Klemens Nanni <k...@openbsd.org> wrote:
> @@ -1117,13 +1117,6 @@ bio_changepass(char *dev)
>
> /* Current passphrase. */
> bio_kdf_derive(&kdfinfo1, &kdfhint, "Old passphrase: ", 0);
> -
> - /*
> - * Unless otherwise specified, keep the previous number of rounds as
> - * long as we're using the same KDF.
> - */
> - if (kdfhint.generic.type == SR_CRYPTOKDFT_BCRYPT_PBKDF && !rflag)
> - rflag = kdfhint.rounds;
>
> /* New passphrase. */
> bio_kdf_generate(&kdfinfo2);
This will potentially downgrade the amount of rounds on password change
if `-r` is omitted, which is not ideal imo. What about the following to
keep the previous amount of rounds if its bigger than the automatic
estimate?
-Lucas
diff refs/heads/master 758422c5a8c4e618082a6dc3dc0f268ed05e9cd9
commit - d4b9d4747036fa562b886f23a67e486ba94b3dc6
commit + 758422c5a8c4e618082a6dc3dc0f268ed05e9cd9
blob - d6617b14595e278f687a9f114767438f5fe51326
blob + 951df4da4db2e69c058a2bcb0d460543b602cc7a
--- sbin/bioctl/bioctl.8
+++ sbin/bioctl/bioctl.8
@@ -282,11 +282,12 @@ If
passphrase of an existing encrypted volume.
A larger number of iterations takes more time, but offers increased resistance
against passphrase guessing attacks.
-If
+By default, or if
.Ar rounds
-is specified as "auto", the number of rounds will be automatically determined
-based on system performance.
-Otherwise the minimum is 4 rounds and the default is 16.
+is specified as
+.Cm auto ,
+the number of rounds will automatically be based on system performance.
+The minimum is 16 rounds.
.It Fl s
Read the passphrase for the selected crypto volume from
.Pa /dev/stdin
blob - 2928cfba3d52f5f3a4c6589d4e363e09f6da30d4
blob + ba4a15bab4d8d1ac1211aec9a6c315bfb6f29bb6
--- sbin/bioctl/bioctl.c
+++ sbin/bioctl/bioctl.c
@@ -66,7 +66,7 @@ void bio_kdf_generate(struct
sr_crypto_kdfinfo *);
int bio_parse_devlist(char *, dev_t *);
void bio_kdf_derive(struct sr_crypto_kdfinfo *,
struct sr_crypto_pbkdf *, char *, int);
-void bio_kdf_generate(struct sr_crypto_kdfinfo *);
+void bio_kdf_generate(struct sr_crypto_kdfinfo *, int);
int bcrypt_pbkdf_autorounds(void);
void derive_key(u_int32_t, int, u_int8_t *, size_t,
u_int8_t *, size_t, char *, int);
@@ -89,7 +89,7 @@ int rflag = 0;
int human;
int verbose;
u_int32_t cflags = 0;
-int rflag = 0;
+int rflag = -1; /* auto */
char *password;
void *bio_cookie;
@@ -182,7 +182,7 @@ main(int argc, char *argv[])
rflag = -1;
break;
}
- rflag = strtonum(optarg, 4, 1<<30, &errstr);
+ rflag = strtonum(optarg, 16, 1<<30, &errstr);
if (errstr != NULL)
errx(1, "number of KDF rounds is %s: %s",
errstr, optarg);
@@ -902,7 +902,7 @@ bio_createraid(u_int16_t level, char *dev_list, char *
bio_kdf_derive(&kdfinfo, &kdfhint, "Passphrase: ", 0);
memset(&kdfhint, 0, sizeof(kdfhint));
} else {
- bio_kdf_generate(&kdfinfo);
+ bio_kdf_generate(&kdfinfo, -1);
}
create.bc_opaque = &kdfinfo;
@@ -968,17 +968,20 @@ bio_kdf_generate(struct sr_crypto_kdfinfo *kdfinfo)
}
void
-bio_kdf_generate(struct sr_crypto_kdfinfo *kdfinfo)
+bio_kdf_generate(struct sr_crypto_kdfinfo *kdfinfo, int hint_rounds)
{
if (!kdfinfo)
errx(1, "invalid KDF info");
- if (rflag == -1)
+ if (rflag == -1) {
rflag = bcrypt_pbkdf_autorounds();
+ if (rflag < hint_rounds)
+ rflag = hint_rounds;
+ }
kdfinfo->pbkdf.generic.len = sizeof(kdfinfo->pbkdf);
kdfinfo->pbkdf.generic.type = SR_CRYPTOKDFT_BCRYPT_PBKDF;
- kdfinfo->pbkdf.rounds = rflag ? rflag : 16;
+ kdfinfo->pbkdf.rounds = rflag;
kdfinfo->flags = SR_CRYPTOKDF_KEY | SR_CRYPTOKDF_HINT;
kdfinfo->len = sizeof(*kdfinfo);
@@ -1097,7 +1100,7 @@ bio_changepass(char *dev)
struct sr_crypto_kdfpair kdfpair;
struct sr_crypto_kdfinfo kdfinfo1, kdfinfo2;
struct sr_crypto_pbkdf kdfhint;
- int rv;
+ int rv, hint_rounds = -1;
memset(&bd, 0, sizeof(bd));
memset(&kdfhint, 0, sizeof(kdfhint));
@@ -1119,14 +1122,14 @@ bio_changepass(char *dev)
bio_kdf_derive(&kdfinfo1, &kdfhint, "Old passphrase: ", 0);
/*
- * Unless otherwise specified, keep the previous number of rounds as
- * long as we're using the same KDF.
+ * Broadcast the previous number of rounds as long as we're using the
+ * same KDF.
*/
- if (kdfhint.generic.type == SR_CRYPTOKDFT_BCRYPT_PBKDF && !rflag)
- rflag = kdfhint.rounds;
+ if (kdfhint.generic.type == SR_CRYPTOKDFT_BCRYPT_PBKDF)
+ hint_rounds = kdfhint.rounds;
/* New passphrase. */
- bio_kdf_generate(&kdfinfo2);
+ bio_kdf_generate(&kdfinfo2, hint_rounds);
kdfpair.kdfinfo1 = &kdfinfo1;
kdfpair.kdfsize1 = sizeof(kdfinfo1);
