1 files changed, 81 insertions, 13 deletions

diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index 92d3d99a9f7b..8901501425f4 100644
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -25,6 +25,7 @@
 int evm_initialized;
 
 char *evm_hmac = "hmac(sha1)";
+char *evm_hash = "sha1";
 
 char *evm_config_xattrnames[] = {
 #ifdef CONFIG_SECURITY_SELINUX
@@ -46,6 +47,29 @@ static int __init evm_set_fixmode(char *str)
 }
 __setup("evm=", evm_set_fixmode);
 
+static int evm_find_protected_xattrs(struct dentry *dentry)
+{
+	struct inode *inode = dentry->d_inode;
+	char **xattr;
+	int error;
+	int count = 0;
+
+	if (!inode->i_op || !inode->i_op->getxattr)
+		return -EOPNOTSUPP;
+
+	for (xattr = evm_config_xattrnames; *xattr != NULL; xattr++) {
+		error = inode->i_op->getxattr(dentry, *xattr, NULL, 0);
+		if (error < 0) {
+			if (error == -ENODATA)
+				continue;
+			return error;
+		}
+		count++;
+	}
+
+	return count;
+}
+
 /*
  * evm_verify_hmac - calculate and compare the HMAC with the EVM xattr
  *
@@ -65,32 +89,72 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry,
 					     size_t xattr_value_len,
 					     struct integrity_iint_cache *iint)
 {
-	struct evm_ima_xattr_data xattr_data;
+	struct evm_ima_xattr_data *xattr_data = NULL;
+	struct evm_ima_xattr_data calc;
 	enum integrity_status evm_status = INTEGRITY_PASS;
-	int rc;
+	int rc, xattr_len;
 
 	if (iint && iint->evm_status == INTEGRITY_PASS)
 		return iint->evm_status;
 
 	/* if status is not PASS, try to check again - against -ENOMEM */
 
-	rc = evm_calc_hmac(dentry, xattr_name, xattr_value,
-			   xattr_value_len, xattr_data.digest);
-	if (rc < 0) {
-		evm_status = (rc == -ENODATA)
-		    ? INTEGRITY_NOXATTRS : INTEGRITY_FAIL;
+	/* first need to know the sig type */
+	rc = vfs_getxattr_alloc(dentry, XATTR_NAME_EVM, (char **)&xattr_data, 0,
+				GFP_NOFS);
+	if (rc <= 0) {
+		if (rc == 0)
+			evm_status = INTEGRITY_FAIL; /* empty */
+		else if (rc == -ENODATA) {
+			rc = evm_find_protected_xattrs(dentry);
+			if (rc > 0)
+				evm_status = INTEGRITY_NOLABEL;
+			else if (rc == 0)
+				evm_status = INTEGRITY_NOXATTRS; /* new file */
+		}
 		goto out;
 	}
 
-	xattr_data.type = EVM_XATTR_HMAC;
-	rc = vfs_xattr_cmp(dentry, XATTR_NAME_EVM, (u8 *)&xattr_data,
-			   sizeof xattr_data, GFP_NOFS);
-	if (rc < 0)
-		evm_status = (rc == -ENODATA)
-		    ? INTEGRITY_NOLABEL : INTEGRITY_FAIL;
+	xattr_len = rc - 1;
+
+	/* check value type */
+	switch (xattr_data->type) {
+	case EVM_XATTR_HMAC:
+		rc = evm_calc_hmac(dentry, xattr_name, xattr_value,
+				   xattr_value_len, calc.digest);
+		if (rc)
+			break;
+		rc = memcmp(xattr_data->digest, calc.digest,
+			    sizeof(calc.digest));
+		if (rc)
+			rc = -EINVAL;
+		break;
+	case EVM_IMA_XATTR_DIGSIG:
+		rc = evm_calc_hash(dentry, xattr_name, xattr_value,
+				xattr_value_len, calc.digest);
+		if (rc)
+			break;
+		rc = integrity_digsig_verify(INTEGRITY_KEYRING_EVM,
+					xattr_data->digest, xattr_len,
+					calc.digest, sizeof(calc.digest));
+		if (!rc) {
+			/* we probably want to replace rsa with hmac here */
+			evm_update_evmxattr(dentry, xattr_name, xattr_value,
+				   xattr_value_len);
+		}
+		break;
+	default:
+		rc = -EINVAL;
+		break;
+	}
+
+	if (rc)
+		evm_status = (rc == -ENODATA) ?
+				INTEGRITY_NOXATTRS : INTEGRITY_FAIL;
 out:
 	if (iint)
 		iint->evm_status = evm_status;
+	kfree(xattr_data);
 	return evm_status;
 }
 
@@ -354,6 +418,8 @@ static int __init init_evm(void)
 		printk(KERN_INFO "EVM: Error registering secfs\n");
 		goto err;
 	}
+
+	return 0;
 err:
 	return error;
 }
@@ -363,6 +429,8 @@ static void __exit cleanup_evm(void)
 	evm_cleanup_secfs();
 	if (hmac_tfm)
 		crypto_free_shash(hmac_tfm);
+	if (hash_tfm)
+		crypto_free_shash(hash_tfm);
 }
 
 /*