From 56820e54392efc5dd59032f8872aaf219190ad4f Mon Sep 17 00:00:00 2001 From: Colin Walters Date: Thu, 14 Jul 2022 14:42:19 -0400 Subject: [PATCH] sign/ed25519: Verify signatures are minimum length The ed25519 signature verification code does not check that the signature is a minimum/correct length. As a result, if the signature is too short, libsodium will end up reading a few bytes out of bounds. Reported-by: Demi Marie Obenour Co-authored-by: Demi Marie Obenour Closes: https://github.com/ostreedev/ostree/security/advisories/GHSA-gqf4-p3gv-g8vw --- src/libostree/ostree-sign-ed25519.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/src/libostree/ostree-sign-ed25519.c b/src/libostree/ostree-sign-ed25519.c index 809ffe87..f271fd49 100644 --- a/src/libostree/ostree-sign-ed25519.c +++ b/src/libostree/ostree-sign-ed25519.c @@ -209,6 +209,9 @@ gboolean ostree_sign_ed25519_data_verify (OstreeSign *self, g_autoptr (GVariant) child = g_variant_get_child_value (signatures, i); g_autoptr (GBytes) signature = g_variant_get_data_as_bytes(child); + if (g_bytes_get_size (signature) != crypto_sign_BYTES) + return glnx_throw (error, "Invalid signature length of %" G_GSIZE_FORMAT " bytes, expected %" G_GSIZE_FORMAT, (gsize) g_bytes_get_size (signature), (gsize) crypto_sign_BYTES); + g_autofree char * hex = g_malloc0 (crypto_sign_PUBLICKEYBYTES*2 + 1); g_debug("Read signature %d: %s", (gint)i, g_variant_print(child, TRUE));