diff options
| author | Thomas Huth <thuth@redhat.com> | 2026-09-16 11:50:10 +0200 |
|---|---|---|
| committer | Eric Biggers <ebiggers@kernel.org> | 2026-09-30 09:33:54 -0700 |
| commit | e09cbc96ff8c94d477a07b2e35b4b4886dc9cf30 (patch) | |
| tree | c135b1c34bbb0ca3ad42a093a83992d58670fed9 | |
| parent | 97560fd98d4d36b2fd656a6270e15cb2218fcbe2 (diff) | |
lib/crypto: sha1: Provide functions for zeroizing hmac_sha1 structures
In certain cases crypto code needs to zeroize their local hmac_sha1_key
or hmac_sha1_ctx structures after use to avoid leaking sensitive material.
Provide hmac_sha1_zeroize_key() and hmac_sha1_zeroize_ctx() helper
functions that e.g. can be used with __cleanup() to automatically zeroize
the structures when they go out of scope.
While we're at it, replace the related memzero_explicit() call in
lib/crypto/sha1.c with a call to the new helper function.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Link: https://patch.msgid.link/20260916095022.604354-9-thuth@redhat.com
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
| -rw-r--r-- | include/crypto/sha1.h | 19 | ||||
| -rw-r--r-- | lib/crypto/sha1.c | 2 |
2 files changed, 20 insertions, 1 deletions
diff --git a/include/crypto/sha1.h b/include/crypto/sha1.h index 4d973e016cd6..bc0046bffeae 100644 --- a/include/crypto/sha1.h +++ b/include/crypto/sha1.h @@ -7,6 +7,7 @@ #define _CRYPTO_SHA1_H #include <linux/types.h> +#include <linux/string.h> #define SHA1_DIGEST_SIZE 20 #define SHA1_BLOCK_SIZE 64 @@ -97,6 +98,15 @@ struct hmac_sha1_key { }; /** + * hmac_sha1_zeroize_key() - Zeroize an hmac_sha1_key structure + * @key: The hmac_sha1_key to zeroize + */ +static inline void hmac_sha1_zeroize_key(struct hmac_sha1_key *key) +{ + memzero_explicit(key, sizeof(*key)); +} + +/** * struct hmac_sha1_ctx - Context for computing HMAC-SHA1 of a message * @sha_ctx: private * @ostate: private @@ -107,6 +117,15 @@ struct hmac_sha1_ctx { }; /** + * hmac_sha1_zeroize_ctx() - Zeroize an hmac_sha1_ctx structure + * @ctx: The hmac_sha1_ctx context to zeroize + */ +static inline void hmac_sha1_zeroize_ctx(struct hmac_sha1_ctx *ctx) +{ + memzero_explicit(ctx, sizeof(*ctx)); +} + +/** * hmac_sha1_preparekey() - Prepare a key for HMAC-SHA1 * @key: (output) the key structure to initialize * @raw_key: the raw HMAC-SHA1 key diff --git a/lib/crypto/sha1.c b/lib/crypto/sha1.c index b687b89d97cb..c4361ef77166 100644 --- a/lib/crypto/sha1.c +++ b/lib/crypto/sha1.c @@ -275,7 +275,7 @@ void hmac_sha1_final(struct hmac_sha1_ctx *ctx, u8 out[SHA1_DIGEST_SIZE]) for (size_t i = 0; i < SHA1_DIGEST_SIZE; i += 4) put_unaligned_be32(ctx->ostate.h[i / 4], out + i); - memzero_explicit(ctx, sizeof(*ctx)); + hmac_sha1_zeroize_ctx(ctx); } EXPORT_SYMBOL_GPL(hmac_sha1_final); |