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 p8_aes_xts_init(struct crypto_tfm *tfm)
{
const char *alg;
struct crypto_skcipher *fallback;
struct p8_aes_xts_ctx *ctx = crypto_tfm_ctx(tfm);
if (!(alg = crypto_tfm_alg_name(tfm))) {
printk(KERN_ERR "Failed to get algorithm name.\n");
return -ENOENT;
}
fallback = crypto_alloc_skcipher(alg, 0,
CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK);
if (IS_ERR(fallback)) {
printk(KERN_ERR
"Failed to allocate transformation for '%s': %ld\n",
alg, PTR_ERR(fallback));
return PTR_ERR(fallback);
}
printk(KERN_INFO "Using '%s' as fallback implementation.\n",
crypto_skcipher_driver_name(fallback));
crypto_skcipher_set_flags(
fallback,
crypto_skcipher_get_flags((struct crypto_skcipher *)tfm));
ctx->fallback = fallback;
return 0;
}
/*
* Initialize big_key crypto and RNG algorithms
*/
static int __init big_key_crypto_init(void)
{
int ret = -EINVAL;
/* init RNG */
big_key_rng = crypto_alloc_rng(big_key_rng_name, 0, 0);
if (IS_ERR(big_key_rng)) {
big_key_rng = NULL;
return -EFAULT;
}
/* seed RNG */
ret = crypto_rng_reset(big_key_rng, NULL, crypto_rng_seedsize(big_key_rng));
if (ret)
goto error;
/* init block cipher */
big_key_skcipher = crypto_alloc_skcipher(big_key_alg_name,
0, CRYPTO_ALG_ASYNC);
if (IS_ERR(big_key_skcipher)) {
big_key_skcipher = NULL;
ret = -EFAULT;
goto error;
}
return 0;
error:
crypto_free_rng(big_key_rng);
big_key_rng = NULL;
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 aes_get_sizes(void)
{
struct crypto_skcipher *tfm;
tfm = crypto_alloc_skcipher(blkcipher_alg, 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(tfm)) {
pr_err("encrypted_key: failed to alloc_cipher (%ld)\n",
PTR_ERR(tfm));
return PTR_ERR(tfm);
}
ivsize = crypto_skcipher_ivsize(tfm);
blksize = crypto_skcipher_blocksize(tfm);
crypto_free_skcipher(tfm);
return 0;
}
/*
* Register key type
*/
static int __init big_key_init(void)
{
struct crypto_skcipher *cipher;
struct crypto_rng *rng;
int ret;
rng = crypto_alloc_rng(big_key_rng_name, 0, 0);
if (IS_ERR(rng)) {
pr_err("Can't alloc rng: %ld\n", PTR_ERR(rng));
return PTR_ERR(rng);
}
big_key_rng = rng;
/* seed RNG */
ret = crypto_rng_reset(rng, NULL, crypto_rng_seedsize(rng));
if (ret) {
pr_err("Can't reset rng: %d\n", ret);
goto error_rng;
}
/* init block cipher */
cipher = crypto_alloc_skcipher(big_key_alg_name, 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(cipher)) {
ret = PTR_ERR(cipher);
pr_err("Can't alloc crypto: %d\n", ret);
goto error_rng;
}
big_key_skcipher = cipher;
ret = register_key_type(&key_type_big_key);
if (ret < 0) {
pr_err("Can't register type: %d\n", ret);
goto error_cipher;
}
return 0;
error_cipher:
crypto_free_skcipher(big_key_skcipher);
error_rng:
crypto_free_rng(big_key_rng);
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;
}
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;
}
struct simd_skcipher_alg *simd_skcipher_create_compat(const char *algname,
const char *drvname,
const char *basename)
{
struct simd_skcipher_alg *salg;
struct crypto_skcipher *tfm;
struct skcipher_alg *ialg;
struct skcipher_alg *alg;
int err;
tfm = crypto_alloc_skcipher(basename, CRYPTO_ALG_INTERNAL,
CRYPTO_ALG_INTERNAL | CRYPTO_ALG_ASYNC);
if (IS_ERR(tfm))
return ERR_CAST(tfm);
ialg = crypto_skcipher_alg(tfm);
salg = kzalloc(sizeof(*salg), GFP_KERNEL);
if (!salg) {
salg = ERR_PTR(-ENOMEM);
goto out_put_tfm;
}
salg->ialg_name = basename;
alg = &salg->alg;
err = -ENAMETOOLONG;
if (snprintf(alg->base.cra_name, CRYPTO_MAX_ALG_NAME, "%s", algname) >=
CRYPTO_MAX_ALG_NAME)
goto out_free_salg;
if (snprintf(alg->base.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
drvname) >= CRYPTO_MAX_ALG_NAME)
goto out_free_salg;
alg->base.cra_flags = CRYPTO_ALG_ASYNC;
alg->base.cra_priority = ialg->base.cra_priority;
alg->base.cra_blocksize = ialg->base.cra_blocksize;
alg->base.cra_alignmask = ialg->base.cra_alignmask;
alg->base.cra_module = ialg->base.cra_module;
alg->base.cra_ctxsize = sizeof(struct simd_skcipher_ctx);
alg->ivsize = ialg->ivsize;
alg->chunksize = ialg->chunksize;
alg->min_keysize = ialg->min_keysize;
alg->max_keysize = ialg->max_keysize;
alg->init = simd_skcipher_init;
alg->exit = simd_skcipher_exit;
alg->setkey = simd_skcipher_setkey;
alg->encrypt = simd_skcipher_encrypt;
alg->decrypt = simd_skcipher_decrypt;
err = crypto_register_skcipher(alg);
if (err)
goto out_free_salg;
out_put_tfm:
crypto_free_skcipher(tfm);
return salg;
out_free_salg:
kfree(salg);
salg = ERR_PTR(err);
goto out_put_tfm;
}
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;
}
