Add crypto callback only mode for curve25519

.github/workflows/cryptocb-only.yml

@@ -1,3 +1,3 @@
 name: cryptocb-only Tests
 
 # START OF COMMON SECTION
@@ -111,9 +111,12 @@
           {"name": "ed25519-no-curve25519",
            "comment": "Same as ed25519 but with curve25519 off. curve25519 is the only other user of the ge/fe math, so without it the strip is complete and nothing must pull the math back in. The ed25519 entry above keeps curve25519 enabled, which leaves fe_operations.c compiled and would hide such a regression at link time.",
            "configure": ["--disable-curve25519", "CPPFLAGS=-DWOLF_CRYPTO_CB_ONLY_ED25519"]},
+          {"name": "curve25519",
+           "comment": "WOLF_CRYPTO_CB_ONLY_CURVE25519: strips software X25519 (keygen/shared-secret); swdev provides the software path via cryptocb. Nonblock and async X25519 have no callback path and are left disabled.",
+           "configure": ["CPPFLAGS=-DWOLF_CRYPTO_CB_ONLY_CURVE25519"]},
           {"name": "all",
-           "comment": "All six ONLY_* macros at once: every supported software primitive is stripped and dispatched through cryptocb. Catches any cross-algorithm call that a single-strip entry would still resolve via the remaining software paths.",
-           "configure": ["CPPFLAGS=-DWOLF_CRYPTO_CB_ONLY_ECC -DWOLF_CRYPTO_CB_ONLY_RSA -DWOLF_CRYPTO_CB_ONLY_SHA256 -DWOLF_CRYPTO_CB_ONLY_SHA512 -DWOLF_CRYPTO_CB_ONLY_AES -DWOLF_CRYPTO_CB_ONLY_ED25519"]}
+           "comment": "All seven ONLY_* macros at once: every supported software primitive is stripped and dispatched through cryptocb. Catches any cross-algorithm call that a single-strip entry would still resolve via the remaining software paths.",
+           "configure": ["CPPFLAGS=-DWOLF_CRYPTO_CB_ONLY_ECC -DWOLF_CRYPTO_CB_ONLY_RSA -DWOLF_CRYPTO_CB_ONLY_SHA256 -DWOLF_CRYPTO_CB_ONLY_SHA512 -DWOLF_CRYPTO_CB_ONLY_AES -DWOLF_CRYPTO_CB_ONLY_ED25519 -DWOLF_CRYPTO_CB_ONLY_CURVE25519"]}
           ]}
           EOF
           .github/scripts/parallel-make-check.py \

tests/api.c

@@ -30160,7 +30160,8 @@ static int test_SSL_CIPHER_get_current_kx(void)
     (!defined(WOLF_CRYPTO_CB_ONLY_SHA256) && !defined(WOLF_CRYPTO_CB_ONLY_AES) && \
      !defined(WOLF_CRYPTO_CB_ONLY_ECC) && !defined(WOLF_CRYPTO_CB_ONLY_RSA) && \
      !defined(WOLF_CRYPTO_CB_ONLY_SHA512) && \
-     !defined(WOLF_CRYPTO_CB_ONLY_ED25519))
+     !defined(WOLF_CRYPTO_CB_ONLY_ED25519) && \
+     !defined(WOLF_CRYPTO_CB_ONLY_CURVE25519))
 
 static int load_pem_key_file_as_der(const char* privKeyFile, DerBuffer** pDer,
     int* keyFormat)
@@ -31265,7 +31266,8 @@ static int test_wc_CryptoCb(void)
     (!defined(WOLF_CRYPTO_CB_ONLY_SHA256) && !defined(WOLF_CRYPTO_CB_ONLY_AES) && \
      !defined(WOLF_CRYPTO_CB_ONLY_ECC) && !defined(WOLF_CRYPTO_CB_ONLY_RSA) && \
      !defined(WOLF_CRYPTO_CB_ONLY_SHA512) && \
-     !defined(WOLF_CRYPTO_CB_ONLY_ED25519))
+     !defined(WOLF_CRYPTO_CB_ONLY_ED25519) && \
+     !defined(WOLF_CRYPTO_CB_ONLY_CURVE25519))
 #if defined(HAVE_IO_TESTS_DEPENDENCIES) && \
     (!defined(NO_RSA) || defined(HAVE_ECC) || defined(HAVE_ED25519))
     int tlsVer;
@@ -37640,15 +37642,13 @@ TEST_CASE testCases[] = {
     /* Can't memory test as client/server Asserts in thread. */
     TEST_DECL(test_prioritize_psk),
 
