Re: [PATCH 01/11] keys-encrypted: add nvdimm key format type to encrypted keys

On Fri, Nov 9, 2018 at 2:13 PM Dave Jiang <dave.jiang(a)intel.com&gt; wrote: > > Adding nvdimm key format type to encrypted keys in order to limit the size s/Adding/Add an/ > of the key to 32-bytes. > > Signed-off-by: Dave Jiang <dave.jiang(a)intel.com&gt; > --- > security/keys/encrypted-keys/encrypted.c | 29 ++++++++++++++++++++--------- > 1 file changed, 20 insertions(+), 9 deletions(-) > > diff --git a/security/keys/encrypted-keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c > index d92cbf9687c3..182b4f136bdf 100644 > --- a/security/keys/encrypted-keys/encrypted.c > +++ b/security/keys/encrypted-keys/encrypted.c > @@ -45,6 +45,7 @@ static const char hmac_alg[] = "hmac(sha256)"; > static const char blkcipher_alg[] = "cbc(aes)"; > static const char key_format_default[] = "default"; > static const char key_format_ecryptfs[] = "ecryptfs"; > +static const char key_format_nvdimm[] = "nvdimm"; > static unsigned int ivsize; > static int blksize; > > @@ -54,6 +55,7 @@ static int blksize; > #define HASH_SIZE SHA256_DIGEST_SIZE > #define MAX_DATA_SIZE 4096 > #define MIN_DATA_SIZE 20 > +#define KEY_NVDIMM_PAYLOAD_LEN 32 > > static struct crypto_shash *hash_tfm; > > @@ -62,12 +64,13 @@ enum { > }; > > enum { > - Opt_error = -1, Opt_default, Opt_ecryptfs > + Opt_error = -1, Opt_default, Opt_ecryptfs, Opt_nvdimm > }; > > static const match_table_t key_format_tokens = { > {Opt_default, "default"}, > {Opt_ecryptfs, "ecryptfs"}, > + {Opt_nvdimm, "nvdimm"}, > {Opt_error, NULL} > }; > > @@ -195,6 +198,7 @@ static int datablob_parse(char *datablob, const char **format, > key_format = match_token(p, key_format_tokens, args); > switch (key_format) { > case Opt_ecryptfs: > + case Opt_nvdimm: > case Opt_default: > *format = p; > *master_desc = strsep(&datablob, " \t"); > @@ -625,15 +629,22 @@ static struct encrypted_key_payload *encrypted_key_alloc(struct key *key, > format_len = (!format) ? strlen(key_format_default) : strlen(format); > decrypted_datalen = dlen; > payload_datalen = decrypted_datalen; > - if (format && !strcmp(format, key_format_ecryptfs)) { > - if (dlen != ECRYPTFS_MAX_KEY_BYTES) { > - pr_err("encrypted_key: keylen for the ecryptfs format " > - "must be equal to %d bytes\n", > - ECRYPTFS_MAX_KEY_BYTES); > - return ERR_PTR(-EINVAL); > + if (format) { > + if (!strcmp(format, key_format_ecryptfs)) { > + if (dlen != ECRYPTFS_MAX_KEY_BYTES) { > + pr_err("encrypted_key: keylen for the ecryptfs format must be equal to %d bytes\n", > + ECRYPTFS_MAX_KEY_BYTES); > + return ERR_PTR(-EINVAL); > + } > + decrypted_datalen = ECRYPTFS_MAX_KEY_BYTES; > + payload_datalen = sizeof(struct ecryptfs_auth_tok); > + } else if (!strcmp(format, key_format_nvdimm)) { > + if (decrypted_datalen != KEY_NVDIMM_PAYLOAD_LEN) { > + pr_err("encrypted_key: nvdimm key payload incorrect length: %d\n", > + decrypted_datalen); > + return ERR_PTR(-EINVAL); > + } I suspect this may not be the last key type that gets added, but I wonder if we should instead create key-types based on the dlen size. I.e. create a generic 32-byte key-type "enc32"? That way if another 32-byte requirement key comes along we don't need to come touch this routine again.