X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=ssl%2Fpacket.c;h=7a4414ae6a8012ffa7bbe39c2c54afbeffa7ef82;hp=8528d8be089f79b638579db05a645eaf0d49a056;hb=67dc995eaf538ea309c6292a1a5073465201f55b;hpb=b7273855acd7ec2d1e7a4ba626ed538808fc7517

diff --git a/ssl/packet.c b/ssl/packet.c
index 8528d8be08..7a4414ae6a 100644
--- a/ssl/packet.c
+++ b/ssl/packet.c
@@ -7,298 +7,363 @@
  * https://www.openssl.org/source/license.html
  */
 
+#include "internal/cryptlib.h"
 #include "packet_locl.h"
 
-/*
- * Allocate bytes in the PACKETW_BUF for the output. This reserves the bytes
- * and count them as "written", but doesn't actually do the writing.
- */
-static unsigned char *PACKETW_BUF_allocate(PACKETW_BUF *wbuf, size_t len)
+#define DEFAULT_BUF_SIZE    256
+
+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;
+}
+
+int WPACKET_sub_allocate_bytes__(WPACKET *pkt, size_t len,
+                                 unsigned char **allocbytes, size_t lenbytes)
 {
-    unsigned char *ret = wbuf->curr;
+    if (!WPACKET_start_sub_packet_len__(pkt, lenbytes)
+            || !WPACKET_allocate_bytes(pkt, len, allocbytes)
+            || !WPACKET_close(pkt))
+        return 0;
+
+    return 1;
+}
+
+#define GETBUF(p)   (((p)->staticbuf != NULL) \
+                     ? (p)->staticbuf : (unsigned char *)(p)->buf->data)
 
-    if (SIZE_MAX - wbuf->written < len)
+int WPACKET_reserve_bytes(WPACKET *pkt, size_t len, unsigned char **allocbytes)
+{
+    /* Internal API, so should not fail */
+    if (!ossl_assert(pkt->subs != NULL && len != 0))
         return 0;
 
-    if (wbuf->maxsize > 0 && wbuf->written + len > wbuf->maxsize)
+    if (pkt->maxsize - pkt->written < len)
         return 0;
 
-    if (wbuf->buf->length - wbuf->written < len) {
+    if (pkt->staticbuf == NULL && (pkt->buf->length - pkt->written < len)) {
         size_t newlen;
+        size_t reflen;
+
+        reflen = (len > pkt->buf->length) ? len : pkt->buf->length;
 
-        if (wbuf->buf->length > SIZE_MAX / 2)
+        if (reflen > SIZE_MAX / 2) {
             newlen = SIZE_MAX;
-        else
-            newlen = wbuf->buf->length * 2;
-        if (BUF_MEM_grow(wbuf->buf, newlen) == 0)
-            return NULL;
+        } else {
+            newlen = reflen * 2;
+            if (newlen < DEFAULT_BUF_SIZE)
+                newlen = DEFAULT_BUF_SIZE;
+        }
+        if (BUF_MEM_grow(pkt->buf, newlen) == 0)
+            return 0;
     }
-    wbuf->written += len;
-    wbuf->curr += len;
+    if (allocbytes != NULL)
+        *allocbytes = WPACKET_get_curr(pkt);
 
-    return ret;
+    return 1;
 }
 
-/*
- * Initialise a PACKETW with the buffer in |buf|. The buffer must exist
- * for the whole time that the PACKETW is being used. Additionally |lenbytes| of
- * data is preallocated at the start of the buffer to store the length of the
- * PACKETW once we know it.
- */
-int PACKETW_init_len(PACKETW *pkt, BUF_MEM *buf, size_t lenbytes)
+int WPACKET_sub_reserve_bytes__(WPACKET *pkt, size_t len,
+                                unsigned char **allocbytes, size_t lenbytes)
 {
-    PACKETW_BUF *wbuf;
-    /* Sanity check */
-    if (buf == NULL)
+    if (!WPACKET_reserve_bytes(pkt, lenbytes + len, allocbytes))
         return 0;
 
