X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=blobdiff_plain;f=ssl%2Fpacket.c;h=3479f1fed8b2a0d4421aef199455d425411fa16b;hp=7c240a4a82b8cfaca096645805ea0aeaace6f8da;hb=4afc60605abcf1ac8373838c71e94a131d29253e;hpb=1ff8434040b35f35c27f77ef064481622490bba9

diff --git a/ssl/packet.c b/ssl/packet.c
index 7c240a4a82..3479f1fed8 100644
--- a/ssl/packet.c
+++ b/ssl/packet.c
@@ -16,9 +16,9 @@ int WPACKET_allocate_bytes(WPACKET *pkt, size_t len, unsigned char **allocbytes)
 {
     if (!WPACKET_reserve_bytes(pkt, len, allocbytes))
         return 0;
+
     pkt->written += len;
     pkt->curr += len;
-
     return 1;
 }
 
@@ -33,6 +33,9 @@ int WPACKET_sub_allocate_bytes__(WPACKET *pkt, size_t len,
     return 1;
 }
 
+#define GETBUF(p)   (((p)->staticbuf != NULL) \
+                     ? (p)->staticbuf : (unsigned char *)(p)->buf->data)
+
 int WPACKET_reserve_bytes(WPACKET *pkt, size_t len, unsigned char **allocbytes)
 {
     /* Internal API, so should not fail */
@@ -43,7 +46,7 @@ int WPACKET_reserve_bytes(WPACKET *pkt, size_t len, unsigned char **allocbytes)
     if (pkt->maxsize - pkt->written < len)
         return 0;
 
-    if (pkt->buf->length - pkt->written < len) {
+    if (pkt->staticbuf == NULL && (pkt->buf->length - pkt->written < len)) {
         size_t newlen;
         size_t reflen;
 
@@ -59,7 +62,8 @@ int WPACKET_reserve_bytes(WPACKET *pkt, size_t len, unsigned char **allocbytes)
         if (BUF_MEM_grow(pkt->buf, newlen) == 0)
             return 0;
     }
-    *allocbytes = (unsigned char *)pkt->buf->data + pkt->curr;
+    if (allocbytes != NULL)
+        *allocbytes = WPACKET_get_curr(pkt);
 
     return 1;
 }
@@ -83,19 +87,12 @@ static size_t maxmaxsize(size_t lenbytes)
     return ((size_t)1 << (lenbytes * 8)) - 1 + lenbytes;
 }
 
-int WPACKET_init_len(WPACKET *pkt, BUF_MEM *buf, size_t lenbytes)
+static int wpacket_intern_init_len(WPACKET *pkt, size_t lenbytes)
 {
     unsigned char *lenchars;
 
-    /* Internal API, so should not fail */
-    assert(buf != NULL);
-    if (buf == NULL)
-        return 0;
-
-    pkt->buf = buf;
     pkt->curr = 0;
     pkt->written = 0;
-    pkt->maxsize = maxmaxsize(lenbytes);
 
     pkt->subs = OPENSSL_zalloc(sizeof(*pkt->subs));
     if (pkt->subs == NULL)
@@ -112,11 +109,42 @@ int WPACKET_init_len(WPACKET *pkt, BUF_MEM *buf, size_t lenbytes)
         pkt->subs = NULL;
         return 0;
     }
-    pkt->subs->packet_len = lenchars - (unsigned char *)pkt->buf->data;
+    pkt->subs->packet_len = lenchars - GETBUF(pkt);
 
     return 1;
 }
 
+int WPACKET_init_static_len(WPACKET *pkt, unsigned char *buf, size_t len,
+                            size_t lenbytes)
+{
+    size_t max = maxmaxsize(lenbytes);
+
+    /* Internal API, so should not fail */
+    assert(buf != NULL && len > 0);
+    if (buf == NULL || len == 0)
+        return 0;
+
+    pkt->staticbuf = buf;
+    pkt->buf = NULL;
+    pkt->maxsize = (max < len) ? max : len;
+
+    return wpacket_intern_init_len(pkt, lenbytes);
+}
+
+int WPACKET_init_len(WPACKET *pkt, BUF_MEM *buf, size_t lenbytes)
+{
+    /* Internal API, so should not fail */
+    assert(buf != NULL);
+    if (buf == NULL)
+        return 0;
+
+    pkt->staticbuf = NULL;
+    pkt->buf = buf;
+    pkt->maxsize = maxmaxsize(lenbytes);
+
+    return wpacket_intern_init_len(pkt, lenbytes);
+}
+
 int WPACKET_init(WPACKET *pkt, BUF_MEM *buf)
 {
     return WPACKET_init_len(pkt, buf, 0);
@@ -152,12 +180,13 @@ static int put_value(unsigned char *data, size_t value, size_t len)
 
