From 29a98c1caf7b37b12a79eee7f839bf2924593c1c Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers@google.com>
Date: Wed, 24 Jul 2019 11:08:00 -0700
Subject: [PATCH] fscrypt: use ENOPKG when crypto API support missing
Return ENOPKG rather than ENOENT when trying to open a file that's
encrypted using algorithms not available in the kernel's crypto API.
This avoids an ambiguity, since ENOENT is also returned when the file
doesn't exist.
Note: this is the same approach I'm taking for fs-verity.
Signed-off-by: Eric Biggers <ebiggers@google.com>
---
fs/crypto/keyinfo.c | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)
diff --git a/fs/crypto/keyinfo.c b/fs/crypto/keyinfo.c
index b75678587c3a8..2129943002335 100644
--- a/fs/crypto/keyinfo.c
+++ b/fs/crypto/keyinfo.c
@@ -237,13 +237,14 @@ allocate_skcipher_for_mode(struct fscrypt_mode *mode, const u8 *raw_key,
tfm = crypto_alloc_skcipher(mode->cipher_str, 0, 0);
if (IS_ERR(tfm)) {
- if (PTR_ERR(tfm) == -ENOENT)
+ if (PTR_ERR(tfm) == -ENOENT) {
fscrypt_warn(inode,
"Missing crypto API support for %s (API name: \"%s\")",
mode->friendly_name, mode->cipher_str);
- else
- fscrypt_err(inode, "Error allocating '%s' transform: %ld",
- mode->cipher_str, PTR_ERR(tfm));
+ return ERR_PTR(-ENOPKG);
+ }
+ fscrypt_err(inode, "Error allocating '%s' transform: %ld",
+ mode->cipher_str, PTR_ERR(tfm));
return tfm;
}
if (unlikely(!mode->logged_impl_name)) {
@@ -389,13 +390,14 @@ static int derive_essiv_salt(const u8 *key, int keysize, u8 *salt)
tfm = crypto_alloc_shash("sha256", 0, 0);
if (IS_ERR(tfm)) {
- if (PTR_ERR(tfm) == -ENOENT)
+ if (PTR_ERR(tfm) == -ENOENT) {
fscrypt_warn(NULL,
"Missing crypto API support for SHA-256");
- else
- fscrypt_err(NULL,
- "Error allocating SHA-256 transform: %ld",
- PTR_ERR(tfm));
+ return -ENOPKG;
+ }
+ fscrypt_err(NULL,
+ "Error allocating SHA-256 transform: %ld",
+ PTR_ERR(tfm));
return PTR_ERR(tfm);
}
prev_tfm = cmpxchg(&essiv_hash_tfm, NULL, tfm);
--
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