Make the PACKET/WPACKET code available to both libcrypto and libssl

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/9111)

1 files changed, 424 insertions, 0 deletions

diff --git a/crypto/packet.c b/crypto/packet.c
new file mode 100644
index 0000000000..cb6739b85b
--- /dev/null
+++ b/crypto/packet.c
@@ -0,0 +1,424 @@
+/*
+ * Copyright 2015-2018 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the Apache License 2.0 (the "License").  You may not use
+ * this file except in compliance with the License.  You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+#include "internal/cryptlib.h"
+#include "internal/packet.h"
+#include <openssl/sslerr.h>
+
+#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)
+{
+    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)
+
+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 (pkt->maxsize - pkt->written < len)
+        return 0;
+
+    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 (reflen > SIZE_MAX / 2) {
+            newlen = SIZE_MAX;
+        } else {
+            newlen = reflen * 2;
+            if (newlen < DEFAULT_BUF_SIZE)
+                newlen = DEFAULT_BUF_SIZE;
+        }
+        if (BUF_MEM_grow(pkt->buf, newlen) == 0)
+            return 0;
+    }
+    if (allocbytes != NULL)
+        *allocbytes = WPACKET_get_curr(pkt);
+
+    return 1;
+}
+
+int WPACKET_sub_reserve_bytes__(WPACKET *pkt, size_t len,
+                                unsigned char **allocbytes, size_t lenbytes)
+{
+    if (!WPACKET_reserve_bytes(pkt, lenbytes + len, allocbytes))
+        return 0;
+
+    *allocbytes += lenbytes;
+
+    return 1;
+}
+
+static size_t maxmaxsize(size_t lenbytes)
+{
+    if (lenbytes >= sizeof(size_t) || lenbytes == 0)
+        return SIZE_MAX;
+
+    return ((size_t)1 << (lenbytes * 8)) - 1 + lenbytes;
+}
+
+static int wpacket_intern_init_len(WPACKET *pkt, size_t lenbytes)
+{
+    unsigned char *lenchars;
+
+    pkt->curr = 0;
+    pkt->written = 0;
+
+    if ((pkt->subs = OPENSSL_zalloc(sizeof(*pkt->subs))) == NULL) {
+        SSLerr(SSL_F_WPACKET_INTERN_INIT_LEN, ERR_R_MALLOC_FAILURE);
+        return 0;
+    }
+
+    if (lenbytes == 0)
+        return 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;
+}
+
+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 */
+    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);
+}
+
+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)
+{
+    /* Internal API, so should not fail */
+    if (!ossl_assert(pkt->subs != NULL))
+        return 0;
+
+    pkt->subs->flags = flags;
+
+    return 1;
+}
+
+/* Store the |value| of length |len| at location |data| */
+static int put_value(unsigned char *data, size_t value, size_t len)
+{
+    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;
+}
+
+
+/*
+ * 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, WPACKET_SUB *sub, int doclose)
+{
+    size_t packlen = pkt->written - sub->pwritten;
+
+    if (packlen == 0
+            && (sub->flags & WPACKET_FLAGS_NON_ZERO_LENGTH) != 0)
+        return 0;
+
+    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;
+            pkt->curr -= sub->lenbytes;
+        }
+
+        /* Don't write out the packet length */
+        sub->packet_len = 0;
+        sub->lenbytes = 0;
+    }
+
+    /* 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);
+    }
+
+    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;
+    }
+
+    return 1;
+}
+
+int WPACKET_close(WPACKET *pkt)
+{
+    /*
+     * 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;
+
+    return wpacket_intern_close(pkt, pkt->subs, 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;
+    }
+
+    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;
+
+    if ((sub = OPENSSL_zalloc(sizeof(*sub))) == NULL) {
+        SSLerr(SSL_F_WPACKET_START_SUB_PACKET_LEN__, ERR_R_MALLOC_FAILURE);
+        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;
+    }
+
+    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;
+}
+
+int WPACKET_start_sub_packet(WPACKET *pkt)
+{
+    return WPACKET_start_sub_packet_len__(pkt, 0);
+}
+
+int WPACKET_put_bytes__(WPACKET *pkt, unsigned int val, size_t size)
+{
+    unsigned char *data;
+
+    /* 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;
+
+    return 1;
+}
+
+int WPACKET_set_max_size(WPACKET *pkt, size_t maxsize)
+{
+    WPACKET_SUB *sub;
+    size_t lenbytes;
+
+    /* Internal API, so should not fail */
+    if (!ossl_assert(pkt->subs != NULL))
+        return 0;
+
+    /* Find the WPACKET_SUB for the top level */
+    for (sub = pkt->subs; sub->parent != NULL; sub = sub->parent)
+        continue;
+
+    lenbytes = sub->lenbytes;
+    if (lenbytes == 0)
+        lenbytes = sizeof(pkt->maxsize);
+
+    if (maxmaxsize(lenbytes) < maxsize || maxsize < pkt->written)
+        return 0;
+
+    pkt->maxsize = maxsize;
+
+    return 1;
+}
+
+int WPACKET_memset(WPACKET *pkt, int ch, size_t len)
+{
+    unsigned char *dest;
+
+    if (len == 0)
+        return 1;
+
+    if (!WPACKET_allocate_bytes(pkt, len, &dest))
+        return 0;
+
+    memset(dest, ch, len);
+
+    return 1;
+}
+
+int WPACKET_memcpy(WPACKET *pkt, const void *src, size_t len)
+{
+    unsigned char *dest;
+
+    if (len == 0)
+        return 1;
+
+    if (!WPACKET_allocate_bytes(pkt, len, &dest))
+        return 0;
+
+    memcpy(dest, src, len);
+
+    return 1;
+}
+
+int WPACKET_sub_memcpy__(WPACKET *pkt, const void *src, size_t len,
+                         size_t lenbytes)
+{
+    if (!WPACKET_start_sub_packet_len__(pkt, lenbytes)
+            || !WPACKET_memcpy(pkt, src, len)
+            || !WPACKET_close(pkt))
+        return 0;
+
+    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;
+}
+
+int WPACKET_get_length(WPACKET *pkt, size_t *len)
+{
+    /* Internal API, so should not fail */
+    if (!ossl_assert(pkt->subs != NULL && len != NULL))
+        return 0;
+
+    *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;
+}