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Diffstat (limited to 'fs/crypto/policy.c')
-rw-r--r--fs/crypto/policy.c433
1 files changed, 281 insertions, 152 deletions
diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c
index d23ff162c78b..bbb2f5ced988 100644
--- a/fs/crypto/policy.c
+++ b/fs/crypto/policy.c
@@ -10,10 +10,13 @@
* Modified by Eric Biggers, 2019 for v2 policy support.
*/
+#include <linux/export.h>
+#include <linux/fs_context.h>
+#include <linux/mount.h>
#include <linux/random.h>
#include <linux/seq_file.h>
#include <linux/string.h>
-#include <linux/mount.h>
+
#include "fscrypt_private.h"
/**
@@ -32,7 +35,41 @@ bool fscrypt_policies_equal(const union fscrypt_policy *policy1,
return !memcmp(policy1, policy2, fscrypt_policy_size(policy1));
}
-static bool fscrypt_valid_enc_modes(u32 contents_mode, u32 filenames_mode)
+int fscrypt_policy_to_key_spec(const union fscrypt_policy *policy,
+ struct fscrypt_key_specifier *key_spec)
+{
+ switch (policy->version) {
+ case FSCRYPT_POLICY_V1:
+ key_spec->type = FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR;
+ memcpy(key_spec->u.descriptor, policy->v1.master_key_descriptor,
+ FSCRYPT_KEY_DESCRIPTOR_SIZE);
+ return 0;
+ case FSCRYPT_POLICY_V2:
+ key_spec->type = FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER;
+ memcpy(key_spec->u.identifier, policy->v2.master_key_identifier,
+ FSCRYPT_KEY_IDENTIFIER_SIZE);
+ return 0;
+ default:
+ WARN_ON_ONCE(1);
+ return -EINVAL;
+ }
+}
+
+const union fscrypt_policy *fscrypt_get_dummy_policy(struct super_block *sb)
+{
+ if (!sb->s_cop->get_dummy_policy)
+ return NULL;
+ return sb->s_cop->get_dummy_policy(sb);
+}
+
+/*
+ * Return %true if the given combination of encryption modes is supported for v1
+ * (and later) encryption policies.
+ *
+ * Do *not* add anything new here, since v1 encryption policies are deprecated.
+ * New combinations of modes should go in fscrypt_valid_enc_modes_v2() only.
+ */
+static bool fscrypt_valid_enc_modes_v1(u32 contents_mode, u32 filenames_mode)
{
if (contents_mode == FSCRYPT_MODE_AES_256_XTS &&
filenames_mode == FSCRYPT_MODE_AES_256_CTS)
@@ -49,6 +86,19 @@ static bool fscrypt_valid_enc_modes(u32 contents_mode, u32 filenames_mode)
return false;
}
+static bool fscrypt_valid_enc_modes_v2(u32 contents_mode, u32 filenames_mode)
+{
+ if (contents_mode == FSCRYPT_MODE_AES_256_XTS &&
+ filenames_mode == FSCRYPT_MODE_AES_256_HCTR2)
+ return true;
+
+ if (contents_mode == FSCRYPT_MODE_SM4_XTS &&
+ filenames_mode == FSCRYPT_MODE_SM4_CTS)
+ return true;
+
+ return fscrypt_valid_enc_modes_v1(contents_mode, filenames_mode);
+}
+
static bool supported_direct_key_modes(const struct inode *inode,
u32 contents_mode, u32 filenames_mode)
{
@@ -70,12 +120,25 @@ static bool supported_direct_key_modes(const struct inode *inode,
}
static bool supported_iv_ino_lblk_policy(const struct fscrypt_policy_v2 *policy,
- const struct inode *inode,
- const char *type,
- int max_ino_bits, int max_lblk_bits)
+ const struct inode *inode)
{
+ const char *type = (policy->flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64)
+ ? "IV_INO_LBLK_64" : "IV_INO_LBLK_32";
struct super_block *sb = inode->i_sb;
- int ino_bits = 64, lblk_bits = 64;
+
+ /*
+ * IV_INO_LBLK_* exist only because of hardware limitations, and
+ * currently the only known use case for them involves AES-256-XTS.
