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authorLinus Torvalds <torvalds@linux-foundation.org>2020-03-31 12:58:36 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-03-31 12:58:36 -0700
commit1455c69900c8c6442b182a74087931f4ffb1cac4 (patch)
tree6a574f2ce6e53e7c384fd8333bbaefd8a49f9350 /fs/crypto
parent42595ce90b9d4a6b9d8c5a1ea78da4eeaf7e086a (diff)
parent861261f2a9cc488c845fc214d9035f7a11094591 (diff)
Merge tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt
Pull fscrypt updates from Eric Biggers: "Add an ioctl FS_IOC_GET_ENCRYPTION_NONCE which retrieves a file's encryption nonce. This makes it easier to write automated tests which verify that fscrypt is doing the encryption correctly" * tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt: ubifs: wire up FS_IOC_GET_ENCRYPTION_NONCE f2fs: wire up FS_IOC_GET_ENCRYPTION_NONCE ext4: wire up FS_IOC_GET_ENCRYPTION_NONCE fscrypt: add FS_IOC_GET_ENCRYPTION_NONCE ioctl
Diffstat (limited to 'fs/crypto')
-rw-r--r--fs/crypto/fscrypt_private.h20
-rw-r--r--fs/crypto/keysetup.c16
-rw-r--r--fs/crypto/policy.c21
3 files changed, 42 insertions, 15 deletions
diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h
index 9aae851409e5..dbced2937ec8 100644
--- a/fs/crypto/fscrypt_private.h
+++ b/fs/crypto/fscrypt_private.h
@@ -76,6 +76,26 @@ static inline int fscrypt_context_size(const union fscrypt_context *ctx)
return 0;
}
+/* Check whether an fscrypt_context has a recognized version number and size */
+static inline bool fscrypt_context_is_valid(const union fscrypt_context *ctx,
+ int ctx_size)
+{
+ return ctx_size >= 1 && ctx_size == fscrypt_context_size(ctx);
+}
+
+/* Retrieve the context's nonce, assuming the context was already validated */
+static inline const u8 *fscrypt_context_nonce(const union fscrypt_context *ctx)
+{
+ switch (ctx->version) {
+ case FSCRYPT_CONTEXT_V1:
+ return ctx->v1.nonce;
+ case FSCRYPT_CONTEXT_V2:
+ return ctx->v2.nonce;
+ }
+ WARN_ON(1);
+ return NULL;
+}
+
#undef fscrypt_policy
union fscrypt_policy {
u8 version;
diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c
index 08c9f216a54d..302375e9f719 100644
--- a/fs/crypto/keysetup.c
+++ b/fs/crypto/keysetup.c
@@ -425,20 +425,8 @@ int fscrypt_get_encryption_info(struct inode *inode)
goto out;
}
- switch (ctx.version) {
- case FSCRYPT_CONTEXT_V1:
- memcpy(crypt_info->ci_nonce, ctx.v1.nonce,
- FS_KEY_DERIVATION_NONCE_SIZE);
- break;
- case FSCRYPT_CONTEXT_V2:
- memcpy(crypt_info->ci_nonce, ctx.v2.nonce,
- FS_KEY_DERIVATION_NONCE_SIZE);
- break;
- default:
- WARN_ON(1);
- res = -EINVAL;
- goto out;
- }
+ memcpy(crypt_info->ci_nonce, fscrypt_context_nonce(&ctx),
+ FS_KEY_DERIVATION_NONCE_SIZE);
if (!fscrypt_supported_policy(&crypt_info->ci_policy, inode)) {
res = -EINVAL;
diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c
index cf2a9d26ef7d..10ccf945020c 100644
--- a/fs/crypto/policy.c
+++ b/fs/crypto/policy.c
@@ -258,7 +258,7 @@ int fscrypt_policy_from_context(union fscrypt_policy *policy_u,
{
memset(policy_u, 0, sizeof(*policy_u));
- if (ctx_size <= 0 || ctx_size != fscrypt_context_size(ctx_u))
+ if (!fscrypt_context_is_valid(ctx_u, ctx_size))
return -EINVAL;
switch (ctx_u->version) {
@@ -481,6 +481,25 @@ int fscrypt_ioctl_get_policy_ex(struct file *filp, void __user *uarg)
}
EXPORT_SYMBOL_GPL(fscrypt_ioctl_get_policy_ex);
+/* FS_IOC_GET_ENCRYPTION_NONCE: retrieve file's encryption nonce for testing */
+int fscrypt_ioctl_get_nonce(struct file *filp, void __user *arg)
+{
+ struct inode *inode = file_inode(filp);
+ union fscrypt_context ctx;
+ int ret;
+
+ ret = inode->i_sb->s_cop->get_context(inode, &ctx, sizeof(ctx));
+ if (ret < 0)
+ return ret;
+ if (!fscrypt_context_is_valid(&ctx, ret))
+ return -EINVAL;
+ if (copy_to_user(arg, fscrypt_context_nonce(&ctx),
+ FS_KEY_DERIVATION_NONCE_SIZE))
+ return -EFAULT;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(fscrypt_ioctl_get_nonce);
+
/**
* fscrypt_has_permitted_context() - is a file's encryption policy permitted
* within its directory?