/*
* ext4_fname_decrypt()
* This function decrypts the input filename, and returns
* the length of the plaintext.
* Errors are returned as negative numbers.
* We trust the caller to allocate sufficient memory to oname string.
*/
static int ext4_fname_decrypt(struct inode *inode,
const struct ext4_str *iname,
struct ext4_str *oname)
{
struct ext4_str tmp_in[2], tmp_out[1];
struct skcipher_request *req = NULL;
DECLARE_EXT4_COMPLETION_RESULT(ecr);
struct scatterlist src_sg, dst_sg;
struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
struct crypto_skcipher *tfm = ci->ci_ctfm;
int res = 0;
char iv[EXT4_CRYPTO_BLOCK_SIZE];
unsigned lim = max_name_len(inode);
if (iname->len <= 0 || iname->len > lim)
return -EIO;
tmp_in[0].name = iname->name;
tmp_in[0].len = iname->len;
tmp_out[0].name = oname->name;
/* Allocate request */
req = skcipher_request_alloc(tfm, GFP_NOFS);
if (!req) {
printk_ratelimited(
KERN_ERR "%s: crypto_request_alloc() failed\n", __func__);
return -ENOMEM;
}
skcipher_request_set_callback(req,
CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
ext4_dir_crypt_complete, &ecr);
/* Initialize IV */
memset(iv, 0, EXT4_CRYPTO_BLOCK_SIZE);
/* Create encryption request */
sg_init_one(&src_sg, iname->name, iname->len);
sg_init_one(&dst_sg, oname->name, oname->len);
skcipher_request_set_crypt(req, &src_sg, &dst_sg, iname->len, iv);
res = crypto_skcipher_decrypt(req);
if (res == -EINPROGRESS || res == -EBUSY) {
wait_for_completion(&ecr.completion);
res = ecr.res;
}
skcipher_request_free(req);
if (res < 0) {
printk_ratelimited(
KERN_ERR "%s: Error in ext4_fname_encrypt (error code %d)\n",
__func__, res);
return res;
}
oname->len = strnlen(oname->name, iname->len);
return oname->len;
}
static int do_page_crypto(struct inode *inode,
fscrypt_direction_t rw, pgoff_t index,
struct page *src_page, struct page *dest_page,
gfp_t gfp_flags)
{
struct {
__le64 index;
u8 padding[FS_XTS_TWEAK_SIZE - sizeof(__le64)];
} xts_tweak;
struct skcipher_request *req = NULL;
DECLARE_FS_COMPLETION_RESULT(ecr);
struct scatterlist dst, src;
struct fscrypt_info *ci = inode->i_crypt_info;
struct crypto_skcipher *tfm = ci->ci_ctfm;
int res = 0;
req = skcipher_request_alloc(tfm, gfp_flags);
if (!req) {
printk_ratelimited(KERN_ERR
"%s: crypto_request_alloc() failed\n",
__func__);
return -ENOMEM;
}
skcipher_request_set_callback(
req, CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
page_crypt_complete, &ecr);
BUILD_BUG_ON(sizeof(xts_tweak) != FS_XTS_TWEAK_SIZE);
xts_tweak.index = cpu_to_le64(index);
memset(xts_tweak.padding, 0, sizeof(xts_tweak.padding));
sg_init_table(&dst, 1);
sg_set_page(&dst, dest_page, PAGE_SIZE, 0);
sg_init_table(&src, 1);
sg_set_page(&src, src_page, PAGE_SIZE, 0);
skcipher_request_set_crypt(req, &src, &dst, PAGE_SIZE, &xts_tweak);
if (rw == FS_DECRYPT)
res = crypto_skcipher_decrypt(req);
else
res = crypto_skcipher_encrypt(req);
if (res == -EINPROGRESS || res == -EBUSY) {
BUG_ON(req->base.data != &ecr);
wait_for_completion(&ecr.completion);
res = ecr.res;
}
skcipher_request_free(req);
if (res) {
printk_ratelimited(KERN_ERR
"%s: crypto_skcipher_encrypt() returned %d\n",
__func__, res);
return res;
}
return 0;
}
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;
}
/**
* fname_encrypt() - encrypt a filename
*
* The output buffer must be at least as large as the input buffer.
* Any extra space is filled with NUL padding before encryption.
