lib/crypto: blake2s: move hmac construction into wireguard

commit d8d83d8ab0a453e17e68b3a3bed1f940c34b8646 upstream.

Basically nobody should use blake2s in an HMAC construction; it already
has a keyed variant. But unfortunately for historical reasons, Noise,
used by WireGuard, uses HKDF quite strictly, which means we have to use
this. Because this really shouldn't be used by others, this commit moves
it into wireguard's noise.c locally, so that kernels that aren't using
WireGuard don't get this superfluous code baked in. On m68k systems,
this shaves off ~314 bytes.

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 0 insertions, 68 deletions

diff --git a/lib/crypto/blake2s-selftest.c b/lib/crypto/blake2s-selftest.c
index 5d9ea53be973..409e4b728770 100644
--- a/lib/crypto/blake2s-selftest.c
+++ b/lib/crypto/blake2s-selftest.c
@@ -15,7 +15,6 @@
  * #include <stdio.h>
  *
  * #include <openssl/evp.h>
- * #include <openssl/hmac.h>
  *
  * #define BLAKE2S_TESTVEC_COUNT	256
  *
@@ -58,16 +57,6 @@
  *	}
  *	printf("};\n\n");
  *
- *	printf("static const u8 blake2s_hmac_testvecs[][BLAKE2S_HASH_SIZE] __initconst = {\n");
- *
- *	HMAC(EVP_blake2s256(), key, sizeof(key), buf, sizeof(buf), hash, NULL);
- *	print_vec(hash, BLAKE2S_OUTBYTES);
- *
- *	HMAC(EVP_blake2s256(), buf, sizeof(buf), key, sizeof(key), hash, NULL);
- *	print_vec(hash, BLAKE2S_OUTBYTES);
- *
- *	printf("};\n");
- *
  *	return 0;
  *}
  */
@@ -554,15 +543,6 @@ static const u8 blake2s_testvecs[][BLAKE2S_HASH_SIZE] __initconst = {
     0xd6, 0x98, 0x6b, 0x07, 0x10, 0x65, 0x52, 0x65, },
 };
 
-static const u8 blake2s_hmac_testvecs[][BLAKE2S_HASH_SIZE] __initconst = {
-  { 0xce, 0xe1, 0x57, 0x69, 0x82, 0xdc, 0xbf, 0x43, 0xad, 0x56, 0x4c, 0x70,
-    0xed, 0x68, 0x16, 0x96, 0xcf, 0xa4, 0x73, 0xe8, 0xe8, 0xfc, 0x32, 0x79,
-    0x08, 0x0a, 0x75, 0x82, 0xda, 0x3f, 0x05, 0x11, },
-  { 0x77, 0x2f, 0x0c, 0x71, 0x41, 0xf4, 0x4b, 0x2b, 0xb3, 0xc6, 0xb6, 0xf9,
-    0x60, 0xde, 0xe4, 0x52, 0x38, 0x66, 0xe8, 0xbf, 0x9b, 0x96, 0xc4, 0x9f,
-    0x60, 0xd9, 0x24, 0x37, 0x99, 0xd6, 0xec, 0x31, },
-};
-
 bool __init blake2s_selftest(void)
 {
 	u8 key[BLAKE2S_KEY_SIZE];
@@ -607,16 +587,5 @@ bool __init blake2s_selftest(void)
 		}
 	}
 
-	if (success) {
-		blake2s256_hmac(hash, buf, key, sizeof(buf), sizeof(key));
-		success &= !memcmp(hash, blake2s_hmac_testvecs[0], BLAKE2S_HASH_SIZE);
-
-		blake2s256_hmac(hash, key, buf, sizeof(key), sizeof(buf));
-		success &= !memcmp(hash, blake2s_hmac_testvecs[1], BLAKE2S_HASH_SIZE);
-
-		if (!success)
-			pr_err("blake2s256_hmac self-test: FAIL\n");
-	}
-
 	return success;
 }
diff --git a/lib/crypto/blake2s.c b/lib/crypto/blake2s.c
index 416a076964a2..bbe387245a01 100644
--- a/lib/crypto/blake2s.c
+++ b/lib/crypto/blake2s.c
@@ -30,43 +30,6 @@ void blake2s_final(struct blake2s_state *state, u8 *out)
 }
 EXPORT_SYMBOL(blake2s_final);
 
-void blake2s256_hmac(u8 *out, const u8 *in, const u8 *key, const size_t inlen,
-		     const size_t keylen)
-{
-	struct blake2s_state state;
-	u8 x_key[BLAKE2S_BLOCK_SIZE] __aligned(__alignof__(u32)) = { 0 };
-	u8 i_hash[BLAKE2S_HASH_SIZE] __aligned(__alignof__(u32));
-	int i;
-
-	if (keylen > BLAKE2S_BLOCK_SIZE) {
-		blake2s_init(&state, BLAKE2S_HASH_SIZE);
-		blake2s_update(&state, key, keylen);
-		blake2s_final(&state, x_key);
-	} else
-		memcpy(x_key, key, keylen);
-
-	for (i = 0; i < BLAKE2S_BLOCK_SIZE; ++i)
-		x_key[i] ^= 0x36;
-
-	blake2s_init(&state, BLAKE2S_HASH_SIZE);
-	blake2s_update(&state, x_key, BLAKE2S_BLOCK_SIZE);
-	blake2s_update(&state, in, inlen);
-	blake2s_final(&state, i_hash);
-
-	for (i = 0; i < BLAKE2S_BLOCK_SIZE; ++i)
-		x_key[i] ^= 0x5c ^ 0x36;
-
-	blake2s_init(&state, BLAKE2S_HASH_SIZE);
-	blake2s_update(&state, x_key, BLAKE2S_BLOCK_SIZE);
-	blake2s_update(&state, i_hash, BLAKE2S_HASH_SIZE);
-	blake2s_final(&state, i_hash);
-
-	memcpy(out, i_hash, BLAKE2S_HASH_SIZE);
-	memzero_explicit(x_key, BLAKE2S_BLOCK_SIZE);
-	memzero_explicit(i_hash, BLAKE2S_HASH_SIZE);
-}
-EXPORT_SYMBOL(blake2s256_hmac);
-
 static int __init mod_init(void)
 {
 	if (!IS_ENABLED(CONFIG_CRYPTO_MANAGER_DISABLE_TESTS) &&