From: Yehuda Sadeh Date: Fri, 12 May 2023 19:55:42 +0000 (-0400) Subject: use alternative ioctl when adding key if getting EOVERFLOW X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=4c39ca0171e3c0ef01c968497d21e2d3171bd335;p=fscrypt.git use alternative ioctl when adding key if getting EOVERFLOW This can indicate that we're using a fuse filesystem that cannot handle the specific ioctl, as there is a mismatch between the declared ioctl size and the data that was sent. Signed-off-by: Yehuda Sadeh --- diff --git a/keyring/fs_keyring.go b/keyring/fs_keyring.go index 9b949b9..700072c 100644 --- a/keyring/fs_keyring.go +++ b/keyring/fs_keyring.go @@ -21,6 +21,10 @@ package keyring /* #include +#include "fscrypt_uapi.h" + +long long fs_ioc_add_encryption_key64 = FS_IOC_ADD_ENCRYPTION_KEY64; + */ import "C" @@ -199,6 +203,9 @@ func fsAddEncryptionKey(key *crypto.Key, descriptor string, } _, _, errno := unix.Syscall(unix.SYS_IOCTL, dir.Fd(), unix.FS_IOC_ADD_ENCRYPTION_KEY, uintptr(argKey.UnsafePtr())) + if errno == unix.EOVERFLOW { + _, _, errno = unix.Syscall(unix.SYS_IOCTL, dir.Fd(), + uintptr(C.fs_ioc_add_encryption_key64), uintptr(argKey.UnsafePtr())) restorePrivs(savedPrivs) log.Printf("FS_IOC_ADD_ENCRYPTION_KEY(%q, %s, ) = %v", mount.Path, descriptor, errno) diff --git a/keyring/fscrypt_uapi.h b/keyring/fscrypt_uapi.h new file mode 100644 index 0000000..c84138a --- /dev/null +++ b/keyring/fscrypt_uapi.h @@ -0,0 +1,206 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +/* + * fscrypt user API + * + * These ioctls can be used on filesystems that support fscrypt. See the + * "User API" section of Documentation/filesystems/fscrypt.rst. + */ +#ifndef _UAPI_LINUX_FSCRYPT_H +#define _UAPI_LINUX_FSCRYPT_H + +#include +#include + +/* Encryption policy flags */ +#define FSCRYPT_POLICY_FLAGS_PAD_4 0x00 +#define FSCRYPT_POLICY_FLAGS_PAD_8 0x01 +#define FSCRYPT_POLICY_FLAGS_PAD_16 0x02 +#define FSCRYPT_POLICY_FLAGS_PAD_32 0x03 +#define FSCRYPT_POLICY_FLAGS_PAD_MASK 0x03 +#define FSCRYPT_POLICY_FLAG_DIRECT_KEY 0x04 +#define FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64 0x08 +#define FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32 0x10 + +/* Encryption algorithms */ +#define FSCRYPT_MODE_AES_256_XTS 1 +#define FSCRYPT_MODE_AES_256_CTS 4 +#define FSCRYPT_MODE_AES_128_CBC 5 +#define FSCRYPT_MODE_AES_128_CTS 6 +#define FSCRYPT_MODE_SM4_XTS 7 +#define FSCRYPT_MODE_SM4_CTS 8 +#define FSCRYPT_MODE_ADIANTUM 9 +#define FSCRYPT_MODE_AES_256_HCTR2 10 +/* If adding a mode number > 10, update FSCRYPT_MODE_MAX in fscrypt_private.h */ + +/* + * Legacy policy version; ad-hoc KDF and no key verification. + * For new encrypted directories, use fscrypt_policy_v2 instead. + * + * Careful: the .version field for this is actually 0, not 1. + */ +#define FSCRYPT_POLICY_V1 0 +#define FSCRYPT_KEY_DESCRIPTOR_SIZE 8 +struct