Re: [PATCH 4/6] crypto/openssl: fix 3DES-CTR with big endian CPUs

[David Marchand <david.marchand@redhat.com>]

On Thu, Oct 24, 2024 at 3:10 PM David Marchand
<david.marchand@redhat.com> wrote:
> > There may be an alignment bug too; the way it is used in process_openssl_cipher_des3ctr(), "ctr" is not guaranteed to be uint64_t aligned.
> >
> > How about this instead:
> >
> > ctr_inc(void *ctr)
> > {
> >         uint64_t ctr64 = rte_be_to_cpu_64(*(unaligned_uint64_t *)ctr);
> >         ctr64++;
> >         *(unaligned_uint64_t *)ctr = rte_cpu_to_be_64(ctr64);
> > }
> >
> > Or this:
> >
> > ctr_inc(void *ctr)
> > {
> >         uint64_t ctr64;
> >
> >         memcpy(&ctr64, ctr, sizeof(uint64_t));
> >         ctr64 = rte_be_to_cpu_64(ctr64);
> >         ctr64++;
> >         ctr64 = rte_cpu_to_be_64(ctr64);
> >         memcpy(ctr, &ctr64, sizeof(uint64_t));
> > }
> >
> > Or use a union in process_openssl_cipher_des3ctr() to ensure it's uint64_t aligned.
>
> Or declare ctr as a uint64_t in process_openssl_cipher_des3ctr
> directly, and remove this casting.

Like:

diff --git a/drivers/crypto/openssl/rte_openssl_pmd.c
b/drivers/crypto/openssl/rte_openssl_pmd.c
index 9657b70c7a..8e193759b7 100644
--- a/drivers/crypto/openssl/rte_openssl_pmd.c
+++ b/drivers/crypto/openssl/rte_openssl_pmd.c
@@ -99,22 +99,6 @@ digest_name_get(enum rte_crypto_auth_algorithm algo)

 static int cryptodev_openssl_remove(struct rte_vdev_device *vdev);

-/*----------------------------------------------------------------------------*/
-
-/**
- * Increment counter by 1
- * Counter is 64 bit array, big-endian
- */
-static void
-ctr_inc(uint8_t *ctr)
-{
-       uint64_t *ctr64 = (uint64_t *)ctr;
-
-       *ctr64 = __builtin_bswap64(*ctr64);
-       (*ctr64)++;
-       *ctr64 = __builtin_bswap64(*ctr64);
-}
-
 /*
  *------------------------------------------------------------------------------
  * Session Prepare
@@ -1192,7 +1176,9 @@ static int
 process_openssl_cipher_des3ctr(struct rte_mbuf *mbuf_src, uint8_t *dst,
                int offset, uint8_t *iv, int srclen, EVP_CIPHER_CTX *ctx)
 {
-       uint8_t ebuf[8], ctr[8];
+       uint8_t ebuf[8];
+       uint64_t host_ctr;
+       uint64_t ctr;
        int unused, n;
        struct rte_mbuf *m;
        uint8_t *src;
@@ -1209,14 +1195,16 @@ process_openssl_cipher_des3ctr(struct rte_mbuf
*mbuf_src, uint8_t *dst,
        l = rte_pktmbuf_data_len(m) - offset;

        memcpy(ctr, iv, 8);
+       host_ctr = rte_be_64_to_cpu(ctr);

        for (n = 0; n < srclen; n++) {
                if (n % 8 == 0) {
+                       ctr = rte_cpu_to_be_64(host_ctr);
                        if (EVP_EncryptUpdate(ctx,
                                        (unsigned char *)&ebuf, &unused,
                                        (const unsigned char *)&ctr, 8) <= 0)
                                goto process_cipher_des3ctr_err;
-                       ctr_inc(ctr);
+                       host_ctr++;
                }
                dst[n] = *(src++) ^ ebuf[n % 8];


-- 
David Marchand