Auto merge of #4359 - str4d:2872-upgrade-libsodium, r=str4d

Upgrade libsodium to 1.0.18 Includes patches that maintain consensus compatibility with libsodium 1.0.15 for Ed25519 pubkey and signature validation. Replaces #4239. Closes #2872.
zcash · Mar 10, 2020 · dcd3614 · dcd3614
2 parents ccd10d5 + 0cca79a
commit dcd3614
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Showing 5 changed files with 171 additions and 3 deletions.
diff --git a/depends/packages/libsodium.mk b/depends/packages/libsodium.mk
@@ -1,12 +1,15 @@
 package=libsodium
-$(package)_version=1.0.15
-$(package)_download_path=https://download.libsodium.org/libsodium/releases/old/unsupported/
+$(package)_version=1.0.18
+$(package)_download_path=https://download.libsodium.org/libsodium/releases/
 $(package)_file_name=$(package)-$($(package)_version).tar.gz
-$(package)_sha256_hash=fb6a9e879a2f674592e4328c5d9f79f082405ee4bb05cb6e679b90afe9e178f4
+$(package)_sha256_hash=6f504490b342a4f8a4c4a02fc9b866cbef8622d5df4e5452b46be121e46636c1
 $(package)_dependencies=
+$(package)_patches=1.0.15-pubkey-validation.diff 1.0.15-signature-validation.diff
 $(package)_config_opts=
 
 define $(package)_preprocess_cmds
+  patch -p1 < $($(package)_patch_dir)/1.0.15-pubkey-validation.diff && \
+  patch -p1 < $($(package)_patch_dir)/1.0.15-signature-validation.diff && \
   cd $($(package)_build_subdir); ./autogen.sh
 endef
 

diff --git a/depends/patches/libsodium/1.0.15-pubkey-validation.diff b/depends/patches/libsodium/1.0.15-pubkey-validation.diff
@@ -0,0 +1,17 @@
+diff -ur libsodium-1.0.18-orig/src/libsodium/crypto_sign/ed25519/ref10/open.c libsodium-1.0.18/src/libsodium/crypto_sign/ed25519/ref10/open.c
+--- libsodium-1.0.18-orig/src/libsodium/crypto_sign/ed25519/ref10/open.c	2019-05-18 16:32:11.000000000 -0400
++++ libsodium-1.0.18/src/libsodium/crypto_sign/ed25519/ref10/open.c	2020-01-21 18:55:22.474233831 -0500
+@@ -32,8 +32,11 @@
+         ge25519_has_small_order(sig) != 0) {
+         return -1;
+     }
+-    if (ge25519_is_canonical(pk) == 0 ||
+-        ge25519_has_small_order(pk) != 0) {
++    unsigned char d = 0;
++    for (int i = 0; i < 32; ++i) {
++        d |= pk[i];
++    }
++    if (d == 0) {
+         return -1;
+     }
+ #endif
diff --git a/depends/patches/libsodium/1.0.15-signature-validation.diff b/depends/patches/libsodium/1.0.15-signature-validation.diff
@@ -0,0 +1,78 @@
+diff -ur libsodium-1.0.18-orig/src/libsodium/crypto_sign/ed25519/ref10/open.c libsodium-1.0.18/src/libsodium/crypto_sign/ed25519/ref10/open.c
+--- libsodium-1.0.18-orig/src/libsodium/crypto_sign/ed25519/ref10/open.c	2019-05-18 21:32:11.000000000 +0100
++++ libsodium-1.0.18/src/libsodium/crypto_sign/ed25519/ref10/open.c	2020-02-18 00:00:08.544107613 +0000
+@@ -10,6 +10,65 @@
+ #include "private/ed25519_ref10.h"
+ #include "utils.h"
+
++#ifndef ED25519_COMPAT
++int
++_crypto_sign_ed25519_small_order(const unsigned char p[32])
++{
++    CRYPTO_ALIGN(16)
++    static const unsigned char blacklist[][32] = {
++        { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
++          0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
++          0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
++        { 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
++          0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
++          0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
++        { 0x26, 0xe8, 0x95, 0x8f, 0xc2, 0xb2, 0x27, 0xb0, 0x45, 0xc3, 0xf4,
++          0x89, 0xf2, 0xef, 0x98, 0xf0, 0xd5, 0xdf, 0xac, 0x05, 0xd3, 0xc6,
++          0x33, 0x39, 0xb1, 0x38, 0x02, 0x88, 0x6d, 0x53, 0xfc, 0x05 },
++        { 0xc7, 0x17, 0x6a, 0x70, 0x3d, 0x4d, 0xd8, 0x4f, 0xba, 0x3c, 0x0b,
