static struct skcipher_request *init_skcipher_req(const u8 *key,
unsigned int key_len)
{
struct skcipher_request *req;
struct crypto_skcipher *tfm;
int ret;
tfm = crypto_alloc_skcipher(blkcipher_alg, 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(tfm)) {
pr_err("encrypted_key: failed to load %s transform (%ld)\n",
blkcipher_alg, PTR_ERR(tfm));
return ERR_CAST(tfm);
}
ret = crypto_skcipher_setkey(tfm, key, key_len);
if (ret < 0) {
pr_err("encrypted_key: failed to setkey (%d)\n", ret);
crypto_free_skcipher(tfm);
return ERR_PTR(ret);
}
req = skcipher_request_alloc(tfm, GFP_KERNEL);
if (!req) {
pr_err("encrypted_key: failed to allocate request for %s\n",
blkcipher_alg);
crypto_free_skcipher(tfm);
return ERR_PTR(-ENOMEM);
}
skcipher_request_set_callback(req, 0, NULL, NULL);
return req;
}
static int crypto_rfc3686_setkey(struct crypto_skcipher *parent,
const u8 *key, unsigned int keylen)
{
struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(parent);
struct crypto_skcipher *child = ctx->child;
int err;
/* the nonce is stored in bytes at end of key */
if (keylen < CTR_RFC3686_NONCE_SIZE)
return -EINVAL;
memcpy(ctx->nonce, key + (keylen - CTR_RFC3686_NONCE_SIZE),
CTR_RFC3686_NONCE_SIZE);
keylen -= CTR_RFC3686_NONCE_SIZE;
crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) &
CRYPTO_TFM_REQ_MASK);
err = crypto_skcipher_setkey(child, key, keylen);
crypto_skcipher_set_flags(parent, crypto_skcipher_get_flags(child) &
CRYPTO_TFM_RES_MASK);
return err;
}
/*
* Encrypt/decrypt big_key data
*/
static int big_key_crypt(enum big_key_op op, u8 *data, size_t datalen, u8 *key)
{
int ret = -EINVAL;
struct scatterlist sgio;
SKCIPHER_REQUEST_ON_STACK(req, big_key_skcipher);
if (crypto_skcipher_setkey(big_key_skcipher, key, ENC_KEY_SIZE)) {
ret = -EAGAIN;
goto error;
}
skcipher_request_set_tfm(req, big_key_skcipher);
skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP,
NULL, NULL);
sg_init_one(&sgio, data, datalen);
skcipher_request_set_crypt(req, &sgio, &sgio, datalen, NULL);
if (op == BIG_KEY_ENC)
ret = crypto_skcipher_encrypt(req);
else
ret = crypto_skcipher_decrypt(req);
skcipher_request_zero(req);
error:
return ret;
}
/*
* WUSB Pseudo Random Function (WUSB1.0[6.5])
*
* @b: buffer to the source data; cannot be a global or const local
* (will confuse the scatterlists)
*/
ssize_t wusb_prf(void *out, size_t out_size,
const u8 key[16], const struct aes_ccm_nonce *_n,
const struct aes_ccm_label *a,
const void *b, size_t blen, size_t len)
{
ssize_t result, bytes = 0, bitr;
struct aes_ccm_nonce n = *_n;
struct crypto_skcipher *tfm_cbc;
struct crypto_cipher *tfm_aes;
u64 sfn = 0;
__le64 sfn_le;
tfm_cbc = crypto_alloc_skcipher("cbc(aes)", 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(tfm_cbc)) {
result = PTR_ERR(tfm_cbc);
printk(KERN_ERR "E: can't load CBC(AES): %d\n", (int)result);
goto error_alloc_cbc;
}
result = crypto_skcipher_setkey(tfm_cbc, key, 16);
if (result < 0) {
printk(KERN_ERR "E: can't set CBC key: %d\n", (int)result);
goto error_setkey_cbc;
}
tfm_aes = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(tfm_aes)) {
result = PTR_ERR(tfm_aes);
printk(KERN_ERR "E: can't load AES: %d\n", (int)result);
goto error_alloc_aes;
}
result = crypto_cipher_setkey(tfm_aes, key, 16);
if (result < 0) {
printk(KERN_ERR "E: can't set AES key: %d\n", (int)result);
goto error_setkey_aes;
}
for (bitr = 0; bitr < (len + 63) / 64; bitr++) {
