From: Aleksander Jan Bajkowski Date: Mon, 26 Jan 2026 22:49:55 +0000 (+0100) Subject: airoha: reduce HWRNG quality X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F21722%2Fhead;p=thirdparty%2Fopenwrt.git airoha: reduce HWRNG quality Backport a patch that reduces the quality of HWRNG. HWRNG has lower entropy than expected. Thanks to this patch, it has a lower priority. Signed-off-by: Aleksander Jan Bajkowski Link: https://github.com/openwrt/openwrt/pull/21722 Signed-off-by: Hauke Mehrtens --- diff --git a/target/linux/airoha/patches-6.12/114-v7.0-hwrng-airoha-set-rng-quality-to-900.patch b/target/linux/airoha/patches-6.12/114-v7.0-hwrng-airoha-set-rng-quality-to-900.patch new file mode 100644 index 00000000000..7df5a18537c --- /dev/null +++ b/target/linux/airoha/patches-6.12/114-v7.0-hwrng-airoha-set-rng-quality-to-900.patch @@ -0,0 +1,57 @@ +From c0008a29a006091d7f9d288620c2456afa23ff27 Mon Sep 17 00:00:00 2001 +From: Aleksander Jan Bajkowski +Date: Mon, 5 Jan 2026 21:41:49 +0100 +Subject: [PATCH] hwrng: airoha - set rng quality to 900 + +Airoha uses RAW mode to collect noise from the TRNG. These appear to +be unprocessed oscillations from the tero loop. For this reason, they +do not have a perfect distribution and entropy. Simple noise compression +reduces its size by 9%, so setting the quality to 900 seems reasonable. +The same value is used by the downstream driver. + +Compare the size before and after compression: +$ ls -l random_airoha* +-rw-r--r-- 1 aleksander aleksander 76546048 Jan 3 23:43 random_airoha +-rw-rw-r-- 1 aleksander aleksander 69783562 Jan 5 20:23 random_airoha.zip + +FIPS test results: +$ cat random_airoha | rngtest -c 10000 +rngtest 2.6 +Copyright (c) 2004 by Henrique de Moraes Holschuh +This is free software; see the source for copying conditions. There is NO +warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. + +rngtest: starting FIPS tests... +rngtest: bits received from input: 200000032 +rngtest: FIPS 140-2 successes: 0 +rngtest: FIPS 140-2 failures: 10000 +rngtest: FIPS 140-2(2001-10-10) Monobit: 9957 +rngtest: FIPS 140-2(2001-10-10) Poker: 10000 +rngtest: FIPS 140-2(2001-10-10) Runs: 10000 +rngtest: FIPS 140-2(2001-10-10) Long run: 4249 +rngtest: FIPS 140-2(2001-10-10) Continuous run: 0 +rngtest: input channel speed: (min=953.674; avg=27698.935; max=19073.486)Mibits/s +rngtest: FIPS tests speed: (min=59.791; avg=298.028; max=328.853)Mibits/s +rngtest: Program run time: 647638 microseconds + +In general, these data look like real noise, but with lower entropy +than expected. + +Fixes: e53ca8efcc5e ("hwrng: airoha - add support for Airoha EN7581 TRNG") +Suggested-by: Benjamin Larsson +Signed-off-by: Aleksander Jan Bajkowski +Signed-off-by: Herbert Xu +--- + drivers/char/hw_random/airoha-trng.c | 1 + + 1 file changed, 1 insertion(+) + +--- a/drivers/char/hw_random/airoha-trng.c ++++ b/drivers/char/hw_random/airoha-trng.c +@@ -212,6 +212,7 @@ static int airoha_trng_probe(struct plat + trng->rng.init = airoha_trng_init; + trng->rng.cleanup = airoha_trng_cleanup; + trng->rng.read = airoha_trng_read; ++ trng->rng.quality = 900; + + ret = devm_hwrng_register(dev, &trng->rng); + if (ret) {