*
* Return: 0 on success, -errno on failure
*/
int fname_encrypt(struct inode *inode, const struct qstr *iname,
u8 *out, unsigned int olen)
{
struct skcipher_request *req = NULL;
DECLARE_CRYPTO_WAIT(wait);
struct fscrypt_info *ci = inode->i_crypt_info;
struct crypto_skcipher *tfm = ci->ci_ctfm;
union fscrypt_iv iv;
struct scatterlist sg;
int res;
/*
* Copy the filename to the output buffer for encrypting in-place and
* pad it with the needed number of NUL bytes.
*/
if (WARN_ON(olen < iname->len))
return -ENOBUFS;
memcpy(out, iname->name, iname->len);
memset(out + iname->len, 0, olen - iname->len);
/* Initialize the IV */
fscrypt_generate_iv(&iv, 0, ci);
/* Set up the encryption request */
req = skcipher_request_alloc(tfm, GFP_NOFS);
if (!req)
return -ENOMEM;
skcipher_request_set_callback(req,
CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
crypto_req_done, &wait);
sg_init_one(&sg, out, olen);
skcipher_request_set_crypt(req, &sg, &sg, olen, &iv);
/* Do the encryption */
res = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
skcipher_request_free(req);
if (res < 0) {
fscrypt_err(inode->i_sb,
"Filename encryption failed for inode %lu: %d",
inode->i_ino, res);
return res;
}
return 0;
}
/* Before returning data to userspace, encrypt decrypted data. */
static int derived_key_encrypt(struct encrypted_key_payload *epayload,
const u8 *derived_key,
unsigned int derived_keylen)
{
struct scatterlist sg_in[2];
struct scatterlist sg_out[1];
struct crypto_skcipher *tfm;
struct skcipher_request *req;
unsigned int encrypted_datalen;
u8 iv[AES_BLOCK_SIZE];
unsigned int padlen;
char pad[16];
int ret;
encrypted_datalen = roundup(epayload->decrypted_datalen, blksize);
padlen = encrypted_datalen - epayload->decrypted_datalen;
req = init_skcipher_req(derived_key, derived_keylen);
ret = PTR_ERR(req);
if (IS_ERR(req))
goto out;
dump_decrypted_data(epayload);
memset(pad, 0, sizeof pad);
sg_init_table(sg_in, 2);
sg_set_buf(&sg_in[0], epayload->decrypted_data,
epayload->decrypted_datalen);
sg_set_buf(&sg_in[1], pad, padlen);
sg_init_table(sg_out, 1);
sg_set_buf(sg_out, epayload->encrypted_data, encrypted_datalen);
memcpy(iv, epayload->iv, sizeof(iv));
skcipher_request_set_crypt(req, sg_in, sg_out, encrypted_datalen, iv);
ret = crypto_skcipher_encrypt(req);
tfm = crypto_skcipher_reqtfm(req);
skcipher_request_free(req);
crypto_free_skcipher(tfm);
if (ret < 0)
pr_err("encrypted_key: failed to encrypt (%d)\n", ret);
else
dump_encrypted_data(epayload, encrypted_datalen);
out:
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;
}
int fscrypt_do_page_crypto(const struct inode *inode, fscrypt_direction_t rw,
u64 lblk_num, struct page *src_page,
struct page *dest_page, unsigned int len,
unsigned int offs, gfp_t gfp_flags)
{
union fscrypt_iv iv;
struct skcipher_request *req = NULL;
DECLARE_CRYPTO_WAIT(wait);
struct scatterlist dst, src;
struct fscrypt_info *ci = inode->i_crypt_info;
struct crypto_skcipher *tfm = ci->ci_ctfm;
int res = 0;
BUG_ON(len == 0);
fscrypt_generate_iv(&iv, lblk_num, ci);
req = skcipher_request_alloc(tfm, gfp_flags);
if (!req)
return -ENOMEM;
skcipher_request_set_callback(
req, CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
crypto_req_done, &wait);
sg_init_table(&dst, 1);
sg_set_page(&dst, dest_page, len, offs);
sg_init_table(&src, 1);
sg_set_page(&src, src_page, len, offs);
skcipher_request_set_crypt(req, &src, &dst, len, &iv);
if (rw == FS_DECRYPT)
res = crypto_wait_req(crypto_skcipher_decrypt(req), &wait);
else
res = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
skcipher_request_free(req);
if (res) {
fscrypt_err(inode->i_sb,
"%scryption failed for inode %lu, block %llu: %d",
(rw == FS_DECRYPT ? "de" : "en"),
inode->i_ino, lblk_num, res);
return res;
}
return 0;
}
/**
* fname_decrypt() - decrypt a filename
*
* The caller must have allocated sufficient memory for the @oname string.
