Re: [RFT PATCH 2/3] crypto: s390/paes - convert to skcipher API

[Harald Freudenberger <freude@linux.ibm.com>]

On 16.10.19 19:05, Eric Biggers wrote:
> On Tue, Oct 15, 2019 at 01:31:39PM +0200, Harald Freudenberger wrote:
>> On 12.10.19 22:18, Eric Biggers wrote:
>>> From: Eric Biggers <ebiggers@google.com>
>>>
>>> Convert the glue code for the S390 CPACF protected key implementations
>>> of AES-ECB, AES-CBC, AES-XTS, and AES-CTR from the deprecated
>>> "blkcipher" API to the "skcipher" API.  This is needed in order for the
>>> blkcipher API to be removed.
>>>
>>> Note: I made CTR use the same function for encryption and decryption,
>>> since CTR encryption and decryption are identical.
>>>
>>> Signed-off-by: Eric Biggers <ebiggers@google.com>
>>> ---
>>>  arch/s390/crypto/paes_s390.c | 414 +++++++++++++++--------------------
>>>  1 file changed, 174 insertions(+), 240 deletions(-)
>>>
>>> diff --git a/arch/s390/crypto/paes_s390.c b/arch/s390/crypto/paes_s390.c
>>> index 6184dceed340..c7119c617b6e 100644
>>> --- a/arch/s390/crypto/paes_s390.c
>>> +++ b/arch/s390/crypto/paes_s390.c
>>> @@ -21,6 +21,7 @@
>>>  #include <linux/cpufeature.h>
>>>  #include <linux/init.h>
>>>  #include <linux/spinlock.h>
>>> +#include <crypto/internal/skcipher.h>
>>>  #include <crypto/xts.h>
>>>  #include <asm/cpacf.h>
>>>  #include <asm/pkey.h>
>>> @@ -123,27 +124,27 @@ static int __paes_set_key(struct s390_paes_ctx *ctx)
>>>  	return ctx->fc ? 0 : -EINVAL;
>>>  }
>>>  
>>> -static int ecb_paes_init(struct crypto_tfm *tfm)
>>> +static int ecb_paes_init(struct crypto_skcipher *tfm)
>>>  {
>>> -	struct s390_paes_ctx *ctx = crypto_tfm_ctx(tfm);
>>> +	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
>>>  
>>>  	ctx->kb.key = NULL;
>>>  
>>>  	return 0;
>>>  }
>>>  
>>> -static void ecb_paes_exit(struct crypto_tfm *tfm)
>>> +static void ecb_paes_exit(struct crypto_skcipher *tfm)
>>>  {
>>> -	struct s390_paes_ctx *ctx = crypto_tfm_ctx(tfm);
>>> +	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
>>>  
>>>  	_free_kb_keybuf(&ctx->kb);
>>>  }
>>>  
>>> -static int ecb_paes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
>>> +static int ecb_paes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
>>>  			    unsigned int key_len)
>>>  {
>>>  	int rc;
>>> -	struct s390_paes_ctx *ctx = crypto_tfm_ctx(tfm);
>>> +	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
>>>  
>>>  	_free_kb_keybuf(&ctx->kb);
>>>  	rc = _copy_key_to_kb(&ctx->kb, in_key, key_len);
>>> @@ -151,91 +152,75 @@ static int ecb_paes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
>>>  		return rc;
>>>  
>>>  	if (__paes_set_key(ctx)) {
>>> -		tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
>>> +		crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
>>>  		return -EINVAL;
>>>  	}
>>>  	return 0;
>>>  }
>>>  
>>> -static int ecb_paes_crypt(struct blkcipher_desc *desc,
>>> -			  unsigned long modifier,
>>> -			  struct blkcipher_walk *walk)
