Imported from /home/lorry/working-area/delta_berkeleydb/db-6.1.23.tar.gz.HEADdb-6.1.23master

1 files changed, 65 insertions, 12 deletions

diff --git a/src/crypto/crypto.c b/src/crypto/crypto.c
index b731496f..ba115dd3 100644
--- a/src/crypto/crypto.c
+++ b/src/crypto/crypto.c
@@ -1,7 +1,7 @@
 /*-
  * See the file LICENSE for redistribution information.
  *
- * Copyright (c) 1996, 2012 Oracle and/or its affiliates.  All rights reserved.
+ * Copyright (c) 1996, 2015 Oracle and/or its affiliates.  All rights reserved.
  *
  * Some parts of this code originally written by Adam Stubblefield
  * -- astubble@rice.edu
@@ -15,6 +15,8 @@
 #include "dbinc/db_page.h"
 #include "dbinc/crypto.h"
 
+static void randomize __P((ENV *, void *, size_t));
+
 /*
  * __crypto_region_init --
  *	Initialize crypto.
@@ -110,7 +112,7 @@ __crypto_region_init(env)
 	 * existing one, we are done with the passwd in the env.  We smash
 	 * N-1 bytes so that we don't overwrite the nul.
 	 */
-	memset(dbenv->passwd, 0xff, dbenv->passwd_len-1);
+	randomize(env, dbenv->passwd, dbenv->passwd_len - 1);
 	__os_free(env, dbenv->passwd);
 	dbenv->passwd = NULL;
 	dbenv->passwd_len = 0;
@@ -135,9 +137,10 @@ __crypto_env_close(env)
 	dbenv = env->dbenv;
 
 	if (dbenv->passwd != NULL) {
-		memset(dbenv->passwd, 0xff, dbenv->passwd_len-1);
+		randomize(env, dbenv->passwd, dbenv->passwd_len - 1);
 		__os_free(env, dbenv->passwd);
 		dbenv->passwd = NULL;
+		dbenv->passwd_len = 0;
 	}
 
 	if (!CRYPTO_ON(env))
@@ -225,7 +228,8 @@ __crypto_algsetup(env, db_cipher, alg, do_init)
 
 /*
  * __crypto_decrypt_meta --
- *	Perform decryption on a metapage if needed.
+ *	Perform decryption on a possible metadata page, if needed. This is used
+ *	to help decide whether this is a real DB. Don't trust random data.
  *
  * PUBLIC:  int __crypto_decrypt_meta __P((ENV *, DB *, u_int8_t *, int));
  */
@@ -241,6 +245,7 @@ __crypto_decrypt_meta(env, dbp, mbuf, do_metachk)
 	DB_CIPHER *db_cipher;
 	size_t pg_off;
 	int ret;
+	unsigned added_flags;
 	u_int8_t *iv;
 
 	/*
@@ -293,6 +298,7 @@ __crypto_decrypt_meta(env, dbp, mbuf, do_metachk)
 	 */
 	if (meta->encrypt_alg != 0) {
 		db_cipher = env->crypto_handle;
+		added_flags = 0;
 		if (!F_ISSET(dbp, DB_AM_ENCRYPT)) {
 			if (!CRYPTO_ON(env)) {
 				__db_errx(env, DB_STR("0178",
@@ -300,12 +306,14 @@ __crypto_decrypt_meta(env, dbp, mbuf, do_metachk)
 				return (EINVAL);
 			}
 			/*
-			 * User has a correct, secure env, but has encountered
-			 * a database in that env that is secure, but user
-			 * didn't dbp->set_flags.  Since it is existing, use
-			 * encryption if it is that way already.
+			 * User has a correct, secure env and has encountered
+			 * a database in that env that APPEARS TO BE secure, but
+			 * user didn't set the encryption flags. Since the db
+			 * already exists, turn encryption on. Remember what was
+			 * set, so the flags can restored if it doesn't decrypt.
 			 */
-			F_SET(dbp, DB_AM_ENCRYPT|DB_AM_CHKSUM);
+			added_flags = DB_AM_ENCRYPT | DB_AM_CHKSUM;
+			F_SET(dbp, added_flags);
 		}
 		/*
 		 * This was checked in set_flags when DB_AM_ENCRYPT was set.
@@ -316,6 +324,7 @@ __crypto_decrypt_meta(env, dbp, mbuf, do_metachk)
 		    meta->encrypt_alg != db_cipher->alg) {
 			__db_errx(env, DB_STR("0179",
 			    "Database encrypted using a different algorithm"));
+			F_CLR(dbp, added_flags);
 			return (EINVAL);
 		}
 		DB_ASSERT(env, F_ISSET(dbp, DB_AM_CHKSUM));
@@ -334,12 +343,14 @@ alg_retry:
 		if (!F_ISSET(db_cipher, CIPHER_ANY)) {
 			if (do_metachk && (ret = db_cipher->decrypt(env,
 			    db_cipher->data, iv, mbuf + pg_off,
-			    DBMETASIZE - pg_off)))
+			    DBMETASIZE - pg_off))) {
+				F_CLR(dbp, added_flags);
 				return (ret);
-			if (((BTMETA *)meta)->crypto_magic !=
-			    meta->magic) {
+			}
+			if (((BTMETA *)meta)->crypto_magic != meta->magic) {
 				__db_errx(env, DB_STR("0180",
 				    "Invalid password"));
+				F_CLR(dbp, added_flags);
 				return (EINVAL);
 			}
 			/*
@@ -409,3 +420,45 @@ __crypto_set_passwd(env_src, env_dest)
 	sh_passwd = R_ADDR(infop, cipher->passwd);
 	return (__env_set_encrypt(env_dest->dbenv, sh_passwd, DB_ENCRYPT_AES));
 }
+
+/*
+ * randomize
+ *	
+ */
+static void
+randomize(env, base, size)
+	ENV *env;
+	void *base;
+	size_t size;
+{
+	size_t i, copysize;
+	u_int8_t  last, *p;
+	u_int32_t value;
+
+	last = ((u_int8_t *)base)[size];
+	for (i = 0, p = base; i < size; i += copysize, p += copysize) {
+		value = __os_random();
+		if ((copysize = (size - i)) > sizeof(int32_t))
+			copysize = sizeof(int32_t);
+		switch (copysize)
+		{
+		default:
+			memmove(p, &value, sizeof(int32_t));
+		    	break;
+		case 3:
+			p[2] = (u_int8_t)(value >> 16);
+			/* FALLTHROUGH */
+		case 2:
+			p[1] = (u_int8_t)(value >> 8);
+			/* FALLTHROUGH */
+		case 1:
+			p[0] = (u_int8_t)(value);
+			break;
+		case 0:
+			DB_ASSERT(env, "randomize size 0?");
+			break;
+		}
+
+	}
+	DB_ASSERT(env, last == *p);
+}