From 0dc7f22e1d5dbf2a974c9400d42a63db095891ed Mon Sep 17 00:00:00 2001
From: Stephan Mueller <smueller@chronox.de>
Date: Sun, 7 Jan 2018 11:49:09 +0100
Subject: [PATCH v10 1/3] crypto: AF_ALG -- add sign/verify API

Add the flags for handling signature generation and signature
verification.

The af_alg helper code as well as the algif_skcipher and algif_aead code
must be changed from a boolean indicating the cipher operation to an
integer because there are now 4 different cipher operations that are
defined. Yet, the algif_aead and algif_skcipher code still only allows
encryption and decryption cipher operations.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
---
 crypto/af_alg.c             | 10 +++++-----
 crypto/algif_aead.c         | 31 ++++++++++++++++++++-----------
 crypto/algif_skcipher.c     | 25 +++++++++++++++++--------
 include/crypto/if_alg.h     |  4 ++--
 include/uapi/linux/if_alg.h |  2 ++
 5 files changed, 46 insertions(+), 26 deletions(-)

diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index 35d4dcea381f..bd3d6e147623 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -831,7 +831,7 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
 	struct af_alg_tsgl *sgl;
 	struct af_alg_control con = {};
 	long copied = 0;
-	bool enc = 0;
+	int op = 0;
 	bool init = 0;
 	int err = 0;
 
@@ -842,11 +842,11 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
 
 		init = 1;
 		switch (con.op) {
+		case ALG_OP_VERIFY:
+		case ALG_OP_SIGN:
 		case ALG_OP_ENCRYPT:
-			enc = 1;
-			break;
 		case ALG_OP_DECRYPT:
-			enc = 0;
+			op = con.op;
 			break;
 		default:
 			return -EINVAL;
@@ -863,7 +863,7 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
 	}
 
 	if (init) {
-		ctx->enc = enc;
+		ctx->op = op;
 		if (con.iv)
 			memcpy(ctx->iv, con.iv->iv, ivsize);
 
diff --git a/crypto/algif_aead.c b/crypto/algif_aead.c
index d963c8cf8a55..f956091e6909 100644
--- a/crypto/algif_aead.c
+++ b/crypto/algif_aead.c
@@ -60,7 +60,7 @@ static inline bool aead_sufficient_data(struct sock *sk)
 	 * The minimum amount of memory needed for an AEAD cipher is
 	 * the AAD and in case of decryption the tag.
 	 */
-	return ctx->used >= ctx->aead_assoclen + (ctx->enc ? 0 : as);
+	return ctx->used >= ctx->aead_assoclen + (ctx->op ? 0 : as);
 }
 
 static int aead_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
@@ -76,6 +76,19 @@ static int aead_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
 	return af_alg_sendmsg(sock, msg, size, ivsize);
 }
 
+static inline int aead_cipher_op(struct af_alg_ctx *ctx,
+				 struct af_alg_async_req *areq)
+{
+	switch (ctx->op) {
+	case ALG_OP_ENCRYPT:
+		return crypto_aead_encrypt(&areq->cra_u.aead_req);
+	case ALG_OP_DECRYPT:
+		return crypto_aead_decrypt(&areq->cra_u.aead_req);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
 static int crypto_aead_copy_sgl(struct crypto_skcipher *null_tfm,
 				struct scatterlist *src,
 				struct scatterlist *dst, unsigned int len)
@@ -143,7 +156,7 @@ static int _aead_recvmsg(struct socket *sock, struct msghdr *msg,
 	 * buffer provides the tag which is consumed resulting in only the
 	 * plaintext without a buffer for the tag returned to the caller.
 	 */
-	if (ctx->enc)
+	if (ctx->op)
 		outlen = used + as;
 	else
 		outlen = used - as;
@@ -217,7 +230,7 @@ static int _aead_recvmsg(struct socket *sock, struct msghdr *msg,
 	/* Use the RX SGL as source (and destination) for crypto op. */
 	rsgl_src = areq->first_rsgl.sgl.sg;
 
-	if (ctx->enc) {
+	if (ctx->op == ALG_OP_ENCRYPT) {
 		/*
 		 * Encryption operation - The in-place cipher operation is
 		 * achieved by the following operation:
@@ -233,7 +246,7 @@ static int _aead_recvmsg(struct socket *sock, struct msghdr *msg,
 		if (err)
 			goto free;
 		af_alg_pull_tsgl(sk, processed, NULL, 0);
-	} else {
+	} else if (ctx->op == ALG_OP_DECRYPT) {
 		/*
 		 * Decryption operation - To achieve an in-place cipher
 		 * operation, the following  SGL structure is used:
@@ -298,8 +311,7 @@ static int _aead_recvmsg(struct socket *sock, struct msghdr *msg,
 		aead_request_set_callback(&areq->cra_u.aead_req,
 					  CRYPTO_TFM_REQ_MAY_BACKLOG,
 					  af_alg_async_cb, areq);
-		err = ctx->enc ? crypto_aead_encrypt(&areq->cra_u.aead_req) :
-				 crypto_aead_decrypt(&areq->cra_u.aead_req);
+		err = aead_cipher_op(ctx, areq);
 