-    wbuf = OPENSSL_zalloc(sizeof(PACKETW_BUF));
-    if (wbuf == NULL) {
-        pkt->isclosed = 1;
-        return 0;
-    }
+    *allocbytes += lenbytes;
+
+    return 1;
+}
 
-    wbuf->buf = buf;
-    wbuf->curr = (unsigned char *)buf->data;
-    wbuf->written = 0;
-    wbuf->maxsize = 0;
+static size_t maxmaxsize(size_t lenbytes)
+{
+    if (lenbytes >= sizeof(size_t) || lenbytes == 0)
+        return SIZE_MAX;
 
-    pkt->parent = NULL;
-    pkt->wbuf = wbuf;
-    pkt->pwritten = lenbytes;
-    pkt->lenbytes = lenbytes;
-    pkt->haschild = 0;
-    pkt->isclosed = 0;
+    return ((size_t)1 << (lenbytes * 8)) - 1 + lenbytes;
+}
 
-    if (lenbytes == 0) {
-        pkt->packet_len = NULL;
+static int wpacket_intern_init_len(WPACKET *pkt, size_t lenbytes)
+{
+    unsigned char *lenchars;
+
+    pkt->curr = 0;
+    pkt->written = 0;
+
+    pkt->subs = OPENSSL_zalloc(sizeof(*pkt->subs));
+    if (pkt->subs == NULL)
+        return 0;
+
+    if (lenbytes == 0)
         return 1;
-    }
 
-    pkt->packet_len = PACKETW_BUF_allocate(wbuf, lenbytes);
-    if (pkt->packet_len == NULL) {
-        OPENSSL_free(wbuf);
-        pkt->wbuf = NULL;
-        pkt->isclosed = 1;
+    pkt->subs->pwritten = lenbytes;
+    pkt->subs->lenbytes = lenbytes;
+
+    if (!WPACKET_allocate_bytes(pkt, lenbytes, &lenchars)) {
+        OPENSSL_free(pkt->subs);
+        pkt->subs = NULL;
         return 0;
     }
+    pkt->subs->packet_len = lenchars - GETBUF(pkt);
 
     return 1;
 }
 
-/*
- * Same as PACKETW_init_len except there is no preallocation of the PACKETW
- * length.
- */
-int PACKETW_init(PACKETW *pkt, BUF_MEM *buf)
+int WPACKET_init_static_len(WPACKET *pkt, unsigned char *buf, size_t len,
+                            size_t lenbytes)
 {
-    return PACKETW_init_len(pkt, buf, 0);
+    size_t max = maxmaxsize(lenbytes);
+
+    /* Internal API, so should not fail */
+    if (!ossl_assert(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);
 }
 
-/*
- * Set the PACKETW length, and the location for where we should write that
- * length. Normally this will be at the start of the PACKETW, and therefore
- * the PACKETW would have been initialised via PACKETW_init_len(). However there
- * is the possibility that the length needs to be written to some other location
- * other than the start of the PACKETW. In that case init via PACKETW_init() and
- * then set the location for the length using this function.
- */
-int PACKETW_set_packet_len(PACKETW *pkt, unsigned char *packet_len,
-                           size_t lenbytes)
+int WPACKET_init_len(WPACKET *pkt, BUF_MEM *buf, size_t lenbytes)
+{
+    /* Internal API, so should not fail */
+    if (!ossl_assert(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);
+}
+
+int WPACKET_set_flags(WPACKET *pkt, unsigned int flags)
 {
-    /* We only allow this to be set once */
-    if (pkt->isclosed || pkt->packet_len != NULL)
+    /* Internal API, so should not fail */
+    if (!ossl_assert(pkt->subs != NULL))
         return 0;
 