>>> +static int ecb_paes_crypt(struct skcipher_request *req, unsigned long modifier)
>>>  {
>>> -	struct s390_paes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
>>> +	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
>>> +	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
>>> +	struct skcipher_walk walk;
>>>  	unsigned int nbytes, n, k;
>>>  	int ret;
>>>  
>>> -	ret = blkcipher_walk_virt(desc, walk);
>>> -	while ((nbytes = walk->nbytes) >= AES_BLOCK_SIZE) {
>>> +	ret = skcipher_walk_virt(&walk, req, false);
>>> +	while ((nbytes = walk.nbytes) != 0) {
>>>  		/* only use complete blocks */
>>>  		n = nbytes & ~(AES_BLOCK_SIZE - 1);
>>>  		k = cpacf_km(ctx->fc | modifier, ctx->pk.protkey,
>>> -			     walk->dst.virt.addr, walk->src.virt.addr, n);
>>> +			     walk.dst.virt.addr, walk.src.virt.addr, n);
>>>  		if (k)
>>> -			ret = blkcipher_walk_done(desc, walk, nbytes - k);
>>> +			ret = skcipher_walk_done(&walk, nbytes - k);
>>>  		if (k < n) {
>>>  			if (__paes_set_key(ctx) != 0)
>>> -				return blkcipher_walk_done(desc, walk, -EIO);
>>> +				return skcipher_walk_done(&walk, -EIO);
>>>  		}
>>>  	}
>>>  	return ret;
>>>  }
>>>  
>>> -static int ecb_paes_encrypt(struct blkcipher_desc *desc,
>>> -			    struct scatterlist *dst, struct scatterlist *src,
>>> -			    unsigned int nbytes)
>>> +static int ecb_paes_encrypt(struct skcipher_request *req)
>>>  {
>>> -	struct blkcipher_walk walk;
>>> -
>>> -	blkcipher_walk_init(&walk, dst, src, nbytes);
>>> -	return ecb_paes_crypt(desc, CPACF_ENCRYPT, &walk);
>>> +	return ecb_paes_crypt(req, 0);
>>>  }
>>>  
>>> -static int ecb_paes_decrypt(struct blkcipher_desc *desc,
>>> -			    struct scatterlist *dst, struct scatterlist *src,
>>> -			    unsigned int nbytes)
>>> +static int ecb_paes_decrypt(struct skcipher_request *req)
>>>  {
>>> -	struct blkcipher_walk walk;
>>> -
>>> -	blkcipher_walk_init(&walk, dst, src, nbytes);
>>> -	return ecb_paes_crypt(desc, CPACF_DECRYPT, &walk);
>>> +	return ecb_paes_crypt(req, CPACF_DECRYPT);
>>>  }
>>>  
>>> -static struct crypto_alg ecb_paes_alg = {
>>> -	.cra_name		=	"ecb(paes)",
>>> -	.cra_driver_name	=	"ecb-paes-s390",
>>> -	.cra_priority		=	401,	/* combo: aes + ecb + 1 */
>>> -	.cra_flags		=	CRYPTO_ALG_TYPE_BLKCIPHER,
>>> -	.cra_blocksize		=	AES_BLOCK_SIZE,
>>> -	.cra_ctxsize		=	sizeof(struct s390_paes_ctx),
>>> -	.cra_type		=	&crypto_blkcipher_type,
>>> -	.cra_module		=	THIS_MODULE,
>>> -	.cra_list		=	LIST_HEAD_INIT(ecb_paes_alg.cra_list),
>>> -	.cra_init		=	ecb_paes_init,
>>> -	.cra_exit		=	ecb_paes_exit,
>>> -	.cra_u			=	{
>>> -		.blkcipher = {
>>> -			.min_keysize		=	PAES_MIN_KEYSIZE,
>>> -			.max_keysize		=	PAES_MAX_KEYSIZE,
>>> -			.setkey			=	ecb_paes_set_key,
>>> -			.encrypt		=	ecb_paes_encrypt,
>>> -			.decrypt		=	ecb_paes_decrypt,
>>> -		}
>>> -	}
>>> +static struct skcipher_alg ecb_paes_alg = {
>>> +	.base.cra_name		=	"ecb(paes)",
>>> +	.base.cra_driver_name	=	"ecb-paes-s390",
>>> +	.base.cra_priority	=	401,	/* combo: aes + ecb + 1 */
