move WC_RNG_BANK_SUPPORT implementation from wolfcrypt/src/random.c and wolfssl/wolfcrypt/random.h to new files wolfcrypt/src/rng_bank.c and wolfssl/wolfcrypt/rng_bank.h;

wolfcrypt/src/rng_bank.c:

  * add wc_local_rng_bank_checkout_for_bankref, wc_BankRef_Release(), wc_rng_bank_new(), and wc_rng_bank_free();

  * in wc_rng_bank_checkin(), take a struct wc_rng_bank_inst **rng_inst and NULL it before return;

  * in wc_rng_bank_init(), add a devId arg, and handle devId in wc_rng_bank_inst_reinit();

  * add WC_RNG_BANK_INST_LOCK_* and use them in wc_rng_bank_checkout() and wc_rng_bank_checkin();

  * fix order of operations in wc_rng_bank_checkout() re DISABLE_VECTOR_REGISTERS();

wolfcrypt/src/random.c:

  * refactor per-instance salting for wc_rng_bank_inst: remove changes in Hash_df(), Hash_DRBG_Instantiate(), and _InitRng(), and in wc_rng_bank_init() and wc_rng_bank_inst_reinit(), use wc_InitRngNonce_ex() and pass the wc_rng_bank_inst pointer as the nonce;

  * simplify the WC_RNG_BANK_SUPPORT variant of wc_RNG_GenerateBlock() -- delegate to wc_local_rng_bank_checkout_for_bankref() and remove supplementary error checking;

  * in wc_FreeRng(), call wc_BankRef_Release() when WC_DRBG_BANKREF, and in wc_BankRef_Release(), fix refcount flub (not wolfSSL_RefFree, rather wolfSSL_RefDec);

  * streamline the WOLFSSL_LINUXKM wc_GenerateSeed();

wolfcrypt/test/test.c: add random_bank_test();

linuxkm/lkcapi_sha_glue.c: use WC_RNG_BANK_INST_TO_RNG() opportunistically;

configure.ac: add --enable-amdrdseed as a synonym for --enable-amdrand;

linuxkm/linuxkm_wc_port.h: when LINUXKM_LKCAPI_REGISTER_HASH_DRBG_DEFAULT, don't include get_random_bytes() in struct wolfssl_linuxkm_pie_redirect_table;

add various comments for clarity.

linuxkm/linuxkm_wc_port.h

@@ -937,7 +937,9 @@
         typeof(kfree) *kfree;
         typeof(ksize) *ksize;
 
+#ifndef LINUXKM_LKCAPI_REGISTER_HASH_DRBG_DEFAULT
         typeof(get_random_bytes) *get_random_bytes;
+#endif
         #if LINUX_VERSION_CODE < KERNEL_VERSION(4, 0, 0)
             typeof(getnstimeofday) *getnstimeofday;
         #elif LINUX_VERSION_CODE < KERNEL_VERSION(5, 0, 0)
@@ -1267,7 +1269,9 @@
     #endif
     #define ksize WC_PIE_INDIRECT_SYM(ksize)
 
+#ifndef LINUXKM_LKCAPI_REGISTER_HASH_DRBG_DEFAULT
     #define get_random_bytes WC_PIE_INDIRECT_SYM(get_random_bytes)
+#endif
     #if LINUX_VERSION_CODE < KERNEL_VERSION(4, 0, 0)
         #define getnstimeofday WC_PIE_INDIRECT_SYM(getnstimeofday)
     #elif LINUX_VERSION_CODE < KERNEL_VERSION(5, 0, 0)

linuxkm/lkcapi_sha_glue.c

@@ -955,6 +955,7 @@ struct wc_swallow_the_semicolon
     #include <wolfssl/wolfcrypt/wolfentropy.h>
 #endif
 #include <wolfssl/wolfcrypt/random.h>
+#include <wolfssl/wolfcrypt/rng_bank.h>
 
 static volatile int wc_linuxkm_drbg_init_tfm_disable_vector_registers = 0;
 
@@ -1000,8 +1001,9 @@ static int wc_linuxkm_drbg_init_tfm(struct crypto_tfm *tfm)
     if (wc_linuxkm_drbg_init_tfm_disable_vector_registers)
         flags |= WC_RNG_BANK_FLAG_NO_VECTOR_OPS;
 
-    ret = wc_rng_bank_init(ctx, nr_cpu_ids + 4, flags,
-                           WC_LINUXKM_INITRNG_TIMEOUT_SEC, NULL /* heap */);
+    ret = wc_rng_bank_init(
+        ctx, nr_cpu_ids + 4, flags, WC_LINUXKM_INITRNG_TIMEOUT_SEC,
+        NULL /* heap */, INVALID_DEVID);
 
     if (ret == 0) {
         ret = wc_rng_bank_set_affinity_handlers(
@@ -1075,7 +1077,7 @@ static struct wc_rng_bank_inst *linuxkm_get_drbg(struct crypto_rng *tfm) {
     return ret;
 }
 