fscrypt_policy_v1 { + __u8 version; + __u8 contents_encryption_mode; + __u8 filenames_encryption_mode; + __u8 flags; + __u8 master_key_descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE]; +}; + +/* + * Process-subscribed "logon" key description prefix and payload format. + * Deprecated; prefer FS_IOC_ADD_ENCRYPTION_KEY instead. + */ +#define FSCRYPT_KEY_DESC_PREFIX "fscrypt:" +#define FSCRYPT_KEY_DESC_PREFIX_SIZE 8 +#define FSCRYPT_MAX_KEY_SIZE 64 +struct fscrypt_key { + __u32 mode; + __u8 raw[FSCRYPT_MAX_KEY_SIZE]; + __u32 size; +}; + +/* + * New policy version with HKDF and key verification (recommended). + */ +#define FSCRYPT_POLICY_V2 2 +#define FSCRYPT_KEY_IDENTIFIER_SIZE 16 +struct fscrypt_policy_v2 { + __u8 version; + __u8 contents_encryption_mode; + __u8 filenames_encryption_mode; + __u8 flags; + __u8 __reserved[4]; + __u8 master_key_identifier[FSCRYPT_KEY_IDENTIFIER_SIZE]; +}; + +/* Struct passed to FS_IOC_GET_ENCRYPTION_POLICY_EX */ +struct fscrypt_get_policy_ex_arg { + __u64 policy_size; /* input/output */ + union { + __u8 version; + struct fscrypt_policy_v1 v1; + struct fscrypt_policy_v2 v2; + } policy; /* output */ +}; + +/* + * v1 policy keys are specified by an arbitrary 8-byte key "descriptor", + * matching fscrypt_policy_v1::master_key_descriptor. + */ +#define FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR 1 + +/* + * v2 policy keys are specified by a 16-byte key "identifier" which the kernel + * calculates as a cryptographic hash of the key itself, + * matching fscrypt_policy_v2::master_key_identifier. + */ +#define FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER 2 + +/* + * Specifies a key, either for v1 or v2 policies. This doesn't contain the + * actual key itself; this is just the "name" of the key. + */ +struct fscrypt_key_specifier { + __u32 type; /* one of FSCRYPT_KEY_SPEC_TYPE_* */ + __u32 __reserved; + union { + __u8 __reserved[32]; /* reserve some extra space */ + __u8 descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE]; + __u8 identifier[FSCRYPT_KEY_IDENTIFIER_SIZE]; + } u; +}; + +/* + * Payload of Linux keyring key of type "fscrypt-provisioning", referenced by + * fscrypt_add_key_arg::key_id as an alternative to fscrypt_add_key_arg::raw. + */ +struct fscrypt_provisioning_key_payload { + __u32 type; + __u32 __reserved; + __u8 raw[]; +}; + +/* Struct passed to FS_IOC_ADD_ENCRYPTION_KEY */ +struct fscrypt_add_key_arg { + struct fscrypt_key_specifier key_spec; + __u32 raw_size; + __u32 key_id; + __u32 __reserved[8]; + __u8 raw[]; +}; + +/* Struct passed to FS_IOC_ADD_ENCRYPTION_KEY */ +struct fscrypt_add_key64_arg { + struct fscrypt_key_specifier key_spec; + __u32 raw_size; + __u32 key_id; + __u32 __reserved[8]; + __u8 raw[64]; +}; + +/* Struct passed to FS_IOC_REMOVE_ENCRYPTION_KEY */ +struct fscrypt_remove_key_arg { + struct fscrypt_key_specifier key_spec; +#define