>>> +	.base.cra_blocksize	=	AES_BLOCK_SIZE,
>>> +	.base.cra_ctxsize	=	sizeof(struct s390_paes_ctx),
>>> +	.base.cra_module	=	THIS_MODULE,
>>> +	.base.cra_list		=	LIST_HEAD_INIT(ecb_paes_alg.base.cra_list),
>>> +	.init			=	ecb_paes_init,
>>> +	.exit			=	ecb_paes_exit,
>>> +	.min_keysize		=	PAES_MIN_KEYSIZE,
>>> +	.max_keysize		=	PAES_MAX_KEYSIZE,
>>> +	.setkey			=	ecb_paes_set_key,
>>> +	.encrypt		=	ecb_paes_encrypt,
>>> +	.decrypt		=	ecb_paes_decrypt,
>>>  };
>>>  
>>> -static int cbc_paes_init(struct crypto_tfm *tfm)
>>> +static int cbc_paes_init(struct crypto_skcipher *tfm)
>>>  {
>>> -	struct s390_paes_ctx *ctx = crypto_tfm_ctx(tfm);
>>> +	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
>>>  
>>>  	ctx->kb.key = NULL;
>>>  
>>>  	return 0;
>>>  }
>>>  
>>> -static void cbc_paes_exit(struct crypto_tfm *tfm)
>>> +static void cbc_paes_exit(struct crypto_skcipher *tfm)
>>>  {
>>> -	struct s390_paes_ctx *ctx = crypto_tfm_ctx(tfm);
>>> +	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
>>>  
>>>  	_free_kb_keybuf(&ctx->kb);
>>>  }
>>> @@ -258,11 +243,11 @@ static int __cbc_paes_set_key(struct s390_paes_ctx *ctx)
>>>  	return ctx->fc ? 0 : -EINVAL;
>>>  }
>>>  
>>> -static int cbc_paes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
>>> +static int cbc_paes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
>>>  			    unsigned int key_len)
>>>  {
>>>  	int rc;
>>> -	struct s390_paes_ctx *ctx = crypto_tfm_ctx(tfm);
>>> +	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
>>>  
>>>  	_free_kb_keybuf(&ctx->kb);
>>>  	rc = _copy_key_to_kb(&ctx->kb, in_key, key_len);
>>> @@ -270,16 +255,17 @@ static int cbc_paes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
>>>  		return rc;
>>>  
>>>  	if (__cbc_paes_set_key(ctx)) {
>>> -		tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
>>> +		crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
>>>  		return -EINVAL;
>>>  	}
>>>  	return 0;
>>>  }
>>>  
>>> -static int cbc_paes_crypt(struct blkcipher_desc *desc, unsigned long modifier,
>>> -			  struct blkcipher_walk *walk)
>>> +static int cbc_paes_crypt(struct skcipher_request *req, unsigned long modifier)
>>>  {
>>> -	struct s390_paes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
>>> +	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
>>> +	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
>>> +	struct skcipher_walk walk;
>>>  	unsigned int nbytes, n, k;
>>>  	int ret;
>>>  	struct {
>>> @@ -287,73 +273,60 @@ static int cbc_paes_crypt(struct blkcipher_desc *desc, unsigned long modifier,
>>>  		u8 key[MAXPROTKEYSIZE];
>>>  	} param;
>>>  
>>> -	ret = blkcipher_walk_virt(desc, walk);
>>> -	memcpy(param.iv, walk->iv, AES_BLOCK_SIZE);
>>> +	ret = skcipher_walk_virt(&walk, req, false);
>>> +	if (ret)
>>> +		return ret;
>>> +	memcpy(param.iv, walk.iv, AES_BLOCK_SIZE);
>>>  	memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
