staging: ccree: add FIPS support

Add FIPS mode support to CryptoCell driver

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 52 insertions, 0 deletions

diff --git a/drivers/staging/ccree/ssi_cipher.c b/drivers/staging/ccree/ssi_cipher.c
index 4a95f1384e3f..664ed7e52cf2 100644
--- a/drivers/staging/ccree/ssi_cipher.c
+++ b/drivers/staging/ccree/ssi_cipher.c
@@ -31,6 +31,7 @@
 #include "ssi_cipher.h"
 #include "ssi_request_mgr.h"
 #include "ssi_sysfs.h"
+#include "ssi_fips_local.h"
 
 #define MAX_ABLKCIPHER_SEQ_LEN 6
 
@@ -191,6 +192,7 @@ static int ssi_blkcipher_init(struct crypto_tfm *tfm)
 	SSI_LOG_DEBUG("Initializing context @%p for %s\n", ctx_p, 
 						crypto_tfm_alg_name(tfm));
 
+	CHECK_AND_RETURN_UPON_FIPS_ERROR();
 	ctx_p->cipher_mode = ssi_alg->cipher_mode;
 	ctx_p->flow_mode = ssi_alg->flow_mode;
 	ctx_p->drvdata = ssi_alg->drvdata;
@@ -269,6 +271,37 @@ static const u8 zero_buff[] = {0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
                                0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 
                                0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0};
 
+/* The function verifies that tdes keys are not weak.*/
+static int ssi_fips_verify_3des_keys(const u8 *key, unsigned int keylen)
+{
+#ifdef CCREE_FIPS_SUPPORT
+        tdes_keys_t *tdes_key = (tdes_keys_t*)key;
+
+	/* verify key1 != key2 and key3 != key2*/
+        if (unlikely( (memcmp((u8*)tdes_key->key1, (u8*)tdes_key->key2, sizeof(tdes_key->key1)) == 0) || 
+		      (memcmp((u8*)tdes_key->key3, (u8*)tdes_key->key2, sizeof(tdes_key->key3)) == 0) )) {
+                return -ENOEXEC;
+        }
+#endif /* CCREE_FIPS_SUPPORT */
+
+        return 0;
+}
+
+/* The function verifies that xts keys are not weak.*/
+static int ssi_fips_verify_xts_keys(const u8 *key, unsigned int keylen)
+{
+#ifdef CCREE_FIPS_SUPPORT
+        /* Weak key is define as key that its first half (128/256 lsb) equals its second half (128/256 msb) */
+        int singleKeySize = keylen >> 1;
+
+	if (unlikely(memcmp(key, &key[singleKeySize], singleKeySize) == 0)) {
+		return -ENOEXEC;
+	}
+#endif /* CCREE_FIPS_SUPPORT */
+
+        return 0;
+}
+
 static enum HwCryptoKey hw_key_to_cc_hw_key(int slot_num)
 {
 	switch (slot_num) {
@@ -298,6 +331,10 @@ static int ssi_blkcipher_setkey(struct crypto_tfm *tfm,
 		ctx_p, crypto_tfm_alg_name(tfm), keylen);
 	dump_byte_array("key", (uint8_t *)key, keylen);
 
+	CHECK_AND_RETURN_UPON_FIPS_ERROR();
+
+	SSI_LOG_DEBUG("ssi_blkcipher_setkey: after FIPS check");
+	
 	/* STAT_PHASE_0: Init and sanity checks */
 	START_CYCLE_COUNT();
 
@@ -359,6 +396,18 @@ static int ssi_blkcipher_setkey(struct crypto_tfm *tfm,
 			return -EINVAL;
 		}
 	}
+	if ((ctx_p->cipher_mode == DRV_CIPHER_XTS) && 
+	    ssi_fips_verify_xts_keys(key, keylen) != 0) {
+		SSI_LOG_DEBUG("ssi_blkcipher_setkey: weak XTS key");
+		return -EINVAL;
+	}
+	if ((ctx_p->flow_mode == S_DIN_to_DES) && 
+	    (keylen == DES3_EDE_KEY_SIZE) && 
+	    ssi_fips_verify_3des_keys(key, keylen) != 0) {
+		SSI_LOG_DEBUG("ssi_blkcipher_setkey: weak 3DES key");
+		return -EINVAL;
+	}
+
 
 	END_CYCLE_COUNT(STAT_OP_TYPE_SETKEY, STAT_PHASE_0);
 
@@ -744,6 +793,7 @@ static int ssi_blkcipher_process(
 		((direction==DRV_CRYPTO_DIRECTION_ENCRYPT)?"Encrypt":"Decrypt"),
 		     areq, info, nbytes);
 
+	CHECK_AND_RETURN_UPON_FIPS_ERROR();
 	/* STAT_PHASE_0: Init and sanity checks */
 	START_CYCLE_COUNT();
 	
@@ -864,6 +914,8 @@ static void ssi_ablkcipher_complete(struct device *dev, void *ssi_req, void __io
 	struct ssi_ablkcipher_ctx *ctx_p = crypto_ablkcipher_ctx(tfm);
 	unsigned int ivsize = crypto_ablkcipher_ivsize(tfm);
 
+	CHECK_AND_RETURN_VOID_UPON_FIPS_ERROR();
+
 	ssi_blkcipher_complete(dev, ctx_p, req_ctx, areq->dst, areq->src, areq->info, ivsize, areq, cc_base);
 }