crypto: Add userspace report for rng type algorithms

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

2 files changed, 26 insertions, 0 deletions

diff --git a/crypto/rng.c b/crypto/rng.c
index 45229ae782be..feb7de00f437 100644
--- a/crypto/rng.c
+++ b/crypto/rng.c
@@ -21,6 +21,8 @@
 #include <linux/seq_file.h>
 #include <linux/slab.h>
 #include <linux/string.h>
+#include <linux/cryptouser.h>
+#include <net/netlink.h>
 
 static DEFINE_MUTEX(crypto_default_rng_lock);
 struct crypto_rng *crypto_default_rng;
@@ -58,6 +60,23 @@ static int crypto_init_rng_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
         return 0;
 }
 
+static int crypto_rng_report(struct sk_buff *skb, struct crypto_alg *alg)
+{
+        struct crypto_report_rng rrng;
+
+        snprintf(rrng.type, CRYPTO_MAX_ALG_NAME, "%s", "rng");
+
+        rrng.seedsize = alg->cra_rng.seedsize;
+
+        NLA_PUT(skb, CRYPTOCFGA_REPORT_RNG,
+                sizeof(struct crypto_report_rng), &rrng);
+
+        return 0;
+
+nla_put_failure:
+        return -EMSGSIZE;
+}
+
 static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
         __attribute__ ((unused));
 static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
@@ -78,6 +97,7 @@ const struct crypto_type crypto_rng_type = {
 #ifdef CONFIG_PROC_FS
         .show = crypto_rng_show,
 #endif
+        .report = crypto_rng_report,
 };
 EXPORT_SYMBOL_GPL(crypto_rng_type);
 
diff --git a/include/linux/cryptouser.h b/include/linux/cryptouser.h
index c8c1dfcb7cf2..ed8a40e8fb6b 100644
--- a/include/linux/cryptouser.h
+++ b/include/linux/cryptouser.h
@@ -41,6 +41,7 @@ enum crypto_attr_type_t {
         CRYPTOCFGA_REPORT_BLKCIPHER,    /* struct crypto_report_blkcipher */
         CRYPTOCFGA_REPORT_AEAD,         /* struct crypto_report_aead */
         CRYPTOCFGA_REPORT_COMPRESS,     /* struct crypto_report_comp */
+        CRYPTOCFGA_REPORT_RNG,          /* struct crypto_report_rng */
         __CRYPTOCFGA_MAX
 
 #define CRYPTOCFGA_MAX (__CRYPTOCFGA_MAX - 1)
@@ -86,3 +87,8 @@ struct crypto_report_aead {
 struct crypto_report_comp {
         char type[CRYPTO_MAX_NAME];
 };
+
+struct crypto_report_rng {
+        char type[CRYPTO_MAX_NAME];
+        unsigned int seedsize;
+};