>>> -	while ((nbytes = walk->nbytes) >= AES_BLOCK_SIZE) {
>>> +	while ((nbytes = walk.nbytes) != 0) {
>>>  		/* only use complete blocks */
>>>  		n = nbytes & ~(AES_BLOCK_SIZE - 1);
>>>  		k = cpacf_kmc(ctx->fc | modifier, &param,
>>> -			      walk->dst.virt.addr, walk->src.virt.addr, n);
>>> -		if (k)
>>> -			ret = blkcipher_walk_done(desc, walk, nbytes - k);
>>> +			      walk.dst.virt.addr, walk.src.virt.addr, n);
>>> +		if (k) {
>>> +			memcpy(walk.iv, param.iv, AES_BLOCK_SIZE);
>>> +			ret = skcipher_walk_done(&walk, nbytes - k);
>>> +		}
>>>  		if (k < n) {
>>>  			if (__cbc_paes_set_key(ctx) != 0)
>>> -				return blkcipher_walk_done(desc, walk, -EIO);
>>> +				return skcipher_walk_done(&walk, -EIO);
>>>  			memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
>>>  		}
>>>  	}
>>> -	memcpy(walk->iv, param.iv, AES_BLOCK_SIZE);
>>>  	return ret;
>>>  }
>>>  
>>> -static int cbc_paes_encrypt(struct blkcipher_desc *desc,
>>> -			    struct scatterlist *dst, struct scatterlist *src,
>>> -			    unsigned int nbytes)
>>> +static int cbc_paes_encrypt(struct skcipher_request *req)
>>>  {
>>> -	struct blkcipher_walk walk;
>>> -
>>> -	blkcipher_walk_init(&walk, dst, src, nbytes);
>>> -	return cbc_paes_crypt(desc, 0, &walk);
>>> +	return cbc_paes_crypt(req, 0);
>>>  }
>>>  
>>> -static int cbc_paes_decrypt(struct blkcipher_desc *desc,
>>> -			    struct scatterlist *dst, struct scatterlist *src,
>>> -			    unsigned int nbytes)
>>> +static int cbc_paes_decrypt(struct skcipher_request *req)
>>>  {
>>> -	struct blkcipher_walk walk;
>>> -
>>> -	blkcipher_walk_init(&walk, dst, src, nbytes);
>>> -	return cbc_paes_crypt(desc, CPACF_DECRYPT, &walk);
>>> +	return cbc_paes_crypt(req, CPACF_DECRYPT);
>>>  }
>>>  
>>> -static struct crypto_alg cbc_paes_alg = {
>>> -	.cra_name		=	"cbc(paes)",
>>> -	.cra_driver_name	=	"cbc-paes-s390",
>>> -	.cra_priority		=	402,	/* ecb-paes-s390 + 1 */
>>> -	.cra_flags		=	CRYPTO_ALG_TYPE_BLKCIPHER,
>>> -	.cra_blocksize		=	AES_BLOCK_SIZE,
>>> -	.cra_ctxsize		=	sizeof(struct s390_paes_ctx),
>>> -	.cra_type		=	&crypto_blkcipher_type,
>>> -	.cra_module		=	THIS_MODULE,
>>> -	.cra_list		=	LIST_HEAD_INIT(cbc_paes_alg.cra_list),
>>> -	.cra_init		=	cbc_paes_init,
>>> -	.cra_exit		=	cbc_paes_exit,
>>> -	.cra_u			=	{
>>> -		.blkcipher = {
>>> -			.min_keysize		=	PAES_MIN_KEYSIZE,
>>> -			.max_keysize		=	PAES_MAX_KEYSIZE,
>>> -			.ivsize			=	AES_BLOCK_SIZE,
>>> -			.setkey			=	cbc_paes_set_key,
>>> -			.encrypt		=	cbc_paes_encrypt,
>>> -			.decrypt		=	cbc_paes_decrypt,
>>> -		}
>>> -	}
>>> +static struct skcipher_alg cbc_paes_alg = {
>>> +	.base.cra_name		=	"cbc(paes)",
>>> +	.base.cra_driver_name	=	"cbc-paes-s390",
>>> +	.base.cra_priority	=	402,	/* ecb-paes-s390 + 1 */
>>> +	.base.cra_blocksize	=	AES_BLOCK_SIZE,
>>> +	.base.cra_ctxsize	=	sizeof(struct s390_paes_ctx),
>>> +	.base.cra_module	=	THIS_MODULE,
>>> +	.base.cra_list		=	LIST_HEAD_INIT(cbc_paes_alg.base.cra_list),
>>> +	.init			=	cbc_paes_init,
>>> +	.exit			=	cbc_paes_exit,