*
* Return: 0 on success, -errno on failure
*/
static int fname_decrypt(struct inode *inode,
const struct fscrypt_str *iname,
struct fscrypt_str *oname)
{
struct skcipher_request *req = NULL;
DECLARE_CRYPTO_WAIT(wait);
struct scatterlist src_sg, dst_sg;
struct fscrypt_info *ci = inode->i_crypt_info;
struct crypto_skcipher *tfm = ci->ci_ctfm;
union fscrypt_iv iv;
int res;
/* Allocate request */
req = skcipher_request_alloc(tfm, GFP_NOFS);
if (!req)
return -ENOMEM;
skcipher_request_set_callback(req,
CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
crypto_req_done, &wait);
/* Initialize IV */
fscrypt_generate_iv(&iv, 0, ci);
/* Create decryption request */
sg_init_one(&src_sg, iname->name, iname->len);
sg_init_one(&dst_sg, oname->name, oname->len);
skcipher_request_set_crypt(req, &src_sg, &dst_sg, iname->len, &iv);
res = crypto_wait_req(crypto_skcipher_decrypt(req), &wait);
skcipher_request_free(req);
if (res < 0) {
fscrypt_err(inode->i_sb,
"Filename decryption failed for inode %lu: %d",
inode->i_ino, res);
return res;
}
oname->len = strnlen(oname->name, iname->len);
return 0;
}
static int derived_key_decrypt(struct encrypted_key_payload *epayload,
const u8 *derived_key,
unsigned int derived_keylen)
{
struct scatterlist sg_in[1];
struct scatterlist sg_out[2];
struct crypto_skcipher *tfm;
struct skcipher_request *req;
unsigned int encrypted_datalen;
char pad[16];
int ret;
encrypted_datalen = roundup(epayload->decrypted_datalen, blksize);
req = init_skcipher_req(derived_key, derived_keylen);
ret = PTR_ERR(req);
if (IS_ERR(req))
goto out;
dump_encrypted_data(epayload, encrypted_datalen);
memset(pad, 0, sizeof pad);
sg_init_table(sg_in, 1);
sg_init_table(sg_out, 2);
sg_set_buf(sg_in, epayload->encrypted_data, encrypted_datalen);
sg_set_buf(&sg_out[0], epayload->decrypted_data,
epayload->decrypted_datalen);
sg_set_buf(&sg_out[1], pad, sizeof pad);
skcipher_request_set_crypt(req, sg_in, sg_out, encrypted_datalen,
epayload->iv);
ret = crypto_skcipher_decrypt(req);
tfm = crypto_skcipher_reqtfm(req);
skcipher_request_free(req);
crypto_free_skcipher(tfm);
if (ret < 0)
goto out;
dump_decrypted_data(epayload);
out:
return ret;
}
/**
* fname_encrypt() - encrypt a filename
*
* The caller must have allocated sufficient memory for the @oname string.
*
* Return: 0 on success, -errno on failure
*/
static int fname_encrypt(struct inode *inode,
const struct qstr *iname, struct fscrypt_str *oname)
{
struct skcipher_request *req = NULL;
DECLARE_FS_COMPLETION_RESULT(ecr);
struct fscrypt_info *ci = inode->i_crypt_info;
struct crypto_skcipher *tfm = ci->ci_ctfm;
int res = 0;
char iv[FS_CRYPTO_BLOCK_SIZE];
struct scatterlist sg;
int padding = 4 << (ci->ci_flags & FS_POLICY_FLAGS_PAD_MASK);
unsigned int lim;
unsigned int cryptlen;
lim = inode->i_sb->s_cop->max_namelen(inode);
if (iname->len <= 0 || iname->len > lim)
return -EIO;
/*
* Copy the filename to the output buffer for encrypting in-place and
* pad it with the needed number of NUL bytes.
