From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/crypto/algif_rng.c | 177 ++++++++++++++++++++++++++++++++++++++++++++++++++++++----
1 files changed, 164 insertions(+), 13 deletions(-)
diff --git a/kernel/crypto/algif_rng.c b/kernel/crypto/algif_rng.c
index 22df379..407408c 100644
--- a/kernel/crypto/algif_rng.c
+++ b/kernel/crypto/algif_rng.c
@@ -38,6 +38,7 @@
* DAMAGE.
*/
+#include <linux/capability.h>
#include <linux/module.h>
#include <crypto/rng.h>
#include <linux/random.h>
@@ -53,15 +54,26 @@
#define MAXSIZE 128
unsigned int len;
struct crypto_rng *drng;
+ u8 *addtl;
+ size_t addtl_len;
};
-static int rng_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
- int flags)
+struct rng_parent_ctx {
+ struct crypto_rng *drng;
+ u8 *entropy;
+};
+
+static void rng_reset_addtl(struct rng_ctx *ctx)
{
- struct sock *sk = sock->sk;
- struct alg_sock *ask = alg_sk(sk);
- struct rng_ctx *ctx = ask->private;
- int err = -EFAULT;
+ kfree_sensitive(ctx->addtl);
+ ctx->addtl = NULL;
+ ctx->addtl_len = 0;
+}
+
+static int _rng_recvmsg(struct crypto_rng *drng, struct msghdr *msg, size_t len,
+ u8 *addtl, size_t addtl_len)
+{
+ int err = 0;
int genlen = 0;
u8 result[MAXSIZE];
@@ -82,13 +94,70 @@
* seeding as they automatically seed. The X9.31 DRNG will return
* an error if it was not seeded properly.
*/
- genlen = crypto_rng_get_bytes(ctx->drng, result, len);
+ genlen = crypto_rng_generate(drng, addtl, addtl_len, result, len);
if (genlen < 0)
return genlen;
err = memcpy_to_msg(msg, result, len);
memzero_explicit(result, len);
+ return err ? err : len;
+}
+
+static int rng_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
+ int flags)
+{
+ struct sock *sk = sock->sk;
+ struct alg_sock *ask = alg_sk(sk);
+ struct rng_ctx *ctx = ask->private;
+
+ return _rng_recvmsg(ctx->drng, msg, len, NULL, 0);
+}
+
+static int rng_test_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
+ int flags)
+{
+ struct sock *sk = sock->sk;
+ struct alg_sock *ask = alg_sk(sk);
+ struct rng_ctx *ctx = ask->private;
+ int ret;
+
+ lock_sock(sock->sk);
+ ret = _rng_recvmsg(ctx->drng, msg, len, ctx->addtl, ctx->addtl_len);
+ rng_reset_addtl(ctx);
+ release_sock(sock->sk);
+
+ return ret;
+}
+
+static int rng_test_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
+{
+ int err;
+ struct alg_sock *ask = alg_sk(sock->sk);
+ struct rng_ctx *ctx = ask->private;
+
+ lock_sock(sock->sk);
+ if (len > MAXSIZE) {
+ err = -EMSGSIZE;
+ goto unlock;
+ }
+
+ rng_reset_addtl(ctx);
+ ctx->addtl = kmalloc(len, GFP_KERNEL);
+ if (!ctx->addtl) {
+ err = -ENOMEM;
+ goto unlock;
+ }
+
+ err = memcpy_from_msg(ctx->addtl, msg, len);
+ if (err) {
+ rng_reset_addtl(ctx);
+ goto unlock;
+ }
+ ctx->addtl_len = len;
+
+unlock:
+ release_sock(sock->sk);
return err ? err : len;
}
@@ -101,11 +170,9 @@
.ioctl = sock_no_ioctl,
.listen = sock_no_listen,
.shutdown = sock_no_shutdown,
- .getsockopt = sock_no_getsockopt,
.mmap = sock_no_mmap,
.bind = sock_no_bind,
.accept = sock_no_accept,
- .setsockopt = sock_no_setsockopt,
.sendmsg = sock_no_sendmsg,
.sendpage = sock_no_sendpage,
@@ -113,14 +180,53 @@
.recvmsg = rng_recvmsg,
};
+static struct proto_ops __maybe_unused algif_rng_test_ops = {
+ .family = PF_ALG,
+
+ .connect = sock_no_connect,
+ .socketpair = sock_no_socketpair,
