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Diffstat (limited to 'security/integrity/evm/evm_main.c')
-rw-r--r--security/integrity/evm/evm_main.c94
1 files changed, 81 insertions, 13 deletions
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index 92d3d99..8901501 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);
}
/*
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