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authorAdam Langley <agl@google.com>2015-01-22 14:27:53 -0800
committerAdam Langley <agl@google.com>2015-01-30 16:52:14 -0800
commitd9e397b599b13d642138480a28c14db7a136bf05 (patch)
tree34bab61dc4ce323b123ad4614dbc07e86ea2f9ef /src/crypto/bytestring/cbb.c
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Initial commit of BoringSSL for Android.
Diffstat (limited to 'src/crypto/bytestring/cbb.c')
-rw-r--r--src/crypto/bytestring/cbb.c375
1 files changed, 375 insertions, 0 deletions
diff --git a/src/crypto/bytestring/cbb.c b/src/crypto/bytestring/cbb.c
new file mode 100644
index 0000000..4428836
--- /dev/null
+++ b/src/crypto/bytestring/cbb.c
@@ -0,0 +1,375 @@
+/* Copyright (c) 2014, Google Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+
+#include <openssl/bytestring.h>
+
+#include <assert.h>
+#include <string.h>
+
+#include <openssl/mem.h>
+
+
+static int cbb_init(CBB *cbb, uint8_t *buf, size_t cap) {
+ struct cbb_buffer_st *base;
+
+ base = OPENSSL_malloc(sizeof(struct cbb_buffer_st));
+ if (base == NULL) {
+ OPENSSL_free(buf);
+ return 0;
+ }
+
+ base->buf = buf;
+ base->len = 0;
+ base->cap = cap;
+ base->can_resize = 1;
+
+ memset(cbb, 0, sizeof(CBB));
+ cbb->base = base;
+ cbb->is_top_level = 1;
+ return 1;
+}
+
+int CBB_init(CBB *cbb, size_t initial_capacity) {
+ uint8_t *buf;
+
+ buf = OPENSSL_malloc(initial_capacity);
+ if (initial_capacity > 0 && buf == NULL) {
+ return 0;
+ }
+
+ return cbb_init(cbb, buf, initial_capacity);
+}
+
+int CBB_init_fixed(CBB *cbb, uint8_t *buf, size_t len) {
+ if (!cbb_init(cbb, buf, len)) {
+ return 0;
+ }
+
+ cbb->base->can_resize = 0;
+ return 1;
+}
+
+void CBB_cleanup(CBB *cbb) {
+ if (cbb->base) {
+ if (cbb->base->buf && cbb->base->can_resize) {
+ OPENSSL_free(cbb->base->buf);
+ }
+ OPENSSL_free(cbb->base);
+ }
+ cbb->base = NULL;
+}
+
+static int cbb_buffer_add(struct cbb_buffer_st *base, uint8_t **out,
+ size_t len) {
+ size_t newlen;
+
+ if (base == NULL) {
+ return 0;
+ }
+
+ newlen = base->len + len;
+ if (newlen < base->len) {
+ /* Overflow */
+ return 0;
+ }
+
+ if (newlen > base->cap) {
+ size_t newcap = base->cap * 2;
+ uint8_t *newbuf;
+
+ if (!base->can_resize) {
+ return 0;
+ }
+
+ if (newcap < base->cap || newcap < newlen) {
+ newcap = newlen;
+ }
+ newbuf = OPENSSL_realloc(base->buf, newcap);
+ if (newbuf == NULL) {
+ return 0;
+ }
+
+ base->buf = newbuf;
+ base->cap = newcap;
+ }
+
+ if (out) {
+ *out = base->buf + base->len;
+ }
+ base->len = newlen;
+ return 1;
+}
+
+static int cbb_buffer_add_u(struct cbb_buffer_st *base, uint32_t v,
+ size_t len_len) {
+ uint8_t *buf;
+ size_t i;
+
+ if (len_len == 0) {
+ return 1;
+ }
+ if (!cbb_buffer_add(base, &buf, len_len)) {
+ return 0;
+ }
+
+ for (i = len_len - 1; i < len_len; i--) {
+ buf[i] = v;
+ v >>= 8;
+ }
+ return 1;
+}
+
+int CBB_finish(CBB *cbb, uint8_t **out_data, size_t *out_len) {
+ if (!cbb->is_top_level) {
