add new system file

hc

2024-02-20 102a0743326a03cd1a1202ceda21e175b7d3575c

 kernel/crypto/algif_rng.c
..
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@@ -38,6 +38,7 @@
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  * DAMAGE.
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  */
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40
 
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+#include <linux/capability.h>
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 #include <linux/module.h>
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 #include <crypto/rng.h>
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 #include <linux/random.h>
..
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@@ -53,15 +54,26 @@
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 #define MAXSIZE 128
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 	unsigned int len;
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 	struct crypto_rng *drng;
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+	u8 *addtl;
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+	size_t addtl_len;
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 };
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-static int rng_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
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-		       int flags)
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+struct rng_parent_ctx {
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+	struct crypto_rng *drng;
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+	u8 *entropy;
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+};
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+
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+static void rng_reset_addtl(struct rng_ctx *ctx)
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 {
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-	struct sock *sk = sock->sk;
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-	struct alg_sock *ask = alg_sk(sk);
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-	struct rng_ctx *ctx = ask->private;
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-	int err = -EFAULT;
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+	kfree_sensitive(ctx->addtl);
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+	ctx->addtl = NULL;
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+	ctx->addtl_len = 0;
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+}
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+
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+static int _rng_recvmsg(struct crypto_rng *drng, struct msghdr *msg, size_t len,
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+			u8 *addtl, size_t addtl_len)
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+{
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+	int err = 0;
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 	int genlen = 0;
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 	u8 result[MAXSIZE];
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@@ -82,13 +94,70 @@
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 	 * seeding as they automatically seed. The X9.31 DRNG will return
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 	 * an error if it was not seeded properly.
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 	 */
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-	genlen = crypto_rng_get_bytes(ctx->drng, result, len);
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+	genlen = crypto_rng_generate(drng, addtl, addtl_len, result, len);
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 	if (genlen < 0)
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 		return genlen;
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 	err = memcpy_to_msg(msg, result, len);
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 	memzero_explicit(result, len);
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+	return err ? err : len;
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+}
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+
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+static int rng_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
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+		       int flags)
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+{
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+	struct sock *sk = sock->sk;
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+	struct alg_sock *ask = alg_sk(sk);
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+	struct rng_ctx *ctx = ask->private;
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+
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+	return _rng_recvmsg(ctx->drng, msg, len, NULL, 0);
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+}
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+
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+static int rng_test_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
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+			    int flags)
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+{
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+	struct sock *sk = sock->sk;
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+	struct alg_sock *ask = alg_sk(sk);
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+	struct rng_ctx *ctx = ask->private;
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+	int ret;
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+
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+	lock_sock(sock->sk);
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+	ret = _rng_recvmsg(ctx->drng, msg, len, ctx->addtl, ctx->addtl_len);
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+	rng_reset_addtl(ctx);
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+	release_sock(sock->sk);
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+
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+	return ret;
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+}
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+
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+static int rng_test_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
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+{
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+	int err;
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+	struct alg_sock *ask = alg_sk(sock->sk);
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+	struct rng_ctx *ctx = ask->private;
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+
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+	lock_sock(sock->sk);
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+	if (len > MAXSIZE) {
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+		err = -EMSGSIZE;
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+		goto unlock;
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+	}
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+
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+	rng_reset_addtl(ctx);
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+	ctx->addtl = kmalloc(len, GFP_KERNEL);
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+	if (!ctx->addtl) {
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+		err = -ENOMEM;
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+		goto unlock;
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+	}
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+
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+	err = memcpy_from_msg(ctx->addtl, msg, len);
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+	if (err) {
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+		rng_reset_addtl(ctx);
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+		goto unlock;
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+	}
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+	ctx->addtl_len = len;
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+
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+unlock:
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+	release_sock(sock->sk);
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 	return err ? err : len;
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 }
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..
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@@ -101,11 +170,9 @@
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 	.ioctl		=	sock_no_ioctl,
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 	.listen		=	sock_no_listen,
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 	.shutdown	=	sock_no_shutdown,
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-	.getsockopt	=	sock_no_getsockopt,
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 	.mmap		=	sock_no_mmap,
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 	.bind		=	sock_no_bind,
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 	.accept		=	sock_no_accept,
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-	.setsockopt	=	sock_no_setsockopt,
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 	.sendmsg	=	sock_no_sendmsg,
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 	.sendpage	=	sock_no_sendpage,
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@@ -113,14 +180,53 @@
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 	.recvmsg	=	rng_recvmsg,
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 };
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182
 
