From 28856a9e52c7cac712af6c143de04766617535dc Mon Sep 17 00:00:00 2001 From: Stephan Mueller Date: Tue, 9 Feb 2016 15:37:47 +0100 Subject: crypto: xts - consolidate sanity check for keys The patch centralizes the XTS key check logic into the service function xts_check_key which is invoked from the different XTS implementations. With this, the XTS implementations in ARM, ARM64, PPC and S390 have now a sanity check for the XTS keys similar to the other arches. In addition, this service function received a check to ensure that the key != the tweak key which is mandated by FIPS 140-2 IG A.9. As the check is not present in the standards defining XTS, it is only enforced in FIPS mode of the kernel. Signed-off-by: Stephan Mueller Signed-off-by: Herbert Xu diff --git a/arch/arm/crypto/aes-ce-glue.c b/arch/arm/crypto/aes-ce-glue.c index b445a5d..85ff69b 100644 --- a/arch/arm/crypto/aes-ce-glue.c +++ b/arch/arm/crypto/aes-ce-glue.c @@ -152,6 +152,10 @@ static int xts_set_key(struct crypto_tfm *tfm, const u8 *in_key, struct crypto_aes_xts_ctx *ctx = crypto_tfm_ctx(tfm); int ret; + ret = xts_check_key(tfm, in_key, key_len); + if (ret) + return ret; + ret = ce_aes_expandkey(&ctx->key1, in_key, key_len / 2); if (!ret) ret = ce_aes_expandkey(&ctx->key2, &in_key[key_len / 2], diff --git a/arch/arm/crypto/aesbs-glue.c b/arch/arm/crypto/aesbs-glue.c index 6d68529..d004bd1 100644 --- a/arch/arm/crypto/aesbs-glue.c +++ b/arch/arm/crypto/aesbs-glue.c @@ -89,6 +89,11 @@ static int aesbs_xts_set_key(struct crypto_tfm *tfm, const u8 *in_key, { struct aesbs_xts_ctx *ctx = crypto_tfm_ctx(tfm); int bits = key_len * 4; + int err; + + err = xts_check_key(tfm, in_key, key_len); + if (err) + return err; if (private_AES_set_encrypt_key(in_key, bits, &ctx->enc.rk)) { tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; diff --git a/arch/arm64/crypto/aes-glue.c b/arch/arm64/crypto/aes-glue.c index 05d9e16..c963d75 100644 --- a/arch/arm64/crypto/aes-glue.c +++ b/arch/arm64/crypto/aes-glue.c @@ -85,6 +85,10 @@ static int xts_set_key(struct crypto_tfm *tfm, const u8 *in_key, struct crypto_aes_xts_ctx *ctx = crypto_tfm_ctx(tfm); int ret; + ret = xts_check_key(tfm, in_key, key_len); + if (ret) + return ret; + ret = aes_expandkey(&ctx->key1, in_key, key_len / 2); if (!ret) ret = aes_expandkey(&ctx->key2, &in_key[key_len / 2], diff --git a/arch/powerpc/crypto/aes-spe-glue.c b/arch/powerpc/crypto/aes-spe-glue.c index 93ee046..1608079 100644 --- a/arch/powerpc/crypto/aes-spe-glue.c +++ b/arch/powerpc/crypto/aes-spe-glue.c @@ -126,6 +126,11 @@ static int ppc_xts_setkey(struct crypto_tfm *tfm, const u8 *in_key, unsigned int key_len) { struct ppc_xts_ctx *ctx = crypto_tfm_ctx(tfm); + int err; + + err = xts_check_key(tfm, in_key, key_len); + if (err) + return err; key_len >>= 1; diff --git a/arch/s390/crypto/aes_s390.c b/arch/s390/crypto/aes_s390.c index 0b9b95f..3f1a1a4 100644 --- a/arch/s390/crypto/aes_s390.c +++ b/arch/s390/crypto/aes_s390.c @@ -587,6 +587,11 @@ static int xts_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, { struct s390_xts_ctx *xts_ctx = crypto_tfm_ctx(tfm); u32 *flags = &tfm->crt_flags; + int err; + + err = xts_check_key(tfm, in_key, key_len); + if (err) + return err; switch (key_len) { case 32: diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c index 3633ad6..064c7e2 100644 --- a/arch/x86/crypto/aesni-intel_glue.c +++ b/arch/x86/crypto/aesni-intel_glue.c @@ -639,16 +639,11 @@ static int xts_aesni_setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen) { struct aesni_xts_ctx *ctx = crypto_tfm_ctx(tfm); - u32 *flags = &tfm->crt_flags; int err; - /* key consists of keys of equal size concatenated, therefore - * the length must be even - */ - if (keylen % 2) { - *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; - return -EINVAL; - } + err = xts_check_key(tfm, key, keylen); + if (err) + return err; /* first half of xts-key is for crypt */ err = aes_set_key_common(tfm, ctx->raw_crypt_ctx, key, keylen / 2); diff --git a/arch/x86/crypto/camellia_glue.c b/arch/x86/crypto/camellia_glue.c index 5c8b626..aa76cad 100644 --- a/arch/x86/crypto/camellia_glue.c +++ b/arch/x86/crypto/camellia_glue.c @@ -1503,13 +1503,9 @@ int xts_camellia_setkey(struct crypto_tfm *tfm, const u8 *key, u32 *flags = &tfm->crt_flags; int err; - /* key consists of keys of equal size concatenated, therefore - * the length must be even - */ - if (keylen % 2) { - *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; - return -EINVAL; - } + err = xts_check_key(tfm, key, keylen); + if (err) + return err; /* first half of xts-key is for crypt */ err = __camellia_setkey(&ctx->crypt_ctx, key, keylen / 2, flags); diff --git a/arch/x86/crypto/cast6_avx_glue.c b/arch/x86/crypto/cast6_avx_glue.c index fca4595..50e6847 100644 --- a/arch/x86/crypto/cast6_avx_glue.c +++ b/arch/x86/crypto/cast6_avx_glue.c @@ -329,13 +329,9 @@ static int xts_cast6_setkey(struct crypto_tfm *tfm, const u8 *key, u32 *flags = &tfm->crt_flags; int err; - /* key consists of keys of equal size concatenated, therefore - * the length must be even - */ - if (keylen % 2) { - *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; - return -EINVAL; - } + err = xts_check_key(tfm, key, keylen); + if (err) + return err; /* first half of xts-key is for crypt */ err = __cast6_setkey(&ctx->crypt_ctx, key, keylen / 2, flags); diff --git a/arch/x86/crypto/serpent_avx_glue.c b/arch/x86/crypto/serpent_avx_glue.c index 5dc3702..6f778d3 100644 --- a/arch/x86/crypto/serpent_avx_glue.c +++ b/arch/x86/crypto/serpent_avx_glue.c @@ -332,16 +332,11 @@ int xts_serpent_setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen) { struct serpent_xts_ctx *ctx = crypto_tfm_ctx(tfm); - u32 *flags = &tfm->crt_flags; int err; - /* key consists of keys of equal size concatenated, therefore - * the length must be even - */ - if (keylen % 2) { - *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; - return -EINVAL; - } + err = xts_check_key(tfm, key, keylen); + if (err) + return err; /* first half of xts-key is for crypt */ err = __serpent_setkey(&ctx->crypt_ctx, key, keylen / 2); diff --git a/arch/x86/crypto/serpent_sse2_glue.c b/arch/x86/crypto/serpent_sse2_glue.c index 3643dd5..8943407 100644 --- a/arch/x86/crypto/serpent_sse2_glue.c +++ b/arch/x86/crypto/serpent_sse2_glue.c @@ -309,16 +309,11 @@ static int xts_serpent_setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen) { struct serpent_xts_ctx *ctx = crypto_tfm_ctx(tfm); - u32 *flags = &tfm->crt_flags; int err; - /* key consists of keys of equal size concatenated, therefore - * the length must be even - */ - if (keylen % 2) { - *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; - return -EINVAL; - } + err = xts_check_key(tfm, key, keylen); + if (err) + return err; /* first half of xts-key is for crypt */ err = __serpent_setkey(&ctx->crypt_ctx, key, keylen / 2); diff --git a/arch/x86/crypto/twofish_glue_3way.c b/arch/x86/crypto/twofish_glue_3way.c index 56d8a08..2ebb5e9 100644 --- a/arch/x86/crypto/twofish_glue_3way.c +++ b/arch/x86/crypto/twofish_glue_3way.c @@ -277,13 +277,9 @@ int xts_twofish_setkey(struct crypto_tfm *tfm, const u8 *key, u32 *flags = &tfm->crt_flags; int err; - /* key consists of keys of equal size concatenated, therefore - * the length must be even - */ - if (keylen % 2) { - *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; - return -EINVAL; - } + err = xts_check_key(tfm, key, keylen); + if (err) + return err; /* first half of xts-key is for crypt */ err = __twofish_setkey(&ctx->crypt_ctx, key, keylen / 2, flags); diff --git a/crypto/xts.c b/crypto/xts.c index f6fd43f..26ba583 100644 --- a/crypto/xts.c +++ b/crypto/xts.c @@ -35,16 +35,11 @@ static int setkey(struct crypto_tfm *parent, const u8 *key, { struct priv *ctx = crypto_tfm_ctx(parent); struct crypto_cipher *child = ctx->tweak; - u32 *flags = &parent->crt_flags; int err; - /* key consists of keys of equal size concatenated, therefore - * the length must be even */ - if (keylen % 2) { - /* tell the user why there was an error */ - *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; - return -EINVAL; - } + err = xts_check_key(parent, key, keylen); + if (err) + return err; /* we need two cipher instances: one to compute the initial 'tweak' * by encrypting the IV (usually the 'plain' iv) and the other diff --git a/include/crypto/xts.h b/include/crypto/xts.h index 72c09eb..ede6b97 100644 --- a/include/crypto/xts.h +++ b/include/crypto/xts.h @@ -2,6 +2,9 @@ #define _CRYPTO_XTS_H #include +#include +#include +#include struct scatterlist; struct blkcipher_desc; @@ -24,4 +27,28 @@ int xts_crypt(struct blkcipher_desc *desc, struct scatterlist *dst, struct scatterlist *src, unsigned int nbytes, struct xts_crypt_req *req); +static inline int xts_check_key(struct crypto_tfm *tfm, + const u8 *key, unsigned int keylen) +{ + u32 *flags = &tfm->crt_flags; + + /* + * key consists of keys of equal size concatenated, therefore + * the length must be even. + */ + if (keylen % 2) { + *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; + return -EINVAL; + } + + /* ensure that the AES and tweak key are not identical */ + if (fips_enabled && + !crypto_memneq(key, key + (keylen / 2), keylen / 2)) { + *flags |= CRYPTO_TFM_RES_WEAK_KEY; + return -EINVAL; + } + + return 0; +} + #endif /* _CRYPTO_XTS_H */ -- cgit v0.10.2