solar's testsuite revealed insufficient validation of invalid input hashes.

add a more complete check for the rounds parameter. ok deraadt

1 files changed, 10 insertions, 8 deletions

diff --git a/src/lib/libc/crypt/bcrypt.c b/src/lib/libc/crypt/bcrypt.c
index 7e283c43f1..b108cfe04c 100644
--- a/src/lib/libc/crypt/bcrypt.c
+++ b/src/lib/libc/crypt/bcrypt.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: bcrypt.c,v 1.28 2014/02/17 09:00:20 tedu Exp $        */
+/*      $OpenBSD: bcrypt.c,v 1.29 2014/02/24 19:45:43 tedu Exp $        */
 
 /*
  * Copyright 1997 Niels Provos <provos@physnet.uni-hamburg.de>
@@ -60,7 +60,7 @@
 #define BCRYPT_VERSION '2'
 #define BCRYPT_MAXSALT 16       /* Precomputation is just so nice */
 #define BCRYPT_BLOCKS 6         /* Ciphertext blocks */
-#define BCRYPT_MINROUNDS 16     /* we have log2(rounds) in salt */
+#define BCRYPT_MINLOGROUNDS 4   /* we have log2(rounds) in salt */
 
 char   *bcrypt_gensalt(u_int8_t);
 
@@ -173,7 +173,7 @@ bcrypt(const char *key, const char *salt)
         u_int8_t ciphertext[4 * BCRYPT_BLOCKS] = "OrpheanBeholderScryDoubt";
         u_int8_t csalt[BCRYPT_MAXSALT];
         u_int32_t cdata[BCRYPT_BLOCKS];
-        int n;
+        char arounds[3];
 
         /* Discard "$" identifier */
         salt++;
@@ -204,13 +204,15 @@ bcrypt(const char *key, const char *salt)
                 /* Out of sync with passwd entry */
                 return error;
 
-        /* Computer power doesn't increase linear, 2^x should be fine */
-        n = atoi(salt);
-        if (n > 31 || n < 0)
+        memcpy(arounds, salt, sizeof(arounds));
+        if (arounds[sizeof(arounds) - 1] != '$')
                 return error;
-        logr = (u_int8_t)n;
-        if ((rounds = (u_int32_t) 1 << logr) < BCRYPT_MINROUNDS)
+        arounds[sizeof(arounds) - 1] = 0;
+        logr = strtonum(arounds, BCRYPT_MINLOGROUNDS, 31, NULL);
+        if (logr == 0)
                 return error;
+        /* Computer power doesn't increase linearly, 2^x should be fine */
+        rounds = 1U << logr;
 
         /* Discard num rounds + "$" identifier */
         salt += 3;