++          0x76, 0x0d, 0x10, 0x67, 0x0f, 0x2a, 0x20, 0x53, 0xfa, 0x2c, 0x39,
++          0xcc, 0xc6, 0x4e, 0xc7, 0xfd, 0x77, 0x92, 0xac, 0x03, 0x7a },
++        { 0x13, 0xe8, 0x95, 0x8f, 0xc2, 0xb2, 0x27, 0xb0, 0x45, 0xc3, 0xf4,
++          0x89, 0xf2, 0xef, 0x98, 0xf0, 0xd5, 0xdf, 0xac, 0x05, 0xd3, 0xc6,
++          0x33, 0x39, 0xb1, 0x38, 0x02, 0x88, 0x6d, 0x53, 0xfc, 0x85 },
++        { 0xb4, 0x17, 0x6a, 0x70, 0x3d, 0x4d, 0xd8, 0x4f, 0xba, 0x3c, 0x0b,
++          0x76, 0x0d, 0x10, 0x67, 0x0f, 0x2a, 0x20, 0x53, 0xfa, 0x2c, 0x39,
++          0xcc, 0xc6, 0x4e, 0xc7, 0xfd, 0x77, 0x92, 0xac, 0x03, 0xfa },
++        { 0xec, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
++          0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
++          0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x7f },
++        { 0xed, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
++          0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
++          0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x7f },
++        { 0xee, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
++          0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
++          0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x7f },
++        { 0xd9, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
++          0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
++          0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff },
++        { 0xda, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
++          0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
++          0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff },
++        { 0xdb, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
++          0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
++          0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }
++    };
++    size_t        i, j;
++    unsigned char c;
++
++    for (i = 0; i < sizeof blacklist / sizeof blacklist[0]; i++) {
++        c = 0;
++        for (j = 0; j < 32; j++) {
++            c |= p[j] ^ blacklist[i][j];
++        }
++        if (c == 0) {
++            return 1;
++        }
++    }
++    return 0;
++}
++#endif
++
+ int
+ _crypto_sign_ed25519_verify_detached(const unsigned char *sig,
+                                      const unsigned char *m,
+@@ -29,7 +88,7 @@
+     }
+ #else
+     if (sc25519_is_canonical(sig + 32) == 0 ||
+-        ge25519_has_small_order(sig) != 0) {
++        _crypto_sign_ed25519_small_order(sig) != 0) {
+         return -1;
+     }
+     if (ge25519_is_canonical(pk) == 0 ||
diff --git a/src/Makefile.gtest.include b/src/Makefile.gtest.include
@@ -12,6 +12,7 @@ zcash_gtest_SOURCES = \
 	gtest/main.cpp \
 	gtest/utils.cpp \
 	gtest/test_checktransaction.cpp \
+	gtest/test_consensus.cpp \
 	gtest/json_test_vectors.cpp \
 	gtest/json_test_vectors.h \
 	gtest/test_foundersreward.cpp

diff --git a/src/gtest/test_consensus.cpp b/src/gtest/test_consensus.cpp
@@ -0,0 +1,69 @@
+#include <gtest/gtest.h>
+#include <sodium.h>
+
+#include "uint256.h"
+#include "utilstrencodings.h"
+
+void TestLibsodiumEd25519SignatureVerification(
+    const std::string &scope,
+    const std::string &msg,
+    std::vector<unsigned char> pubkey,
+    std::vector<unsigned char> sig)
+{
+    SCOPED_TRACE(scope);
+
+    EXPECT_EQ(
+        crypto_sign_verify_detached(
+            sig.data(),
+            (const unsigned char*)msg.data(), msg.size(),
+            pubkey.data()),
+        0);
+}
+
+TEST(ConsensusTests, LibsodiumPubkeyValidation) {
+    // libsodium <= 1.0.15 accepts valid signatures for a non-zero pubkey with
+    // small order; this is currently part of our consensus rules.