sfn_le = cpu_to_le64(sfn++);
memcpy(&n.sfn, &sfn_le, sizeof(n.sfn)); /* n.sfn++... */
result = wusb_ccm_mac(tfm_cbc, tfm_aes, out + bytes,
&n, a, b, blen);
if (result < 0)
goto error_ccm_mac;
bytes += result;
}
result = bytes;
error_ccm_mac:
error_setkey_aes:
crypto_free_cipher(tfm_aes);
error_alloc_aes:
error_setkey_cbc:
crypto_free_skcipher(tfm_cbc);
error_alloc_cbc:
return result;
}
static inline const void *
get_key(const void *p, const void *end,
struct krb5_ctx *ctx, struct crypto_skcipher **res)
{
struct xdr_netobj key;
int alg;
p = simple_get_bytes(p, end, &alg, sizeof(alg));
if (IS_ERR(p))
goto out_err;
switch (alg) {
case ENCTYPE_DES_CBC_CRC:
case ENCTYPE_DES_CBC_MD4:
case ENCTYPE_DES_CBC_MD5:
/* Map all these key types to ENCTYPE_DES_CBC_RAW */
alg = ENCTYPE_DES_CBC_RAW;
break;
}
if (!supported_gss_krb5_enctype(alg)) {
printk(KERN_WARNING "gss_kerberos_mech: unsupported "
"encryption key algorithm %d\n", alg);
p = ERR_PTR(-EINVAL);
goto out_err;
}
p = simple_get_netobj(p, end, &key);
if (IS_ERR(p))
goto out_err;
*res = crypto_alloc_skcipher(ctx->gk5e->encrypt_name, 0,
CRYPTO_ALG_ASYNC);
if (IS_ERR(*res)) {
printk(KERN_WARNING "gss_kerberos_mech: unable to initialize "
"crypto algorithm %s\n", ctx->gk5e->encrypt_name);
*res = NULL;
goto out_err_free_key;
}
if (crypto_skcipher_setkey(*res, key.data, key.len)) {
printk(KERN_WARNING "gss_kerberos_mech: error setting key for "
"crypto algorithm %s\n", ctx->gk5e->encrypt_name);
goto out_err_free_tfm;
}
kfree(key.data);
return p;
out_err_free_tfm:
crypto_free_skcipher(*res);
out_err_free_key:
kfree(key.data);
p = ERR_PTR(-EINVAL);
out_err:
return p;
}
static int simd_skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key,
unsigned int key_len)
{
struct simd_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
struct crypto_skcipher *child = &ctx->cryptd_tfm->base;
int err;
crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(tfm) &
CRYPTO_TFM_REQ_MASK);
err = crypto_skcipher_setkey(child, key, key_len);
crypto_skcipher_set_flags(tfm, crypto_skcipher_get_flags(child) &
CRYPTO_TFM_RES_MASK);
return err;
}
static int do_encrypt_iv(struct aead_request *req, u32 *tag, u32 *iv)
{
struct scatterlist iv_sg, tag_sg;
struct skcipher_request *sk_req;
struct omap_aes_gcm_result result;
struct omap_aes_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
int ret = 0;
sk_req = skcipher_request_alloc(ctx->ctr, GFP_KERNEL);
if (!sk_req) {
pr_err("skcipher: Failed to allocate request\n");
return -ENOMEM;
}
init_completion(&result.completion);
sg_init_one(&iv_sg, iv, AES_BLOCK_SIZE);
sg_init_one(&tag_sg, tag, AES_BLOCK_SIZE);
skcipher_request_set_callback(sk_req, CRYPTO_TFM_REQ_MAY_BACKLOG,
omap_aes_gcm_complete, &result);
ret = crypto_skcipher_setkey(ctx->ctr, (u8 *)ctx->key, ctx->keylen);
skcipher_request_set_crypt(sk_req, &iv_sg, &tag_sg, AES_BLOCK_SIZE,
NULL);
ret = crypto_skcipher_encrypt(sk_req);
switch (ret) {
case 0:
break;
case -EINPROGRESS:
case -EBUSY:
ret = wait_for_completion_interruptible(&result.completion);
if (!ret) {
ret = result.err;
if (!ret) {
reinit_completion(&result.completion);
break;
}
}
/* fall through */
default:
pr_err("Encryption of IV failed for GCM mode\n");
break;
}
skcipher_request_free(sk_req);
return ret;
}
/**
* f2fs_derive_key_aes() - Derive a key using AES-128-ECB
* @deriving_key: Encryption key used for derivatio.