-static void linuxkm_put_drbg(struct crypto_rng *tfm, struct wc_rng_bank_inst *drbg) {
+static void linuxkm_put_drbg(struct crypto_rng *tfm, struct wc_rng_bank_inst **drbg) {
     struct wc_rng_bank *ctx = (struct wc_rng_bank *)crypto_rng_ctx(tfm);
     int ret = wc_rng_bank_checkin(ctx, drbg);
     if (ret != 0) {
@@ -1114,6 +1116,10 @@ static inline struct crypto_rng *get_crypto_default_rng(void) {
     return current_crypto_default_rng;
 }
 
+#ifndef WC_DRBG_BANKREF
+    #error LINUXKM_LKCAPI_REGISTER_HASH_DRBG_DEFAULT requires WC_DRBG_BANKREF support.
+#endif
+
 WC_MAYBE_UNUSED static int linuxkm_InitRng_DefaultRef(WC_RNG* rng) {
     int ret;
     struct crypto_rng *current_crypto_default_rng = get_crypto_default_rng();
@@ -1146,7 +1152,7 @@ static int wc_linuxkm_drbg_generate(struct crypto_rng *tfm,
     }
 
     if (slen > 0) {
-        ret = wc_RNG_DRBG_Reseed(&drbg->rng, src, slen);
+        ret = wc_RNG_DRBG_Reseed(WC_RNG_BANK_INST_TO_RNG(drbg), src, slen);
         if (ret != 0) {
             pr_warn_once("WARNING: wc_RNG_DRBG_Reseed returned %d\n",ret);
             ret = -EINVAL;
@@ -1157,7 +1163,7 @@ static int wc_linuxkm_drbg_generate(struct crypto_rng *tfm,
     for (;;) {
         #define RNG_MAX_BLOCK_LEN_ROUNDED (RNG_MAX_BLOCK_LEN & ~0xfU)
         if (dlen > RNG_MAX_BLOCK_LEN_ROUNDED) {
-            ret = wc_RNG_GenerateBlock(&drbg->rng, dst, RNG_MAX_BLOCK_LEN_ROUNDED);
+            ret = wc_RNG_GenerateBlock(WC_RNG_BANK_INST_TO_RNG(drbg), dst, RNG_MAX_BLOCK_LEN_ROUNDED);
             if (ret == 0) {
                 dlen -= RNG_MAX_BLOCK_LEN_ROUNDED;
                 dst += RNG_MAX_BLOCK_LEN_ROUNDED;
@@ -1165,7 +1171,7 @@ static int wc_linuxkm_drbg_generate(struct crypto_rng *tfm,
         }
         #undef RNG_MAX_BLOCK_LEN_ROUNDED
         else {
-            ret = wc_RNG_GenerateBlock(&drbg->rng, dst, dlen);
+            ret = wc_RNG_GenerateBlock(WC_RNG_BANK_INST_TO_RNG(drbg), dst, dlen);
             if (ret == 0)
                 dlen = 0;
         }
@@ -1206,7 +1212,7 @@ static int wc_linuxkm_drbg_generate(struct crypto_rng *tfm,
 
 out:
 
-    linuxkm_put_drbg(tfm, drbg);
+    linuxkm_put_drbg(tfm, &drbg);
 
     return ret;
 }
@@ -1438,12 +1444,12 @@ static int wc_mix_pool_bytes(const void *buf, size_t len) {
             continue;
 
         for (i = 0, V_offset = 0; i < len; ++i) {
-            ((struct DRBG_internal *)drbg->rng.drbg)->V[V_offset++] += ((byte *)buf)[i];
-            if (V_offset == (int)sizeof ((struct DRBG_internal *)drbg->rng.drbg)->V)
+            ((struct DRBG_internal *)WC_RNG_BANK_INST_TO_RNG(drbg)->drbg)->V[V_offset++] += ((byte *)buf)[i];
+            if (V_offset == (int)sizeof ((struct DRBG_internal *)WC_RNG_BANK_INST_TO_RNG(drbg)->drbg)->V)
                 V_offset = 0;
         }
 
-        wc_rng_bank_checkin(ctx, drbg);
+        wc_rng_bank_checkin(ctx, &drbg);
         if (can_sleep) {
             if (signal_pending(current))
                 return -EINTR;

linuxkm/module_exports.c.template

@@ -66,6 +66,9 @@
         #include <wolfssl/wolfcrypt/wolfentropy.h>
     #endif
     #include <wolfssl/wolfcrypt/random.h>
+    #ifdef WC_RNG_BANK_SUPPORT
+        #include <wolfssl/wolfcrypt/rng_bank.h>
+    #endif
 #endif
 #include <wolfssl/wolfcrypt/coding.h>
 #include <wolfssl/wolfcrypt/signature.h>

linuxkm/module_hooks.c

@@ -1288,7 +1288,9 @@ static int set_up_wolfssl_linuxkm_pie_redirect_table(void) {
     wolfssl_linuxkm_pie_redirect_table.kvfree = kvfree;
 #endif
 
+#ifndef LINUXKM_LKCAPI_REGISTER_HASH_DRBG_DEFAULT
     wolfssl_linuxkm_pie_redirect_table.get_random_bytes = get_random_bytes;
+#endif
     #if LINUX_VERSION_CODE < KERNEL_VERSION(4, 0, 0)
         wolfssl_linuxkm_pie_redirect_table.getnstimeofday =
             getnstimeofday;