-    pkt->lenbytes = lenbytes;
-    pkt->packet_len = packet_len;
+    pkt->subs->flags = flags;
 
     return 1;
 }
 
-int PACKETW_set_flags(PACKETW *pkt, unsigned int flags)
+/* Store the |value| of length |len| at location |data| */
+static int put_value(unsigned char *data, size_t value, size_t len)
 {
-    pkt->flags = flags;
+    for (data += len - 1; len > 0; len--) {
+        *data = (unsigned char)(value & 0xff);
+        data--;
+        value >>= 8;
+    }
+
+    /* Check whether we could fit the value in the assigned number of bytes */
+    if (value > 0)
+        return 0;
 
     return 1;
 }
 
+
 /*
- * Closes the PACKETW and marks it as invalid for future writes. It also writes
- * out the length of the packet to the required location (normally the start
- * of the PACKETW) if appropriate. A PACKETW cannot be closed if it has an
- * active sub-packet.
+ * 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.
  */
-int PACKETW_close(PACKETW *pkt)
+static int wpacket_intern_close(WPACKET *pkt, WPACKET_SUB *sub, int doclose)
 {
-    size_t packlen;
-
-    if (pkt->isclosed || pkt->haschild)
-        return 0;
+    size_t packlen = pkt->written - sub->pwritten;
 
-    packlen = pkt->wbuf->written - pkt->pwritten;
-    if (packlen == 0 && pkt->flags & OPENSSL_PACKETW_FLAGS_NON_ZERO_LENGTH)
+    if (packlen == 0
+            && (sub->flags & WPACKET_FLAGS_NON_ZERO_LENGTH) != 0)
         return 0;
 
     if (packlen == 0
-            && pkt->flags & OPENSSL_PACKETW_FLAGS_ABANDON_ON_ZERO_LENGTH) {
-        /* Deallocate any bytes allocated for the length of the PACKETW */
-        if ((pkt->wbuf->curr - pkt->lenbytes) == pkt->packet_len) {
-            pkt->wbuf->written -= pkt->lenbytes;
-            pkt->wbuf->curr -= pkt->lenbytes;
+            && 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;
+            pkt->curr -= sub->lenbytes;
         }
 
         /* Don't write out the packet length */
-        pkt->packet_len = NULL;
+        sub->packet_len = 0;
+        sub->lenbytes = 0;
     }
 
-    /* Write out the PACKETW length if needed */
-    if (pkt->packet_len != NULL) {
-        size_t lenbytes;
-
-        lenbytes = pkt->lenbytes;
-
-        for (; lenbytes > 0; lenbytes--) {
-            pkt->packet_len[lenbytes - 1] = (unsigned char)(packlen & 0xff);
-            packlen >>= 8;
-        }
-        if (packlen > 0) {
-            /*
-             * We've extended beyond the max allowed for the number of len bytes
-             */
+    /* Write out the WPACKET length if needed */
+    if (sub->lenbytes > 0
+                && !put_value(&GETBUF(pkt)[sub->packet_len], packlen,
+                              sub->lenbytes))
             return 0;
-        }
+
+    if (doclose) {
+        pkt->subs = sub->parent;
+        OPENSSL_free(sub);
     }
 
-    if (pkt->parent != NULL) {
-        if (pkt->parent->haschild != 1) {
-            /* Should not happen! */
+    return 1;
+}
+
+int WPACKET_fill_lengths(WPACKET *pkt)
+{
+    WPACKET_SUB *sub;
+
+    if (!ossl_assert(pkt->subs != NULL))
+        return 0;
+
+    for (sub = pkt->subs; sub != NULL; sub = sub->parent) {
+        if (!wpacket_intern_close(pkt, sub, 0))
             return 0;
-        }
-        pkt->parent->haschild = 0;
-        pkt->parent = NULL;
     }
 
-    pkt->isclosed = 1;
-
     return 1;
 }
 
-/*
- * Initialise a new sub-packet (|subpkt|), based on a parent (|pkt|).
- * Additionally |lenbytes| of data is preallocated at the start of the
- * sub-packet to store its length once we know it.
- */
-int PACKETW_get_sub_packet_len(PACKETW *pkt, PACKETW *subpkt, size_t lenbytes)
+int WPACKET_close(WPACKET *pkt)
 {
-    if (pkt->isclosed || pkt->haschild || subpkt == NULL)
+    /*
+     * Internal API, so should not fail - but we do negative testing of this
+     * so no assert (otherwise the tests fail)
+     */
+    if (pkt->subs == NULL || pkt->subs->parent == NULL)
         return 0;
 
