backport from 20251222-linuxkm-PK-initrng-optimize: wolfcrypt/src/rsa.c and wolfssl/wolfcrypt/rsa.h: make RsaKey.rng and wc_RsaSetRNG() available unconditionally, rather than only if WC_RSA_BLINDING, for use by wc_CheckRsaKey().

Author: douzzer

wolfcrypt/src/rsa.c

@@ -677,25 +677,37 @@ int wc_CheckRsaKey(RsaKey* key)
 #endif
 #ifdef WOLFSSL_SMALL_STACK
     mp_int *tmp = NULL;
-    WC_RNG *rng = NULL;
 #else
     mp_int tmp[1];
-    WC_RNG rng[1];
+#endif
+    WC_RNG *rng = NULL;
+#if !defined(WOLFSSL_SMALL_STACK) || defined(WOLFSSL_NO_MALLOC)
+    WC_RNG rng_buf;
 #endif
     int ret = 0;
 
+    if (key == NULL)
+        return BAD_FUNC_ARG;
+
 #ifdef WOLFSSL_SMALL_STACK
-    rng = (WC_RNG*)XMALLOC(sizeof(WC_RNG), NULL, DYNAMIC_TYPE_RNG);
-    if (rng != NULL)
-        tmp = (mp_int*)XMALLOC(sizeof(mp_int), NULL, DYNAMIC_TYPE_RSA);
-    if (rng == NULL || tmp == NULL) {
-        XFREE(rng, NULL, DYNAMIC_TYPE_RNG);
-        XFREE(tmp, NULL, DYNAMIC_TYPE_RSA);
+    tmp = (mp_int*)XMALLOC(sizeof(mp_int), NULL, DYNAMIC_TYPE_RSA);
+    if (tmp == NULL) {
         return MEMORY_E;
     }
 #endif
 
-    ret = wc_InitRng(rng);
+    if (key->rng)
+        rng = key->rng;
+    else {
+#if !defined(WOLFSSL_SMALL_STACK) || defined(WOLFSSL_NO_MALLOC)
+        rng = &rng_buf;
+#else
+        rng = (WC_RNG *)XMALLOC(sizeof(*rng), NULL, DYNAMIC_TYPE_RNG);
+        if (rng == NULL)
+            return MEMORY_E;
+#endif
+        ret = wc_InitRng(rng);
+    }
 
     if (ret == 0)
         SAVE_VECTOR_REGISTERS(ret = _svr_ret;);
@@ -705,11 +717,6 @@ int wc_CheckRsaKey(RsaKey* key)
             ret = MP_INIT_E;
     }
 
-    if (ret == 0) {
-        if (key == NULL)
-            ret = BAD_FUNC_ARG;
-    }
-
     if (ret == 0)
         ret = _ifc_pairwise_consistency_test(key, rng);
 
@@ -801,10 +808,15 @@ int wc_CheckRsaKey(RsaKey* key)
 
     RESTORE_VECTOR_REGISTERS();
 
-    wc_FreeRng(rng);
+    if ((rng != NULL) && (rng != key->rng)) {
+        wc_FreeRng(rng);
+#ifdef WOLFSSL_SMALL_STACK
+        XFREE(rng, NULL, DYNAMIC_TYPE_RNG);
+#endif
+    }
+
 #ifdef WOLFSSL_SMALL_STACK
     XFREE(tmp, NULL, DYNAMIC_TYPE_RSA);
-    XFREE(rng, NULL, DYNAMIC_TYPE_RNG);
 #endif
 
     return ret;
@@ -4686,7 +4698,6 @@ int wc_MakeRsaKey(RsaKey* key, int size, long e, WC_RNG* rng)
 #endif /* WOLFSSL_KEY_GEN */
 
 
-#ifdef WC_RSA_BLINDING
 int wc_RsaSetRNG(RsaKey* key, WC_RNG* rng)
 {
     if (key == NULL || rng == NULL)
@@ -4696,7 +4707,6 @@ int wc_RsaSetRNG(RsaKey* key, WC_RNG* rng)
 
     return 0;
 }
-#endif /* WC_RSA_BLINDING */
 
 #ifdef WC_RSA_NONBLOCK
 int wc_RsaSetNonBlock(RsaKey* key, RsaNb* nb)

wolfssl/wolfcrypt/rsa.h

@@ -175,9 +175,7 @@ struct RsaKey {
     int   type;                               /* public or private */
     int   state;
     word32 dataLen;
-#ifdef WC_RSA_BLINDING
     WC_RNG* rng;                              /* for PrivateDecrypt blinding */
-#endif
 #ifdef WOLF_CRYPTO_CB
     int   devId;
 #endif
@@ -313,9 +311,7 @@ WOLFSSL_API int  wc_RsaPublicKeyDecodeRaw(const byte* n, word32 nSz,
     WOLFSSL_API int wc_RsaKeyToDer(RsaKey*, byte* output, word32 inLen);
 #endif
 
-#ifdef WC_RSA_BLINDING
     WOLFSSL_API int wc_RsaSetRNG(RsaKey* key, WC_RNG* rng);
-#endif
 #ifdef WC_RSA_NONBLOCK
     WOLFSSL_API int wc_RsaSetNonBlock(RsaKey* key, RsaNb* nb);
     #ifdef WC_RSA_NONBLOCK_TIME