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>

3 files changed, 42 insertions, 21 deletions

diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index e893c0f6c879..a5c01cd02b5c 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -834,6 +834,7 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
 	struct af_alg_control con = {};
 	long copied = 0;
 	bool enc = false;
+	int op = 0;
 	bool init = false;
 	int err = 0;
 
@@ -844,11 +845,11 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
 
 		init = true;
 		switch (con.op) {
+		case ALG_OP_VERIFY:
+		case ALG_OP_SIGN:
 		case ALG_OP_ENCRYPT:
-			enc = true;
-			break;
 		case ALG_OP_DECRYPT:
-			enc = false;
+			op = con.op;
 			break;
 		default:
 			return -EINVAL;
@@ -872,7 +873,7 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
 	ctx->init = true;
 
 	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 42493b4d8ce4..403486b70ce3 100644
--- a/crypto/algif_aead.c
+++ b/crypto/algif_aead.c
@@ -55,7 +55,7 @@ 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)
@@ -71,6 +71,19 @@ 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_sync_skcipher *null_tfm,
 				struct scatterlist *src,
 				struct scatterlist *dst, unsigned int len)
@@ -138,7 +151,7 @@ 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;
@@ -212,7 +225,7 @@ 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:
@@ -228,7 +241,7 @@ 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:
@@ -293,8 +306,7 @@ static int _aead_recvmsg(struct socket *sock, struct msghdr *msg,
 		aead_request_set_callback(&areq->cra_u.aead_req,
 					  CRYPTO_TFM_REQ_MAY_SLEEP,
 					  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)
@@ -307,10 +319,7 @@ static int _aead_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_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);
 	}
 
 
@@ -555,6 +564,7 @@ static int aead_accept_parent_nokey(void *private, struct sock *sk)
 
 	INIT_LIST_HEAD(&ctx->tsgl_list);
 	ctx->len = len;
+	ctx->op = 0;
 	crypto_init_wait(&ctx->wait);
 
 	ask->private = ctx;
diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c
index ee8890ee8f33..eed6277825c1 100644
--- a/crypto/algif_skcipher.c
+++ b/crypto/algif_skcipher.c
@@ -47,6 +47,19 @@ 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)
 {
@@ -118,9 +131,7 @@ 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)
@@ -133,10 +144,8 @@ 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);
 	}
 
 
@@ -341,6 +350,7 @@ static int skcipher_accept_parent_nokey(void *private, struct sock *sk)
 
 	INIT_LIST_HEAD(&ctx->tsgl_list);
 	ctx->len = len;
+	ctx->op = 0;
 	crypto_init_wait(&ctx->wait);
 
 	ask->private = ctx;