+ * That's also all we test currently. For these reasons, for now only
+ * allow AES-256-XTS here. This can be relaxed later if a use case for
+ * IV_INO_LBLK_* with other encryption modes arises.
+ */
+ if (policy->contents_encryption_mode != FSCRYPT_MODE_AES_256_XTS) {
+ fscrypt_warn(inode,
+ "Can't use %s policy with contents mode other than AES-256-XTS",
+ type);
+ return false;
+ }
/*
* It's unsafe to include inode numbers in the IVs if the filesystem can
@@ -88,17 +151,29 @@ static bool supported_iv_ino_lblk_policy(const struct fscrypt_policy_v2 *policy,
type, sb->s_id);
return false;
}
- if (sb->s_cop->get_ino_and_lblk_bits)
- sb->s_cop->get_ino_and_lblk_bits(sb, &ino_bits, &lblk_bits);
- if (ino_bits > max_ino_bits) {
+
+ /*
+ * IV_INO_LBLK_64 and IV_INO_LBLK_32 both require that inode numbers fit
+ * in 32 bits. In principle, IV_INO_LBLK_32 could support longer inode
+ * numbers because it hashes the inode number; however, currently the
+ * inode number is gotten from inode::i_ino which is 'unsigned long'.
+ * So for now the implementation limit is 32 bits.
+ */
+ if (!sb->s_cop->has_32bit_inodes) {
fscrypt_warn(inode,
"Can't use %s policy on filesystem '%s' because its inode numbers are too long",
type, sb->s_id);
return false;
}
- if (lblk_bits > max_lblk_bits) {
+
+ /*
+ * IV_INO_LBLK_64 and IV_INO_LBLK_32 both require that file data unit
+ * indices fit in 32 bits.
+ */
+ if (fscrypt_max_file_dun_bits(sb,
+ fscrypt_policy_v2_du_bits(policy, inode)) > 32) {
fscrypt_warn(inode,
- "Can't use %s policy on filesystem '%s' because its block numbers are too long",
+ "Can't use %s policy on filesystem '%s' because its maximum file size is too large",
type, sb->s_id);
return false;
}
@@ -108,7 +183,7 @@ static bool supported_iv_ino_lblk_policy(const struct fscrypt_policy_v2 *policy,
static bool fscrypt_supported_v1_policy(const struct fscrypt_policy_v1 *policy,
const struct inode *inode)
{
- if (!fscrypt_valid_enc_modes(policy->contents_encryption_mode,
+ if (!fscrypt_valid_enc_modes_v1(policy->contents_encryption_mode,
policy->filenames_encryption_mode)) {
fscrypt_warn(inode,
"Unsupported encryption modes (contents %d, filenames %d)",
@@ -144,7 +219,7 @@ static bool fscrypt_supported_v2_policy(const struct fscrypt_policy_v2 *policy,
{
int count = 0;
- if (!fscrypt_valid_enc_modes(policy->contents_encryption_mode,
+ if (!fscrypt_valid_enc_modes_v2(policy->contents_encryption_mode,
policy->filenames_encryption_mode)) {
fscrypt_warn(inode,
"Unsupported encryption modes (contents %d, filenames %d)",
@@ -153,7 +228,10 @@ static bool fscrypt_supported_v2_policy(const struct fscrypt_policy_v2 *policy,
return false;
}
- if (policy->flags & ~FSCRYPT_POLICY_FLAGS_VALID) {
+ if (policy->flags & ~(FSCRYPT_POLICY_FLAGS_PAD_MASK |
+ FSCRYPT_POLICY_FLAG_DIRECT_KEY |
+ FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64 |
+ FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32)) {
fscrypt_warn(inode, "Unsupported encryption flags (0x%02x)",
policy->flags);
return false;
@@ -168,20 +246,39 @@ static bool fscrypt_supported_v2_policy(const struct fscrypt_policy_v2 *policy,
return false;
}
+ if (policy->log2_data_unit_size) {
+ if (!inode->i_sb->s_cop->supports_subblock_data_units) {
+ fscrypt_warn(inode,
+ "Filesystem does not support configuring crypto data unit size");
+ return false;
+ }
+ if (policy->log2_data_unit_size > inode->i_blkbits ||
+ policy->log2_data_unit_size < SECTOR_SHIFT /* 9 */) {
+ fscrypt_warn(inode,
+ "Unsupported log2_data_unit_size in encryption policy: %d",
+ policy->log2_data_unit_size);
+ return false;
+ }
+ if (policy->log2_data_unit_size != inode->i_blkbits &&
+ (policy->flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32)) {
+ /*
+ * Not safe to enable yet, as we need to ensure that DUN
+ * wraparound can only occur on a FS block boundary.
