Merge pull request from GHSA-xqhj-fmc7-f8mv

ecdsautils: verify: fix signature verification (CVE-2022-24884)

patches/packages/packages/0002-ecdsautils-verify-fix-signature-verification-CVE-2022-24884.patch

+From: Matthias Schiffer <mschiffer@universe-factory.net>
+Date: Wed, 27 Apr 2022 19:01:39 +0200
+Subject: ecdsautils: verify: fix signature verification (CVE-2022-24884)
+
+Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
+
+diff --git a/utils/ecdsautils/Makefile b/utils/ecdsautils/Makefile
+index e6f5a916e63e9914369ae7e47106230346f9322c..096827494befad193c5904e1748c4e6768bbb15e 100644
+--- a/utils/ecdsautils/Makefile
++++ b/utils/ecdsautils/Makefile
+@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
+ 
+ PKG_NAME:=ecdsautils
+ PKG_VERSION:=0.3.2.20160630
+-PKG_RELEASE:=1
++PKG_RELEASE:=2
+ 
+ PKG_SOURCE_PROTO:=git
+ PKG_SOURCE_URL:=https://github.com/freifunk-gluon/ecdsautils
+diff --git a/utils/ecdsautils/patches/0001-verify-fix-signature-verification-CVE-2022-24884.patch b/utils/ecdsautils/patches/0001-verify-fix-signature-verification-CVE-2022-24884.patch
+new file mode 100644
+index 0000000000000000000000000000000000000000..34d80cc201c0e87ca654c3def4fbbbddf622b0ba
+--- /dev/null
++++ b/utils/ecdsautils/patches/0001-verify-fix-signature-verification-CVE-2022-24884.patch
+@@ -0,0 +1,48 @@
++From 1d4b091abdf15ad7b2312535b5b95ad70f6dbd08 Mon Sep 17 00:00:00 2001
++Message-Id: <1d4b091abdf15ad7b2312535b5b95ad70f6dbd08.1651078760.git.mschiffer@universe-factory.net>
++From: Matthias Schiffer <mschiffer@universe-factory.net>
++Date: Wed, 20 Apr 2022 22:04:07 +0200
++Subject: [PATCH] verify: fix signature verification (CVE-2022-24884)
++
++Verify that r and s are non-zero. Without these checks, an all-zero
++signature is always considered valid.
++
++While it would be nicer to error out in ecdsa_verify_prepare_legacy()
++already, that would require users of libecdsautil to check a return value
++of the prepare step. To be safe, implement the fix in an API/ABI-compatible
++way that doesn't need changes to the users.
++---
++ src/lib/ecdsa.c | 10 ++++++++++
++ 1 file changed, 10 insertions(+)
++
++diff --git a/src/lib/ecdsa.c b/src/lib/ecdsa.c
++index 8cd7722be8cd..a661b56bd7c8 100644
++--- a/src/lib/ecdsa.c
+++++ b/src/lib/ecdsa.c
++@@ -135,6 +135,12 @@ regenerate:
++ void ecdsa_verify_prepare_legacy(ecdsa_verify_context_t *ctx, const ecc_int256_t *hash, const ecdsa_signature_t *signature) {
++   ecc_int256_t w, u1, tmp;
++ 
+++  if (ecc_25519_gf_is_zero(&signature->s) || ecc_25519_gf_is_zero(&signature->r)) {
+++    // Signature is invalid, mark by setting ctx->r to an invalid value
+++    memset(&ctx->r, 0, sizeof(ctx->r));
+++    return;
+++  }
+++
++   ctx->r = signature->r;
++ 
++   ecc_25519_gf_recip(&w, &signature->s);
++@@ -149,6 +155,10 @@ bool ecdsa_verify_legacy(const ecdsa_verify_context_t *ctx, const ecc_25519_work
++   ecc_25519_work_t s2, work;
++   ecc_int256_t w, tmp;
++ 
+++  // Signature was detected as invalid in prepare step
+++  if (ecc_25519_gf_is_zero(&ctx->r))
+++    return false;
+++
++   ecc_25519_scalarmult(&s2, &ctx->u2, pubkey);
++   ecc_25519_add(&work, &ctx->s1, &s2);
++   ecc_25519_store_xy_legacy(&w, NULL, &work);
++-- 
++2.36.0
++