* @source_key: Source key to which to apply derivation.
* @derived_key: Derived key.
*
* Return: Zero on success; non-zero otherwise.
*/
static int f2fs_derive_key_aes(char deriving_key[F2FS_AES_128_ECB_KEY_SIZE],
char source_key[F2FS_AES_256_XTS_KEY_SIZE],
char derived_key[F2FS_AES_256_XTS_KEY_SIZE])
{
int res = 0;
struct skcipher_request *req = NULL;
DECLARE_F2FS_COMPLETION_RESULT(ecr);
struct scatterlist src_sg, dst_sg;
struct crypto_skcipher *tfm = crypto_alloc_skcipher("ecb(aes)", 0, 0);
if (IS_ERR(tfm)) {
res = PTR_ERR(tfm);
tfm = NULL;
goto out;
}
crypto_skcipher_set_flags(tfm, CRYPTO_TFM_REQ_WEAK_KEY);
req = skcipher_request_alloc(tfm, GFP_NOFS);
if (!req) {
res = -ENOMEM;
goto out;
}
skcipher_request_set_callback(req,
CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
derive_crypt_complete, &ecr);
res = crypto_skcipher_setkey(tfm, deriving_key,
F2FS_AES_128_ECB_KEY_SIZE);
if (res < 0)
goto out;
sg_init_one(&src_sg, source_key, F2FS_AES_256_XTS_KEY_SIZE);
sg_init_one(&dst_sg, derived_key, F2FS_AES_256_XTS_KEY_SIZE);
skcipher_request_set_crypt(req, &src_sg, &dst_sg,
F2FS_AES_256_XTS_KEY_SIZE, NULL);
res = crypto_skcipher_encrypt(req);
if (res == -EINPROGRESS || res == -EBUSY) {
BUG_ON(req->base.data != &ecr);
wait_for_completion(&ecr.completion);
res = ecr.res;
}
out:
skcipher_request_free(req);
crypto_free_skcipher(tfm);
return res;
}
static struct crypto_skcipher *
context_v2_alloc_cipher(struct krb5_ctx *ctx, const char *cname, u8 *key)
{
struct crypto_skcipher *cp;
cp = crypto_alloc_skcipher(cname, 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(cp)) {
dprintk("gss_kerberos_mech: unable to initialize "
"crypto algorithm %s\n", cname);
return NULL;
}
if (crypto_skcipher_setkey(cp, key, ctx->gk5e->keylength)) {
dprintk("gss_kerberos_mech: error setting key for "
"crypto algorithm %s\n", cname);
crypto_free_skcipher(cp);
return NULL;
}
return cp;
}
static int p8_aes_xts_setkey(struct crypto_tfm *tfm, const u8 *key,
unsigned int keylen)
{
int ret;
struct p8_aes_xts_ctx *ctx = crypto_tfm_ctx(tfm);
ret = xts_check_key(tfm, key, keylen);
if (ret)
return ret;
preempt_disable();
pagefault_disable();
enable_kernel_vsx();
ret = aes_p8_set_encrypt_key(key + keylen/2, (keylen/2) * 8, &ctx->tweak_key);
ret += aes_p8_set_encrypt_key(key, (keylen/2) * 8, &ctx->enc_key);
ret += aes_p8_set_decrypt_key(key, (keylen/2) * 8, &ctx->dec_key);
disable_kernel_vsx();
pagefault_enable();
preempt_enable();
ret += crypto_skcipher_setkey(ctx->fallback, key, keylen);
return ret;
}
