linux/security/integrity/integrity.h
Dmitry Kasatkin d3634d0f42 ima: read and use signature hash algorithm
All files on the filesystem, currently, are hashed using the same hash
algorithm.  In preparation for files from different packages being
signed using different hash algorithms, this patch adds support for
reading the signature hash algorithm from the 'security.ima' extended
attribute and calculates the appropriate file data hash based on it.

Changelog:
- fix scripts Lindent and checkpatch msgs - Mimi
- fix md5 support for older version, which occupied 20 bytes in the
  xattr, not the expected 16 bytes.  Fix the comparison to compare
  only the first 16 bytes.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-10-25 17:16:59 -04:00

152 lines
4.3 KiB
C

/*
* Copyright (C) 2009-2010 IBM Corporation
*
* Authors:
* Mimi Zohar <zohar@us.ibm.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation, version 2 of the
* License.
*
*/
#include <linux/types.h>
#include <linux/integrity.h>
#include <crypto/sha.h>
#include <linux/key.h>
/* iint action cache flags */
#define IMA_MEASURE 0x00000001
#define IMA_MEASURED 0x00000002
#define IMA_APPRAISE 0x00000004
#define IMA_APPRAISED 0x00000008
/*#define IMA_COLLECT 0x00000010 do not use this flag */
#define IMA_COLLECTED 0x00000020
#define IMA_AUDIT 0x00000040
#define IMA_AUDITED 0x00000080
/* iint cache flags */
#define IMA_ACTION_FLAGS 0xff000000
#define IMA_DIGSIG 0x01000000
#define IMA_DIGSIG_REQUIRED 0x02000000
#define IMA_DO_MASK (IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \
IMA_APPRAISE_SUBMASK)
#define IMA_DONE_MASK (IMA_MEASURED | IMA_APPRAISED | IMA_AUDITED | \
IMA_COLLECTED | IMA_APPRAISED_SUBMASK)
/* iint subaction appraise cache flags */
#define IMA_FILE_APPRAISE 0x00000100
#define IMA_FILE_APPRAISED 0x00000200
#define IMA_MMAP_APPRAISE 0x00000400
#define IMA_MMAP_APPRAISED 0x00000800
#define IMA_BPRM_APPRAISE 0x00001000
#define IMA_BPRM_APPRAISED 0x00002000
#define IMA_MODULE_APPRAISE 0x00004000
#define IMA_MODULE_APPRAISED 0x00008000
#define IMA_APPRAISE_SUBMASK (IMA_FILE_APPRAISE | IMA_MMAP_APPRAISE | \
IMA_BPRM_APPRAISE | IMA_MODULE_APPRAISE)
#define IMA_APPRAISED_SUBMASK (IMA_FILE_APPRAISED | IMA_MMAP_APPRAISED | \
IMA_BPRM_APPRAISED | IMA_MODULE_APPRAISED)
enum evm_ima_xattr_type {
IMA_XATTR_DIGEST = 0x01,
EVM_XATTR_HMAC,
EVM_IMA_XATTR_DIGSIG,
};
struct evm_ima_xattr_data {
u8 type;
u8 digest[SHA1_DIGEST_SIZE];
} __packed;
#define IMA_MAX_DIGEST_SIZE 64
struct ima_digest_data {
u8 algo;
u8 length;
u8 type;
u8 digest[IMA_MAX_DIGEST_SIZE];
} __packed;
/*
* signature format v2 - for using with asymmetric keys
*/
struct signature_v2_hdr {
uint8_t version; /* signature format version */
uint8_t hash_algo; /* Digest algorithm [enum pkey_hash_algo] */
uint32_t keyid; /* IMA key identifier - not X509/PGP specific */
uint16_t sig_size; /* signature size */
uint8_t sig[0]; /* signature payload */
} __packed;
/* integrity data associated with an inode */
struct integrity_iint_cache {
struct rb_node rb_node; /* rooted in integrity_iint_tree */
struct inode *inode; /* back pointer to inode in question */
u64 version; /* track inode changes */
unsigned long flags;
enum integrity_status ima_file_status:4;
enum integrity_status ima_mmap_status:4;
enum integrity_status ima_bprm_status:4;
enum integrity_status ima_module_status:4;
enum integrity_status evm_status:4;
struct ima_digest_data ima_hash;
};
/* rbtree tree calls to lookup, insert, delete
* integrity data associated with an inode.
*/
struct integrity_iint_cache *integrity_iint_insert(struct inode *inode);
struct integrity_iint_cache *integrity_iint_find(struct inode *inode);
#define INTEGRITY_KEYRING_EVM 0
#define INTEGRITY_KEYRING_MODULE 1
#define INTEGRITY_KEYRING_IMA 2
#define INTEGRITY_KEYRING_MAX 3
#ifdef CONFIG_INTEGRITY_SIGNATURE
int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
const char *digest, int digestlen);
#else
static inline int integrity_digsig_verify(const unsigned int id,
const char *sig, int siglen,
const char *digest, int digestlen)
{
return -EOPNOTSUPP;
}
#endif /* CONFIG_INTEGRITY_SIGNATURE */
#ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
int asymmetric_verify(struct key *keyring, const char *sig,
int siglen, const char *data, int datalen);
#else
static inline int asymmetric_verify(struct key *keyring, const char *sig,
int siglen, const char *data, int datalen)
{
return -EOPNOTSUPP;
}
#endif
#ifdef CONFIG_INTEGRITY_AUDIT
/* declarations */
void integrity_audit_msg(int audit_msgno, struct inode *inode,
const unsigned char *fname, const char *op,
const char *cause, int result, int info);
#else
static inline void integrity_audit_msg(int audit_msgno, struct inode *inode,
const unsigned char *fname,
const char *op, const char *cause,
int result, int info)
{
}
#endif
/* set during initialization */
extern int iint_initialized;