FSCRYPT_KEY_REMOVAL_STATUS_FLAG_FILES_BUSY 0x00000001 +#define FSCRYPT_KEY_REMOVAL_STATUS_FLAG_OTHER_USERS 0x00000002 + __u32 removal_status_flags; /* output */ + __u32 __reserved[5]; +}; + +/* Struct passed to FS_IOC_GET_ENCRYPTION_KEY_STATUS */ +struct fscrypt_get_key_status_arg { + /* input */ + struct fscrypt_key_specifier key_spec; + __u32 __reserved[6]; + + /* output */ +#define FSCRYPT_KEY_STATUS_ABSENT 1 +#define FSCRYPT_KEY_STATUS_PRESENT 2 +#define FSCRYPT_KEY_STATUS_INCOMPLETELY_REMOVED 3 + __u32 status; +#define FSCRYPT_KEY_STATUS_FLAG_ADDED_BY_SELF 0x00000001 + __u32 status_flags; + __u32 user_count; + __u32 __out_reserved[13]; +}; + +#define FS_IOC_SET_ENCRYPTION_POLICY _IOR('f', 19, struct fscrypt_policy_v1) +#define FS_IOC_GET_ENCRYPTION_PWSALT _IOW('f', 20, __u8[16]) +#define FS_IOC_GET_ENCRYPTION_POLICY _IOW('f', 21, struct fscrypt_policy_v1) +#define FS_IOC_GET_ENCRYPTION_POLICY_EX _IOWR('f', 22, __u8[9]) /* size + version */ +#define FS_IOC_ADD_ENCRYPTION_KEY _IOWR('f', 23, struct fscrypt_add_key_arg) +#define FS_IOC_ADD_ENCRYPTION_KEY64 _IOWR('f', 23, struct fscrypt_add_key64_arg) +#define FS_IOC_REMOVE_ENCRYPTION_KEY _IOWR('f', 24, struct fscrypt_remove_key_arg) +#define FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS _IOWR('f', 25, struct fscrypt_remove_key_arg) +#define FS_IOC_GET_ENCRYPTION_KEY_STATUS _IOWR('f', 26, struct fscrypt_get_key_status_arg) +#define FS_IOC_GET_ENCRYPTION_NONCE _IOR('f', 27, __u8[16]) + +/**********************************************************************/ + +/* old names; don't add anything new here! */ +#ifndef __KERNEL__ +#define fscrypt_policy fscrypt_policy_v1 +#define FS_KEY_DESCRIPTOR_SIZE FSCRYPT_KEY_DESCRIPTOR_SIZE +#define FS_POLICY_FLAGS_PAD_4 FSCRYPT_POLICY_FLAGS_PAD_4 +#define FS_POLICY_FLAGS_PAD_8 FSCRYPT_POLICY_FLAGS_PAD_8 +#define FS_POLICY_FLAGS_PAD_16 FSCRYPT_POLICY_FLAGS_PAD_16 +#define FS_POLICY_FLAGS_PAD_32 FSCRYPT_POLICY_FLAGS_PAD_32 +#define FS_POLICY_FLAGS_PAD_MASK FSCRYPT_POLICY_FLAGS_PAD_MASK +#define FS_POLICY_FLAG_DIRECT_KEY FSCRYPT_POLICY_FLAG_DIRECT_KEY +#define FS_POLICY_FLAGS_VALID 0x07 /* contains old flags only */ +#define FS_ENCRYPTION_MODE_INVALID 0 /* never used */ +#define FS_ENCRYPTION_MODE_AES_256_XTS FSCRYPT_MODE_AES_256_XTS +#define FS_ENCRYPTION_MODE_AES_256_GCM 2 /* never used */ +#define FS_ENCRYPTION_MODE_AES_256_CBC 3 /* never used */ +#define FS_ENCRYPTION_MODE_AES_256_CTS FSCRYPT_MODE_AES_256_CTS +#define FS_ENCRYPTION_MODE_AES_128_CBC FSCRYPT_MODE_AES_128_CBC +#define FS_ENCRYPTION_MODE_AES_128_CTS FSCRYPT_MODE_AES_128_CTS +#define FS_ENCRYPTION_MODE_ADIANTUM FSCRYPT_MODE_ADIANTUM +#define FS_KEY_DESC_PREFIX FSCRYPT_KEY_DESC_PREFIX +#define FS_KEY_DESC_PREFIX_SIZE FSCRYPT_KEY_DESC_PREFIX_SIZE +#define FS_MAX_KEY_SIZE FSCRYPT_MAX_KEY_SIZE +#endif /* !__KERNEL__ */ + +#endif /* _UAPI_LINUX_FSCRYPT_H */