+ */
+ fscrypt_warn(inode,
+ "Sub-block data units not yet supported with IV_INO_LBLK_32");
+ return false;
+ }
+ }
+
if ((policy->flags & FSCRYPT_POLICY_FLAG_DIRECT_KEY) &&
!supported_direct_key_modes(inode, policy->contents_encryption_mode,
policy->filenames_encryption_mode))
return false;
- if ((policy->flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64) &&
- !supported_iv_ino_lblk_policy(policy, inode, "IV_INO_LBLK_64",
- 32, 32))
- return false;
-
- if ((policy->flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32) &&
- /* This uses hashed inode numbers, so ino_bits doesn't matter. */
- !supported_iv_ino_lblk_policy(policy, inode, "IV_INO_LBLK_32",
- INT_MAX, 32))
+ if ((policy->flags & (FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64 |
+ FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32)) &&
+ !supported_iv_ino_lblk_policy(policy, inode))
return false;
if (memchr_inv(policy->__reserved, 0, sizeof(policy->__reserved))) {
@@ -217,18 +314,19 @@ bool fscrypt_supported_policy(const union fscrypt_policy *policy_u,
}
/**
- * fscrypt_new_context_from_policy() - create a new fscrypt_context from
- * an fscrypt_policy
+ * fscrypt_new_context() - create a new fscrypt_context
* @ctx_u: output context
* @policy_u: input policy
+ * @nonce: nonce to use
*
* Create an fscrypt_context for an inode that is being assigned the given
- * encryption policy. A new nonce is randomly generated.
+ * encryption policy. @nonce must be a new random nonce.
*
* Return: the size of the new context in bytes.
*/
-static int fscrypt_new_context_from_policy(union fscrypt_context *ctx_u,
- const union fscrypt_policy *policy_u)
+static int fscrypt_new_context(union fscrypt_context *ctx_u,
+ const union fscrypt_policy *policy_u,
+ const u8 nonce[FSCRYPT_FILE_NONCE_SIZE])
{
memset(ctx_u, 0, sizeof(*ctx_u));
@@ -246,7 +344,7 @@ static int fscrypt_new_context_from_policy(union fscrypt_context *ctx_u,
memcpy(ctx->master_key_descriptor,
policy->master_key_descriptor,
sizeof(ctx->master_key_descriptor));
- get_random_bytes(ctx->nonce, sizeof(ctx->nonce));
+ memcpy(ctx->nonce, nonce, FSCRYPT_FILE_NONCE_SIZE);
return sizeof(*ctx);
}
case FSCRYPT_POLICY_V2: {
@@ -259,10 +357,11 @@ static int fscrypt_new_context_from_policy(union fscrypt_context *ctx_u,
ctx->filenames_encryption_mode =
policy->filenames_encryption_mode;
ctx->flags = policy->flags;
+ ctx->log2_data_unit_size = policy->log2_data_unit_size;
memcpy(ctx->master_key_identifier,
policy->master_key_identifier,
sizeof(ctx->master_key_identifier));
- get_random_bytes(ctx->nonce, sizeof(ctx->nonce));
+ memcpy(ctx->nonce, nonce, FSCRYPT_FILE_NONCE_SIZE);
return sizeof(*ctx);
}
}
@@ -319,6 +418,7 @@ int fscrypt_policy_from_context(union fscrypt_policy *policy_u,
policy->filenames_encryption_mode =
ctx->filenames_encryption_mode;
policy->flags = ctx->flags;
+ policy->log2_data_unit_size = ctx->log2_data_unit_size;
memcpy(policy->__reserved, ctx->__reserved,
sizeof(policy->__reserved));
memcpy(policy->master_key_identifier,
@@ -334,11 +434,11 @@ int fscrypt_policy_from_context(union fscrypt_policy *policy_u,
/* Retrieve an inode's encryption policy */