+ .getname = sock_no_getname,
+ .ioctl = sock_no_ioctl,
+ .listen = sock_no_listen,
+ .shutdown = sock_no_shutdown,
+ .mmap = sock_no_mmap,
+ .bind = sock_no_bind,
+ .accept = sock_no_accept,
+ .sendpage = sock_no_sendpage,
+
+ .release = af_alg_release,
+ .recvmsg = rng_test_recvmsg,
+ .sendmsg = rng_test_sendmsg,
+};
+
static void *rng_bind(const char *name, u32 type, u32 mask)
{
- return crypto_alloc_rng(name, type, mask);
+ struct rng_parent_ctx *pctx;
+ struct crypto_rng *rng;
+
+ pctx = kzalloc(sizeof(*pctx), GFP_KERNEL);
+ if (!pctx)
+ return ERR_PTR(-ENOMEM);
+
+ rng = crypto_alloc_rng(name, type, mask);
+ if (IS_ERR(rng)) {
+ kfree(pctx);
+ return ERR_CAST(rng);
+ }
+
+ pctx->drng = rng;
+ return pctx;
}
static void rng_release(void *private)
{
- crypto_free_rng(private);
+ struct rng_parent_ctx *pctx = private;
+
+ if (unlikely(!pctx))
+ return;
+ crypto_free_rng(pctx->drng);
+ kfree_sensitive(pctx->entropy);
+ kfree_sensitive(pctx);
}
static void rng_sock_destruct(struct sock *sk)
@@ -128,6 +234,7 @@
struct alg_sock *ask = alg_sk(sk);
struct rng_ctx *ctx = ask->private;
+ rng_reset_addtl(ctx);
sock_kfree_s(sk, ctx, ctx->len);
af_alg_release_parent(sk);
}
@@ -135,6 +242,7 @@
static int rng_accept_parent(void *private, struct sock *sk)
{
struct rng_ctx *ctx;
+ struct rng_parent_ctx *pctx = private;
struct alg_sock *ask = alg_sk(sk);
unsigned int len = sizeof(*ctx);
@@ -143,6 +251,8 @@
return -ENOMEM;
ctx->len = len;
+ ctx->addtl = NULL;
+ ctx->addtl_len = 0;
/*
* No seeding done at that point -- if multiple accepts are
@@ -150,20 +260,58 @@
* state of the RNG.
*/
- ctx->drng = private;
+ ctx->drng = pctx->drng;
ask->private = ctx;
sk->sk_destruct = rng_sock_destruct;
+
+ /*
+ * Non NULL pctx->entropy means that CAVP test has been initiated on
+ * this socket, replace proto_ops algif_rng_ops with algif_rng_test_ops.
+ */
+ if (IS_ENABLED(CONFIG_CRYPTO_USER_API_RNG_CAVP) && pctx->entropy)
+ sk->sk_socket->ops = &algif_rng_test_ops;
return 0;
}
static int rng_setkey(void *private, const u8 *seed, unsigned int seedlen)
{
+ struct rng_parent_ctx *pctx = private;
/*
* Check whether seedlen is of sufficient size is done in RNG
* implementations.
*/
- return crypto_rng_reset(private, seed, seedlen);
+ return crypto_rng_reset(pctx->drng, seed, seedlen);
+}
+
+static int __maybe_unused rng_setentropy(void *private, sockptr_t entropy,
+ unsigned int len)
+{
+ struct rng_parent_ctx *pctx = private;
+ u8 *kentropy = NULL;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ if (pctx->entropy)
+ return -EINVAL;
+
+ if (len > MAXSIZE)
+ return -EMSGSIZE;
+
+ if (len) {
+ kentropy = memdup_sockptr(entropy, len);
+ if (IS_ERR(kentropy))
+ return PTR_ERR(kentropy);
+ }
+
+ crypto_rng_alg(pctx->drng)->set_ent(pctx->drng, kentropy, len);
+ /*
+ * Since rng doesn't perform any memory management for the entropy
+ * buffer, save kentropy pointer to pctx now to free it after use.
+ */
+ pctx->entropy = kentropy;
+ return 0;
}
static const struct af_alg_type algif_type_rng = {
@@ -171,6 +319,9 @@
.release = rng_release,
.accept = rng_accept_parent,
.setkey = rng_setkey,
+#ifdef CONFIG_CRYPTO_USER_API_RNG_CAVP
+ .setentropy = rng_setentropy,
+#endif
.ops = &algif_rng_ops,
.name = "rng",
.owner = THIS_MODULE
--
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