 
 /*
- * Internal helper function used by WPACKET_close() and WPACKET_finish() to
- * close a sub-packet and write out its length if necessary.
+ * Internal helper function used by WPACKET_close(), WPACKET_finish() and
+ * WPACKET_fill_lengths() to close a sub-packet and write out its length if
+ * necessary. If |doclose| is 0 then it goes through the motions of closing
+ * (i.e. it fills in all the lengths), but doesn't actually close anything.
  */
-static int wpacket_intern_close(WPACKET *pkt)
+static int wpacket_intern_close(WPACKET *pkt, WPACKET_SUB *sub, int doclose)
 {
-    WPACKET_SUB *sub = pkt->subs;
     size_t packlen = pkt->written - sub->pwritten;
 
     if (packlen == 0
@@ -166,6 +195,10 @@ static int wpacket_intern_close(WPACKET *pkt)
 
     if (packlen == 0
             && sub->flags & WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH) {
+        /* We can't handle this case. Return an error */
+        if (!doclose)
+            return 0;
+
         /* Deallocate any bytes allocated for the length of the WPACKET */
         if ((pkt->curr - sub->lenbytes) == sub->packet_len) {
             pkt->written -= sub->lenbytes;
@@ -178,13 +211,31 @@ static int wpacket_intern_close(WPACKET *pkt)
     }
 
     /* Write out the WPACKET length if needed */
-    if (sub->lenbytes > 0 
-                && !put_value((unsigned char *)&pkt->buf->data[sub->packet_len],
-                              packlen, sub->lenbytes))
+    if (sub->lenbytes > 0
+                && !put_value(&GETBUF(pkt)[sub->packet_len], packlen,
+                              sub->lenbytes))
             return 0;
 
-    pkt->subs = sub->parent;
-    OPENSSL_free(sub);
+    if (doclose) {
+        pkt->subs = sub->parent;
+        OPENSSL_free(sub);
+    }
+
+    return 1;
+}
+
+int WPACKET_fill_lengths(WPACKET *pkt)
+{
+    WPACKET_SUB *sub;
+
+    assert(pkt->subs != NULL);
+    if (pkt->subs == NULL)
+        return 0;
+
+    for (sub = pkt->subs; sub != NULL; sub = sub->parent) {
+        if (!wpacket_intern_close(pkt, sub, 0))
+            return 0;
+    }
 
     return 1;
 }
@@ -198,7 +249,7 @@ int WPACKET_close(WPACKET *pkt)
     if (pkt->subs == NULL || pkt->subs->parent == NULL)
         return 0;
 
-    return wpacket_intern_close(pkt);
+    return wpacket_intern_close(pkt, pkt->subs, 1);
 }
 
 int WPACKET_finish(WPACKET *pkt)
@@ -212,7 +263,7 @@ int WPACKET_finish(WPACKET *pkt)
     if (pkt->subs == NULL || pkt->subs->parent != NULL)
         return 0;
 
-    ret = wpacket_intern_close(pkt);
+    ret = wpacket_intern_close(pkt, pkt->subs, 1);
     if (ret) {
         OPENSSL_free(pkt->subs);
         pkt->subs = NULL;
@@ -248,7 +299,7 @@ int WPACKET_start_sub_packet_len__(WPACKET *pkt, size_t lenbytes)
     if (!WPACKET_allocate_bytes(pkt, lenbytes, &lenchars))
         return 0;
     /* Convert to an offset in case the underlying BUF_MEM gets realloc'd */
-    sub->packet_len = lenchars - (unsigned char *)pkt->buf->data;
+    sub->packet_len = lenchars - GETBUF(pkt);
 
     return 1;
 }
@@ -349,6 +400,11 @@ int WPACKET_get_length(WPACKET *pkt, size_t *len)
     return 1;
 }
 
+unsigned char *WPACKET_get_curr(WPACKET *pkt)
+{
+    return GETBUF(pkt) + pkt->curr;
+}
+
 void WPACKET_cleanup(WPACKET *pkt)
 {
     WPACKET_SUB *sub, *parent;