fscrypt.h 6.6 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_SM4_XTS 7
  27. #define FSCRYPT_MODE_SM4_CTS 8
  28. #define FSCRYPT_MODE_ADIANTUM 9
  29. #define FSCRYPT_MODE_AES_256_HCTR2 10
  30. /* If adding a mode number > 10, update FSCRYPT_MODE_MAX in fscrypt_private.h */
  31. /*
  32. * Legacy policy version; ad-hoc KDF and no key verification.
  33. * For new encrypted directories, use fscrypt_policy_v2 instead.
  34. *
  35. * Careful: the .version field for this is actually 0, not 1.
  36. */
  37. #define FSCRYPT_POLICY_V1 0
  38. #define FSCRYPT_KEY_DESCRIPTOR_SIZE 8
  39. struct fscrypt_policy_v1 {
  40. __u8 version;
  41. __u8 contents_encryption_mode;
  42. __u8 filenames_encryption_mode;
  43. __u8 flags;
  44. __u8 master_key_descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE];
  45. };
  46. /*
  47. * Process-subscribed "logon" key description prefix and payload format.
  48. * Deprecated; prefer FS_IOC_ADD_ENCRYPTION_KEY instead.
  49. */
  50. #define FSCRYPT_KEY_DESC_PREFIX "fscrypt:"
  51. #define FSCRYPT_KEY_DESC_PREFIX_SIZE 8
  52. #define FSCRYPT_MAX_KEY_SIZE 64
  53. struct fscrypt_key {
  54. __u32 mode;
  55. __u8 raw[FSCRYPT_MAX_KEY_SIZE];
  56. __u32 size;
  57. };
  58. /*
  59. * New policy version with HKDF and key verification (recommended).
  60. */
  61. #define FSCRYPT_POLICY_V2 2
  62. #define FSCRYPT_KEY_IDENTIFIER_SIZE 16
  63. struct fscrypt_policy_v2 {
  64. __u8 version;
  65. __u8 contents_encryption_mode;
  66. __u8 filenames_encryption_mode;
  67. __u8 flags;
  68. __u8 log2_data_unit_size;
  69. __u8 __reserved[3];
  70. __u8 master_key_identifier[FSCRYPT_KEY_IDENTIFIER_SIZE];
  71. };
  72. /* Struct passed to FS_IOC_GET_ENCRYPTION_POLICY_EX */
  73. struct fscrypt_get_policy_ex_arg {
  74. __u64 policy_size; /* input/output */
  75. union {
  76. __u8 version;
  77. struct fscrypt_policy_v1 v1;
  78. struct fscrypt_policy_v2 v2;
  79. } policy; /* output */
  80. };
  81. /*
  82. * v1 policy keys are specified by an arbitrary 8-byte key "descriptor",
  83. * matching fscrypt_policy_v1::master_key_descriptor.
  84. */
  85. #define FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR 1
  86. /*
  87. * v2 policy keys are specified by a 16-byte key "identifier" which the kernel
  88. * calculates as a cryptographic hash of the key itself,
  89. * matching fscrypt_policy_v2::master_key_identifier.
  90. */
  91. #define FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER 2
  92. /*
  93. * Specifies a key, either for v1 or v2 policies. This doesn't contain the
  94. * actual key itself; this is just the "name" of the key.
  95. */
  96. struct fscrypt_key_specifier {
  97. __u32 type; /* one of FSCRYPT_KEY_SPEC_TYPE_* */
  98. __u32 __reserved;
  99. union {
  100. __u8 __reserved[32]; /* reserve some extra space */
  101. __u8 descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE];
  102. __u8 identifier[FSCRYPT_KEY_IDENTIFIER_SIZE];
  103. } u;
  104. };
  105. /*
  106. * Payload of Linux keyring key of type "fscrypt-provisioning", referenced by
  107. * fscrypt_add_key_arg::key_id as an alternative to fscrypt_add_key_arg::raw.
