From a890ef833d114da3430c2f2efd95e01714704d34 Mon Sep 17 00:00:00 2001 From: Patrick Steuer Date: Mon, 5 Aug 2019 16:53:16 +0200 Subject: [PATCH] Directly return from final sha3/keccak_final if no bytes are requested Requesting zero bytes from shake previously led to out-of-bounds write on some platforms. Signed-off-by: Patrick Steuer Reviewed-by: Richard Levitte (Merged from https://github.com/openssl/openssl/pull/9433) --- crypto/sha/sha3.c | 3 +++ providers/common/digests/sha3_prov.c | 6 ++++-- 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/crypto/sha/sha3.c b/crypto/sha/sha3.c index 19ef4266d0..fafa3556f3 100644 --- a/crypto/sha/sha3.c +++ b/crypto/sha/sha3.c @@ -89,6 +89,9 @@ int sha3_final(unsigned char *md, KECCAK1600_CTX *ctx) size_t bsz = ctx->block_size; size_t num = ctx->bufsz; + if (ctx->md_size == 0) + return 1; + /* * Pad the data with 10*1. Note that |num| can be |bsz - 1| * in which case both byte operations below are performed on diff --git a/providers/common/digests/sha3_prov.c b/providers/common/digests/sha3_prov.c index 469a1606ff..17b15b7ca2 100644 --- a/providers/common/digests/sha3_prov.c +++ b/providers/common/digests/sha3_prov.c @@ -90,10 +90,12 @@ static int keccak_update(void *vctx, const unsigned char *inp, size_t len) static int keccak_final(void *vctx, unsigned char *out, size_t *outl, size_t outsz) { - int ret; + int ret = 1; KECCAK1600_CTX *ctx = vctx; - ret = ctx->meth.final(out, ctx); + if (outsz > 0) + ret = ctx->meth.final(out, ctx); + *outl = ctx->md_size; return ret; } -- 2.25.1