From: Eric Biggers <ebiggers@xxxxxxxxxx> The latest UAPI header includes the declarations of fsverity_descriptor and fsverity_formatted_digest (previously fsverity_signed_digest). Therefore they no longer need to be declared in other files. Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx> --- common/fsverity_uapi.h | 49 ++++++++++++++++++++++++++++++++++++++++++ lib/compute_digest.c | 17 --------------- lib/sign_digest.c | 15 +------------ programs/cmd_digest.c | 11 ++-------- 4 files changed, 52 insertions(+), 40 deletions(-) diff --git a/common/fsverity_uapi.h b/common/fsverity_uapi.h index da0daf6..260017a 100644 --- a/common/fsverity_uapi.h +++ b/common/fsverity_uapi.h @@ -34,6 +34,55 @@ struct fsverity_digest { __u8 digest[]; }; +/* + * Struct containing a file's Merkle tree properties. The fs-verity file digest + * is the hash of this struct. A userspace program needs this struct only if it + * needs to compute fs-verity file digests itself, e.g. in order to sign files. + * It isn't needed just to enable fs-verity on a file. + * + * Note: when computing the file digest, 'sig_size' and 'signature' must be left + * zero and empty, respectively. These fields are present only because some + * filesystems reuse this struct as part of their on-disk format. + */ +struct fsverity_descriptor { + __u8 version; /* must be 1 */ + __u8 hash_algorithm; /* Merkle tree hash algorithm */ + __u8 log_blocksize; /* log2 of size of data and tree blocks */ + __u8 salt_size; /* size of salt in bytes; 0 if none */ +#ifdef __KERNEL__ + __le32 sig_size; +#else + __le32 __reserved_0x04; +#endif + __le64 data_size; /* size of file the Merkle tree is built over */ + __u8 root_hash[64]; /* Merkle tree root hash */ + __u8 salt[32]; /* salt prepended to each hashed block */ + __u8 __reserved[144]; /* must be 0's */ +#ifdef __KERNEL__ + __u8 signature[]; +#endif +}; + +/* + * Format in which fs-verity file digests are signed in built-in signatures. + * This is the same as 'struct fsverity_digest', except here some magic bytes + * are prepended to provide some context about what is being signed in case the + * same key is used for non-fsverity purposes, and here the fields have fixed + * endianness. + * + * This struct is specific to the built-in signature verification support, which + * is optional. fs-verity users may also verify signatures in userspace, in + * which case userspace is responsible for deciding on what bytes are signed. + * This struct may still be used, but it doesn't have to be. For example, + * userspace could instead use a string like "sha256:$digest_as_hex_string". + */ +struct fsverity_formatted_digest { + char magic[8]; /* must be "FSVerity" */ + __le16 digest_algorithm; + __le16 digest_size; + __u8 digest[]; +}; + #define FS_IOC_ENABLE_VERITY _IOW('f', 133, struct fsverity_enable_arg) #define FS_IOC_MEASURE_VERITY _IOWR('f', 134, struct fsverity_digest) diff --git a/lib/compute_digest.c b/lib/compute_digest.c index e0b213b..25bba1f 100644 --- a/lib/compute_digest.c +++ b/lib/compute_digest.c @@ -17,23 +17,6 @@ #define FS_VERITY_MAX_LEVELS 64 -/* - * Merkle tree properties. The file measurement is the hash of this structure - * excluding the signature and with the sig_size field set to 0. - */ -struct fsverity_descriptor { - __u8 version; /* must be 1 */ - __u8 hash_algorithm; /* Merkle tree hash algorithm */ - __u8 log_blocksize; /* log2 of size of data and tree blocks */ - __u8 salt_size; /* size of salt in bytes; 0 if none */ - __le32 sig_size; /* size of signature in bytes; 0 if none */ - __le64 data_size; /* size of file the Merkle tree is built over */ - __u8 root_hash[64]; /* Merkle tree root hash */ - __u8 salt[32]; /* salt prepended to each hashed block */ - __u8 __reserved[144]; /* must be 0's */ - __u8 signature[]; /* optional PKCS#7 signature */ -}; - struct block_buffer { u32 filled; u8 *data; diff --git a/lib/sign_digest.c b/lib/sign_digest.c index 1f73007..9a35256 100644 --- a/lib/sign_digest.c +++ b/lib/sign_digest.c @@ -19,19 +19,6 @@ #include <openssl/pkcs7.h> #include <string.h> -/* - * Format in which verity file measurements are signed. This is the same as - * 'struct fsverity_digest', except here some magic bytes are prepended to - * provide some context about what is being signed in case the same key is used - * for non-fsverity purposes, and here the fields have fixed endianness. - */ -struct fsverity_signed_digest { - char magic[8]; /* must be "FSVerity" */ - __le16 digest_algorithm; - __le16 digest_size; - __u8 digest[]; -}; - static int print_openssl_err_cb(const char *str, size_t len __attribute__((unused)), void *u __attribute__((unused))) @@ -339,7 +326,7 @@ libfsverity_sign_digest(const struct libfsverity_digest *digest, EVP_PKEY *pkey = NULL; X509 *cert = NULL; const EVP_MD *md; - struct fsverity_signed_digest *d = NULL; + struct fsverity_formatted_digest *d = NULL; int err; if (!digest || !sig_params || !sig_ret || !sig_size_ret) { diff --git a/programs/cmd_digest.c b/programs/cmd_digest.c index 180f438..420ba82 100644 --- a/programs/cmd_digest.c +++ b/programs/cmd_digest.c @@ -31,13 +31,6 @@ static const struct option longopts[] = { {NULL, 0, NULL, 0} }; -struct fsverity_signed_digest { - char magic[8]; /* must be "FSVerity" */ - __le16 digest_algorithm; - __le16 digest_size; - __u8 digest[]; -}; - /* * Compute the fs-verity measurement of the given file(s), for offline signing. */ @@ -93,10 +86,10 @@ int fsverity_cmd_digest(const struct fsverity_command *cmd, tree_params.block_size = get_default_block_size(); for (int i = 0; i < argc; i++) { - struct fsverity_signed_digest *d = NULL; + struct fsverity_formatted_digest *d = NULL; struct libfsverity_digest *digest = NULL; char digest_hex[FS_VERITY_MAX_DIGEST_SIZE * 2 + - sizeof(struct fsverity_signed_digest) * 2 + 1]; + sizeof(*d) * 2 + 1]; if (!open_file(&file, argv[i], O_RDONLY, 0)) goto out_err; -- 2.29.2