dedup

commit d0213e5514ecb4a49986054e94943ff3016c5766
parent 606b9b2b5560acf057d87bacb67d18512c3c1653
Author: sin <sin@2f30.org>
Date:   Thu,  2 May 2019 16:37:38 +0100

Add some comments to bencrypt.c

Diffstat:
M
bencrypt.c
 | 
8
++++++++

1 file changed, 8 insertions(+), 0 deletions(-)
diff --git a/bencrypt.c b/bencrypt.c
@@ -174,6 +174,7 @@ beput(struct bctx *bctx, void *buf, size_t n, unsigned char *md)
 	char *ebuf;
 	size_t en;
 
+	/* Calculate size of encrypted block */
 	ectx = bctx->ectx;
 	if (ectx->type == EDNONETYPE)
 		en = n;
@@ -182,12 +183,15 @@ beput(struct bctx *bctx, void *buf, size_t n, unsigned char *md)
 	else
 		return -1;
 
+	/* Allocate encrypted block */
 	ebuf = malloc(EDSIZE + en);
 	if (ebuf == NULL)
 		return -1;
 
+	/* Prepend the encryption descriptor */
 	ed.type = ectx->type;
 	ed.size = en;
+	/* Fill nonce buffer */
 	if (ectx->type == EDNONETYPE) {
 		memset(ed.nonce, 0, sizeof(ed.nonce));
 	} else if (ectx->type == EDCHACHATYPE) {
@@ -198,6 +202,7 @@ beput(struct bctx *bctx, void *buf, size_t n, unsigned char *md)
 	}
 	packed(ebuf, &ed);
 
+	/* Encrypt block */
 	if (ectx->type == EDNONETYPE) {
 		memcpy(&ebuf[EDSIZE], buf, en);
 	} else if (ectx->type == EDCHACHATYPE) {
@@ -230,17 +235,20 @@ beget(struct bctx *bctx, unsigned char *md, void *buf, size_t *n)
 	char *ebuf;
 	size_t dn, size;
 
+	/* Calculate maximum size of encrypted block */
 	size = EDSIZE + *n + crypto_aead_xchacha20poly1305_ietf_ABYTES;
 	ebuf = malloc(size);
 	if (ebuf == NULL)
 		return -1;
 
+	/* Read encrypted block */
 	bops = bstorageops();
 	if (bops->get(bctx, md, ebuf, &size) < 0) {
 		free(ebuf);
 		return -1;
 	}
 
+	/* Decrypt block */
 	unpacked(ebuf, &ed);
 	if (ed.type == EDNONETYPE) {
 		dn = ed.size;