-    /* test_wc_CryptoCb_registry is defined only inside the
-     * WOLF_CRYPTO_CB + HAVE_IO_TESTS_DEPENDENCIES block below; register it under
-     * the same condition so it is neither undeclared (when absent) nor
-     * defined-but-unused. */
+    /* Must match the guard on the definition of test_wc_CryptoCb_registry. */
 #if defined(WOLF_CRYPTO_CB) && defined(HAVE_IO_TESTS_DEPENDENCIES) && \
     (!defined(WOLF_CRYPTO_CB_ONLY_SHA256) && !defined(WOLF_CRYPTO_CB_ONLY_AES) && \
      !defined(WOLF_CRYPTO_CB_ONLY_ECC) && !defined(WOLF_CRYPTO_CB_ONLY_RSA) && \
      !defined(WOLF_CRYPTO_CB_ONLY_SHA512) && \
-     !defined(WOLF_CRYPTO_CB_ONLY_ED25519))
+     !defined(WOLF_CRYPTO_CB_ONLY_ED25519) && \
+     !defined(WOLF_CRYPTO_CB_ONLY_CURVE25519))
     /* Can't memory test as client/server hangs. */
     TEST_DECL(test_wc_CryptoCb_registry),
 #endif

tests/swdev/README.md

@@ -16,6 +16,7 @@ The switches it supports are:
 | `WOLF_CRYPTO_CB_ONLY_SHA512`   | software SHA-512 | SHA-512 via CryptoCb |
 | `WOLF_CRYPTO_CB_ONLY_AES`      | software AES   | AES via CryptoCb   |
 | `WOLF_CRYPTO_CB_ONLY_ED25519`  | software Ed25519 | Ed25519 via CryptoCb |
+| `WOLF_CRYPTO_CB_ONLY_CURVE25519` | software X25519 | X25519 via CryptoCb |
 
 When a test program calls e.g. `wc_AesCbcEncrypt()` against a libwolfssl
 built with `-DWOLF_CRYPTO_CB_ONLY_AES`, the software AES path is gone;
@@ -57,7 +58,7 @@ internal copy of the AES code, and returns the result.
    |   wc_SwDev_Callback(devId, info, ctx)                     |
    |     - swdev_ensure_init() lazy wolfCrypt_Init             |
    |     - switch (info->algo_type):                           |
-   |         PK     -> RSA / ECC / Ed25519 software impl       |
+   |         PK     -> RSA/ECC/Ed25519/X25519 software impl    |
    |         HASH   -> SHA-256 software impl                   |
    |         CIPHER -> AES (CBC/CTR/ECB/GCM/CCM) software impl |
    |                                                           |
@@ -72,7 +73,8 @@ internal copy of the AES code, and returns the result.
 The whole mechanism rests on compiling the wolfcrypt sources twice:
 
 1. **libwolfssl** is built normally with the user's `_ONLY_*` flags
-   set, so its software RSA/ECC/SHA-256/SHA-512/AES/Ed25519 paths are gone.
+   set, so its software RSA/ECC/SHA-256/SHA-512/AES/Ed25519/X25519 paths
+   are gone.
 2. **swdev** recompiles the same source set under
    `tests/swdev/user_settings.h`, which `#undef`s every `_ONLY_*`
    macro. swdev therefore contains the full software implementations.

tests/swdev/swdev.c

@@ -43,6 +43,9 @@
 #ifdef HAVE_ED25519
 #include <wolfssl/wolfcrypt/ed25519.h>
 #endif
+#ifdef HAVE_CURVE25519
+#include <wolfssl/wolfcrypt/curve25519.h>
+#endif
 
 static int swdev_initialized = 0;
 
