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| author | Mimi Zohar <zohar@linux.ibm.com> | 2021-05-14 00:36:04 +0200 |
|---|---|---|
| committer | Mimi Zohar <zohar@linux.ibm.com> | 2021-06-20 17:10:25 +0200 |
| commit | 87ac3d002d567fac3527d6612865e81cfd783727 (patch) | |
| tree | 9a43cd3d52a0edb7817d8efecb5ec868f3c7c7d1 /security/integrity/evm | |
| parent | IMA: support for duplicate measurement records (diff) | |
| download | linux-87ac3d002d567fac3527d6612865e81cfd783727.tar.xz linux-87ac3d002d567fac3527d6612865e81cfd783727.zip | |
evm: output EVM digest calculation info
Output the data used in calculating the EVM digest and the resulting
digest as ascii hexadecimal strings.
Suggested-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> (CONFIG_DYNAMIC_DEBUG)
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Reported-by: kernel test robot <lkp@intel.com> (Use %zu for size_t)
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Diffstat (limited to 'security/integrity/evm')
| -rw-r--r-- | security/integrity/evm/evm_crypto.c | 43 | ||||
| -rw-r--r-- | security/integrity/evm/evm_main.c | 4 |
2 files changed, 47 insertions, 0 deletions
diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c index 1628e2ca9862..bebe160c57b9 100644 --- a/security/integrity/evm/evm_crypto.c +++ b/security/integrity/evm/evm_crypto.c @@ -10,6 +10,8 @@ * Using root's kernel master key (kmk), calculate the HMAC */ +#define pr_fmt(fmt) "EVM: "fmt + #include <linux/export.h> #include <linux/crypto.h> #include <linux/xattr.h> @@ -175,6 +177,30 @@ static void hmac_add_misc(struct shash_desc *desc, struct inode *inode, type != EVM_XATTR_PORTABLE_DIGSIG) crypto_shash_update(desc, (u8 *)&inode->i_sb->s_uuid, UUID_SIZE); crypto_shash_final(desc, digest); + + pr_debug("hmac_misc: (%zu) [%*phN]\n", sizeof(struct h_misc), + (int)sizeof(struct h_misc), &hmac_misc); +} + +/* + * Dump large security xattr values as a continuous ascii hexademical string. + * (pr_debug is limited to 64 bytes.) + */ +static void dump_security_xattr(const char *prefix, const void *src, + size_t count) +{ +#if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG) + char *asciihex, *p; + + p = asciihex = kmalloc(count * 2 + 1, GFP_KERNEL); + if (!asciihex) + return; + + p = bin2hex(p, src, count); + *p = 0; + pr_debug("%s: (%zu) %.*s\n", prefix, count, (int)count * 2, asciihex); + kfree(asciihex); +#endif } /* @@ -230,6 +256,16 @@ static int evm_calc_hmac_or_hash(struct dentry *dentry, req_xattr_value_len); if (is_ima) ima_present = true; + + if (req_xattr_value_len < 64) + pr_debug("%s: (%zu) [%*phN]\n", req_xattr_name, + req_xattr_value_len, + (int)req_xattr_value_len, + req_xattr_value); + else + dump_security_xattr(req_xattr_name, + req_xattr_value, + req_xattr_value_len); continue; } size = vfs_getxattr_alloc(&init_user_ns, dentry, xattr->name, @@ -246,6 +282,13 @@ static int evm_calc_hmac_or_hash(struct dentry *dentry, crypto_shash_update(desc, (const u8 *)xattr_value, xattr_size); if (is_ima) ima_present = true; + + if (xattr_size < 64) + pr_debug("%s: (%zu) [%*phN]", xattr->name, xattr_size, + (int)xattr_size, xattr_value); + else + dump_security_xattr(xattr->name, xattr_value, + xattr_size); } hmac_add_misc(desc, inode, type, data->digest); diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index 977208aecd06..1c8435dfabee 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -11,6 +11,8 @@ * evm_inode_removexattr, and evm_verifyxattr */ +#define pr_fmt(fmt) "EVM: "fmt + #include <linux/init.h> #include <linux/crypto.h> #include <linux/audit.h> @@ -272,6 +274,8 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry, else evm_status = INTEGRITY_FAIL; } + pr_debug("digest: (%d) [%*phN]\n", digest.hdr.length, digest.hdr.length, + digest.digest); out: if (iint) iint->evm_status = evm_status; |