static int setkey(struct crypto_skcipher *parent, const u8 *key,
unsigned int keylen)
{
struct priv *ctx = crypto_skcipher_ctx(parent);
struct crypto_skcipher *child = ctx->child;
int err, bsize = LRW_BLOCK_SIZE;
const u8 *tweak = key + keylen - bsize;
be128 tmp = { 0 };
int i;
crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) &
CRYPTO_TFM_REQ_MASK);
err = crypto_skcipher_setkey(child, key, keylen - bsize);
crypto_skcipher_set_flags(parent, crypto_skcipher_get_flags(child) &
CRYPTO_TFM_RES_MASK);
if (err)
return err;
if (ctx->table)
gf128mul_free_64k(ctx->table);
/* initialize multiplication table for Key2 */
ctx->table = gf128mul_init_64k_bbe((be128 *)tweak);
if (!ctx->table)
return -ENOMEM;
/* initialize optimization table */
for (i = 0; i < 128; i++) {
setbit128_bbe(&tmp, i);
ctx->mulinc[i] = tmp;
gf128mul_64k_bbe(&ctx->mulinc[i], ctx->table);
}
return 0;
}
int fscrypt_get_crypt_info(struct inode *inode)
{
struct fscrypt_info *crypt_info;
struct fscrypt_context ctx;
struct crypto_skcipher *ctfm;
const char *cipher_str;
int keysize;
u8 *raw_key = NULL;
int res;
res = fscrypt_initialize(inode->i_sb->s_cop->flags);
if (res)
return res;
if (!inode->i_sb->s_cop->get_context)
return -EOPNOTSUPP;
retry:
crypt_info = ACCESS_ONCE(inode->i_crypt_info);
if (crypt_info) {
if (!crypt_info->ci_keyring_key ||
key_validate(crypt_info->ci_keyring_key) == 0)
return 0;
fscrypt_put_encryption_info(inode, crypt_info);
goto retry;
}
res = inode->i_sb->s_cop->get_context(inode, &ctx, sizeof(ctx));
if (res < 0) {
if (!fscrypt_dummy_context_enabled(inode))
return res;
ctx.format = FS_ENCRYPTION_CONTEXT_FORMAT_V1;
ctx.contents_encryption_mode = FS_ENCRYPTION_MODE_AES_256_XTS;
ctx.filenames_encryption_mode = FS_ENCRYPTION_MODE_AES_256_CTS;
ctx.flags = 0;
} else if (res != sizeof(ctx)) {
return -EINVAL;
}
if (ctx.format != FS_ENCRYPTION_CONTEXT_FORMAT_V1)
return -EINVAL;
if (ctx.flags & ~FS_POLICY_FLAGS_VALID)
return -EINVAL;
crypt_info = kmem_cache_alloc(fscrypt_info_cachep, GFP_NOFS);
if (!crypt_info)
return -ENOMEM;
crypt_info->ci_flags = ctx.flags;
crypt_info->ci_data_mode = ctx.contents_encryption_mode;
crypt_info->ci_filename_mode = ctx.filenames_encryption_mode;
crypt_info->ci_ctfm = NULL;
crypt_info->ci_keyring_key = NULL;
memcpy(crypt_info->ci_master_key, ctx.master_key_descriptor,
sizeof(crypt_info->ci_master_key));
res = determine_cipher_type(crypt_info, inode, &cipher_str, &keysize);
if (res)
goto out;
/*
* This cannot be a stack buffer because it is passed to the scatterlist
* crypto API as part of key derivation.