@@ -318,6 +321,23 @@ static int swdev_ed25519_check_key(wc_CryptoInfo* info)
 }
 #endif /* HAVE_ED25519 */
 
+#ifdef HAVE_CURVE25519
+static int swdev_curve25519_keygen(wc_CryptoInfo* info)
+{
+    return wc_curve25519_make_key(info->pk.curve25519kg.rng,
+        info->pk.curve25519kg.size, info->pk.curve25519kg.key);
+}
+
+#ifdef HAVE_CURVE25519_SHARED_SECRET
+static int swdev_curve25519(wc_CryptoInfo* info)
+{
+    return wc_curve25519_shared_secret_ex(info->pk.curve25519.private_key,
+        info->pk.curve25519.public_key, info->pk.curve25519.out,
+        info->pk.curve25519.outlen, info->pk.curve25519.endian);
+}
+#endif /* HAVE_CURVE25519_SHARED_SECRET */
+#endif /* HAVE_CURVE25519 */
+
 #ifndef NO_SHA256
 /* Copy hash state between caller's wc_Sha256 and swdev's shadow, leaving
  * admin fields (heap, devId, devCtx, W, async, HW ctx) per-side. */
@@ -913,7 +933,8 @@ WC_SWDEV_EXPORT int wc_SwDev_Callback(int devId, wc_CryptoInfo* info,
         return ret;
 
     switch (info->algo_type) {
-#if !defined(NO_RSA) || defined(HAVE_ECC) || defined(HAVE_ED25519)
+#if !defined(NO_RSA) || defined(HAVE_ECC) || defined(HAVE_ED25519) || \
+    defined(HAVE_CURVE25519)
     case WC_ALGO_TYPE_PK:
         switch (info->pk.type) {
     #ifndef NO_RSA
@@ -964,6 +985,14 @@ WC_SWDEV_EXPORT int wc_SwDev_Callback(int devId, wc_CryptoInfo* info,
         case WC_PK_TYPE_ED25519_CHECK_KEY:
             return swdev_ed25519_check_key(info);
     #endif /* HAVE_ED25519 */
+    #ifdef HAVE_CURVE25519
+        case WC_PK_TYPE_CURVE25519_KEYGEN:
+            return swdev_curve25519_keygen(info);
+        #ifdef HAVE_CURVE25519_SHARED_SECRET
+        case WC_PK_TYPE_CURVE25519:
+            return swdev_curve25519(info);
+        #endif
+    #endif /* HAVE_CURVE25519 */
         default:
             return CRYPTOCB_UNAVAILABLE;
         }

tests/swdev/user_settings.h

@@ -28,6 +28,7 @@
 #undef WOLF_CRYPTO_CB_ONLY_SHA512
 #undef WOLF_CRYPTO_CB_ONLY_AES
 #undef WOLF_CRYPTO_CB_ONLY_ED25519
+#undef WOLF_CRYPTO_CB_ONLY_CURVE25519
 
 #ifndef WOLF_CRYPTO_CB
     #error "wc_swdev requires the main build to define WOLF_CRYPTO_CB"

wolfcrypt/src/cryptocb.c

@@ -65,6 +65,7 @@ Crypto Callback Build Options:
  * WOLF_CRYPTO_CB_ONLY_SHA512: Use only callbacks for SHA-512   default: off
  * WOLF_CRYPTO_CB_ONLY_AES: Use only callbacks for AES          default: off
  * WOLF_CRYPTO_CB_ONLY_ED25519: Use only callbacks for Ed25519  default: off
+ * WOLF_CRYPTO_CB_ONLY_CURVE25519: Use only callbacks for X25519 default: off
  */
 
 #include <wolfssl/wolfcrypt/libwolfssl_sources.h>

wolfcrypt/src/curve25519.c

@@ -563,14 +563,21 @@ int wc_curve25519_make_key(WC_RNG* rng, int keysize, curve25519_key* key)
         return BAD_FUNC_ARG;
 
