Make Bcrypt thread safe (#7)

* Make Bcrypt thread safe

* swift format

Sources/CBcrypt/bcrypt.c

@@ -58,8 +58,8 @@ static int decode_base64(u_int8_t *, size_t, const char *);
 /*
  * Generates a salt for this version of crypt.
  */
-static int
-bcrypt_initsalt_with_csalt(int log_rounds, char *salt, size_t saltbuflen, const uint8_t *csalt)
+int
+c_hb_bcrypt_initsalt_with_csalt(int log_rounds, char *salt, size_t saltbuflen, const uint8_t *csalt)
 {
     if (saltbuflen < BCRYPT_SALTSPACE) {
         errno = EINVAL;
@@ -309,28 +309,3 @@ encode_base64(char *b64buffer, const u_int8_t *data, size_t len)
     *bp = '\0';
     return 0;
 }
-
-/*
- * classic interface
- */
-char *
-c_hb_bcrypt_gensalt_with_csalt(u_int8_t log_rounds, const u_int8_t *csalt)
-{
-    static char    gsalt[BCRYPT_SALTSPACE];
-
-    bcrypt_initsalt_with_csalt(log_rounds, gsalt, sizeof(gsalt), csalt);
-
-    return gsalt;
-}
-
-char *
-c_hb_bcrypt(const char *pass, const char *salt)
-{
-    static char    gencrypted[BCRYPT_HASHSPACE];
-
-    if (c_hb_bcrypt_hashpass(pass, salt, gencrypted, sizeof(gencrypted)) != 0)
-        return NULL;
-
-    return gencrypted;
-}
-DEF_WEAK(bcrypt);

Sources/CBcrypt/include/bcrypt.h

@@ -40,12 +40,12 @@
 #define BCRYPT_WORDS 6        /* Ciphertext words */
 #define BCRYPT_MINLOGROUNDS 4    /* we have log2(rounds) in salt */
 
-#define    BCRYPT_SALTSPACE    (7 + (BCRYPT_MAXSALT * 4 + 2) / 3 + 1)
+#define    BCRYPT_SALTSPACE    30 /* (7 + (BCRYPT_MAXSALT * 4 + 2) / 3 + 1) */
 #define    BCRYPT_HASHSPACE    61
 
 /// generate salt given a cost and random buffer of 16 bytes
-char *c_hb_bcrypt_gensalt_with_csalt(u_int8_t cost, const uint8_t *csalt);
+int c_hb_bcrypt_initsalt_with_csalt(int log_rounds, char *salt, size_t saltbuflen, const uint8_t *csalt);
 /// encrypt `pass` using `salt`
-char *c_hb_bcrypt(const char *pass, const char *salt);
+int c_hb_bcrypt_hashpass(const char *key, const char *salt, char *encrypted, size_t encryptedlen);
 /// check `pass` against hash
 int c_hb_bcrypt_checkpass(const char *pass, const char *goodhash);

Sources/HummingbirdAuth/BCrypt/Bcrypt.swift

@@ -31,13 +31,15 @@ public enum Bcrypt {
 
         // create random salt here, instead of using C as arc4random_buf is not always available
         let csalt: [UInt8] = (0..<BCRYPT_MAXSALT).map { _ in UInt8.random(in: .min ... .max) }
-        // can guarantee salt if non nil
-        let salt = csalt.withUnsafeBufferPointer {
-            c_hb_bcrypt_gensalt_with_csalt(cost, $0.baseAddress)!
+        let salt = [CChar](unsafeUninitializedCapacity: Int(BCRYPT_SALTSPACE)) { bytes, _ in
+            _ = c_hb_bcrypt_initsalt_with_csalt(Int32(cost), bytes.baseAddress, Int(BCRYPT_SALTSPACE), csalt)
+        }
+
+        // create hashed data
+        let hashedData = [CChar](unsafeUninitializedCapacity: Int(BCRYPT_HASHSPACE)) { bytes, _ in
+            _ = c_hb_bcrypt_hashpass(text, salt, bytes.baseAddress, Int(BCRYPT_HASHSPACE))
         }
 
-        // can guarantee hash data is valid as salt was created correctly
-        let hashedData = c_hb_bcrypt(text, salt)!
         return String(cString: hashedData)
     }