*/
res = -ENOMEM;
raw_key = kmalloc(FS_MAX_KEY_SIZE, GFP_NOFS);
if (!raw_key)
goto out;
if (fscrypt_dummy_context_enabled(inode)) {
memset(raw_key, 0x42, FS_AES_256_XTS_KEY_SIZE);
goto got_key;
}
res = validate_user_key(crypt_info, &ctx, raw_key,
FS_KEY_DESC_PREFIX, FS_KEY_DESC_PREFIX_SIZE);
if (res && inode->i_sb->s_cop->key_prefix) {
u8 *prefix = NULL;
int prefix_size, res2;
prefix_size = inode->i_sb->s_cop->key_prefix(inode, &prefix);
res2 = validate_user_key(crypt_info, &ctx, raw_key,
prefix, prefix_size);
if (res2) {
if (res2 == -ENOKEY)
res = -ENOKEY;
goto out;
}
} else if (res) {
goto out;
}
got_key:
ctfm = crypto_alloc_skcipher(cipher_str, 0, 0);
if (!ctfm || IS_ERR(ctfm)) {
res = ctfm ? PTR_ERR(ctfm) : -ENOMEM;
printk(KERN_DEBUG
"%s: error %d (inode %u) allocating crypto tfm\n",
__func__, res, (unsigned) inode->i_ino);
goto out;
}
crypt_info->ci_ctfm = ctfm;
crypto_skcipher_clear_flags(ctfm, ~0);
crypto_skcipher_set_flags(ctfm, CRYPTO_TFM_REQ_WEAK_KEY);
res = crypto_skcipher_setkey(ctfm, raw_key, keysize);
if (res)
goto out;
kzfree(raw_key);
raw_key = NULL;
if (cmpxchg(&inode->i_crypt_info, NULL, crypt_info) != NULL) {
put_crypt_info(crypt_info);
goto retry;
}
return 0;
out:
if (res == -ENOKEY)
res = 0;
put_crypt_info(crypt_info);
kzfree(raw_key);
return res;
}
int get_crypt_info(struct inode *inode)
{
struct fscrypt_info *crypt_info;
struct fscrypt_context ctx;
struct crypto_skcipher *ctfm;
const char *cipher_str;
u8 raw_key[FS_MAX_KEY_SIZE];
u8 mode;
int res;
res = fscrypt_initialize();
if (res)
return res;
if (!inode->i_sb->s_cop->get_context)
return -EOPNOTSUPP;
retry:
crypt_info = ACCESS_ONCE(inode->i_crypt_info);
if (crypt_info) {
if (!crypt_info->ci_keyring_key ||
key_validate(crypt_info->ci_keyring_key) == 0)
return 0;
fscrypt_put_encryption_info(inode, crypt_info);
goto retry;
}
res = inode->i_sb->s_cop->get_context(inode, &ctx, sizeof(ctx));
if (res < 0) {
if (!fscrypt_dummy_context_enabled(inode))
return res;
ctx.contents_encryption_mode = FS_ENCRYPTION_MODE_AES_256_XTS;
ctx.filenames_encryption_mode = FS_ENCRYPTION_MODE_AES_256_CTS;
ctx.flags = 0;
} else if (res != sizeof(ctx)) {
return -EINVAL;
}
res = 0;
crypt_info = kmem_cache_alloc(fscrypt_info_cachep, GFP_NOFS);
if (!crypt_info)
return -ENOMEM;
crypt_info->ci_flags = ctx.flags;
crypt_info->ci_data_mode = ctx.contents_encryption_mode;
crypt_info->ci_filename_mode = ctx.filenames_encryption_mode;
crypt_info->ci_ctfm = NULL;
crypt_info->ci_keyring_key = NULL;
memcpy(crypt_info->ci_master_key, ctx.master_key_descriptor,
sizeof(crypt_info->ci_master_key));
if (S_ISREG(inode->i_mode))
mode = crypt_info->ci_data_mode;
else if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
