From: "Timothy R. Chavez" <tinytim@us.ibm.com>
To: Mike Halcrow <mhalcrow@us.ibm.com>
Cc: Andrew Morton <akpm@osdl.org>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
Mike Halcrow <mike@halcrow.us>
Subject: Re: [PATCH 2/12] Support for larger maximum key size
Date: Wed, 21 Jun 2006 09:49:57 -0500 [thread overview]
Message-ID: <1150901397.24002.11.camel@localhost.localdomain> (raw)
In-Reply-To: <E1FsngZ-00078k-Jc@localhost.localdomain>
<snip>
> @@ -806,24 +815,18 @@ write_tag_3_packet(char *dest, int max,
> ECRYPTFS_SIG_SIZE);
> (*key_rec).enc_key_size_bits = crypt_stat->key_size_bits;
> encrypted_session_key_valid = 0;
> - if (auth_tok->session_key.encrypted_key_size == 0)
> - auth_tok->session_key.encrypted_key_size =
> - ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES;
> - for (i = 0; i < auth_tok->session_key.encrypted_key_size; i++)
> + for (i = 0; i < (crypt_stat->key_size_bits / 8); i++)
Hey Mike,
Why don't you just do this particular calculation once? Just looking
down, you do this same calculation at least 4 other potential times.
int key_size_bytes = crypt_stat->key_size_bits / 8;
for (i = 0; i < key_size_bytes; i++)
-tim
> encrypted_session_key_valid |=
> auth_tok->session_key.encrypted_key[i];
> - if (auth_tok->session_key.encrypted_key_size == 0) {
> - ecryptfs_printk(KERN_WARNING, "auth_tok->session_key."
> - "encrypted_key_size == 0");
> - auth_tok->session_key.encrypted_key_size =
> - ECRYPTFS_DEFAULT_KEY_BYTES;
> - }
> if (encrypted_session_key_valid) {
> memcpy((*key_rec).enc_key,
> auth_tok->session_key.encrypted_key,
> auth_tok->session_key.encrypted_key_size);
> goto encrypted_session_key_set;
> }
> + if (auth_tok->session_key.encrypted_key_size == 0)
> + auth_tok->session_key.encrypted_key_size =
> + (crypt_stat->key_size_bits / 8);
> if (ECRYPTFS_CHECK_FLAG(auth_tok->token.password.flags,
> ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET)) {
> ecryptfs_printk(KERN_DEBUG, "Using previously generated "
> @@ -832,8 +835,7 @@ write_tag_3_packet(char *dest, int max,
> session_key_encryption_key_bytes);
> memcpy(session_key_encryption_key,
> auth_tok->token.password.session_key_encryption_key,
> - auth_tok->token.password.
> - session_key_encryption_key_bytes);
> + (crypt_stat->key_size_bits / 8));
> ecryptfs_printk(KERN_DEBUG,
> "Cached session key " "encryption key: \n");
> if (ecryptfs_verbosity > 0)
> @@ -870,7 +872,7 @@ write_tag_3_packet(char *dest, int max,
> goto out;
> }
> rc = crypto_cipher_setkey(tfm, session_key_encryption_key,
> - ECRYPTFS_DEFAULT_KEY_BYTES);
> + (crypt_stat->key_size_bits / 8));
> if (rc < 0) {
> ecryptfs_printk(KERN_ERR, "Error setting key for crypto "
> "context\n");
> @@ -880,7 +882,7 @@ write_tag_3_packet(char *dest, int max,
> ecryptfs_printk(KERN_DEBUG, "Encrypting [%d] bytes of the key\n",
> crypt_stat->key_size_bits / 8);
> crypto_cipher_encrypt(tfm, dest_sg, src_sg,
> - crypt_stat->key_size_bits / 8);
> + (crypt_stat->key_size_bits / 8));
> ecryptfs_printk(KERN_DEBUG, "This should be the encrypted key:\n");
> if (ecryptfs_verbosity > 0)
> ecryptfs_dump_hex((*key_rec).enc_key,
> @@ -889,7 +891,7 @@ encrypted_session_key_set:
> /* Now we have a valid key_rec. Append it to the
> * key_rec set. */
> key_rec_size = (sizeof(struct ecryptfs_key_record)
> - - ECRYPTFS_MAX_KEY_BYTES
> + - ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES
> + ((*key_rec).enc_key_size_bits / 8) );
> /* TODO: Include a packet size limit as a parameter to this
> * function once we have multi-packet headers (for versions
next prev parent reply other threads:[~2006-06-21 14:49 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-06-20 21:21 [PATCH 0/12] eCryptfs minor fixes; support for cipher/key size selection Michael Halcrow
2006-06-20 21:22 ` [PATCH 1/12] asm/scatterlist.h -> linux/scatterlist.h Mike Halcrow
2006-06-20 21:22 ` [PATCH 2/12] Support for larger maximum key size Mike Halcrow
2006-06-21 14:49 ` Timothy R. Chavez [this message]
2006-06-21 15:50 ` Michael Halcrow
2006-06-20 21:23 ` [PATCH 3/12] Add codes for additional ciphers Mike Halcrow
2006-06-21 15:08 ` Timothy R. Chavez
2006-06-20 21:23 ` [PATCH 4/12] Unencrypted key size based on encrypted key size Mike Halcrow
2006-06-20 21:23 ` [PATCH 5/12] Packet and key management update for variable " Mike Halcrow
2006-06-20 21:23 ` [PATCH 6/12] Add ecryptfs_ prefix to mount options; key size parameter Mike Halcrow
2006-06-20 21:23 ` [PATCH 7/12] Set the key size from the default for the mount Mike Halcrow
2006-06-20 21:23 ` [PATCH 8/12] Check for weak keys Mike Halcrow
2006-06-20 21:24 ` [PATCH 9/12] Add #define values for cipher codes from RFC2440 (OpenPGP) Mike Halcrow
2006-06-20 21:24 ` [PATCH 10/12] Convert bits to bytes Mike Halcrow
2006-06-20 21:24 ` [PATCH 11/12] More elegant AES key size manipulation Mike Halcrow
2006-06-20 21:24 ` [PATCH 12/12] More intelligent use of TFM objects Mike Halcrow
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