From 1a62c23ecf1f38d999f7d94d8d27fbc97483b35d Mon Sep 17 00:00:00 2001 From: Heiko Stuebner Date: Thu, 18 Jun 2020 16:23:26 +0200 Subject: [PATCH] lib: rsa: add documentation to padding_pss_verify to document limitations padding_pss_verify only works with the default pss salt setting of -2 (length to be automatically determined based on the PSS block structure) not -1 (salt length set to the maximum permissible value), which makes verifications of signatures with that saltlen fail. Until this gets implemented at least document this behaviour. Signed-off-by: Heiko Stuebner Reviewed-by: Simon Glass --- lib/rsa/rsa-verify.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/lib/rsa/rsa-verify.c b/lib/rsa/rsa-verify.c index 048f1ab7893..61d98e6e2d5 100644 --- a/lib/rsa/rsa-verify.c +++ b/lib/rsa/rsa-verify.c @@ -194,6 +194,19 @@ out: return ret; } +/* + * padding_pss_verify() - verify the pss padding of a signature + * + * Only works with a rsa_pss_saltlen:-2 (default value) right now + * saltlen:-1 "set the salt length to the digest length" is currently + * not supported. + * + * @info: Specifies key and FIT information + * @msg: byte array of message, len equal to msg_len + * @msg_len: Message length + * @hash: Pointer to the expected hash + * @hash_len: Length of the hash + */ int padding_pss_verify(struct image_sign_info *info, uint8_t *msg, int msg_len, const uint8_t *hash, int hash_len)