mode = crypt_info->ci_filename_mode;
else
BUG();
switch (mode) {
case FS_ENCRYPTION_MODE_AES_256_XTS:
cipher_str = "xts(aes)";
break;
case FS_ENCRYPTION_MODE_AES_256_CTS:
cipher_str = "cts(cbc(aes))";
break;
default:
printk_once(KERN_WARNING
"%s: unsupported key mode %d (ino %u)\n",
__func__, mode, (unsigned) inode->i_ino);
res = -ENOKEY;
goto out;
}
if (fscrypt_dummy_context_enabled(inode)) {
memset(raw_key, 0x42, FS_AES_256_XTS_KEY_SIZE);
goto got_key;
}
res = validate_user_key(crypt_info, &ctx, raw_key,
FS_KEY_DESC_PREFIX, FS_KEY_DESC_PREFIX_SIZE);
if (res && inode->i_sb->s_cop->key_prefix) {
u8 *prefix = NULL;
int prefix_size, res2;
prefix_size = inode->i_sb->s_cop->key_prefix(inode, &prefix);
res2 = validate_user_key(crypt_info, &ctx, raw_key,
prefix, prefix_size);
if (res2) {
if (res2 == -ENOKEY)
res = -ENOKEY;
goto out;
}
} else if (res) {
goto out;
}
got_key:
ctfm = crypto_alloc_skcipher(cipher_str, 0, 0);
if (!ctfm || IS_ERR(ctfm)) {
res = ctfm ? PTR_ERR(ctfm) : -ENOMEM;
printk(KERN_DEBUG
"%s: error %d (inode %u) allocating crypto tfm\n",
__func__, res, (unsigned) inode->i_ino);
goto out;
}
crypt_info->ci_ctfm = ctfm;
crypto_skcipher_clear_flags(ctfm, ~0);
crypto_skcipher_set_flags(ctfm, CRYPTO_TFM_REQ_WEAK_KEY);
res = crypto_skcipher_setkey(ctfm, raw_key, fscrypt_key_size(mode));
if (res)
goto out;
memzero_explicit(raw_key, sizeof(raw_key));
if (cmpxchg(&inode->i_crypt_info, NULL, crypt_info) != NULL) {
put_crypt_info(crypt_info);
goto retry;
}
return 0;
out:
if (res == -ENOKEY)
res = 0;
put_crypt_info(crypt_info);
memzero_explicit(raw_key, sizeof(raw_key));
return res;
}
int _f2fs_get_encryption_info(struct inode *inode)
{
struct f2fs_inode_info *fi = F2FS_I(inode);
struct f2fs_crypt_info *crypt_info;
char full_key_descriptor[F2FS_KEY_DESC_PREFIX_SIZE +
(F2FS_KEY_DESCRIPTOR_SIZE * 2) + 1];
struct key *keyring_key = NULL;
struct f2fs_encryption_key *master_key;
struct f2fs_encryption_context ctx;
const struct user_key_payload *ukp;
struct crypto_skcipher *ctfm;
const char *cipher_str;
char raw_key[F2FS_MAX_KEY_SIZE];
char mode;
int res;
res = f2fs_crypto_initialize();
if (res)
return res;
retry:
crypt_info = ACCESS_ONCE(fi->i_crypt_info);
if (crypt_info) {
if (!crypt_info->ci_keyring_key ||
key_validate(crypt_info->ci_keyring_key) == 0)
return 0;
f2fs_free_encryption_info(inode, crypt_info);
goto retry;
}
res = f2fs_getxattr(inode, F2FS_XATTR_INDEX_ENCRYPTION,
F2FS_XATTR_NAME_ENCRYPTION_CONTEXT,
&ctx, sizeof(ctx), NULL);
if (res < 0)
return res;
else if (res != sizeof(ctx))
return -EINVAL;
res = 0;
crypt_info = kmem_cache_alloc(f2fs_crypt_info_cachep, GFP_NOFS);
if (!crypt_info)
return -ENOMEM;
crypt_info->ci_flags = ctx.flags;
