1 files changed, 255 insertions, 0 deletions
diff --git a/crypto/rng.c b/crypto/rng.c
new file mode 100644
index 000000000..279dffdeb
--- /dev/null
+++ b/crypto/rng.c
@@ -0,0 +1,255 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Cryptographic API.
+ *
+ * RNG operations.
+ *
+ * Copyright (c) 2008 Neil Horman <nhorman@tuxdriver.com>
+ * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au>
+ */
+
+#include <crypto/internal/rng.h>
+#include <linux/atomic.h>
+#include <linux/cryptouser.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/random.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <net/netlink.h>
+
+#include "internal.h"
+
+static DEFINE_MUTEX(crypto_default_rng_lock);
+struct crypto_rng *crypto_default_rng;
+EXPORT_SYMBOL_GPL(crypto_default_rng);
+static int crypto_default_rng_refcnt;
+
+int crypto_rng_reset(struct crypto_rng *tfm, const u8 *seed, unsigned int slen)
+{
+	struct rng_alg *alg = crypto_rng_alg(tfm);
+	u8 *buf = NULL;
+	int err;
+
+	if (IS_ENABLED(CONFIG_CRYPTO_STATS))
+		atomic64_inc(&rng_get_stat(alg)->seed_cnt);
+
+	if (!seed && slen) {
+		buf = kmalloc(slen, GFP_KERNEL);
+		err = -ENOMEM;
+		if (!buf)
+			goto out;
+
+		err = get_random_bytes_wait(buf, slen);
+		if (err)
+			goto free_buf;
+		seed = buf;
+	}
+
+	err = alg->seed(tfm, seed, slen);
+free_buf:
+	kfree_sensitive(buf);
+out:
+	return crypto_rng_errstat(alg, err);
+}
+EXPORT_SYMBOL_GPL(crypto_rng_reset);
+
+static int crypto_rng_init_tfm(struct crypto_tfm *tfm)
+{
+	return 0;
+}
+
+static unsigned int seedsize(struct crypto_alg *alg)
+{
+	struct rng_alg *ralg = container_of(alg, struct rng_alg, base);
+
+	return ralg->seedsize;
+}
+
+static int __maybe_unused crypto_rng_report(
+	struct sk_buff *skb, struct crypto_alg *alg)
+{
+	struct crypto_report_rng rrng;
+
+	memset(&rrng, 0, sizeof(rrng));
+
+	strscpy(rrng.type, "rng", sizeof(rrng.type));
+
+	rrng.seedsize = seedsize(alg);
+
+	return nla_put(skb, CRYPTOCFGA_REPORT_RNG, sizeof(rrng), &rrng);
+}
+
+static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
+	__maybe_unused;
+static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
+{
+	seq_printf(m, "type         : rng\n");
+	seq_printf(m, "seedsize     : %u\n", seedsize(alg));
+}
+
+static int __maybe_unused crypto_rng_report_stat(
+	struct sk_buff *skb, struct crypto_alg *alg)
+{
+	struct rng_alg *rng = __crypto_rng_alg(alg);
+	struct crypto_istat_rng *istat;
+	struct crypto_stat_rng rrng;
+
+	istat = rng_get_stat(rng);
+
+	memset(&rrng, 0, sizeof(rrng));
+
+	strscpy(rrng.type, "rng", sizeof(rrng.type));
+
+	rrng.stat_generate_cnt = atomic64_read(&istat->generate_cnt);
+	rrng.stat_generate_tlen = atomic64_read(&istat->generate_tlen);
+	rrng.stat_seed_cnt = atomic64_read(&istat->seed_cnt);
+	rrng.stat_err_cnt = atomic64_read(&istat->err_cnt);
+
+	return nla_put(skb, CRYPTOCFGA_STAT_RNG, sizeof(rrng), &rrng);
+}
+
+static const struct crypto_type crypto_rng_type = {
+	.extsize = crypto_alg_extsize,
+	.init_tfm = crypto_rng_init_tfm,
+#ifdef CONFIG_PROC_FS
