Calculate tag and destination buffer length in a single place to avoid
code duplication. The TLS case is fixed by rounding the destination
length to cipher block size.
Signed-off-by: Cristian Stoica <cristian.sto...@freescale.com>
---
authenc.c | 54 +++++++++++++++++++++++++++++++++++++++---------------
1 file changed, 39 insertions(+), 15 deletions(-)
diff --git a/authenc.c b/authenc.c
index a183820..1bd7377 100644
--- a/authenc.c
+++ b/authenc.c
@@ -172,6 +172,42 @@ static int get_userbuf_srtp(struct csession *ses, struct
kernel_crypt_auth_op *k
return 0;
}
+/*
+ * Return tag (digest) length for authenticated encryption
+ * If the cipher and digest are separate, hdata.init is set - just return
+ * digest length. Otherwise return digest length for aead ciphers
+ */
+static int cryptodev_get_tag_len(struct csession *ses_ptr)
+{
+ if (ses_ptr->hdata.init)
+ return ses_ptr->hdata.digestsize;
+ else
+ return cryptodev_cipher_get_tag_size(&ses_ptr->cdata);
+}
+
+/*
+ * Calculate destination buffer length for authenticated encryption. The
+ * expectation is that user-space code allocates exactly the same space for
+ * destination buffer before calling cryptodev. The result is cipher-dependent.
+ */
+static int cryptodev_get_dst_len(struct crypt_auth_op *caop, struct csession
*ses_ptr)
+{
+ int dst_len = caop->len;
+ if (caop->op == COP_DECRYPT)
+ return dst_len;
+
+ dst_len += caop->tag_len;
+
+ /* for TLS always add some padding so the total length is rounded to
+ * cipher block size */
+ if (caop->flags & COP_FLAG_AEAD_TLS_TYPE) {
+ int bs = ses_ptr->cdata.blocksize;
+ dst_len += bs - (dst_len % bs);
+ }
+
+ return dst_len;
+}
+
static int fill_kcaop_from_caop(struct kernel_crypt_auth_op *kcaop, struct
fcrypt *fcr)
{
struct crypt_auth_op *caop = &kcaop->caop;
@@ -194,15 +230,10 @@ static int fill_kcaop_from_caop(struct
kernel_crypt_auth_op *kcaop, struct fcryp
}
if (caop->tag_len == 0)
- caop->tag_len = ses_ptr->hdata.digestsize;
+ caop->tag_len = cryptodev_get_tag_len(ses_ptr);
kcaop->ivlen = caop->iv ? ses_ptr->cdata.ivsize : 0;
-
- if (caop->flags & COP_FLAG_AEAD_TLS_TYPE)
- kcaop->dst_len = caop->len + ses_ptr->cdata.blocksize /* pad */
+ caop->tag_len;
- else
- kcaop->dst_len = caop->len;
-
+ kcaop->dst_len = cryptodev_get_dst_len(caop, ses_ptr);
kcaop->task = current;
kcaop->mm = current->mm;
@@ -645,8 +676,6 @@ __crypto_auth_run_zc(struct csession *ses_ptr, struct
kernel_crypt_auth_op *kcao
ret = tls_auth_n_crypt(ses_ptr, kcaop, auth_sg,
caop->auth_len,
dst_sg, caop->len);
} else {
- int dst_len;
-
if (unlikely(ses_ptr->cdata.init == 0 ||
(ses_ptr->cdata.stream == 0 &&
ses_ptr->cdata.aead == 0))) {
@@ -655,12 +684,7 @@ __crypto_auth_run_zc(struct csession *ses_ptr, struct
kernel_crypt_auth_op *kcao
goto free_auth_buf;
}
- if (caop->op == COP_ENCRYPT)
- dst_len = caop->len +
cryptodev_cipher_get_tag_size(&ses_ptr->cdata);
- else
- dst_len = caop->len;
-
- ret = get_userbuf(ses_ptr, caop->src, caop->len,
caop->dst, dst_len,
+ ret = get_userbuf(ses_ptr, caop->src, caop->len,
caop->dst, kcaop->dst_len,
kcaop->task, kcaop->mm, &src_sg,
&dst_sg);
if (unlikely(ret)) {
derr(1, "get_userbuf(): Error getting user
pages.");
--
1.8.3.1
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