From 71c11c378f46e42ca67c1e227646ce23bf43a8c6 Mon Sep 17 00:00:00 2001 From: Michael Halcrow Date: Tue, 6 Jan 2009 14:42:05 -0800 Subject: [PATCH] eCryptfs: Clean up ecryptfs_decode_from_filename() Flesh out the comments for ecryptfs_decode_from_filename(). Remove the return condition, since it is always 0. Signed-off-by: Michael Halcrow Cc: Dustin Kirkland Cc: Eric Sandeen Cc: Tyler Hicks Cc: David Kleikamp Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ecryptfs/crypto.c | 51 +++++++++++++++++++++----------------------- 1 file changed, 24 insertions(+), 27 deletions(-) diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c index e935a2224982..c01e043670e2 100644 --- a/fs/ecryptfs/crypto.c +++ b/fs/ecryptfs/crypto.c @@ -1931,7 +1931,7 @@ static unsigned char *portable_filename_chars = ("-.0123456789ABCD" /* We could either offset on every reverse map or just pad some 0x00's * at the front here */ -static unsigned char filename_rev_map[] = { +static const unsigned char filename_rev_map[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 7 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 15 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 23 */ @@ -2012,16 +2012,30 @@ void ecryptfs_encode_for_filename(unsigned char *dst, size_t *dst_size, return; } -int ecryptfs_decode_from_filename(unsigned char *dst, size_t *dst_size, - const unsigned char *src, size_t src_size) +/** + * ecryptfs_decode_from_filename + * @dst: If NULL, this function only sets @dst_size and returns. If + * non-NULL, this function decodes the encoded octets in @src + * into the memory that @dst points to. + * @dst_size: Set to the size of the decoded string. + * @src: The encoded set of octets to decode. + * @src_size: The size of the encoded set of octets to decode. + */ +static void +ecryptfs_decode_from_filename(unsigned char *dst, size_t *dst_size, + const unsigned char *src, size_t src_size) { u8 current_bit_offset = 0; size_t src_byte_offset = 0; size_t dst_byte_offset = 0; - int rc = 0; if (dst == NULL) { - /* Not exact; conservatively long */ + /* Not exact; conservatively long. Every block of 4 + * encoded characters decodes into a block of 3 + * decoded characters. This segment of code provides + * the caller with the maximum amount of allocated + * space that @dst will need to point to in a + * subsequent call. */ (*dst_size) = (((src_size + 1) * 3) / 4); goto out; } @@ -2055,7 +2069,7 @@ int ecryptfs_decode_from_filename(unsigned char *dst, size_t *dst_size, } (*dst_size) = dst_byte_offset; out: - return rc; + return; } /** @@ -2208,16 +2222,8 @@ int ecryptfs_decode_and_decrypt_filename(char **plaintext_name, name += ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE; name_size -= ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE; - rc = ecryptfs_decode_from_filename(NULL, &decoded_name_size, - name, name_size); - if (rc) { - printk(KERN_ERR "%s: Error attempting to decode " - "filename; rc = [%d]\n", __func__, rc); - rc = ecryptfs_copy_filename(plaintext_name, - plaintext_name_size, - orig_name, orig_name_size); - goto out; - } + ecryptfs_decode_from_filename(NULL, &decoded_name_size, + name, name_size); decoded_name = kmalloc(decoded_name_size, GFP_KERNEL); if (!decoded_name) { printk(KERN_ERR "%s: Out of memory whilst attempting " @@ -2226,17 +2232,8 @@ int ecryptfs_decode_and_decrypt_filename(char **plaintext_name, rc = -ENOMEM; goto out; } - rc = ecryptfs_decode_from_filename(decoded_name, - &decoded_name_size, - name, name_size); - if (rc) { - printk(KERN_ERR "%s: Error attempting to decode " - "filename; rc = [%d]\n", __func__, rc); - rc = ecryptfs_copy_filename(plaintext_name, - plaintext_name_size, - orig_name, orig_name_size); - goto out_free; - } + ecryptfs_decode_from_filename(decoded_name, &decoded_name_size, + name, name_size); rc = ecryptfs_parse_tag_70_packet(plaintext_name, plaintext_name_size, &packet_size,