+	.show = crypto_rng_show,
+#endif
+#if IS_ENABLED(CONFIG_CRYPTO_USER)
+	.report = crypto_rng_report,
+#endif
+#ifdef CONFIG_CRYPTO_STATS
+	.report_stat = crypto_rng_report_stat,
+#endif
+	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
+	.maskset = CRYPTO_ALG_TYPE_MASK,
+	.type = CRYPTO_ALG_TYPE_RNG,
+	.tfmsize = offsetof(struct crypto_rng, base),
+};
+
+struct crypto_rng *crypto_alloc_rng(const char *alg_name, u32 type, u32 mask)
+{
+	return crypto_alloc_tfm(alg_name, &crypto_rng_type, type, mask);
+}
+EXPORT_SYMBOL_GPL(crypto_alloc_rng);
+
+int crypto_get_default_rng(void)
+{
+	struct crypto_rng *rng;
+	int err;
+
+	mutex_lock(&crypto_default_rng_lock);
+	if (!crypto_default_rng) {
+		rng = crypto_alloc_rng("stdrng", 0, 0);
+		err = PTR_ERR(rng);
+		if (IS_ERR(rng))
+			goto unlock;
+
+		err = crypto_rng_reset(rng, NULL, crypto_rng_seedsize(rng));
+		if (err) {
+			crypto_free_rng(rng);
+			goto unlock;
+		}
+
+		crypto_default_rng = rng;
+	}
+
+	crypto_default_rng_refcnt++;
+	err = 0;
+
+unlock:
+	mutex_unlock(&crypto_default_rng_lock);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(crypto_get_default_rng);
+
+void crypto_put_default_rng(void)
+{
+	mutex_lock(&crypto_default_rng_lock);
+	crypto_default_rng_refcnt--;
+	mutex_unlock(&crypto_default_rng_lock);
+}
+EXPORT_SYMBOL_GPL(crypto_put_default_rng);
+
+#if defined(CONFIG_CRYPTO_RNG) || defined(CONFIG_CRYPTO_RNG_MODULE)
+int crypto_del_default_rng(void)
+{
+	int err = -EBUSY;
+
+	mutex_lock(&crypto_default_rng_lock);
+	if (crypto_default_rng_refcnt)
+		goto out;
+
+	crypto_free_rng(crypto_default_rng);
+	crypto_default_rng = NULL;
+
+	err = 0;
+
+out:
+	mutex_unlock(&crypto_default_rng_lock);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(crypto_del_default_rng);
+#endif
+
+int crypto_register_rng(struct rng_alg *alg)
+{
+	struct crypto_istat_rng *istat = rng_get_stat(alg);
+	struct crypto_alg *base = &alg->base;
+
+	if (alg->seedsize > PAGE_SIZE / 8)
+		return -EINVAL;
+
+	base->cra_type = &crypto_rng_type;
+	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
+	base->cra_flags |= CRYPTO_ALG_TYPE_RNG;
+
+	if (IS_ENABLED(CONFIG_CRYPTO_STATS))
+		memset(istat, 0, sizeof(*istat));
+
+	return crypto_register_alg(base);
+}
+EXPORT_SYMBOL_GPL(crypto_register_rng);
+
+void crypto_unregister_rng(struct rng_alg *alg)
+{
+	crypto_unregister_alg(&alg->base);
+}
+EXPORT_SYMBOL_GPL(crypto_unregister_rng);
+
+int crypto_register_rngs(struct rng_alg *algs, int count)
+{
+	int i, ret;
+
+	for (i = 0; i < count; i++) {
+		ret = crypto_register_rng(algs + i);
+		if (ret)
+			goto err;
+	}
+
+	return 0;
+
+err:
+	for (--i; i >= 0; --i)
+		crypto_unregister_rng(algs + i);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(crypto_register_rngs);
+
+void crypto_unregister_rngs(struct rng_alg *algs, int count)
+{
+	int i;
+
+	for (i = count - 1; i >= 0; --i)
+		crypto_unregister_rng(algs + i);
+}
+EXPORT_SYMBOL_GPL(crypto_unregister_rngs);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Random Number Generator");