>>> +	.min_keysize		=	PAES_MIN_KEYSIZE,
>>> +	.max_keysize		=	PAES_MAX_KEYSIZE,
>>> +	.ivsize			=	AES_BLOCK_SIZE,
>>> +	.setkey			=	cbc_paes_set_key,
>>> +	.encrypt		=	cbc_paes_encrypt,
>>> +	.decrypt		=	cbc_paes_decrypt,
>>>  };
>>>  
>>> -static int xts_paes_init(struct crypto_tfm *tfm)
>>> +static int xts_paes_init(struct crypto_skcipher *tfm)
>>>  {
>>> -	struct s390_pxts_ctx *ctx = crypto_tfm_ctx(tfm);
>>> +	struct s390_pxts_ctx *ctx = crypto_skcipher_ctx(tfm);
>>>  
>>>  	ctx->kb[0].key = NULL;
>>>  	ctx->kb[1].key = NULL;
>>> @@ -361,9 +334,9 @@ static int xts_paes_init(struct crypto_tfm *tfm)
>>>  	return 0;
>>>  }
>>>  
>>> -static void xts_paes_exit(struct crypto_tfm *tfm)
>>> +static void xts_paes_exit(struct crypto_skcipher *tfm)
>>>  {
>>> -	struct s390_pxts_ctx *ctx = crypto_tfm_ctx(tfm);
>>> +	struct s390_pxts_ctx *ctx = crypto_skcipher_ctx(tfm);
>>>  
>>>  	_free_kb_keybuf(&ctx->kb[0]);
>>>  	_free_kb_keybuf(&ctx->kb[1]);
>>> @@ -391,11 +364,11 @@ static int __xts_paes_set_key(struct s390_pxts_ctx *ctx)
>>>  	return ctx->fc ? 0 : -EINVAL;
>>>  }
>>>  
>>> -static int xts_paes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
>>> +static int xts_paes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
>>>  			    unsigned int xts_key_len)
>>>  {
>>>  	int rc;
>>> -	struct s390_pxts_ctx *ctx = crypto_tfm_ctx(tfm);
>>> +	struct s390_pxts_ctx *ctx = crypto_skcipher_ctx(tfm);
>>>  	u8 ckey[2 * AES_MAX_KEY_SIZE];
>>>  	unsigned int ckey_len, key_len;
>>>  
>>> @@ -414,7 +387,7 @@ static int xts_paes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
>>>  		return rc;
>>>  
>>>  	if (__xts_paes_set_key(ctx)) {
>>> -		tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
>>> +		crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
>>>  		return -EINVAL;
>>>  	}
>>>  
>>> @@ -427,13 +400,14 @@ static int xts_paes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
>>>  		AES_KEYSIZE_128 : AES_KEYSIZE_256;
>>>  	memcpy(ckey, ctx->pk[0].protkey, ckey_len);
>>>  	memcpy(ckey + ckey_len, ctx->pk[1].protkey, ckey_len);
>>> -	return xts_check_key(tfm, ckey, 2*ckey_len);
>>> +	return xts_verify_key(tfm, ckey, 2*ckey_len);
>>>  }
>>>  
>>> -static int xts_paes_crypt(struct blkcipher_desc *desc, unsigned long modifier,
>>> -			  struct blkcipher_walk *walk)
>>> +static int xts_paes_crypt(struct skcipher_request *req, unsigned long modifier)
>>>  {
>>> -	struct s390_pxts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
>>> +	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
>>> +	struct s390_pxts_ctx *ctx = crypto_skcipher_ctx(tfm);
>>> +	struct skcipher_walk walk;
>>>  	unsigned int keylen, offset, nbytes, n, k;
>>>  	int ret;
>>>  	struct {
>>> @@ -448,90 +422,76 @@ static int xts_paes_crypt(struct blkcipher_desc *desc, unsigned long modifier,
>>>  		u8 init[16];
>>>  	} xts_param;
>>>  
>>> -	ret = blkcipher_walk_virt(desc, walk);
>>> +	ret = skcipher_walk_virt(&walk, req, false);