  108. */
  109. struct fscrypt_provisioning_key_payload {
  110. __u32 type;
  111. __u32 __reserved;
  112. __u8 raw[];
  113. };
  114. /* Struct passed to FS_IOC_ADD_ENCRYPTION_KEY */
  115. struct fscrypt_add_key_arg {
  116. struct fscrypt_key_specifier key_spec;
  117. __u32 raw_size;
  118. __u32 key_id;
  119. __u32 __reserved[7];
  120. /* N.B.: "temporary" flag, not reserved upstream */
  121. #define __FSCRYPT_ADD_KEY_FLAG_HW_WRAPPED 0x00000001
  122. __u32 __flags;
  123. __u8 raw[];
  124. };
  125. /* Struct passed to FS_IOC_REMOVE_ENCRYPTION_KEY */
  126. struct fscrypt_remove_key_arg {
  127. struct fscrypt_key_specifier key_spec;
  128. #define FSCRYPT_KEY_REMOVAL_STATUS_FLAG_FILES_BUSY 0x00000001
  129. #define FSCRYPT_KEY_REMOVAL_STATUS_FLAG_OTHER_USERS 0x00000002
  130. __u32 removal_status_flags; /* output */
  131. __u32 __reserved[5];
  132. };
  133. /* Struct passed to FS_IOC_GET_ENCRYPTION_KEY_STATUS */
  134. struct fscrypt_get_key_status_arg {
  135. /* input */
  136. struct fscrypt_key_specifier key_spec;
  137. __u32 __reserved[6];
  138. /* output */
  139. #define FSCRYPT_KEY_STATUS_ABSENT 1
  140. #define FSCRYPT_KEY_STATUS_PRESENT 2
  141. #define FSCRYPT_KEY_STATUS_INCOMPLETELY_REMOVED 3
  142. __u32 status;
  143. #define FSCRYPT_KEY_STATUS_FLAG_ADDED_BY_SELF 0x00000001
  144. __u32 status_flags;
  145. __u32 user_count;
  146. __u32 __out_reserved[13];
  147. };
  148. #define FS_IOC_SET_ENCRYPTION_POLICY _IOR('f', 19, struct fscrypt_policy_v1)
  149. #define FS_IOC_GET_ENCRYPTION_PWSALT _IOW('f', 20, __u8[16])
  150. #define FS_IOC_GET_ENCRYPTION_POLICY _IOW('f', 21, struct fscrypt_policy_v1)
  151. #define FS_IOC_GET_ENCRYPTION_POLICY_EX _IOWR('f', 22, __u8[9]) /* size + version */
  152. #define FS_IOC_ADD_ENCRYPTION_KEY _IOWR('f', 23, struct fscrypt_add_key_arg)
  153. #define FS_IOC_REMOVE_ENCRYPTION_KEY _IOWR('f', 24, struct fscrypt_remove_key_arg)
  154. #define FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS _IOWR('f', 25, struct fscrypt_remove_key_arg)
  155. #define FS_IOC_GET_ENCRYPTION_KEY_STATUS _IOWR('f', 26, struct fscrypt_get_key_status_arg)
  156. #define FS_IOC_GET_ENCRYPTION_NONCE _IOR('f', 27, __u8[16])
  157. /**********************************************************************/
  158. /* old names; don't add anything new here! */
  159. #ifndef __KERNEL__
  160. #define fscrypt_policy fscrypt_policy_v1
  161. #define FS_KEY_DESCRIPTOR_SIZE FSCRYPT_KEY_DESCRIPTOR_SIZE
  162. #define FS_POLICY_FLAGS_PAD_4 FSCRYPT_POLICY_FLAGS_PAD_4
  163. #define FS_POLICY_FLAGS_PAD_8 FSCRYPT_POLICY_FLAGS_PAD_8
  164. #define FS_POLICY_FLAGS_PAD_16 FSCRYPT_POLICY_FLAGS_PAD_16
  165. #define FS_POLICY_FLAGS_PAD_32 FSCRYPT_POLICY_FLAGS_PAD_32
  166. #define FS_POLICY_FLAGS_PAD_MASK FSCRYPT_POLICY_FLAGS_PAD_MASK
  167. #define FS_POLICY_FLAG_DIRECT_KEY FSCRYPT_POLICY_FLAG_DIRECT_KEY
  168. #define FS_POLICY_FLAGS_VALID 0x07 /* contains old flags only */
  169. #define FS_ENCRYPTION_MODE_INVALID 0 /* never used */
  170. #define FS_ENCRYPTION_MODE_AES_256_XTS FSCRYPT_MODE_AES_256_XTS
  171. #define FS_ENCRYPTION_MODE_AES_256_GCM 2 /* never used */
  172. #define FS_ENCRYPTION_MODE_AES_256_CBC 3 /* never used */
  173. #define FS_ENCRYPTION_MODE_AES_256_CTS FSCRYPT_MODE_AES_256_CTS
  174. #define FS_ENCRYPTION_MODE_AES_128_CBC FSCRYPT_MODE_AES_128_CBC
  175. #define FS_ENCRYPTION_MODE_AES_128_CTS FSCRYPT_MODE_AES_128_CTS
  176. #define FS_ENCRYPTION_MODE_ADIANTUM FSCRYPT_MODE_ADIANTUM
  177. #define FS_KEY_DESC_PREFIX FSCRYPT_KEY_DESC_PREFIX
  178. #define FS_KEY_DESC_PREFIX_SIZE FSCRYPT_KEY_DESC_PREFIX_SIZE
  179. #define FS_MAX_KEY_SIZE FSCRYPT_MAX_KEY_SIZE
  180. #endif /* !__KERNEL__ */
  181. #endif /* _UAPI_LINUX_FSCRYPT_H */