static int fscrypt_get_policy(struct inode *inode, union fscrypt_policy *policy)
{
- const struct fscrypt_info *ci;
+ const struct fscrypt_inode_info *ci;
union fscrypt_context ctx;
int ret;
- ci = READ_ONCE(inode->i_crypt_info);
+ ci = fscrypt_get_inode_info(inode);
if (ci) {
/* key available, use the cached policy */
*policy = ci->ci_policy;
@@ -358,6 +458,7 @@ static int fscrypt_get_policy(struct inode *inode, union fscrypt_policy *policy)
static int set_encryption_policy(struct inode *inode,
const union fscrypt_policy *policy)
{
+ u8 nonce[FSCRYPT_FILE_NONCE_SIZE];
union fscrypt_context ctx;
int ctxsize;
int err;
@@ -391,11 +492,12 @@ static int set_encryption_policy(struct inode *inode,
current->comm, current->pid);
break;
default:
- WARN_ON(1);
+ WARN_ON_ONCE(1);
return -EINVAL;
}
- ctxsize = fscrypt_new_context_from_policy(&ctx, policy);
+ get_random_bytes(nonce, FSCRYPT_FILE_NONCE_SIZE);
+ ctxsize = fscrypt_new_context(&ctx, policy, nonce);
return inode->i_sb->s_cop->set_context(inode, &ctx, ctxsize, NULL);
}
@@ -432,7 +534,7 @@ int fscrypt_ioctl_set_policy(struct file *filp, const void __user *arg)
return -EFAULT;
policy.version = version;
- if (!inode_owner_or_capable(inode))
+ if (!inode_owner_or_capable(&nop_mnt_idmap, inode))
return -EACCES;
ret = mnt_want_write_file(filp);
@@ -529,7 +631,7 @@ int fscrypt_ioctl_get_nonce(struct file *filp, void __user *arg)
if (!fscrypt_context_is_valid(&ctx, ret))
return -EINVAL;
if (copy_to_user(arg, fscrypt_context_nonce(&ctx),
- FS_KEY_DERIVATION_NONCE_SIZE))
+ FSCRYPT_FILE_NONCE_SIZE))
return -EFAULT;
return 0;
}
@@ -557,7 +659,7 @@ EXPORT_SYMBOL_GPL(fscrypt_ioctl_get_nonce);
int fscrypt_has_permitted_context(struct inode *parent, struct inode *child)
{
union fscrypt_policy parent_policy, child_policy;
- int err;
+ int err, err1, err2;
/* No restrictions on file types which are never encrypted */
if (!S_ISREG(child->i_mode) && !S_ISDIR(child->i_mode) &&
@@ -574,7 +676,7 @@ int fscrypt_has_permitted_context(struct inode *parent, struct inode *child)
/*
* Both parent and child are encrypted, so verify they use the same
- * encryption policy. Compare the fscrypt_info structs if the keys are
+ * encryption policy. Compare the cached policies if the keys are
* available, otherwise retrieve and compare the fscrypt_contexts.
*
* Note that the fscrypt_context retrieval will be required frequently
@@ -587,163 +689,184 @@ int fscrypt_has_permitted_context(struct inode *parent, struct inode *child)
* In any case, if an unexpected error occurs, fall back to "forbidden".
*/
- err = fscrypt_get_encryption_info(parent);
+ err = fscrypt_get_encryption_info(parent, true);
if (err)
return 0;
- err = fscrypt_get_encryption_info(child);
+ err = fscrypt_get_encryption_info(child, true);
if (err)
return 0;
- err = fscrypt_get_policy(parent, &parent_policy);
- if (err)
- return 0;
+ err1 = fscrypt_get_policy(parent, &parent_policy);
+ err2 = fscrypt_get_policy(child, &child_policy);
- err = fscrypt_get_policy(child, &child_policy);
- if (err)
+ /*
+ * Allow the case where the parent and child both have an unrecognized
+ * encryption policy, so that files with an unrecognized encryption
+ * policy can be deleted.