>>> +	if (ret)
>>> +		return ret;
>>>  	keylen = (ctx->pk[0].type == PKEY_KEYTYPE_AES_128) ? 48 : 64;
>>>  	offset = (ctx->pk[0].type == PKEY_KEYTYPE_AES_128) ? 16 : 0;
>>>  retry:
>>>  	memset(&pcc_param, 0, sizeof(pcc_param));
>>> -	memcpy(pcc_param.tweak, walk->iv, sizeof(pcc_param.tweak));
>>> +	memcpy(pcc_param.tweak, walk.iv, sizeof(pcc_param.tweak));
>>>  	memcpy(pcc_param.key + offset, ctx->pk[1].protkey, keylen);
>>>  	cpacf_pcc(ctx->fc, pcc_param.key + offset);
>>>  
>>>  	memcpy(xts_param.key + offset, ctx->pk[0].protkey, keylen);
>>>  	memcpy(xts_param.init, pcc_param.xts, 16);
>>>  
>>> -	while ((nbytes = walk->nbytes) >= AES_BLOCK_SIZE) {
>>> +	while ((nbytes = walk.nbytes) != 0) {
>>>  		/* only use complete blocks */
>>>  		n = nbytes & ~(AES_BLOCK_SIZE - 1);
>>>  		k = cpacf_km(ctx->fc | modifier, xts_param.key + offset,
>>> -			     walk->dst.virt.addr, walk->src.virt.addr, n);
>>> +			     walk.dst.virt.addr, walk.src.virt.addr, n);
>>>  		if (k)
>>> -			ret = blkcipher_walk_done(desc, walk, nbytes - k);
>>> +			ret = skcipher_walk_done(&walk, nbytes - k);
>>>  		if (k < n) {
>>>  			if (__xts_paes_set_key(ctx) != 0)
>>> -				return blkcipher_walk_done(desc, walk, -EIO);
>>> +				return skcipher_walk_done(&walk, -EIO);
>>>  			goto retry;
>>>  		}
>>>  	}
>>>  	return ret;
>>>  }
>>>  
>>> -static int xts_paes_encrypt(struct blkcipher_desc *desc,
>>> -			    struct scatterlist *dst, struct scatterlist *src,
>>> -			    unsigned int nbytes)
>>> +static int xts_paes_encrypt(struct skcipher_request *req)
>>>  {
>>> -	struct blkcipher_walk walk;
>>> -
>>> -	blkcipher_walk_init(&walk, dst, src, nbytes);
>>> -	return xts_paes_crypt(desc, 0, &walk);
>>> +	return xts_paes_crypt(req, 0);
>>>  }
>>>  
>>> -static int xts_paes_decrypt(struct blkcipher_desc *desc,
>>> -			    struct scatterlist *dst, struct scatterlist *src,
>>> -			    unsigned int nbytes)
>>> +static int xts_paes_decrypt(struct skcipher_request *req)
>>>  {
>>> -	struct blkcipher_walk walk;
>>> -
>>> -	blkcipher_walk_init(&walk, dst, src, nbytes);
>>> -	return xts_paes_crypt(desc, CPACF_DECRYPT, &walk);
>>> +	return xts_paes_crypt(req, CPACF_DECRYPT);
>>>  }
>>>  
>>> -static struct crypto_alg xts_paes_alg = {
>>> -	.cra_name		=	"xts(paes)",
>>> -	.cra_driver_name	=	"xts-paes-s390",
>>> -	.cra_priority		=	402,	/* ecb-paes-s390 + 1 */
>>> -	.cra_flags		=	CRYPTO_ALG_TYPE_BLKCIPHER,
>>> -	.cra_blocksize		=	AES_BLOCK_SIZE,
>>> -	.cra_ctxsize		=	sizeof(struct s390_pxts_ctx),
>>> -	.cra_type		=	&crypto_blkcipher_type,
>>> -	.cra_module		=	THIS_MODULE,
>>> -	.cra_list		=	LIST_HEAD_INIT(xts_paes_alg.cra_list),
>>> -	.cra_init		=	xts_paes_init,
>>> -	.cra_exit		=	xts_paes_exit,
>>> -	.cra_u			=	{
>>> -		.blkcipher = {
>>> -			.min_keysize		=	2 * PAES_MIN_KEYSIZE,
>>> -			.max_keysize		=	2 * PAES_MAX_KEYSIZE,
>>> -			.ivsize			=	AES_BLOCK_SIZE,
>>> -			.setkey			=	xts_paes_set_key,
>>> -			.encrypt		=	xts_paes_encrypt,
>>> -			.decrypt		=	xts_paes_decrypt,
