Fix riscv64 chacha crash due to unaligned data

The linux-riscv64 test machine crashes due to unaligned data,
when the V extension is enabled, while QEMU seems to have no
problems with unaligned data.

So check for aligned data and fall back to C code in case the
input or output values are unaligned.

Author: bernd-edlinger

crypto/chacha/chacha_riscv.c

@@ -51,7 +51,9 @@ void ChaCha20_ctr32_v_zbb(unsigned char *out, const unsigned char *inp,
 void ChaCha20_ctr32(unsigned char *out, const unsigned char *inp, size_t len,
                     const unsigned int key[8], const unsigned int counter[4])
 {
-    if (len > CHACHA_BLK_SIZE && RISCV_HAS_ZBB() && riscv_vlen() >= 128) {
+    if (len > CHACHA_BLK_SIZE && RISCV_HAS_ZBB() && riscv_vlen() >= 128
+            && (size_t)out % sizeof(size_t) == 0
+            && (size_t)inp % sizeof(size_t) == 0) {
         if (RISCV_HAS_ZVKB()) {
             ChaCha20_ctr32_v_zbb_zvkb(out, inp, len, key, counter);
         } else {