 #ifdef WOLF_CRYPTO_CB
-    if (key->devId != INVALID_DEVID) {
+    #ifndef WOLF_CRYPTO_CB_FIND
+    if (key->devId != INVALID_DEVID)
+    #endif
+    {
         ret = wc_CryptoCb_Curve25519Gen(rng, keysize, key);
         if (ret != WC_NO_ERR_TRACE(CRYPTOCB_UNAVAILABLE))
             return ret;
         /* fall-through when unavailable */
     }
 #endif
 
+#ifdef WOLF_CRYPTO_CB_ONLY_CURVE25519
+    /* software path stripped; callback is the only provider */
+    return NO_VALID_DEVID;
+#else
 #if defined(WOLFSSL_ASYNC_CRYPT) && defined(WC_ASYNC_ENABLE_X25519) && \
     defined(WOLFSSL_ASYNC_CRYPT_SW)
     if (key->asyncDev.marker == WOLFSSL_ASYNC_MARKER_X25519) {
@@ -614,6 +621,7 @@ int wc_curve25519_make_key(WC_RNG* rng, int keysize, curve25519_key* key)
 #endif /* !WOLFSSL_SE050 */
 
     return ret;
+#endif /* WOLF_CRYPTO_CB_ONLY_CURVE25519 */
 }
 
 #ifdef HAVE_CURVE25519_SHARED_SECRET
@@ -720,7 +728,10 @@ int wc_curve25519_shared_secret_ex(curve25519_key* private_key,
 #endif
 
 #ifdef WOLF_CRYPTO_CB
-    if (private_key->devId != INVALID_DEVID) {
+    #ifndef WOLF_CRYPTO_CB_FIND
+    if (private_key->devId != INVALID_DEVID)
+    #endif
+    {
         ret = wc_CryptoCb_Curve25519(private_key, public_key, out, outlen,
             endian);
         if (ret != WC_NO_ERR_TRACE(CRYPTOCB_UNAVAILABLE))
@@ -729,6 +740,10 @@ int wc_curve25519_shared_secret_ex(curve25519_key* private_key,
     }
 #endif
 
+#ifdef WOLF_CRYPTO_CB_ONLY_CURVE25519
+    /* software path stripped; callback is the only provider */
+    return NO_VALID_DEVID;
+#else
 #ifdef WC_X25519_NONBLOCK
 
 #if defined(WOLFSSL_ASYNC_CRYPT) && defined(WC_ASYNC_ENABLE_X25519) && \
@@ -814,6 +829,7 @@ int wc_curve25519_shared_secret_ex(curve25519_key* private_key,
     }
 
     return ret;
+#endif /* WOLF_CRYPTO_CB_ONLY_CURVE25519 */
 }
 
 #endif /* HAVE_CURVE25519_SHARED_SECRET */

wolfcrypt/test/test.c

@@ -3157,7 +3157,8 @@ options: [-s max_relative_stack_bytes] [-m max_relative_heap_memory_bytes]\n\
         TEST_PASS("FLATTEN ALT NAMES test passed!\n");
 #endif
 
-#ifdef HAVE_CURVE25519
+#if defined(HAVE_CURVE25519) && \
+    (!defined(WOLF_CRYPTO_CB_ONLY_CURVE25519) || defined(WOLFSSL_SWDEV))
     if ( (ret = curve25519_test()) != 0)
         TEST_FAIL("CURVE25519 test failed!\n", ret);
     else
@@ -76148,6 +76149,88 @@ static wc_test_ret_t ed25519_onlycb_test(myCryptoDevCtx *ctx)
 }
 #endif /* WOLF_CRYPTO_CB_ONLY_ED25519 */
 
+#ifdef WOLF_CRYPTO_CB_ONLY_CURVE25519
+/* Exercise Curve25519 dispatch under CB_ONLY_CURVE25519: cb-handled then
+ * cb-delegated. */
+static wc_test_ret_t curve25519_onlycb_test(myCryptoDevCtx *ctx)
+{
+    wc_test_ret_t ret = 0;
+    curve25519_key key;
+#if defined(HAVE_CURVE25519_SHARED_SECRET) && \
+    defined(HAVE_CURVE25519_KEY_IMPORT)
+    curve25519_key pubKey;
+    const byte priv[CURVE25519_KEYSIZE] = {1};
+    const byte pub[CURVE25519_KEYSIZE] = {9};
+    byte out[CURVE25519_KEYSIZE];
+    word32 outLen = (word32)sizeof(out);
+#endif
+    WC_RNG rng;
+
+    ret = wc_curve25519_init_ex(&key, HEAP_HINT, devId);
+    if (ret != 0)
+        return WC_TEST_RET_ENC_EC(ret);
+
+    ret = wc_InitRng(&rng);
+    if (ret != 0) {
+        wc_curve25519_free(&key);
+        return WC_TEST_RET_ENC_EC(ret);
+    }
+
+    /* cb handles the op, expects 0(success) */
+    ctx->exampleVar = 99;
+    ret = wc_curve25519_make_key(&rng, CURVE25519_KEYSIZE, &key);
+    if (ret != 0)
+        ERROR_OUT(WC_TEST_RET_ENC_EC(ret), exit_onlycb);
+
+    /* cb delegates to software, expects NO_VALID_DEVID(failure) */
+    ctx->exampleVar = 1;
+    ret = wc_curve25519_make_key(&rng, CURVE25519_KEYSIZE, &key);
+    if (ret != WC_NO_ERR_TRACE(NO_VALID_DEVID)) {
+        ERROR_OUT(WC_TEST_RET_ENC_EC(ret), exit_onlycb);
+    } else {
+        ret = 0;
+    }
+
+#if defined(HAVE_CURVE25519_SHARED_SECRET) && \
+    defined(HAVE_CURVE25519_KEY_IMPORT)
+    ret = wc_curve25519_init_ex(&pubKey, HEAP_HINT, devId);
+    if (ret != 0)
+        ERROR_OUT(WC_TEST_RET_ENC_EC(ret), exit_onlycb);
+
+    ret = wc_curve25519_import_private(priv, sizeof(priv), &key);
+    if (ret != 0)
+        ERROR_OUT(WC_TEST_RET_ENC_EC(ret), exit_onlycb_pub);
+    ret = wc_curve25519_import_public(pub, sizeof(pub), &pubKey);
+    if (ret != 0)
+        ERROR_OUT(WC_TEST_RET_ENC_EC(ret), exit_onlycb_pub);
+
+    /* cb handles the op, expects 0(success) */
+    ctx->exampleVar = 99;
+    ret = wc_curve25519_shared_secret(&key, &pubKey, out, &outLen);
+    if (ret != 0)
+        ERROR_OUT(WC_TEST_RET_ENC_EC(ret), exit_onlycb_pub);
+
+    /* cb delegates to software, expects NO_VALID_DEVID(failure) */
+    ctx->exampleVar = 1;
+    ret = wc_curve25519_shared_secret(&key, &pubKey, out, &outLen);
+    if (ret != WC_NO_ERR_TRACE(NO_VALID_DEVID)) {
+        ERROR_OUT(WC_TEST_RET_ENC_EC(ret), exit_onlycb_pub);
+    } else {
+        ret = 0;
+    }
+
+exit_onlycb_pub:
+    wc_curve25519_free(&pubKey);
+#endif /* HAVE_CURVE25519_SHARED_SECRET && HAVE_CURVE25519_KEY_IMPORT */
+
+exit_onlycb:
+    wc_FreeRng(&rng);
+    wc_curve25519_free(&key);
+    (void)ctx;
+    return ret;
+}
+#endif /* WOLF_CRYPTO_CB_ONLY_CURVE25519 */
+
 #if defined(HAVE_ECC) && !defined(WOLFSSL_NO_MALLOC) && \
     defined(HAVE_ECC_KEY_EXPORT)
 /* Serialize pub to X9.63 uncompressed (0x04 || X || Y) using the curve size
@@ -76543,6 +76626,15 @@ static int myCryptoDevCb(int devIdArg, wc_CryptoInfo* info, void* ctx)
         if (info->pk.type == WC_PK_TYPE_CURVE25519_KEYGEN) {
             /* set devId to invalid, so software is used */
             info->pk.curve25519kg.key->devId = INVALID_DEVID;
+            #if defined(WOLF_CRYPTO_CB_ONLY_CURVE25519)
+            #ifdef DEBUG_WOLFSSL
+            printf("CryptoDevCb: exampleVar %d\n", myCtx->exampleVar);
+            #endif
+            if (myCtx->exampleVar == 99) {
+                info->pk.curve25519kg.key->devId = devIdArg;
+                return 0;
+            }
+            #endif
 
             ret = wc_curve25519_make_key(info->pk.curve25519kg.rng,
                 info->pk.curve25519kg.size, info->pk.curve25519kg.key);
@@ -76553,6 +76645,15 @@ static int myCryptoDevCb(int devIdArg, wc_CryptoInfo* info, void* ctx)
         else if (info->pk.type == WC_PK_TYPE_CURVE25519) {
             /* set devId to invalid, so software is used */
             info->pk.curve25519.private_key->devId = INVALID_DEVID;
+            #if defined(WOLF_CRYPTO_CB_ONLY_CURVE25519)
+            #ifdef DEBUG_WOLFSSL
+            printf("CryptoDevCb: exampleVar %d\n", myCtx->exampleVar);
+            #endif
+            if (myCtx->exampleVar == 99) {
+                info->pk.curve25519.private_key->devId = devIdArg;
+                return 0;
+            }
+            #endif
 
             ret = wc_curve25519_shared_secret_ex(
                 info->pk.curve25519.private_key, info->pk.curve25519.public_key,
@@ -78860,10 +78961,17 @@ WOLFSSL_TEST_SUBROUTINE wc_test_ret_t cryptocb_test(void)
         ret = ed25519_onlycb_test(&myCtx);
     PRIVATE_KEY_LOCK();
 #endif
-#ifdef HAVE_CURVE25519
+#if defined(HAVE_CURVE25519) && \
+    (!defined(WOLF_CRYPTO_CB_ONLY_CURVE25519) || defined(WOLFSSL_SWDEV))
     if (ret == 0)
         ret = curve25519_test();
 #endif
+#if defined(WOLF_CRYPTO_CB_ONLY_CURVE25519) && !defined(WOLFSSL_SWDEV)
+    PRIVATE_KEY_UNLOCK();
+    if (ret == 0)
+        ret = curve25519_onlycb_test(&myCtx);
+    PRIVATE_KEY_LOCK();
+#endif
 #if !defined(NO_AES) && !defined(WOLF_CRYPTO_CB_ONLY_AES)
     /* CB_ONLY_AES skips these (aes_onlycb_test covers that path). */
     #ifdef HAVE_AESGCM

wolfssl/wolfcrypt/fe_operations.h

@@ -63,14 +63,15 @@
     #define CURVED25519_ASM
 #endif
 
-/* curve25519 shares the ed25519 field math, and borrows the group math
- * on some builds.
- * For WOLF_CRYPTO_CB_ONLY_ED25519 to strip the fe/ge modules, ensure that
- * curve25519 is disabled. */
+/* curve25519 always uses its own field math, but on some builds it borrows
+ * ed25519's group math via WOLFSSL_CURVE25519_USE_ED25519 below. Under
+ * WOLF_CRYPTO_CB_ONLY_ED25519 ed25519's group math is removed. */
 #if (defined(CURVED25519_ASM_64BIT) || defined(HAVE_ED25519)) && \
         !defined(WOLFSSL_CURVE25519_BLINDING) && \
         !defined(WOLFSSL_CURVE25519_NOT_USE_ED25519) && \
-        (!defined(WOLF_CRYPTO_CB_ONLY_ED25519) || defined(HAVE_CURVE25519))
+        (!defined(WOLF_CRYPTO_CB_ONLY_ED25519) || \
+         (defined(HAVE_CURVE25519) && \
+          !defined(WOLF_CRYPTO_CB_ONLY_CURVE25519)))
     #undef  WOLFSSL_CURVE25519_USE_ED25519
     #define WOLFSSL_CURVE25519_USE_ED25519
 #endif