From d4ee08ab8a1c674203796161af6d013283b33d69 Mon Sep 17 00:00:00 2001
From: Frank Denis <github@pureftpd.org>
Date: Mon, 7 Mar 2022 16:38:37 +0100
Subject: [PATCH] Add memory fences where supported

---
 src/libsodium/crypto_hash/sha256/cp/hash_sha256_cp.c        | 2 ++
 src/libsodium/crypto_hash/sha512/cp/hash_sha512_cp.c        | 2 ++
 .../scryptsalsa208sha256/pwhash_scryptsalsa208sha256.c      | 1 +
 src/libsodium/crypto_sign/ed25519/ref10/open.c              | 2 ++
 src/libsodium/include/sodium/private/common.h               | 6 ++++++
 src/libsodium/sodium/codecs.c                               | 2 ++
 6 files changed, 15 insertions(+)

diff --git a/src/libsodium/crypto_hash/sha256/cp/hash_sha256_cp.c b/src/libsodium/crypto_hash/sha256/cp/hash_sha256_cp.c
index 264054f9..394c3914 100644
--- a/src/libsodium/crypto_hash/sha256/cp/hash_sha256_cp.c
+++ b/src/libsodium/crypto_hash/sha256/cp/hash_sha256_cp.c
@@ -156,6 +156,7 @@ SHA256_Pad(crypto_hash_sha256_state *state, uint32_t tmp32[64 + 8])
     unsigned int r;
     unsigned int i;
 
+    ACQUIRE_FENCE;
     r = (unsigned int) ((state->count >> 3) & 0x3f);
     if (r < 56) {
         for (i = 0; i < 56 - r; i++) {
@@ -197,6 +198,7 @@ crypto_hash_sha256_update(crypto_hash_sha256_state *state,
     if (inlen <= 0U) {
         return 0;
     }
+    ACQUIRE_FENCE;
     r = (unsigned long long) ((state->count >> 3) & 0x3f);
 
     state->count += ((uint64_t) inlen) << 3;
diff --git a/src/libsodium/crypto_hash/sha512/cp/hash_sha512_cp.c b/src/libsodium/crypto_hash/sha512/cp/hash_sha512_cp.c
index 8e0f36fb..a36841b9 100644
--- a/src/libsodium/crypto_hash/sha512/cp/hash_sha512_cp.c
+++ b/src/libsodium/crypto_hash/sha512/cp/hash_sha512_cp.c
@@ -175,6 +175,7 @@ SHA512_Pad(crypto_hash_sha512_state *state, uint64_t tmp64[80 + 8])
     unsigned int r;
     unsigned int i;
 
+    ACQUIRE_FENCE;
     r = (unsigned int) ((state->count[1] >> 3) & 0x7f);
     if (r < 112) {
         for (i = 0; i < 112 - r; i++) {
@@ -218,6 +219,7 @@ crypto_hash_sha512_update(crypto_hash_sha512_state *state,
     if (inlen <= 0U) {
         return 0;
     }
+    ACQUIRE_FENCE;
     r = (unsigned long long) ((state->count[1] >> 3) & 0x7f);
 
     bitlen[1] = ((uint64_t) inlen) << 3;
diff --git a/src/libsodium/crypto_pwhash/scryptsalsa208sha256/pwhash_scryptsalsa208sha256.c b/src/libsodium/crypto_pwhash/scryptsalsa208sha256/pwhash_scryptsalsa208sha256.c
index 4378b22d..fdf0836b 100644
--- a/src/libsodium/crypto_pwhash/scryptsalsa208sha256/pwhash_scryptsalsa208sha256.c
+++ b/src/libsodium/crypto_pwhash/scryptsalsa208sha256/pwhash_scryptsalsa208sha256.c
@@ -57,6 +57,7 @@ sodium_strnlen(const char *str, size_t maxlen)
 {
     size_t i = 0U;
 
+    ACQUIRE_FENCE;
     while (i < maxlen && str[i] != 0) {
         i++;
     }
diff --git a/src/libsodium/crypto_sign/ed25519/ref10/open.c b/src/libsodium/crypto_sign/ed25519/ref10/open.c
index 3631edaf..0ee7547c 100644
--- a/src/libsodium/crypto_sign/ed25519/ref10/open.c
+++ b/src/libsodium/crypto_sign/ed25519/ref10/open.c
@@ -7,6 +7,7 @@
 #include "crypto_sign_ed25519.h"
 #include "crypto_verify_32.h"
 #include "sign_ed25519_ref10.h"
+#include "private/common.h"
 #include "private/ed25519_ref10.h"
 #include "utils.h"
 
@@ -23,6 +24,7 @@ _crypto_sign_ed25519_verify_detached(const unsigned char *sig,
     ge25519_p3               A;
     ge25519_p2               R;
 
+    ACQUIRE_FENCE;
 #ifdef ED25519_COMPAT
     if (sig[63] & 224) {
         return -1;
diff --git a/src/libsodium/include/sodium/private/common.h b/src/libsodium/include/sodium/private/common.h
index 2ea7a1b2..7d86b96a 100644
--- a/src/libsodium/include/sodium/private/common.h
+++ b/src/libsodium/include/sodium/private/common.h
@@ -260,4 +260,10 @@ extern void ct_unpoison(const void *, size_t);
 # define UNPOISON(X, L) (void) 0
 #endif
 
+#ifdef __ATOMIC_ACQUIRE
+# define ACQUIRE_FENCE __atomic_thread_fence(__ATOMIC_ACQUIRE)
+#else
+# define ACQUIRE_FENCE (void) 0
+#endif
+
 #endif
diff --git a/src/libsodium/sodium/codecs.c b/src/libsodium/sodium/codecs.c
index 77fa464c..36508089 100644
--- a/src/libsodium/sodium/codecs.c
+++ b/src/libsodium/sodium/codecs.c
@@ -7,6 +7,7 @@
 #include <string.h>
 
 #include "core.h"
+#include "private/common.h"
 #include "utils.h"
 
 /* Derived from original code by CodesInChaos */
@@ -250,6 +251,7 @@ _sodium_base642bin_skip_padding(const char * const b64, const size_t b64_len,
             errno = ERANGE;
             return -1;
         }
+        ACQUIRE_FENCE;
         c = b64[*b64_pos_p];
         if (c == '=') {
             padding_len--;