Messages in this thread | | | Subject | Re: [RFC PATCH v3 4/4] ceph: replace base64url by the encoding used for mailbox names | From | Xiubo Li <> | Date | Fri, 18 Mar 2022 16:32:15 +0800 |
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On 3/17/22 11:45 PM, Luís Henriques wrote: > The base64url encoding includes the '_' character, which may cause problems > in snapshot names (if the name starts with '_'). Thus, use the base64 > encoding defined for IMAP mailbox names (RFC 3501), which uses '+' and ',' > instead of '-' and '_'. > > Signed-off-by: Luís Henriques <lhenriques@suse.de> > --- > fs/ceph/crypto.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++-- > fs/ceph/crypto.h | 3 +++ > fs/ceph/dir.c | 2 +- > fs/ceph/inode.c | 2 +- > 4 files changed, 54 insertions(+), 4 deletions(-) > > diff --git a/fs/ceph/crypto.c b/fs/ceph/crypto.c > index caa9863dee93..d6f1c444ce91 100644 > --- a/fs/ceph/crypto.c > +++ b/fs/ceph/crypto.c > @@ -7,6 +7,53 @@ > #include "mds_client.h" > #include "crypto.h" > > +static const char base64_table[65] = > + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+,"; > + > +int ceph_base64_encode(const u8 *src, int srclen, char *dst) > +{ > + u32 ac = 0; > + int bits = 0; > + int i; > + char *cp = dst; > + > + for (i = 0; i < srclen; i++) { > + ac = (ac << 8) | src[i]; > + bits += 8; > + do { > + bits -= 6; > + *cp++ = base64_table[(ac >> bits) & 0x3f]; > + } while (bits >= 6); > + } > + if (bits) > + *cp++ = base64_table[(ac << (6 - bits)) & 0x3f]; > + return cp - dst; > +} > + > +int ceph_base64_decode(const char *src, int srclen, u8 *dst) > +{ > + u32 ac = 0; > + int bits = 0; > + int i; > + u8 *bp = dst; > + > + for (i = 0; i < srclen; i++) { > + const char *p = strchr(base64_table, src[i]); > + > + if (p == NULL || src[i] == 0) > + return -1; > + ac = (ac << 6) | (p - base64_table); > + bits += 6; > + if (bits >= 8) { > + bits -= 8; > + *bp++ = (u8)(ac >> bits); > + } > + } > + if (ac & ((1 << bits) - 1)) > + return -1; > + return bp - dst; > +}
Maybe this should be in fs/crypto.c ?
-- Xiubo
> + > static int ceph_crypt_get_context(struct inode *inode, void *ctx, size_t len) > { > struct ceph_inode_info *ci = ceph_inode(inode); > @@ -260,7 +307,7 @@ int ceph_encode_encrypted_dname(struct inode *parent, struct qstr *d_name, char > } > > /* base64 encode the encrypted name */ > - elen = fscrypt_base64url_encode(cryptbuf, len, buf); > + elen = ceph_base64_encode(cryptbuf, len, buf); > dout("base64-encoded ciphertext name = %.*s\n", elen, buf); > > WARN_ON(elen > (CEPH_NOHASH_NAME_MAX + SHA256_DIGEST_SIZE)); > @@ -365,7 +412,7 @@ int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname, > tname = &_tname; > } > > - declen = fscrypt_base64url_decode(name, name_len, tname->name); > + declen = ceph_base64_decode(name, name_len, tname->name); > if (declen <= 0) { > ret = -EIO; > goto out; > diff --git a/fs/ceph/crypto.h b/fs/ceph/crypto.h > index 3273d076a9e5..d22316011810 100644 > --- a/fs/ceph/crypto.h > +++ b/fs/ceph/crypto.h > @@ -93,6 +93,9 @@ static inline u32 ceph_fscrypt_auth_len(struct ceph_fscrypt_auth *fa) > */ > #define CEPH_NOHASH_NAME_MAX (180 - SHA256_DIGEST_SIZE) > > +int ceph_base64_encode(const u8 *src, int srclen, char *dst); > +int ceph_base64_decode(const char *src, int srclen, u8 *dst); > + > void ceph_fscrypt_set_ops(struct super_block *sb); > > void ceph_fscrypt_free_dummy_policy(struct ceph_fs_client *fsc); > diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c > index 5ae5cb778389..417d8c3a7edd 100644 > --- a/fs/ceph/dir.c > +++ b/fs/ceph/dir.c > @@ -960,7 +960,7 @@ static int prep_encrypted_symlink_target(struct ceph_mds_request *req, const cha > goto out; > } > > - len = fscrypt_base64url_encode(osd_link.name, osd_link.len, req->r_path2); > + len = ceph_base64_encode(osd_link.name, osd_link.len, req->r_path2); > req->r_path2[len] = '\0'; > out: > fscrypt_fname_free_buffer(&osd_link); > diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c > index 359e29896f16..8fd493257e0b 100644 > --- a/fs/ceph/inode.c > +++ b/fs/ceph/inode.c > @@ -875,7 +875,7 @@ static int decode_encrypted_symlink(const char *encsym, int enclen, u8 **decsym) > if (!sym) > return -ENOMEM; > > - declen = fscrypt_base64url_decode(encsym, enclen, sym); > + declen = ceph_base64_decode(encsym, enclen, sym); > if (declen < 0) { > pr_err("%s: can't decode symlink (%d). Content: %.*s\n", __func__, declen, enclen, encsym); > kfree(sym); >
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