From d7198ce46d10712b6fdd66e35237d7d0d51afcd6 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Thu, 11 Apr 2019 16:50:56 +0800 Subject: [PATCH] crypto: des_generic - Forbid 2-key in 3DES and add helpers This patch adds a requirement to the generic 3DES implementation such that 2-key 3DES (K1 == K3) is no longer allowed in FIPS mode. We will also provide helpers that may be used by drivers that implement 3DES to make the same check. Signed-off-by: Herbert Xu --- crypto/des_generic.c | 11 ++++------- include/crypto/des.h | 43 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 47 insertions(+), 7 deletions(-) diff --git a/crypto/des_generic.c b/crypto/des_generic.c index 1e6621665dd9..ebec1fb08c45 100644 --- a/crypto/des_generic.c +++ b/crypto/des_generic.c @@ -862,14 +862,11 @@ static void des_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) int __des3_ede_setkey(u32 *expkey, u32 *flags, const u8 *key, unsigned int keylen) { - const u32 *K = (const u32 *)key; + int err; - if (unlikely(!((K[0] ^ K[2]) | (K[1] ^ K[3])) || - !((K[2] ^ K[4]) | (K[3] ^ K[5]))) && - (*flags & CRYPTO_TFM_REQ_FORBID_WEAK_KEYS)) { - *flags |= CRYPTO_TFM_RES_WEAK_KEY; - return -EINVAL; - } + err = __des3_verify_key(flags, key); + if (unlikely(err)) + return err; des_ekey(expkey, key); expkey += DES_EXPKEY_WORDS; key += DES_KEY_SIZE; dkey(expkey, key); expkey += DES_EXPKEY_WORDS; key += DES_KEY_SIZE; diff --git a/include/crypto/des.h b/include/crypto/des.h index d4094d58ac54..72c7c8e5a5a7 100644 --- a/include/crypto/des.h +++ b/include/crypto/des.h @@ -6,6 +6,11 @@ #ifndef __CRYPTO_DES_H #define __CRYPTO_DES_H +#include +#include +#include +#include + #define DES_KEY_SIZE 8 #define DES_EXPKEY_WORDS 32 #define DES_BLOCK_SIZE 8 @@ -14,6 +19,44 @@ #define DES3_EDE_EXPKEY_WORDS (3 * DES_EXPKEY_WORDS) #define DES3_EDE_BLOCK_SIZE DES_BLOCK_SIZE +static inline int __des3_verify_key(u32 *flags, const u8 *key) +{ + int err = -EINVAL; + u32 K[6]; + + memcpy(K, key, DES3_EDE_KEY_SIZE); + + if (unlikely(!((K[0] ^ K[2]) | (K[1] ^ K[3])) || + !((K[2] ^ K[4]) | (K[3] ^ K[5]))) && + (fips_enabled || + (*flags & CRYPTO_TFM_REQ_FORBID_WEAK_KEYS))) + goto bad; + + if (unlikely(!((K[0] ^ K[4]) | (K[1] ^ K[5]))) && fips_enabled) + goto bad; + + err = 0; + +out: + memzero_explicit(K, DES3_EDE_KEY_SIZE); + + return err; + +bad: + *flags |= CRYPTO_TFM_RES_WEAK_KEY; + goto out; +} + +static inline int des3_verify_key(struct crypto_skcipher *tfm, const u8 *key) +{ + u32 flags; + int err; + + flags = crypto_skcipher_get_flags(tfm); + err = __des3_verify_key(&flags, key); + crypto_skcipher_set_flags(tfm, flags); + return err; +} extern unsigned long des_ekey(u32 *pe, const u8 *k); -- 2.39.5