+ */
+ if (err1 == -EINVAL && err2 == -EINVAL)
+ return 1;
+
+ if (err1 || err2)
return 0;
return fscrypt_policies_equal(&parent_policy, &child_policy);
}
EXPORT_SYMBOL(fscrypt_has_permitted_context);
+/*
+ * Return the encryption policy that new files in the directory will inherit, or
+ * NULL if none, or an ERR_PTR() on error. If the directory is encrypted, also
+ * ensure that its key is set up, so that the new filename can be encrypted.
+ */
+const union fscrypt_policy *fscrypt_policy_to_inherit(struct inode *dir)
+{
+ int err;
+
+ if (IS_ENCRYPTED(dir)) {
+ err = fscrypt_require_key(dir);
+ if (err)
+ return ERR_PTR(err);
+ return &fscrypt_get_inode_info_raw(dir)->ci_policy;
+ }
+
+ return fscrypt_get_dummy_policy(dir->i_sb);
+}
+
/**
- * fscrypt_inherit_context() - Sets a child context from its parent
- * @parent: Parent inode from which the context is inherited.
- * @child: Child inode that inherits the context from @parent.
- * @fs_data: private data given by FS.
- * @preload: preload child i_crypt_info if true
+ * fscrypt_context_for_new_inode() - create an encryption context for a new inode
+ * @ctx: where context should be written
+ * @inode: inode from which to fetch policy and nonce
*
- * Return: 0 on success, -errno on failure
+ * Given an in-core "prepared" (via fscrypt_prepare_new_inode) inode,
+ * generate a new context and write it to ctx. ctx _must_ be at least
+ * FSCRYPT_SET_CONTEXT_MAX_SIZE bytes.
+ *
+ * Return: size of the resulting context or a negative error code.
*/
-int fscrypt_inherit_context(struct inode *parent, struct inode *child,
- void *fs_data, bool preload)
+int fscrypt_context_for_new_inode(void *ctx, struct inode *inode)
{
- union fscrypt_context ctx;
- int ctxsize;
- struct fscrypt_info *ci;
- int res;
+ struct fscrypt_inode_info *ci = fscrypt_get_inode_info_raw(inode);
- res = fscrypt_get_encryption_info(parent);
- if (res < 0)
- return res;
+ BUILD_BUG_ON(sizeof(union fscrypt_context) !=
+ FSCRYPT_SET_CONTEXT_MAX_SIZE);
- ci = READ_ONCE(parent->i_crypt_info);
- if (ci == NULL)
+ /* fscrypt_prepare_new_inode() should have set up the key already. */
+ if (WARN_ON_ONCE(!ci))
return -ENOKEY;
- ctxsize = fscrypt_new_context_from_policy(&ctx, &ci->ci_policy);
-
- BUILD_BUG_ON(sizeof(ctx) != FSCRYPT_SET_CONTEXT_MAX_SIZE);
- res = parent->i_sb->s_cop->set_context(child, &ctx, ctxsize, fs_data);
- if (res)
- return res;
- return preload ? fscrypt_get_encryption_info(child): 0;
+ return fscrypt_new_context(ctx, &ci->ci_policy, ci->ci_nonce);
}
-EXPORT_SYMBOL(fscrypt_inherit_context);
+EXPORT_SYMBOL_GPL(fscrypt_context_for_new_inode);
/**
- * fscrypt_set_test_dummy_encryption() - handle '-o test_dummy_encryption'
- * @sb: the filesystem on which test_dummy_encryption is being specified
- * @arg: the argument to the test_dummy_encryption option.
- * If no argument was specified, then @arg->from == NULL.
- * @dummy_ctx: the filesystem's current dummy context (input/output, see below)
+ * fscrypt_set_context() - Set the fscrypt context of a new inode
+ * @inode: a new inode
+ * @fs_data: private data given by FS and passed to ->set_context()
*
- * Handle the test_dummy_encryption mount option by creating a dummy encryption
- * context, saving it in @dummy_ctx, and adding the corresponding dummy
- * encryption key to the filesystem. If the @dummy_ctx is already set, then
- * instead validate that it matches @arg. Don't support changing it via
- * remount, as that is difficult to do safely.
+ * This should be called after fscrypt_prepare_new_inode(), generally during a
+ * filesystem transaction. Everything here must be %GFP_NOFS-safe.
*
- * The reason we use an fscrypt_context rather than an fscrypt_policy is because
- * we mustn't generate a new nonce each time we access a dummy-encrypted
- * directory, as that would change the way filenames are encrypted.
+ * Return: 0 on success, -errno on failure
+ */
+int fscrypt_set_context(struct inode *inode, void *fs_data)
+{
+ struct fscrypt_inode_info *ci;
+ union fscrypt_context ctx;
+ int ctxsize;
+
+ ctxsize = fscrypt_context_for_new_inode(&ctx, inode);
+ if (ctxsize < 0)
+ return ctxsize;
+
+ /*
+ * This may be the first time the inode number is available, so do any
+ * delayed key setup that requires the inode number.
+ */
+ ci = fscrypt_get_inode_info_raw(inode);
+ if (ci->ci_policy.version == FSCRYPT_POLICY_V2 &&
+ (ci->ci_policy.v2.flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32))
+ fscrypt_hash_inode_number(ci, ci->ci_master_key);
+
+ return inode->i_sb->s_cop->set_context(inode, &ctx, ctxsize, fs_data);
+}
+EXPORT_SYMBOL_GPL(fscrypt_set_context);
+
+/**
+ * fscrypt_parse_test_dummy_encryption() - parse the test_dummy_encryption mount option
+ * @param: the mount option
+ * @dummy_policy: (input/output) the place to write the dummy policy that will
+ * result from parsing the option. Zero-initialize this. If a policy is
+ * already set here (due to test_dummy_encryption being given multiple
+ * times), then this function will verify that the policies are the same.
*
- * Return: 0 on success (dummy context set, or the same context is already set);
- * -EEXIST if a different dummy context is already set;
- * or another -errno value.
+ * Return: 0 on success; -EINVAL if the argument is invalid; -EEXIST if the
+ * argument conflicts with one already specified; or -ENOMEM.
*/
-int fscrypt_set_test_dummy_encryption(struct super_block *sb,
- const substring_t *arg,
- struct fscrypt_dummy_context *dummy_ctx)
+int fscrypt_parse_test_dummy_encryption(const struct fs_parameter *param,
+ struct fscrypt_dummy_policy *dummy_policy)
{
- const char *argstr = "v2";
- const char *argstr_to_free = NULL;
- struct fscrypt_key_specifier key_spec = { 0 };
- int version;
- union fscrypt_context *ctx = NULL;
+ const char *arg = "v2";
+ union fscrypt_policy *policy;
int err;
- if (arg->from) {
- argstr = argstr_to_free = match_strdup(arg);
- if (!argstr)
- return -ENOMEM;
- }
+ if (param->type == fs_value_is_string && *param->string)
+ arg = param->string;
+
+ policy = kzalloc(sizeof(*policy), GFP_KERNEL);
+ if (!policy)
+ return -ENOMEM;
- if (!strcmp(argstr, "v1")) {
- version = FSCRYPT_CONTEXT_V1;
- key_spec.type = FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR;
- memset(key_spec.u.descriptor, 0x42,
+ if (!strcmp(arg, "v1")) {
+ policy->version = FSCRYPT_POLICY_V1;
+ policy->v1.contents_encryption_mode = FSCRYPT_MODE_AES_256_XTS;
+ policy->v1.filenames_encryption_mode = FSCRYPT_MODE_AES_256_CTS;
+ memset(policy->v1.master_key_descriptor, 0x42,
FSCRYPT_KEY_DESCRIPTOR_SIZE);
- } else if (!strcmp(argstr, "v2")) {
- version = FSCRYPT_CONTEXT_V2;
- key_spec.type = FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER;
- /* key_spec.u.identifier gets filled in when adding the key */
+ } else if (!strcmp(arg, "v2")) {
+ policy->version = FSCRYPT_POLICY_V2;
+ policy->v2.contents_encryption_mode = FSCRYPT_MODE_AES_256_XTS;
+ policy->v2.filenames_encryption_mode = FSCRYPT_MODE_AES_256_CTS;
+ fscrypt_get_test_dummy_key_identifier(
+ policy->v2.master_key_identifier);
} else {
err = -EINVAL;
goto out;
}
- if (dummy_ctx->ctx) {
- /*
- * Note: if we ever make test_dummy_encryption support
- * specifying other encryption settings, such as the encryption
- * modes, we'll need to compare those settings here.