 		/* AIO operation in progress */
 		if (err == -EINPROGRESS || err == -EBUSY)
@@ -311,10 +323,7 @@ static int _aead_recvmsg(struct socket *sock, struct msghdr *msg,
 		aead_request_set_callback(&areq->cra_u.aead_req,
 					  CRYPTO_TFM_REQ_MAY_BACKLOG,
 					  crypto_req_done, &ctx->wait);
-		err = crypto_wait_req(ctx->enc ?
-				crypto_aead_encrypt(&areq->cra_u.aead_req) :
-				crypto_aead_decrypt(&areq->cra_u.aead_req),
-				&ctx->wait);
+		err = crypto_wait_req(aead_cipher_op(ctx, areq), &ctx->wait);
 	}
 
 
@@ -574,7 +583,7 @@ static int aead_accept_parent_nokey(void *private, struct sock *sk)
 	atomic_set(&ctx->rcvused, 0);
 	ctx->more = 0;
 	ctx->merge = 0;
-	ctx->enc = 0;
+	ctx->op = 0;
 	ctx->aead_assoclen = 0;
 	crypto_init_wait(&ctx->wait);
 
diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c
index c5c47b680152..950b33946a27 100644
--- a/crypto/algif_skcipher.c
+++ b/crypto/algif_skcipher.c
@@ -57,6 +57,19 @@ static int skcipher_sendmsg(struct socket *sock, struct msghdr *msg,
 	return af_alg_sendmsg(sock, msg, size, ivsize);
 }
 
+static inline int skcipher_cipher_op(struct af_alg_ctx *ctx,
+				     struct af_alg_async_req *areq)
+{
+	switch (ctx->op) {
+	case ALG_OP_ENCRYPT:
+		return crypto_skcipher_encrypt(&areq->cra_u.skcipher_req);
+	case ALG_OP_DECRYPT:
+		return crypto_skcipher_decrypt(&areq->cra_u.skcipher_req);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
 static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
 			     size_t ignored, int flags)
 {
@@ -132,9 +145,7 @@ static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
 		skcipher_request_set_callback(&areq->cra_u.skcipher_req,
 					      CRYPTO_TFM_REQ_MAY_SLEEP,
 					      af_alg_async_cb, areq);
-		err = ctx->enc ?
-			crypto_skcipher_encrypt(&areq->cra_u.skcipher_req) :
-			crypto_skcipher_decrypt(&areq->cra_u.skcipher_req);
+		err = skcipher_cipher_op(ctx, areq);
 
 		/* AIO operation in progress */
 		if (err == -EINPROGRESS || err == -EBUSY)
@@ -147,10 +158,8 @@ static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
 					      CRYPTO_TFM_REQ_MAY_SLEEP |
 					      CRYPTO_TFM_REQ_MAY_BACKLOG,
 					      crypto_req_done, &ctx->wait);
-		err = crypto_wait_req(ctx->enc ?
-			crypto_skcipher_encrypt(&areq->cra_u.skcipher_req) :
-			crypto_skcipher_decrypt(&areq->cra_u.skcipher_req),
-						 &ctx->wait);
+		err = crypto_wait_req(skcipher_cipher_op(ctx, areq),
+				      &ctx->wait);
 	}
 
 
@@ -393,7 +402,7 @@ static int skcipher_accept_parent_nokey(void *private, struct sock *sk)
 	atomic_set(&ctx->rcvused, 0);
 	ctx->more = 0;
 	ctx->merge = 0;
-	ctx->enc = 0;
+	ctx->op = 0;
 	crypto_init_wait(&ctx->wait);
 
 	ask->private = ctx;
diff --git a/include/crypto/if_alg.h b/include/crypto/if_alg.h
index f38227a78eae..712a3d1cd466 100644
--- a/include/crypto/if_alg.h
+++ b/include/crypto/if_alg.h
@@ -138,7 +138,7 @@ struct af_alg_async_req {
  * @more:		More data to be expected from user space?
  * @merge:		Shall new data from user space be merged into existing
  *			SG?
- * @enc:		Cryptographic operation to be performed when
+ * @op:			Cryptographic operation to be performed when
  *			recvmsg is invoked.
  * @len:		Length of memory allocated for this data structure.
  */
@@ -155,7 +155,7 @@ struct af_alg_ctx {
 
 	bool more;
 	bool merge;
-	bool enc;
+	int op;
 
 	unsigned int len;
 };
diff --git a/include/uapi/linux/if_alg.h b/include/uapi/linux/if_alg.h
index bc2bcdec377b..e61e9fc353ec 100644
--- a/include/uapi/linux/if_alg.h
+++ b/include/uapi/linux/if_alg.h
@@ -39,5 +39,7 @@ struct af_alg_iv {
 /* Operations */
 #define ALG_OP_DECRYPT			0
 #define ALG_OP_ENCRYPT			1
+#define ALG_OP_SIGN			2
+#define ALG_OP_VERIFY			3
 
 #endif	/* _LINUX_IF_ALG_H */
-- 
2.14.3