>>> -		}
>>> -	}
>>> +static struct skcipher_alg xts_paes_alg = {
>>> +	.base.cra_name		=	"xts(paes)",
>>> +	.base.cra_driver_name	=	"xts-paes-s390",
>>> +	.base.cra_priority	=	402,	/* ecb-paes-s390 + 1 */
>>> +	.base.cra_blocksize	=	AES_BLOCK_SIZE,
>>> +	.base.cra_ctxsize	=	sizeof(struct s390_pxts_ctx),
>>> +	.base.cra_module	=	THIS_MODULE,
>>> +	.base.cra_list		=	LIST_HEAD_INIT(xts_paes_alg.base.cra_list),
>>> +	.init			=	xts_paes_init,
>>> +	.exit			=	xts_paes_exit,
>>> +	.min_keysize		=	2 * PAES_MIN_KEYSIZE,
>>> +	.max_keysize		=	2 * PAES_MAX_KEYSIZE,
>>> +	.ivsize			=	AES_BLOCK_SIZE,
>>> +	.setkey			=	xts_paes_set_key,
>>> +	.encrypt		=	xts_paes_encrypt,
>>> +	.decrypt		=	xts_paes_decrypt,
>>>  };
>>>  
>>> -static int ctr_paes_init(struct crypto_tfm *tfm)
>>> +static int ctr_paes_init(struct crypto_skcipher *tfm)
>>>  {
>>> -	struct s390_paes_ctx *ctx = crypto_tfm_ctx(tfm);
>>> +	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
>>>  
>>>  	ctx->kb.key = NULL;
>>>  
>>>  	return 0;
>>>  }
>>>  
>>> -static void ctr_paes_exit(struct crypto_tfm *tfm)
>>> +static void ctr_paes_exit(struct crypto_skcipher *tfm)
>>>  {
>>> -	struct s390_paes_ctx *ctx = crypto_tfm_ctx(tfm);
>>> +	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
>>>  
>>>  	_free_kb_keybuf(&ctx->kb);
>>>  }
>>> @@ -555,11 +515,11 @@ static int __ctr_paes_set_key(struct s390_paes_ctx *ctx)
>>>  	return ctx->fc ? 0 : -EINVAL;
>>>  }
>>>  
>>> -static int ctr_paes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
>>> +static int ctr_paes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
>>>  			    unsigned int key_len)
>>>  {
>>>  	int rc;
>>> -	struct s390_paes_ctx *ctx = crypto_tfm_ctx(tfm);
>>> +	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
>>>  
>>>  	_free_kb_keybuf(&ctx->kb);
>>>  	rc = _copy_key_to_kb(&ctx->kb, in_key, key_len);
>>> @@ -567,7 +527,7 @@ static int ctr_paes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
>>>  		return rc;
>>>  
>>>  	if (__ctr_paes_set_key(ctx)) {
>>> -		tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
>>> +		crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
>>>  		return -EINVAL;
>>>  	}
>>>  	return 0;
>>> @@ -588,37 +548,37 @@ static unsigned int __ctrblk_init(u8 *ctrptr, u8 *iv, unsigned int nbytes)
>>>  	return n;
>>>  }
>>>  
>>> -static int ctr_paes_crypt(struct blkcipher_desc *desc, unsigned long modifier,
>>> -			  struct blkcipher_walk *walk)
>>> +static int ctr_paes_crypt(struct skcipher_request *req)
>>>  {
>>> -	struct s390_paes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
>>> +	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
>>> +	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
>>>  	u8 buf[AES_BLOCK_SIZE], *ctrptr;
>>> +	struct skcipher_walk walk;
>>>  	unsigned int nbytes, n, k;
>>>  	int ret, locked;
>>>  
>>>  	locked = spin_trylock(&ctrblk_lock);
>>>  
>>> -	ret = blkcipher_walk_virt_block(desc, walk, AES_BLOCK_SIZE);
