From:   Stephan =?ISO-8859-1?Q?M=FCller?= <smueller@chronox.de>
Subject: [PATCH v2 2/2] crypto: HMAC - disallow keys < 112 bits in FIPS mode
Date:   Tue, 01 Feb 2022 09:41:32 +0100
References: jsc#SLE-21132,bsc#1193136
Patch-mainline: Submitted, linux-crypto ML

FIPS 140 requires a minimum security strength of 112 bits. This implies
that the HMAC key must not be smaller than 112 in FIPS mode.

This restriction implies that the test vectors for HMAC that have a key
that is smaller than 112 bits must be disabled when FIPS support is
compiled.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Nicolai Stange <nstange@suse.de>
---
 crypto/hmac.c    |    4 ++++
 crypto/testmgr.h |    9 +++++++++
 2 files changed, 13 insertions(+)

--- a/crypto/hmac.c
+++ b/crypto/hmac.c
@@ -15,6 +15,7 @@
 #include <crypto/internal/hash.h>
 #include <crypto/scatterwalk.h>
 #include <linux/err.h>
+#include <linux/fips.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -51,6 +52,9 @@ static int hmac_setkey(struct crypto_sha
 	SHASH_DESC_ON_STACK(shash, hash);
 	unsigned int i;
 
+	if (fips_enabled && (keylen < 112 / 8))
+		return -EINVAL;
+
 	shash->tfm = hash;
 
 	if (keylen > bs) {
--- a/crypto/testmgr.h
+++ b/crypto/testmgr.h
@@ -6095,6 +6095,7 @@ static const struct hash_testvec hmac_sh
 		.psize	= 28,
 		.digest	= "\xef\xfc\xdf\x6a\xe5\xeb\x2f\xa2\xd2\x74"
 			  "\x16\xd5\xf1\x84\xdf\x9c\x25\x9a\x7c\x79",
+		.fips_skip = 1,
 	}, {
 		.key	= "\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa",
 		.ksize	= 20,
@@ -6184,6 +6185,7 @@ static const struct hash_testvec hmac_sh
 			"\x45\x69\x0f\x3a\x7e\x9e\x6d\x0f"
 			"\x8b\xbe\xa2\xa3\x9e\x61\x48\x00"
 			"\x8f\xd0\x5e\x44",
+		.fips_skip = 1,
 	}, {
 		.key    = "\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa"
 			"\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa"
@@ -6327,6 +6329,7 @@ static const struct hash_testvec hmac_sh
 			  "\x6a\x04\x24\x26\x08\x95\x75\xc7"
 			  "\x5a\x00\x3f\x08\x9d\x27\x39\x83"
 			  "\x9d\xec\x58\xb9\x64\xec\x38\x43",
+		.fips_skip = 1,
 	}, {
 		.key	= "\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa"
 			"\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa"
@@ -6825,6 +6828,7 @@ static const struct hash_testvec hmac_sh
 			  "\xe4\x2e\xc3\x73\x63\x22\x44\x5e"
 			  "\x8e\x22\x40\xca\x5e\x69\xe2\xc7"
 			  "\x8b\x32\x39\xec\xfa\xb2\x16\x49",
+		.fips_skip = 1,
 	}, {
 		.key	= "\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa"
 			  "\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa"
@@ -6925,6 +6929,7 @@ static const struct hash_testvec hmac_sh
 			  "\x6d\x03\x4f\x65\xf8\xf0\xe6\xfd"
 			  "\xca\xea\xb1\xa3\x4d\x4a\x6b\x4b"
 			  "\x63\x6e\x07\x0a\x38\xbc\xe7\x37",
+		.fips_skip = 1,
 	}, {
 		.key	= "\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa"
 			  "\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa"
@@ -7020,6 +7025,7 @@ static const struct hash_testvec hmac_sh
 			  "\x1b\x79\x86\x34\xad\x38\x68\x11"
 			  "\xc2\xcf\xc8\x5b\xfa\xf5\xd5\x2b"
 			  "\xba\xce\x5e\x66",
+		.fips_skip = 1,
 	}, {
 		.key	= "\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa"
 			  "\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa"
@@ -7107,6 +7113,7 @@ static const struct hash_testvec hmac_sh
 			  "\x35\x96\xbb\xb0\xda\x73\xb8\x87"
 			  "\xc9\x17\x1f\x93\x09\x5b\x29\x4a"
 			  "\xe8\x57\xfb\xe2\x64\x5e\x1b\xa5",
+		.fips_skip = 1,
 	}, {
 		.key	= "\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa"
 			  "\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa"
@@ -7198,6 +7205,7 @@ static const struct hash_testvec hmac_sh
 			  "\x3c\xa1\x35\x08\xa9\x32\x43\xce"
 			  "\x48\xc0\x45\xdc\x00\x7f\x26\xa2"
 			  "\x1b\x3f\x5e\x0e\x9d\xf4\xc2\x0a",
+		.fips_skip = 1,
 	}, {
 		.key	= "\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa"
 			  "\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa"
@@ -7297,6 +7305,7 @@ static const struct hash_testvec hmac_sh
 			  "\xee\x7a\x0c\x31\xd0\x22\xa9\x5e"
 			  "\x1f\xc9\x2b\xa9\xd7\x7d\xf8\x83"
 			  "\x96\x02\x75\xbe\xb4\xe6\x20\x24",
+		.fips_skip = 1,
 	}, {
 		.key	= "\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa"
 			  "\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa"