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| author | Thomas Huth <thuth@redhat.com> | 2026-09-16 11:50:07 +0200 |
|---|---|---|
| committer | Eric Biggers <ebiggers@kernel.org> | 2026-09-30 09:33:54 -0700 |
| commit | 91b4ebff7a88ee3a0570b0058b054ecf527cefa2 (patch) | |
| tree | cbb5304054e0093d959e6c55dcf6e2b663bcde74 /include | |
| parent | dbb5091fb6c937ff312257aaf9b772216c3ca8f6 (diff) | |
| download | linux-91b4ebff7a88ee3a0570b0058b054ecf527cefa2.tar.gz linux-91b4ebff7a88ee3a0570b0058b054ecf527cefa2.zip | |
lib/crypto: md5: Provide functions for zeroizing hmac_md5 structures
In certain cases crypto code functions need to zeroize their local
hmac_md5_key or hmac_md5_ctx structures after use to avoid leaking
sensitive material on the stack.
Provide hmac_md5_zeroize_key() and hmac_md5_zeroize_ctx() helper
functions that e.g. can be used with __cleanup() to automatically
zeroize the structure when it goes out of scope.
While we're at it, replace the related memzero_explicit() call in
lib/crypto/md5.c with a call to the new helper function.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Link: https://patch.msgid.link/20260916095022.604354-6-thuth@redhat.com
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/crypto/md5.h | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/include/crypto/md5.h b/include/crypto/md5.h index c47aedfe67ec..1ed89c15b662 100644 --- a/include/crypto/md5.h +++ b/include/crypto/md5.h @@ -4,6 +4,7 @@ #include <crypto/hash.h> #include <linux/types.h> +#include <linux/string.h> #define MD5_DIGEST_SIZE 16 #define MD5_HMAC_BLOCK_SIZE 64 @@ -99,6 +100,15 @@ struct hmac_md5_key { }; /** + * hmac_md5_zeroize_key() - Zeroize an hmac_md5_key structure + * @key: The hmac_md5_key to zeroize + */ +static inline void hmac_md5_zeroize_key(struct hmac_md5_key *key) +{ + memzero_explicit(key, sizeof(*key)); +} + +/** * struct hmac_md5_ctx - Context for computing HMAC-MD5 of a message * @hash_ctx: private * @ostate: private @@ -109,6 +119,15 @@ struct hmac_md5_ctx { }; /** + * hmac_md5_zeroize_ctx() - Zeroize an hmac_md5_ctx structure + * @ctx: The hmac_md5_ctx context to zeroize + */ +static inline void hmac_md5_zeroize_ctx(struct hmac_md5_ctx *ctx) +{ + memzero_explicit(ctx, sizeof(*ctx)); +} + +/** * hmac_md5_preparekey() - Prepare a key for HMAC-MD5 * @key: (output) the key structure to initialize * @raw_key: the raw HMAC-MD5 key |