-    subpkt->parent = pkt;
-    subpkt->wbuf = pkt->wbuf;
-    subpkt->pwritten = pkt->wbuf->written + lenbytes;
-    subpkt->lenbytes = lenbytes;
-    subpkt->haschild = 0;
-    subpkt->isclosed = 0;
+    return wpacket_intern_close(pkt, pkt->subs, 1);
+}
 
-    if (lenbytes == 0) {
-        subpkt->packet_len = NULL;
-        pkt->haschild = 1;
-        return 1;
+int WPACKET_finish(WPACKET *pkt)
+{
+    int ret;
+
+    /*
+     * Internal API, so should not fail - but we do negative testing of this
+     * so no assert (otherwise the tests fail)
+     */
+    if (pkt->subs == NULL || pkt->subs->parent != NULL)
+        return 0;
+
+    ret = wpacket_intern_close(pkt, pkt->subs, 1);
+    if (ret) {
+        OPENSSL_free(pkt->subs);
+        pkt->subs = NULL;
     }
 
-    subpkt->packet_len = PACKETW_BUF_allocate(pkt->wbuf, lenbytes);
-    if (subpkt->packet_len == NULL) {
-        subpkt->isclosed = 1;
+    return ret;
+}
+
+int WPACKET_start_sub_packet_len__(WPACKET *pkt, size_t lenbytes)
+{
+    WPACKET_SUB *sub;
+    unsigned char *lenchars;
+
+    /* Internal API, so should not fail */
+    if (!ossl_assert(pkt->subs != NULL))
+        return 0;
+
+    sub = OPENSSL_zalloc(sizeof(*sub));
+    if (sub == NULL)
         return 0;
+
+    sub->parent = pkt->subs;
+    pkt->subs = sub;
+    sub->pwritten = pkt->written + lenbytes;
+    sub->lenbytes = lenbytes;
+
+    if (lenbytes == 0) {
+        sub->packet_len = 0;
+        return 1;
     }
 
-    pkt->haschild = 1;
+    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 - GETBUF(pkt);
 
     return 1;
 }
 
-/*
- * Same as PACKETW_get_sub_packet_len() except no bytes are pre-allocated for
- * the sub-packet length.
- */
-int PACKETW_get_sub_packet(PACKETW *pkt, PACKETW *subpkt)
+int WPACKET_start_sub_packet(WPACKET *pkt)
 {
-    return PACKETW_get_sub_packet_len(pkt, subpkt, 0);
+    return WPACKET_start_sub_packet_len__(pkt, 0);
 }
 
-/*
- * Allocate some bytes in the PACKETW for writing. That number of bytes is
- * marked as having been written, and a pointer to their location is stored in
- * |*allocbytes|.
- */
-int PACKETW_allocate_bytes(PACKETW *pkt, size_t bytes,
-                           unsigned char **allocbytes)
+int WPACKET_put_bytes__(WPACKET *pkt, unsigned int val, size_t size)
 {
     unsigned char *data;
 
-    if (pkt->isclosed || pkt->haschild || bytes == 0)
+    /* Internal API, so should not fail */
+    if (!ossl_assert(size <= sizeof(unsigned int))
+            || !WPACKET_allocate_bytes(pkt, size, &data)
+            || !put_value(data, val, size))
         return 0;
 
-    data = PACKETW_BUF_allocate(pkt->wbuf, bytes);
-    if (data == NULL)
-        return 0;
-
-    *allocbytes = data;
-
     return 1;
 }
 
-/*
- * Write the value stored in |val| into the PACKETW. The value will consome
- * |bytes| amount of storage. An error will occur if |val| cannot be accommdated
- * in |bytes| storage, e.g. attempting to write the value 256 into 1 byte will
- * fail.
- */
-int PACKETW_put_bytes(PACKETW *pkt, unsigned int val, size_t bytes)
+int WPACKET_set_max_size(WPACKET *pkt, size_t maxsize)
 {
-    unsigned char *data;
+    WPACKET_SUB *sub;
+    size_t lenbytes;
 
-    if (bytes > sizeof(unsigned int)
-            || !PACKETW_allocate_bytes(pkt, bytes, &data))
+    /* Internal API, so should not fail */
+    if (!ossl_assert(pkt->subs != NULL))
         return 0;
 