+    // libsodium >= 1.0.16 rejects all pubkeys with small order.
+    //
+    // These test vectors were generated by finding pairs of points (A, P) both
+    // in the eight-torsion subgroup such that R = B + P and R = [1] B - [k] A
+    // (where SHA512(bytes(R) || bytes(A) || message) represents k in
+    // little-endian order, as in Ed25519).
+    TestLibsodiumEd25519SignatureVerification(
+        "Test vector 1",
+        "zcash ed25519 libsodium compatibility",
+        ParseHex("0100000000000000000000000000000000000000000000000000000000000000"),
+        ParseHex("58666666666666666666666666666666666666666666666666666666666666660100000000000000000000000000000000000000000000000000000000000000"));
+    TestLibsodiumEd25519SignatureVerification(
+        "Test vector 2",
+        "zcash ed25519 libsodium compatibility",
+        ParseHex("0000000000000000000000000000000000000000000000000000000000000080"),
+        ParseHex("58666666666666666666666666666666666666666666666666666666666666660100000000000000000000000000000000000000000000000000000000000000"));
+    TestLibsodiumEd25519SignatureVerification(
+        "Test vector 3",
+        "zcash ed25519 libsodium compatibility",
+        ParseHex("26e8958fc2b227b045c3f489f2ef98f0d5dfac05d3c63339b13802886d53fc85"),
+        ParseHex("da99e28ba529cdde35a25fba9059e78ecaee239f99755b9b1aa4f65df00803e20100000000000000000000000000000000000000000000000000000000000000"));
+    TestLibsodiumEd25519SignatureVerification(
+        "Test vector 4",
+        "zcash ed25519 libsodium compatibility",
+        ParseHex("c7176a703d4dd84fba3c0b760d10670f2a2053fa2c39ccc64ec7fd7792ac037a"),
+        ParseHex("95999999999999999999999999999999999999999999999999999999999999990100000000000000000000000000000000000000000000000000000000000000"));
+    TestLibsodiumEd25519SignatureVerification(
+        "Test vector 5",
+        "zcash ed25519 libsodium compatibility",
+        ParseHex("26e8958fc2b227b045c3f489f2ef98f0d5dfac05d3c63339b13802886d53fc85"),
+        ParseHex("13661d745ad63221ca5da0456fa618713511dc60668aa464e55b09a20ff7fc1d0100000000000000000000000000000000000000000000000000000000000000"));
+
+    // libsodium <= 1.0.15 contains a blocklist of small-order points that R is
+    // checked against. However, it does not contain all canonical small-order
+    // points; in particular, it is missing the negative of one of the points.
+    //
+    // This test case is the only pair of points (A, R) both in the eight-torsion
+    // subgroup, that satisfies R = [0] B - [k] A and also evades the blocklist.
+    TestLibsodiumEd25519SignatureVerification(
+        "Small order R that is not rejected by libsodium <= 1.0.15",
+        "zcash ed25519 libsodium compatibility",
+        ParseHex("c7176a703d4dd84fba3c0b760d10670f2a2053fa2c39ccc64ec7fd7792ac037a"),
+        ParseHex("26e8958fc2b227b045c3f489f2ef98f0d5dfac05d3c63339b13802886d53fc850000000000000000000000000000000000000000000000000000000000000000"));
+}