>>> -	while ((nbytes = walk->nbytes) >= AES_BLOCK_SIZE) {
>>> +	ret = skcipher_walk_virt(&walk, req, false);
>>> +	while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) {
>>>  		n = AES_BLOCK_SIZE;
>>>  		if (nbytes >= 2*AES_BLOCK_SIZE && locked)
>>> -			n = __ctrblk_init(ctrblk, walk->iv, nbytes);
>>> -		ctrptr = (n > AES_BLOCK_SIZE) ? ctrblk : walk->iv;
>>> -		k = cpacf_kmctr(ctx->fc | modifier, ctx->pk.protkey,
>>> -				walk->dst.virt.addr, walk->src.virt.addr,
>>> -				n, ctrptr);
>>> +			n = __ctrblk_init(ctrblk, walk.iv, nbytes);
>>> +		ctrptr = (n > AES_BLOCK_SIZE) ? ctrblk : walk.iv;
>>> +		k = cpacf_kmctr(ctx->fc, ctx->pk.protkey, walk.dst.virt.addr,
>>> +				walk.src.virt.addr, n, ctrptr);
>>>  		if (k) {
>>>  			if (ctrptr == ctrblk)
>>> -				memcpy(walk->iv, ctrptr + k - AES_BLOCK_SIZE,
>>> +				memcpy(walk.iv, ctrptr + k - AES_BLOCK_SIZE,
>>>  				       AES_BLOCK_SIZE);
>>> -			crypto_inc(walk->iv, AES_BLOCK_SIZE);
>>> -			ret = blkcipher_walk_done(desc, walk, nbytes - n);
>>> +			crypto_inc(walk.iv, AES_BLOCK_SIZE);
>>> +			ret = skcipher_walk_done(&walk, nbytes - n);
>> Looks like a bug here. It should be
>>
>> ret = skcipher_walk_done(&walk, nbytes - k);
>>
>> similar to the other modes.
>> You can add this in your patch or leave it to me to provide a separate patch.
> I'm not planning to fix this since it's an existing bug, I can't test this code
> myself, and the paes code is different from the regular algorithms so it's hard
> to work with.  So I suggest you provide a patch later.
Ok, will do.
>
>>>  		}
>>>  		if (k < n) {
>>>  			if (__ctr_paes_set_key(ctx) != 0) {
>>>  				if (locked)
>>>  					spin_unlock(&ctrblk_lock);
>>> -				return blkcipher_walk_done(desc, walk, -EIO);
>>> +				return skcipher_walk_done(&walk, -EIO);
>>>  			}
>>>  		}
>>>  	}
> Note that __ctr_paes_set_key() is modifying the tfm_ctx which can be shared
> between multiple threads.  So this code seems broken in other ways too.
Ok, I'll check this.
>
> How is "paes" tested, given that it isn't covered by the crypto subsystem's
> self-tests?  How do you know it isn't completely broken?
>
> - Eric

As you can see paes is an ordinary aes with just a special key - we call it "protected key".
I have written selftests to be integrated into the kernel (will send out patches soon) which
take a known clearkey AES value, derive a protected key with exactly this AES value and
so I can use regular testvectors. I also have testcases which are using the AF_ALG interface
and run common available NIST testvectors. There is also another way to create a protected
key from a secure key (which requires to have crypto cards within the s390). As I have
access to some s390 machines with crypto cards in, I ran all these tests. Have a look into
the pkey code (drivers/s390/crypto/pkey_api.c) for even more details.

regards Harald Freudenberger

keaSo I can test the paes implementation
and in fact the paes implementation is used