s390/crypto: Enhance paes cipher to accept variable length key material

Enhance the paes_s390 kernel module to allow the paes cipher to
accept variable length key material. The key material accepted by
the paes cipher is a key blob of various types. As of today, two
key blob types are supported: CCA secure key blobs and protected
key blobs.
Signed-off-by: Ingo Franzki <ifranzki@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/crypto/paes_s390.c

@@ -30,26 +30,31 @@ static DEFINE_SPINLOCK(ctrblk_lock);
 
 static cpacf_mask_t km_functions, kmc_functions, kmctr_functions;
 
+struct key_blob {
+	__u8 key[MAXKEYBLOBSIZE];
+	unsigned int keylen;
+};
+
 struct s390_paes_ctx {
-	struct pkey_seckey sk;
+	struct key_blob kb;
 	struct pkey_protkey pk;
 	unsigned long fc;
 };
 
 struct s390_pxts_ctx {
-	struct pkey_seckey sk[2];
+	struct key_blob kb[2];
 	struct pkey_protkey pk[2];
 	unsigned long fc;
 };
 
-static inline int __paes_convert_key(struct pkey_seckey *sk,
+static inline int __paes_convert_key(struct key_blob *kb,
 				     struct pkey_protkey *pk)
 {
 	int i, ret;
 
 	/* try three times in case of failure */
 	for (i = 0; i < 3; i++) {
-		ret = pkey_skey2pkey(sk, pk);
+		ret = pkey_keyblob2pkey(kb->key, kb->keylen, pk);
 		if (ret == 0)
 			break;
 	}
@@ -61,7 +66,7 @@ static int __paes_set_key(struct s390_paes_ctx *ctx)
 {
 	unsigned long fc;
 
-	if (__paes_convert_key(&ctx->sk, &ctx->pk))
+	if (__paes_convert_key(&ctx->kb, &ctx->pk))
 		return -EINVAL;
 
 	/* Pick the correct function code based on the protected key type */
@@ -80,10 +85,8 @@ static int ecb_paes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
 {
 	struct s390_paes_ctx *ctx = crypto_tfm_ctx(tfm);
 
-	if (key_len != SECKEYBLOBSIZE)
-		return -EINVAL;
-
-	memcpy(ctx->sk.seckey, in_key, SECKEYBLOBSIZE);
+	memcpy(ctx->kb.key, in_key, key_len);
+	ctx->kb.keylen = key_len;
 	if (__paes_set_key(ctx)) {
 		tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
 		return -EINVAL;
@@ -147,8 +150,8 @@ static struct crypto_alg ecb_paes_alg = {
 	.cra_list		=	LIST_HEAD_INIT(ecb_paes_alg.cra_list),
 	.cra_u			=	{
 		.blkcipher = {
-			.min_keysize		=	SECKEYBLOBSIZE,
-			.max_keysize		=	SECKEYBLOBSIZE,
+			.min_keysize		=	MINKEYBLOBSIZE,
+			.max_keysize		=	MAXKEYBLOBSIZE,
 			.setkey			=	ecb_paes_set_key,
 			.encrypt		=	ecb_paes_encrypt,
 			.decrypt		=	ecb_paes_decrypt,
@@ -160,7 +163,7 @@ static int __cbc_paes_set_key(struct s390_paes_ctx *ctx)
 {
 	unsigned long fc;
 
-	if (__paes_convert_key(&ctx->sk, &ctx->pk))
+	if (__paes_convert_key(&ctx->kb, &ctx->pk))
 		return -EINVAL;
 
 	/* Pick the correct function code based on the protected key type */
@@ -179,7 +182,8 @@ static int cbc_paes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
 {
 	struct s390_paes_ctx *ctx = crypto_tfm_ctx(tfm);
 
