aW7ou */
 
 void
-bcrypt(const char *key, const char *salt, char *encrypted)
+bcrypt(const char *key, size_t key_len, const char *salt, char *encrypted)
 {
 	blf_ctx state;
 	u_int32_t rounds, i, k;
 	u_int16_t j;
-	size_t key_len;
 	u_int8_t salt_len, logr, minor;
 	u_int8_t ciphertext[4 * BCRYPT_BLOCKS+1] = "OrpheanBeholderScryDoubt";
 	u_int8_t csalt[BCRYPT_MAXSALT];
@@ -215,14 +214,13 @@ bcrypt(const char *key, const char *salt, char *encrypted)
 	decode_base64(csalt, BCRYPT_MAXSALT, (u_int8_t *) salt);
 	salt_len = BCRYPT_MAXSALT;
 	if (minor <= 'a')
-		key_len = (u_int8_t)(strlen(key) + (minor >= 'a' ? 1 : 0));
+		key_len = (u_int8_t)(key_len + (minor >= 'a' ? 1 : 0));
 	else
 	{
-		/* strlen() returns a size_t, but the function calls
+		/* size_t, but the function calls
 		* below result in implicit casts to a narrower integer
 		* type, so cap key_len at the actual maximum supported
 		* length here to avoid integer wraparound */
-		key_len = strlen(key);
 		if (key_len > 72)
 			key_len = 72;
 		key_len++; /* include the NUL */
diff --git a/src/bcrypt_node.cc b/src/bcrypt_node.cc
index 37c67a6f..a5b6c4fd 100644
--- a/src/bcrypt_node.cc
+++ b/src/bcrypt_node.cc
@@ -148,7 +148,7 @@ namespace {
                     SetError("Invalid salt. Salt must be in the form of: $Vers$log2(NumRounds)$saltvalue");
                 }
                 char bcrypted[_PASSWORD_LEN];
-                bcrypt(input.c_str(), salt.c_str(), bcrypted);
+                bcrypt(input.c_str(), input.length(), salt.c_str(), bcrypted);
                 output = std::string(bcrypted);
             }
 
@@ -185,7 +185,7 @@ namespace {
             throw Napi::Error::New(env, "Invalid salt. Salt must be in the form of: $Vers$log2(NumRounds)$saltvalue");
         }
         char bcrypted[_PASSWORD_LEN];
-        bcrypt(data.c_str(), salt.c_str(), bcrypted);
+        bcrypt(data.c_str(), data.length(), salt.c_str(), bcrypted);
         return Napi::String::New(env, bcrypted, strlen(bcrypted));
     }
 
@@ -206,7 +206,7 @@ namespace {
             void Execute() {
                 char bcrypted[_PASSWORD_LEN];
                 if (ValidateSalt(encrypted.c_str())) {
-                    bcrypt(input.c_str(), encrypted.c_str(), bcrypted);
+                    bcrypt(input.c_str(), input.length(), encrypted.c_str(), bcrypted);
                     result = CompareStrings(bcrypted, encrypted.c_str());
                 }
             }
@@ -243,7 +243,7 @@ namespace {
         std::string hash = info[1].As<Napi::String>();
         char bcrypted[_PASSWORD_LEN];
         if (ValidateSalt(hash.c_str())) {
-            bcrypt(pw.c_str(), hash.c_str(), bcrypted);
+            bcrypt(pw.c_str(), pw.length(), hash.c_str(), bcrypted);
             return Napi::Boolean::New(env, CompareStrings(bcrypted, hash.c_str()));
         } else {
             return Napi::Boolean::New(env, false);
diff --git a/src/node_blf.h b/src/node_blf.h
index 770b51a0..2d50a39b 100644
--- a/src/node_blf.h
+++ b/src/node_blf.h
@@ -125,7 +125,7 @@ u_int32_t Blowfish_stream2word(const u_int8_t *, u_int16_t , u_int16_t *);
 
 /* bcrypt functions*/
 void bcrypt_gensalt(char, u_int8_t, u_int8_t*, char *);
-void bcrypt(const char *, const char *, char *);
+void bcrypt(const char *, size_t key_len, const char *, char *);
 void encode_salt(char *, u_int8_t *, char, u_int16_t, u_int8_t);
 u_int32_t bcrypt_get_rounds(const char *);