From fc4c034ee823c18de34d72dc46da6aabbb6f551e Mon Sep 17 00:00:00 2001 From: Guido Vranken Date: Mon, 22 Apr 2019 14:11:12 +0200 Subject: [PATCH] Enforce a strict output length check in CRYPTO_ccm128_tag Return error if the output tag buffer size doesn't match the tag size exactly. This prevents the caller from using that portion of the tag buffer that remains uninitialized after an otherwise succesfull call to CRYPTO_ccm128_tag. Bug found by OSS-Fuzz. Fix suggested by Kurt Roeckx. Signed-off-by: Guido Vranken Reviewed-by: Matthias St. Pierre Reviewed-by: Paul Dale Reviewed-by: Matt Caswell (Merged from https://github.com/openssl/openssl/pull/8810) (cherry picked from commit 514c9da48b860153079748b0d588cd42191f0b6a) --- crypto/modes/ccm128.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/crypto/modes/ccm128.c b/crypto/modes/ccm128.c index 85ce84f10d..742c63f0a9 100644 --- a/crypto/modes/ccm128.c +++ b/crypto/modes/ccm128.c @@ -425,7 +425,7 @@ size_t CRYPTO_ccm128_tag(CCM128_CONTEXT *ctx, unsigned char *tag, size_t len) M *= 2; M += 2; - if (len < M) + if (len != M) return 0; memcpy(tag, ctx->cmac.c, M); return M; -- 2.50.1