From 2c4c53c98140fdd8c359c25a402125528aed655c Mon Sep 17 00:00:00 2001
From: tedu <tedu@openbsd.org>
Date: Sat, 3 May 2014 16:33:35 +0000
Subject: [PATCH] 1. Drop support for no minor. This variant doesn't exist
 anymore. 2. Pull up the actual minor processing code into the switch that
 parses it. 3. atoi is actually simpler than strtonum in this case, but check
 the input beforehand so we don't get unexpected results. 4. Slightly more
 consistent style between various parse and check and increment operations on
 salt. ok deraadt

---
 lib/libc/crypt/bcrypt.c | 74 +++++++++++++++++------------------------
 1 file changed, 30 insertions(+), 44 deletions(-)

diff --git a/lib/libc/crypt/bcrypt.c b/lib/libc/crypt/bcrypt.c
index 7fcb2a51874..8c6d50c0a61 100644
--- a/lib/libc/crypt/bcrypt.c
+++ b/lib/libc/crypt/bcrypt.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bcrypt.c,v 1.39 2014/04/19 15:19:20 tedu Exp $	*/
+/*	$OpenBSD: bcrypt.c,v 1.40 2014/05/03 16:33:35 tedu Exp $	*/
 
 /*
  * Copyright (c) 2014 Ted Unangst <tedu@openbsd.org>
@@ -94,45 +94,44 @@ bcrypt_hashpass(const char *key, const char *salt, char *encrypted,
 	u_int8_t ciphertext[4 * BCRYPT_BLOCKS] = "OrpheanBeholderScryDoubt";
 	u_int8_t csalt[BCRYPT_MAXSALT];
 	u_int32_t cdata[BCRYPT_BLOCKS];
-	char arounds[3];
 
-	/* Discard "$" identifier */
-	if (*salt != '$')
+	/* Check and discard "$" identifier */
+	if (salt[0] != '$')
 		return -1;
-	salt++;
+	salt += 1;
 
-	if (*salt != BCRYPT_VERSION)
+	if (salt[0] != BCRYPT_VERSION)
 		return -1;
 
 	/* Check for minor versions */
-	if (salt[1] != '$') {
-		 switch (salt[1]) {
-		 case 'a':	/* 'ab' should not yield the same as 'abab' */
-		 case 'b':	/* cap input length at 72 bytes */
-			 minor = salt[1];
-			 salt++;
-			 if (salt[1] != '$')
-				 return -1;
-			 break;
-		 default:
-			 return -1;
-		 }
-	} else
-		 minor = 0;
-
-	/* Discard version + "$" identifier */
-	salt += 2;
-
+	switch ((minor = salt[1])) {
+	case 'a':
+		key_len = (u_int8_t)(strlen(key) + 1);
+		break;
+	case 'b':
+		/* strlen() returns a size_t, but the function calls
+		 * below result in implicit casts to a narrower integer
+		 * type, so cap key_len at the actual maximum supported
+		 * length here to avoid integer wraparound */
+		key_len = strlen(key);
+		if (key_len > 72)
+			key_len = 72;
+		key_len++; /* include the NUL */
+		break;
+	default:
+		 return -1;
+	}
 	if (salt[2] != '$')
-		/* Out of sync with passwd entry */
 		return -1;
+	/* Discard version + "$" identifier */
+	salt += 3;
 
-	memcpy(arounds, salt, sizeof(arounds));
-	if (arounds[sizeof(arounds) - 1] != '$')
+	/* Check and parse num rounds */
+	if (!isdigit((unsigned char)salt[0]) ||
+	    !isdigit((unsigned char)salt[1]) || salt[2] != '$')
 		return -1;
-	arounds[sizeof(arounds) - 1] = 0;
-	logr = strtonum(arounds, BCRYPT_MINLOGROUNDS, 31, NULL);
-	if (logr == 0)
+	logr = atoi(salt);
+	if (logr < BCRYPT_MINLOGROUNDS || logr > 31)
 		return -1;
 	/* Computer power doesn't increase linearly, 2^x should be fine */
 	rounds = 1U << logr;
@@ -147,18 +146,6 @@ bcrypt_hashpass(const char *key, const char *salt, char *encrypted,
 	if (decode_base64(csalt, BCRYPT_MAXSALT, salt))
 		return -1;
 	salt_len = BCRYPT_MAXSALT;
-	if (minor <= 'a')
-		key_len = (u_int8_t)(strlen(key) + (minor >= 'a' ? 1 : 0));
-	else {
-		/* strlen() returns a 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 */
-	}
 
 	/* Setting up S-Boxes and Subkeys */
 	Blowfish_initstate(&state);
@@ -192,8 +179,7 @@ bcrypt_hashpass(const char *key, const char *salt, char *encrypted,
 	i = 0;
 	encrypted[i++] = '$';
 	encrypted[i++] = BCRYPT_VERSION;
-	if (minor)
-		encrypted[i++] = minor;
+	encrypted[i++] = minor;
 	encrypted[i++] = '$';
 
 	snprintf(encrypted + i, 4, "%2.2u$", logr);
-- 
2.20.1