-	memcpy(ctx->sk.seckey, in_key, SECKEYBLOBSIZE);
+	memcpy(ctx->kb.key, in_key, key_len);
+	ctx->kb.keylen = key_len;
 	if (__cbc_paes_set_key(ctx)) {
 		tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
 		return -EINVAL;
@@ -250,8 +254,8 @@ static struct crypto_alg cbc_paes_alg = {
 	.cra_list		=	LIST_HEAD_INIT(cbc_paes_alg.cra_list),
 	.cra_u			=	{
 		.blkcipher = {
-			.min_keysize		=	SECKEYBLOBSIZE,
-			.max_keysize		=	SECKEYBLOBSIZE,
+			.min_keysize		=	MINKEYBLOBSIZE,
+			.max_keysize		=	MAXKEYBLOBSIZE,
 			.ivsize			=	AES_BLOCK_SIZE,
 			.setkey			=	cbc_paes_set_key,
 			.encrypt		=	cbc_paes_encrypt,
@@ -264,8 +268,8 @@ static int __xts_paes_set_key(struct s390_pxts_ctx *ctx)
 {
 	unsigned long fc;
 
-	if (__paes_convert_key(&ctx->sk[0], &ctx->pk[0]) ||
-	    __paes_convert_key(&ctx->sk[1], &ctx->pk[1]))
+	if (__paes_convert_key(&ctx->kb[0], &ctx->pk[0]) ||
+	    __paes_convert_key(&ctx->kb[1], &ctx->pk[1]))
 		return -EINVAL;
 
 	if (ctx->pk[0].type != ctx->pk[1].type)
@@ -287,10 +291,16 @@ static int xts_paes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
 {
 	struct s390_pxts_ctx *ctx = crypto_tfm_ctx(tfm);
 	u8 ckey[2 * AES_MAX_KEY_SIZE];
-	unsigned int ckey_len;
+	unsigned int ckey_len, keytok_len;
+
+	if (key_len % 2)
+		return -EINVAL;
 
-	memcpy(ctx->sk[0].seckey, in_key, SECKEYBLOBSIZE);
-	memcpy(ctx->sk[1].seckey, in_key + SECKEYBLOBSIZE, SECKEYBLOBSIZE);
+	keytok_len = key_len / 2;
+	memcpy(ctx->kb[0].key, in_key, keytok_len);
+	ctx->kb[0].keylen = keytok_len;
+	memcpy(ctx->kb[1].key, in_key + keytok_len, keytok_len);
+	ctx->kb[1].keylen = keytok_len;
 	if (__xts_paes_set_key(ctx)) {
 		tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
 		return -EINVAL;
@@ -386,8 +396,8 @@ static struct crypto_alg xts_paes_alg = {
 	.cra_list		=	LIST_HEAD_INIT(xts_paes_alg.cra_list),
 	.cra_u			=	{
 		.blkcipher = {
-			.min_keysize		=	2 * SECKEYBLOBSIZE,
-			.max_keysize		=	2 * SECKEYBLOBSIZE,
+			.min_keysize		=	2 * MINKEYBLOBSIZE,
+			.max_keysize		=	2 * MAXKEYBLOBSIZE,
 			.ivsize			=	AES_BLOCK_SIZE,
 			.setkey			=	xts_paes_set_key,
 			.encrypt		=	xts_paes_encrypt,
@@ -400,7 +410,7 @@ static int __ctr_paes_set_key(struct s390_paes_ctx *ctx)
 {
 	unsigned long fc;
 
-	if (__paes_convert_key(&ctx->sk, &ctx->pk))
+	if (__paes_convert_key(&ctx->kb, &ctx->pk))
 		return -EINVAL;
 
 	/* Pick the correct function code based on the protected key type */
@@ -420,7 +430,8 @@ static int ctr_paes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
 {
 	struct s390_paes_ctx *ctx = crypto_tfm_ctx(tfm);
 
-	memcpy(ctx->sk.seckey, in_key, key_len);
+	memcpy(ctx->kb.key, in_key, key_len);
+	ctx->kb.keylen = key_len;
 	if (__ctr_paes_set_key(ctx)) {
 		tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
 		return -EINVAL;
@@ -532,8 +543,8 @@ static struct crypto_alg ctr_paes_alg = {
 	.cra_list		=	LIST_HEAD_INIT(ctr_paes_alg.cra_list),
 	.cra_u			=	{
 		.blkcipher = {
-			.min_keysize		=	SECKEYBLOBSIZE,
-			.max_keysize		=	SECKEYBLOBSIZE,
+			.min_keysize		=	MINKEYBLOBSIZE,
+			.max_keysize		=	MAXKEYBLOBSIZE,
 			.ivsize			=	AES_BLOCK_SIZE,
 			.setkey			=	ctr_paes_set_key,
 			.encrypt		=	ctr_paes_encrypt,