- */
- if (dummy_ctx->ctx->version == version)
+ if (dummy_policy->policy) {
+ if (fscrypt_policies_equal(policy, dummy_policy->policy))
err = 0;
else
err = -EEXIST;
goto out;
}
-
- ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
- if (!ctx) {
- err = -ENOMEM;
- goto out;
- }
-
- err = fscrypt_add_test_dummy_key(sb, &key_spec);
- if (err)
- goto out;
-
- ctx->version = version;
- switch (ctx->version) {
- case FSCRYPT_CONTEXT_V1:
- ctx->v1.contents_encryption_mode = FSCRYPT_MODE_AES_256_XTS;
- ctx->v1.filenames_encryption_mode = FSCRYPT_MODE_AES_256_CTS;
- memcpy(ctx->v1.master_key_descriptor, key_spec.u.descriptor,
- FSCRYPT_KEY_DESCRIPTOR_SIZE);
- break;
- case FSCRYPT_CONTEXT_V2:
- ctx->v2.contents_encryption_mode = FSCRYPT_MODE_AES_256_XTS;
- ctx->v2.filenames_encryption_mode = FSCRYPT_MODE_AES_256_CTS;
- memcpy(ctx->v2.master_key_identifier, key_spec.u.identifier,
- FSCRYPT_KEY_IDENTIFIER_SIZE);
- break;
- default:
- WARN_ON(1);
- err = -EINVAL;
- goto out;
- }
- dummy_ctx->ctx = ctx;
- ctx = NULL;
+ dummy_policy->policy = policy;
+ policy = NULL;
err = 0;
out:
- kfree(ctx);
- kfree(argstr_to_free);
+ kfree(policy);
return err;
}
-EXPORT_SYMBOL_GPL(fscrypt_set_test_dummy_encryption);
+EXPORT_SYMBOL_GPL(fscrypt_parse_test_dummy_encryption);
+
+/**
+ * fscrypt_dummy_policies_equal() - check whether two dummy policies are equal
+ * @p1: the first test dummy policy (may be unset)
+ * @p2: the second test dummy policy (may be unset)
+ *
+ * Return: %true if the dummy policies are both set and equal, or both unset.
+ */
+bool fscrypt_dummy_policies_equal(const struct fscrypt_dummy_policy *p1,
+ const struct fscrypt_dummy_policy *p2)
+{
+ if (!p1->policy && !p2->policy)
+ return true;
+ if (!p1->policy || !p2->policy)
+ return false;
+ return fscrypt_policies_equal(p1->policy, p2->policy);
+}
+EXPORT_SYMBOL_GPL(fscrypt_dummy_policies_equal);
/**
* fscrypt_show_test_dummy_encryption() - show '-o test_dummy_encryption'
@@ -757,10 +880,16 @@ EXPORT_SYMBOL_GPL(fscrypt_set_test_dummy_encryption);
void fscrypt_show_test_dummy_encryption(struct seq_file *seq, char sep,
struct super_block *sb)
{
- const union fscrypt_context *ctx = fscrypt_get_dummy_context(sb);
+ const union fscrypt_policy *policy = fscrypt_get_dummy_policy(sb);
+ int vers;
- if (!ctx)
+ if (!policy)
return;
- seq_printf(seq, "%ctest_dummy_encryption=v%d", sep, ctx->version);
+
+ vers = policy->version;
+ if (vers == FSCRYPT_POLICY_V1) /* Handle numbering quirk */
+ vers = 1;
+
+ seq_printf(seq, "%ctest_dummy_encryption=v%d", sep, vers);
}
EXPORT_SYMBOL_GPL(fscrypt_show_test_dummy_encryption);