fscrypt.h 6.5 KB

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  1. /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
  2. /*
  3. * fscrypt user API
  4. *
  5. * These ioctls can be used on filesystems that support fscrypt. See the
  6. * "User API" section of Documentation/filesystems/fscrypt.rst.
  7. */
  8. #ifndef _UAPI_LINUX_FSCRYPT_H
  9. #define _UAPI_LINUX_FSCRYPT_H
  10. #include <linux/ioctl.h>
  11. #include <linux/types.h>
  12. /* Encryption policy flags */
  13. #define FSCRYPT_POLICY_FLAGS_PAD_4 0x00
  14. #define FSCRYPT_POLICY_FLAGS_PAD_8 0x01
  15. #define FSCRYPT_POLICY_FLAGS_PAD_16 0x02
  16. #define FSCRYPT_POLICY_FLAGS_PAD_32 0x03
  17. #define FSCRYPT_POLICY_FLAGS_PAD_MASK 0x03
  18. #define FSCRYPT_POLICY_FLAG_DIRECT_KEY 0x04
  19. #define FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64 0x08
  20. #define FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32 0x10
  21. /* Encryption algorithms */
  22. #define FSCRYPT_MODE_AES_256_XTS 1
  23. #define FSCRYPT_MODE_AES_256_CTS 4
  24. #define FSCRYPT_MODE_AES_128_CBC 5
  25. #define FSCRYPT_MODE_AES_128_CTS 6
  26. #define FSCRYPT_MODE_ADIANTUM 9
  27. #define FSCRYPT_MODE_AES_256_HCTR2 10
  28. /* If adding a mode number > 10, update FSCRYPT_MODE_MAX in fscrypt_private.h */
  29. /*
  30. * Legacy policy version; ad-hoc KDF and no key verification.
  31. * For new encrypted directories, use fscrypt_policy_v2 instead.
  32. *
  33. * Careful: the .version field for this is actually 0, not 1.
  34. */
  35. #define FSCRYPT_POLICY_V1 0
  36. #define FSCRYPT_KEY_DESCRIPTOR_SIZE 8
  37. struct fscrypt_policy_v1 {
  38. __u8 version;
  39. __u8 contents_encryption_mode;
  40. __u8 filenames_encryption_mode;
  41. __u8 flags;
  42. __u8 master_key_descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE];
  43. };
  44. /*
  45. * Process-subscribed "logon" key description prefix and payload format.
  46. * Deprecated; prefer FS_IOC_ADD_ENCRYPTION_KEY instead.
  47. */
  48. #define FSCRYPT_KEY_DESC_PREFIX "fscrypt:"
  49. #define FSCRYPT_KEY_DESC_PREFIX_SIZE 8
  50. #define FSCRYPT_MAX_KEY_SIZE 64
  51. struct fscrypt_key {
  52. __u32 mode;
  53. __u8 raw[FSCRYPT_MAX_KEY_SIZE];
  54. __u32 size;
  55. };
  56. /*
  57. * New policy version with HKDF and key verification (recommended).
  58. */
  59. #define FSCRYPT_POLICY_V2 2
  60. #define FSCRYPT_KEY_IDENTIFIER_SIZE 16
  61. struct fscrypt_policy_v2 {
  62. __u8 version;
  63. __u8 contents_encryption_mode;
  64. __u8 filenames_encryption_mode;
  65. __u8 flags;
  66. __u8 __reserved[4];
  67. __u8 master_key_identifier[FSCRYPT_KEY_IDENTIFIER_SIZE];
  68. };
  69. /* Struct passed to FS_IOC_GET_ENCRYPTION_POLICY_EX */
  70. struct fscrypt_get_policy_ex_arg {
  71. __u64 policy_size; /* input/output */
  72. union {
  73. __u8 version;
  74. struct fscrypt_policy_v1 v1;
  75. struct fscrypt_policy_v2 v2;
  76. } policy; /* output */
  77. };
  78. /*
  79. * v1 policy keys are specified by an arbitrary 8-byte key "descriptor",
  80. * matching fscrypt_policy_v1::master_key_descriptor.
  81. */
  82. #define FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR 1
  83. /*
  84. * v2 policy keys are specified by a 16-byte key "identifier" which the kernel
  85. * calculates as a cryptographic hash of the key itself,
  86. * matching fscrypt_policy_v2::master_key_identifier.
  87. */
  88. #define FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER 2
  89. /*
  90. * Specifies a key, either for v1 or v2 policies. This doesn't contain the
  91. * actual key itself; this is just the "name" of the key.
  92. */
  93. struct fscrypt_key_specifier {
  94. __u32 type; /* one of FSCRYPT_KEY_SPEC_TYPE_* */
  95. __u32 __reserved;
  96. union {
  97. __u8 __reserved[32]; /* reserve some extra space */
  98. __u8 descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE];
  99. __u8 identifier[FSCRYPT_KEY_IDENTIFIER_SIZE];
  100. } u;
  101. };
  102. /*
  103. * Payload of Linux keyring key of type "fscrypt-provisioning", referenced by
  104. * fscrypt_add_key_arg::key_id as an alternative to fscrypt_add_key_arg::raw.