*/
cryptlen = max_t(unsigned int, iname->len, FS_CRYPTO_BLOCK_SIZE);
cryptlen = round_up(cryptlen, padding);
cryptlen = min(cryptlen, lim);
memcpy(oname->name, iname->name, iname->len);
memset(oname->name + iname->len, 0, cryptlen - iname->len);
/* Initialize the IV */
memset(iv, 0, FS_CRYPTO_BLOCK_SIZE);
/* Set up the encryption request */
req = skcipher_request_alloc(tfm, GFP_NOFS);
if (!req) {
printk_ratelimited(KERN_ERR
"%s: skcipher_request_alloc() failed\n", __func__);
return -ENOMEM;
}
skcipher_request_set_callback(req,
CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
fname_crypt_complete, &ecr);
sg_init_one(&sg, oname->name, cryptlen);
skcipher_request_set_crypt(req, &sg, &sg, cryptlen, iv);
/* Do the encryption */
res = crypto_skcipher_encrypt(req);
if (res == -EINPROGRESS || res == -EBUSY) {
/* Request is being completed asynchronously; wait for it */
wait_for_completion(&ecr.completion);
res = ecr.res;
}
skcipher_request_free(req);
if (res < 0) {
printk_ratelimited(KERN_ERR
"%s: Error (error code %d)\n", __func__, res);
return res;
}
oname->len = cryptlen;
return 0;
}
/**
* ext4_fname_encrypt() -
*
* This function encrypts the input filename, and returns the length of the
* ciphertext. Errors are returned as negative numbers. We trust the caller to
* allocate sufficient memory to oname string.
*/
static int ext4_fname_encrypt(struct inode *inode,
const struct qstr *iname,
struct ext4_str *oname)
{
u32 ciphertext_len;
struct skcipher_request *req = NULL;
DECLARE_EXT4_COMPLETION_RESULT(ecr);
struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
struct crypto_skcipher *tfm = ci->ci_ctfm;
int res = 0;
char iv[EXT4_CRYPTO_BLOCK_SIZE];
struct scatterlist src_sg, dst_sg;
int padding = 4 << (ci->ci_flags & EXT4_POLICY_FLAGS_PAD_MASK);
char *workbuf, buf[32], *alloc_buf = NULL;
unsigned lim = max_name_len(inode);
if (iname->len <= 0 || iname->len > lim)
return -EIO;
ciphertext_len = (iname->len < EXT4_CRYPTO_BLOCK_SIZE) ?
EXT4_CRYPTO_BLOCK_SIZE : iname->len;
ciphertext_len = ext4_fname_crypto_round_up(ciphertext_len, padding);
ciphertext_len = (ciphertext_len > lim)
? lim : ciphertext_len;
if (ciphertext_len <= sizeof(buf)) {
workbuf = buf;
} else {
alloc_buf = kmalloc(ciphertext_len, GFP_NOFS);
if (!alloc_buf)
return -ENOMEM;
workbuf = alloc_buf;
}
/* Allocate request */
req = skcipher_request_alloc(tfm, GFP_NOFS);
if (!req) {
printk_ratelimited(
KERN_ERR "%s: crypto_request_alloc() failed\n", __func__);
kfree(alloc_buf);
return -ENOMEM;
}
skcipher_request_set_callback(req,
CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
ext4_dir_crypt_complete, &ecr);
/* Copy the input */
memcpy(workbuf, iname->name, iname->len);
if (iname->len < ciphertext_len)
memset(workbuf + iname->len, 0, ciphertext_len - iname->len);
/* Initialize IV */
memset(iv, 0, EXT4_CRYPTO_BLOCK_SIZE);
/* Create encryption request */
sg_init_one(&src_sg, workbuf, ciphertext_len);
sg_init_one(&dst_sg, oname->name, ciphertext_len);
skcipher_request_set_crypt(req, &src_sg, &dst_sg, ciphertext_len, iv);
res = crypto_skcipher_encrypt(req);
if (res == -EINPROGRESS || res == -EBUSY) {
wait_for_completion(&ecr.completion);
res = ecr.res;
}
kfree(alloc_buf);
skcipher_request_free(req);
if (res < 0) {
printk_ratelimited(
KERN_ERR "%s: Error (error code %d)\n", __func__, res);
}
oname->len = ciphertext_len;
return res;
}