crypt_info->ci_data_mode = ctx.contents_encryption_mode;
crypt_info->ci_filename_mode = ctx.filenames_encryption_mode;
crypt_info->ci_ctfm = NULL;
crypt_info->ci_keyring_key = NULL;
memcpy(crypt_info->ci_master_key, ctx.master_key_descriptor,
sizeof(crypt_info->ci_master_key));
if (S_ISREG(inode->i_mode))
mode = crypt_info->ci_data_mode;
else if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
mode = crypt_info->ci_filename_mode;
else
BUG();
switch (mode) {
case F2FS_ENCRYPTION_MODE_AES_256_XTS:
cipher_str = "xts(aes)";
break;
case F2FS_ENCRYPTION_MODE_AES_256_CTS:
cipher_str = "cts(cbc(aes))";
break;
default:
printk_once(KERN_WARNING
"f2fs: unsupported key mode %d (ino %u)\n",
mode, (unsigned) inode->i_ino);
res = -ENOKEY;
goto out;
}
memcpy(full_key_descriptor, F2FS_KEY_DESC_PREFIX,
F2FS_KEY_DESC_PREFIX_SIZE);
sprintf(full_key_descriptor + F2FS_KEY_DESC_PREFIX_SIZE,
"%*phN", F2FS_KEY_DESCRIPTOR_SIZE,
ctx.master_key_descriptor);
full_key_descriptor[F2FS_KEY_DESC_PREFIX_SIZE +
(2 * F2FS_KEY_DESCRIPTOR_SIZE)] = '\0';
keyring_key = request_key(&key_type_logon, full_key_descriptor, NULL);
if (IS_ERR(keyring_key)) {
res = PTR_ERR(keyring_key);
keyring_key = NULL;
goto out;
}
crypt_info->ci_keyring_key = keyring_key;
BUG_ON(keyring_key->type != &key_type_logon);
ukp = user_key_payload(keyring_key);
if (ukp->datalen != sizeof(struct f2fs_encryption_key)) {
res = -EINVAL;
goto out;
}
master_key = (struct f2fs_encryption_key *)ukp->data;
BUILD_BUG_ON(F2FS_AES_128_ECB_KEY_SIZE !=
F2FS_KEY_DERIVATION_NONCE_SIZE);
BUG_ON(master_key->size != F2FS_AES_256_XTS_KEY_SIZE);
res = f2fs_derive_key_aes(ctx.nonce, master_key->raw,
raw_key);
if (res)
goto out;
ctfm = crypto_alloc_skcipher(cipher_str, 0, 0);
if (!ctfm || IS_ERR(ctfm)) {
res = ctfm ? PTR_ERR(ctfm) : -ENOMEM;
printk(KERN_DEBUG
"%s: error %d (inode %u) allocating crypto tfm\n",
__func__, res, (unsigned) inode->i_ino);
goto out;
}
crypt_info->ci_ctfm = ctfm;
crypto_skcipher_clear_flags(ctfm, ~0);
crypto_skcipher_set_flags(ctfm, CRYPTO_TFM_REQ_WEAK_KEY);
res = crypto_skcipher_setkey(ctfm, raw_key,
f2fs_encryption_key_size(mode));
if (res)
goto out;
memzero_explicit(raw_key, sizeof(raw_key));
if (cmpxchg(&fi->i_crypt_info, NULL, crypt_info) != NULL) {
f2fs_free_crypt_info(crypt_info);
goto retry;
}
return 0;
out:
if (res == -ENOKEY && !S_ISREG(inode->i_mode))
res = 0;
f2fs_free_crypt_info(crypt_info);
memzero_explicit(raw_key, sizeof(raw_key));
return res;
}
int fscrypt_get_encryption_info(struct inode *inode)
{
struct fscrypt_info *crypt_info;
struct fscrypt_context ctx;
struct crypto_skcipher *ctfm;
const char *cipher_str;
int keysize;
u8 *raw_key = NULL;
int res;
if (inode->i_crypt_info)
return 0;
