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

On 11/27/18 12:20 AM, Dan Williams wrote: > 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. > I'm ok with that if Mimi is.