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+static struct proto_ops __maybe_unused algif_rng_test_ops = {
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+	.family		=	PF_ALG,
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+
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+	.connect	=	sock_no_connect,
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+	.socketpair	=	sock_no_socketpair,
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+	.getname	=	sock_no_getname,
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+	.ioctl		=	sock_no_ioctl,
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+	.listen		=	sock_no_listen,
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+	.shutdown	=	sock_no_shutdown,
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+	.mmap		=	sock_no_mmap,
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+	.bind		=	sock_no_bind,
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+	.accept		=	sock_no_accept,
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+	.sendpage	=	sock_no_sendpage,
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+
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+	.release	=	af_alg_release,
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+	.recvmsg	=	rng_test_recvmsg,
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+	.sendmsg	=	rng_test_sendmsg,
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+};
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+
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 static void *rng_bind(const char *name, u32 type, u32 mask)
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 {
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-	return crypto_alloc_rng(name, type, mask);
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+	struct rng_parent_ctx *pctx;
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+	struct crypto_rng *rng;
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+
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+	pctx = kzalloc(sizeof(*pctx), GFP_KERNEL);
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+	if (!pctx)
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+		return ERR_PTR(-ENOMEM);
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+
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+	rng = crypto_alloc_rng(name, type, mask);
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+	if (IS_ERR(rng)) {
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+		kfree(pctx);
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+		return ERR_CAST(rng);
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+	}
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+
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+	pctx->drng = rng;
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+	return pctx;
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 }
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 static void rng_release(void *private)
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 {
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-	crypto_free_rng(private);
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+	struct rng_parent_ctx *pctx = private;
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+
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+	if (unlikely(!pctx))
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+		return;
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+	crypto_free_rng(pctx->drng);
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+	kfree_sensitive(pctx->entropy);
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+	kfree_sensitive(pctx);
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 }
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 static void rng_sock_destruct(struct sock *sk)
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@@ -128,6 +234,7 @@
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 	struct alg_sock *ask = alg_sk(sk);
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 	struct rng_ctx *ctx = ask->private;
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+	rng_reset_addtl(ctx);
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 	sock_kfree_s(sk, ctx, ctx->len);
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 	af_alg_release_parent(sk);
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 }
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@@ -135,6 +242,7 @@
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 static int rng_accept_parent(void *private, struct sock *sk)
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 {
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 	struct rng_ctx *ctx;
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+	struct rng_parent_ctx *pctx = private;
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 	struct alg_sock *ask = alg_sk(sk);
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 	unsigned int len = sizeof(*ctx);
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@@ -143,6 +251,8 @@
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 		return -ENOMEM;
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 	ctx->len = len;
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+	ctx->addtl = NULL;
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+	ctx->addtl_len = 0;
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 	/*
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 	 * No seeding done at that point -- if multiple accepts are
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@@ -150,20 +260,58 @@
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 	 * state of the RNG.
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 	 */
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-	ctx->drng = private;
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+	ctx->drng = pctx->drng;
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 	ask->private = ctx;
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 	sk->sk_destruct = rng_sock_destruct;
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+
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+	/*
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+	 * Non NULL pctx->entropy means that CAVP test has been initiated on
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+	 * this socket, replace proto_ops algif_rng_ops with algif_rng_test_ops.
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+	 */
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+	if (IS_ENABLED(CONFIG_CRYPTO_USER_API_RNG_CAVP) && pctx->entropy)
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+		sk->sk_socket->ops = &algif_rng_test_ops;
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 	return 0;
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 }
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 static int rng_setkey(void *private, const u8 *seed, unsigned int seedlen)
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 {
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+	struct rng_parent_ctx *pctx = private;
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 	/*
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 	 * Check whether seedlen is of sufficient size is done in RNG
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 	 * implementations.
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 	 */
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-	return crypto_rng_reset(private, seed, seedlen);
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+	return crypto_rng_reset(pctx->drng, seed, seedlen);
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+}
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+
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+static int __maybe_unused rng_setentropy(void *private, sockptr_t entropy,
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+					 unsigned int len)
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+{
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+	struct rng_parent_ctx *pctx = private;
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+	u8 *kentropy = NULL;
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+
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+	if (!capable(CAP_SYS_ADMIN))
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+		return -EACCES;
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+
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+	if (pctx->entropy)
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+		return -EINVAL;
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+
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+	if (len > MAXSIZE)
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+		return -EMSGSIZE;
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+
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+	if (len) {
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+		kentropy = memdup_sockptr(entropy, len);
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+		if (IS_ERR(kentropy))
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+			return PTR_ERR(kentropy);
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+	}
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+
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+	crypto_rng_alg(pctx->drng)->set_ent(pctx->drng, kentropy, len);
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+	/*
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+	 * Since rng doesn't perform any memory management for the entropy
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+	 * buffer, save kentropy pointer to pctx now to free it after use.
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+	 */
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+	pctx->entropy = kentropy;
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+	return 0;
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 }
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 static const struct af_alg_type algif_type_rng = {
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@@ -171,6 +319,9 @@
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 	.release	=	rng_release,
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 	.accept		=	rng_accept_parent,
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 	.setkey		=	rng_setkey,
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+#ifdef CONFIG_CRYPTO_USER_API_RNG_CAVP
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+	.setentropy	=	rng_setentropy,
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+#endif
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 	.ops		=	&algif_rng_ops,
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 	.name		=	"rng",
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 	.owner		=	THIS_MODULE