res = fscrypt_initialize(inode->i_sb->s_cop->flags);
if (res)
return res;
res = inode->i_sb->s_cop->get_context(inode, &ctx, sizeof(ctx));
if (res < 0) {
if (!fscrypt_dummy_context_enabled(inode) ||
inode->i_sb->s_cop->is_encrypted(inode))
return res;
/* Fake up a context for an unencrypted directory */
memset(&ctx, 0, sizeof(ctx));
ctx.format = FS_ENCRYPTION_CONTEXT_FORMAT_V1;
ctx.contents_encryption_mode = FS_ENCRYPTION_MODE_AES_256_XTS;
ctx.filenames_encryption_mode = FS_ENCRYPTION_MODE_AES_256_CTS;
memset(ctx.master_key_descriptor, 0x42, FS_KEY_DESCRIPTOR_SIZE);
} else if (res != sizeof(ctx)) {
return -EINVAL;
}
if (ctx.format != FS_ENCRYPTION_CONTEXT_FORMAT_V1)
return -EINVAL;
if (ctx.flags & ~FS_POLICY_FLAGS_VALID)
return -EINVAL;
crypt_info = kmem_cache_alloc(fscrypt_info_cachep, GFP_NOFS);
if (!crypt_info)
return -ENOMEM;
crypt_info->ci_flags = ctx.flags;
crypt_info->ci_data_mode = ctx.contents_encryption_mode;
crypt_info->ci_filename_mode = ctx.filenames_encryption_mode;
crypt_info->ci_ctfm = NULL;
crypt_info->ci_essiv_tfm = NULL;
memcpy(crypt_info->ci_master_key, ctx.master_key_descriptor,
sizeof(crypt_info->ci_master_key));
res = determine_cipher_type(crypt_info, inode, &cipher_str, &keysize);
if (res)
goto out;
/*
* This cannot be a stack buffer because it is passed to the scatterlist
* crypto API as part of key derivation.
*/
res = -ENOMEM;
raw_key = kmalloc(FS_MAX_KEY_SIZE, GFP_NOFS);
if (!raw_key)
goto out;
res = validate_user_key(crypt_info, &ctx, raw_key, FS_KEY_DESC_PREFIX,
keysize);
if (res && inode->i_sb->s_cop->key_prefix) {
int res2 = validate_user_key(crypt_info, &ctx, raw_key,
inode->i_sb->s_cop->key_prefix,
keysize);
if (res2) {
if (res2 == -ENOKEY)
res = -ENOKEY;
goto out;
}
} else if (res) {
goto out;
}
ctfm = crypto_alloc_skcipher(cipher_str, 0, 0);
if (!ctfm || IS_ERR(ctfm)) {
res = ctfm ? PTR_ERR(ctfm) : -ENOMEM;
pr_debug("%s: error %d (inode %lu) allocating crypto tfm\n",
__func__, res, inode->i_ino);
goto out;
}
crypt_info->ci_ctfm = ctfm;
crypto_skcipher_clear_flags(ctfm, ~0);
crypto_skcipher_set_flags(ctfm, CRYPTO_TFM_REQ_WEAK_KEY);
/*
* if the provided key is longer than keysize, we use the first
* keysize bytes of the derived key only
*/
res = crypto_skcipher_setkey(ctfm, raw_key, keysize);
if (res)
goto out;
if (S_ISREG(inode->i_mode) &&
crypt_info->ci_data_mode == FS_ENCRYPTION_MODE_AES_128_CBC) {
res = init_essiv_generator(crypt_info, raw_key, keysize);
if (res) {
pr_debug("%s: error %d (inode %lu) allocating essiv tfm\n",
__func__, res, inode->i_ino);
goto out;
}
}
if (cmpxchg(&inode->i_crypt_info, NULL, crypt_info) == NULL)
crypt_info = NULL;
out:
if (res == -ENOKEY)
res = 0;
put_crypt_info(crypt_info);
kzfree(raw_key);
return res;
}