  105. */
  106. struct fscrypt_provisioning_key_payload {
  107. __u32 type;
  108. __u32 __reserved;
  109. __u8 raw[];
  110. };
  111. /* Struct passed to FS_IOC_ADD_ENCRYPTION_KEY */
  112. struct fscrypt_add_key_arg {
  113. struct fscrypt_key_specifier key_spec;
  114. __u32 raw_size;
  115. __u32 key_id;
  116. __u32 __reserved[8];
  117. __u8 raw[];
  118. };
  119. /* Struct passed to FS_IOC_REMOVE_ENCRYPTION_KEY */
  120. struct fscrypt_remove_key_arg {
  121. struct fscrypt_key_specifier key_spec;
  122. #define FSCRYPT_KEY_REMOVAL_STATUS_FLAG_FILES_BUSY 0x00000001
  123. #define FSCRYPT_KEY_REMOVAL_STATUS_FLAG_OTHER_USERS 0x00000002
  124. __u32 removal_status_flags; /* output */
  125. __u32 __reserved[5];
  126. };
  127. /* Struct passed to FS_IOC_GET_ENCRYPTION_KEY_STATUS */
  128. struct fscrypt_get_key_status_arg {
  129. /* input */
  130. struct fscrypt_key_specifier key_spec;
  131. __u32 __reserved[6];
  132. /* output */
  133. #define FSCRYPT_KEY_STATUS_ABSENT 1
  134. #define FSCRYPT_KEY_STATUS_PRESENT 2
  135. #define FSCRYPT_KEY_STATUS_INCOMPLETELY_REMOVED 3
  136. __u32 status;
  137. #define FSCRYPT_KEY_STATUS_FLAG_ADDED_BY_SELF 0x00000001
  138. __u32 status_flags;
  139. __u32 user_count;
  140. __u32 __out_reserved[13];
  141. };
  142. #define FS_IOC_SET_ENCRYPTION_POLICY _IOR('f', 19, struct fscrypt_policy_v1)
  143. #define FS_IOC_GET_ENCRYPTION_PWSALT _IOW('f', 20, __u8[16])
  144. #define FS_IOC_GET_ENCRYPTION_POLICY _IOW('f', 21, struct fscrypt_policy_v1)
  145. #define FS_IOC_GET_ENCRYPTION_POLICY_EX _IOWR('f', 22, __u8[9]) /* size + version */
  146. #define FS_IOC_ADD_ENCRYPTION_KEY _IOWR('f', 23, struct fscrypt_add_key_arg)
  147. #define FS_IOC_REMOVE_ENCRYPTION_KEY _IOWR('f', 24, struct fscrypt_remove_key_arg)
  148. #define FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS _IOWR('f', 25, struct fscrypt_remove_key_arg)
  149. #define FS_IOC_GET_ENCRYPTION_KEY_STATUS _IOWR('f', 26, struct fscrypt_get_key_status_arg)
  150. #define FS_IOC_GET_ENCRYPTION_NONCE _IOR('f', 27, __u8[16])
  151. /**********************************************************************/
  152. /* old names; don't add anything new here! */
  153. #ifndef __KERNEL__
  154. #define fscrypt_policy fscrypt_policy_v1
  155. #define FS_KEY_DESCRIPTOR_SIZE FSCRYPT_KEY_DESCRIPTOR_SIZE
  156. #define FS_POLICY_FLAGS_PAD_4 FSCRYPT_POLICY_FLAGS_PAD_4
  157. #define FS_POLICY_FLAGS_PAD_8 FSCRYPT_POLICY_FLAGS_PAD_8
  158. #define FS_POLICY_FLAGS_PAD_16 FSCRYPT_POLICY_FLAGS_PAD_16
  159. #define FS_POLICY_FLAGS_PAD_32 FSCRYPT_POLICY_FLAGS_PAD_32
  160. #define FS_POLICY_FLAGS_PAD_MASK FSCRYPT_POLICY_FLAGS_PAD_MASK
  161. #define FS_POLICY_FLAG_DIRECT_KEY FSCRYPT_POLICY_FLAG_DIRECT_KEY
  162. #define FS_POLICY_FLAGS_VALID 0x07 /* contains old flags only */
  163. #define FS_ENCRYPTION_MODE_INVALID 0 /* never used */
  164. #define FS_ENCRYPTION_MODE_AES_256_XTS FSCRYPT_MODE_AES_256_XTS
  165. #define FS_ENCRYPTION_MODE_AES_256_GCM 2 /* never used */
  166. #define FS_ENCRYPTION_MODE_AES_256_CBC 3 /* never used */
  167. #define FS_ENCRYPTION_MODE_AES_256_CTS FSCRYPT_MODE_AES_256_CTS
  168. #define FS_ENCRYPTION_MODE_AES_128_CBC FSCRYPT_MODE_AES_128_CBC
  169. #define FS_ENCRYPTION_MODE_AES_128_CTS FSCRYPT_MODE_AES_128_CTS
  170. #define FS_ENCRYPTION_MODE_SPECK128_256_XTS 7 /* removed */
  171. #define FS_ENCRYPTION_MODE_SPECK128_256_CTS 8 /* removed */
  172. #define FS_ENCRYPTION_MODE_ADIANTUM FSCRYPT_MODE_ADIANTUM
  173. #define FS_KEY_DESC_PREFIX FSCRYPT_KEY_DESC_PREFIX
  174. #define FS_KEY_DESC_PREFIX_SIZE FSCRYPT_KEY_DESC_PREFIX_SIZE
  175. #define FS_MAX_KEY_SIZE FSCRYPT_MAX_KEY_SIZE
  176. #endif /* !__KERNEL__ */
  177. #endif /* _UAPI_LINUX_FSCRYPT_H */