-    data += bytes - 1;
-    for (; bytes > 0; bytes--) {
-        *data = (unsigned char)(val & 0xff);
-        data--;
-        val >>= 8;
-    }
+    /* Find the WPACKET_SUB for the top level */
+    for (sub = pkt->subs; sub->parent != NULL; sub = sub->parent)
+        continue;
 
-    /* Check whether we could fit the value in the assigned number of bytes */
-    if (val > 0)
+    lenbytes = sub->lenbytes;
+    if (lenbytes == 0)
+        lenbytes = sizeof(pkt->maxsize);
+
+    if (maxmaxsize(lenbytes) < maxsize || maxsize < pkt->written)
         return 0;
 
+    pkt->maxsize = maxsize;
+
     return 1;
 }
 
-/*
- * Set a maximum size that we will not allow the PACKETW to grow beyond. If not
- * set then there is no maximum.
- */
-int PACKETW_set_max_size(PACKETW *pkt, size_t maxsize)
+int WPACKET_memset(WPACKET *pkt, int ch, size_t len)
 {
-    pkt->wbuf->maxsize = maxsize;
+    unsigned char *dest;
+
+    if (len == 0)
+        return 1;
+
+    if (!WPACKET_allocate_bytes(pkt, len, &dest))
+        return 0;
+
+    memset(dest, ch, len);
 
     return 1;
 }
 
-/*
- * Copy |len| bytes of data from |*src| into the PACKETW.
- */
-int PACKETW_memcpy(PACKETW *pkt, const void *src, size_t len)
+int WPACKET_memcpy(WPACKET *pkt, const void *src, size_t len)
 {
     unsigned char *dest;
 
     if (len == 0)
         return 1;
 
-    if (!PACKETW_allocate_bytes(pkt, len, &dest))
+    if (!WPACKET_allocate_bytes(pkt, len, &dest))
         return 0;
 
     memcpy(dest, src, len);
@@ -306,30 +371,51 @@ int PACKETW_memcpy(PACKETW *pkt, const void *src, size_t len)
     return 1;
 }
 
-/*
- * Return the total number of bytes written so far to the underlying buffer.
- * This might includes bytes written by a parent PACKETW.
- */
-int PACKETW_get_total_written(PACKETW *pkt, size_t *written)
+int WPACKET_sub_memcpy__(WPACKET *pkt, const void *src, size_t len,
+                         size_t lenbytes)
 {
-    if (pkt->isclosed || written == NULL)
+    if (!WPACKET_start_sub_packet_len__(pkt, lenbytes)
+            || !WPACKET_memcpy(pkt, src, len)
+            || !WPACKET_close(pkt))
         return 0;
 
-    *written = pkt->wbuf->curr - (unsigned char *)pkt->wbuf->buf->data;
+    return 1;
+}
+
+int WPACKET_get_total_written(WPACKET *pkt, size_t *written)
+{
+    /* Internal API, so should not fail */
+    if (!ossl_assert(written != NULL))
+        return 0;
+
+    *written = pkt->written;
 
     return 1;
 }
 
-/*
- * Returns the length of this PACKETW so far. This excludes any bytes allocated
- * for the length itself.
- */
-int PACKETW_get_length(PACKETW *pkt, size_t *len)
+int WPACKET_get_length(WPACKET *pkt, size_t *len)
 {
-    if (pkt->isclosed || len == NULL)
+    /* Internal API, so should not fail */
+    if (!ossl_assert(pkt->subs != NULL && len != NULL))
         return 0;
 
-    *len = pkt->wbuf->written - pkt->pwritten;
+    *len = pkt->written - pkt->subs->pwritten;
 
     return 1;
 }
+
+unsigned char *WPACKET_get_curr(WPACKET *pkt)
+{
+    return GETBUF(pkt) + pkt->curr;
+}
+
+void WPACKET_cleanup(WPACKET *pkt)
+{
+    WPACKET_SUB *sub, *parent;
+
+    for (sub = pkt->subs; sub != NULL; sub = parent) {
+        parent = sub->parent;
+        OPENSSL_free(sub);
+    }
+    pkt->subs = NULL;
+}