+ return 0;
+ }
+
+ if (!CBB_flush(cbb)) {
+ return 0;
+ }
+
+ if (cbb->base->can_resize && (out_data == NULL || out_len == NULL)) {
+ /* |out_data| and |out_len| can only be NULL if the CBB is fixed. */
+ return 0;
+ }
+
+ if (out_data != NULL) {
+ *out_data = cbb->base->buf;
+ }
+ if (out_len != NULL) {
+ *out_len = cbb->base->len;
+ }
+ cbb->base->buf = NULL;
+ CBB_cleanup(cbb);
+ return 1;
+}
+
+/* CBB_flush recurses and then writes out any pending length prefix. The
+ * current length of the underlying base is taken to be the length of the
+ * length-prefixed data. */
+int CBB_flush(CBB *cbb) {
+ size_t child_start, i, len;
+
+ if (cbb->base == NULL) {
+ return 0;
+ }
+
+ if (cbb->child == NULL || cbb->pending_len_len == 0) {
+ return 1;
+ }
+
+ child_start = cbb->offset + cbb->pending_len_len;
+
+ if (!CBB_flush(cbb->child) ||
+ child_start < cbb->offset ||
+ cbb->base->len < child_start) {
+ return 0;
+ }
+
+ len = cbb->base->len - child_start;
+
+ if (cbb->pending_is_asn1) {
+ /* For ASN.1 we assume that we'll only need a single byte for the length.
+ * If that turned out to be incorrect, we have to move the contents along
+ * in order to make space. */
+ size_t len_len;
+ uint8_t initial_length_byte;
+
+ assert (cbb->pending_len_len == 1);
+
+ if (len > 0xfffffffe) {
+ /* Too large. */
+ return 0;
+ } else if (len > 0xffffff) {
+ len_len = 5;
+ initial_length_byte = 0x80 | 4;
+ } else if (len > 0xffff) {
+ len_len = 4;
+ initial_length_byte = 0x80 | 3;
+ } else if (len > 0xff) {
+ len_len = 3;
+ initial_length_byte = 0x80 | 2;
+ } else if (len > 0x7f) {
+ len_len = 2;
+ initial_length_byte = 0x80 | 1;
+ } else {
+ len_len = 1;
+ initial_length_byte = len;
+ len = 0;
+ }
+
+ if (len_len != 1) {
+ /* We need to move the contents along in order to make space. */
+ size_t extra_bytes = len_len - 1;
+ if (!cbb_buffer_add(cbb->base, NULL, extra_bytes)) {
+ return 0;
+ }
+ memmove(cbb->base->buf + child_start + extra_bytes,
+ cbb->base->buf + child_start, len);
+ }
+ cbb->base->buf[cbb->offset++] = initial_length_byte;
+ cbb->pending_len_len = len_len - 1;
+ }
+
+ for (i = cbb->pending_len_len - 1; i < cbb->pending_len_len; i--) {
+ cbb->base->buf[cbb->offset + i] = len;
+ len >>= 8;
+ }
+ if (len != 0) {
+ return 0;
+ }
+
+ cbb->child->base = NULL;
+ cbb->child = NULL;
+ cbb->pending_len_len = 0;
+ cbb->pending_is_asn1 = 0;
+ cbb->offset = 0;
+
+ return 1;
+}
+
+
+static int cbb_add_length_prefixed(CBB *cbb, CBB *out_contents,
+ size_t len_len) {
+ uint8_t *prefix_bytes;
+
+ if (!CBB_flush(cbb)) {
+ return 0;
+ }
+
+ cbb->offset = cbb->base->len;
+ if (!cbb_buffer_add(cbb->base, &prefix_bytes, len_len)) {
+ return 0;
+ }
+
+ memset(prefix_bytes, 0, len_len);
+ memset(out_contents, 0, sizeof(CBB));
+ out_contents->base = cbb->base;
+ cbb->child = out_contents;
+ cbb->pending_len_len = len_len;
+ cbb->pending_is_asn1 = 0;
+
+ return 1;
+}
+
+int CBB_add_u8_length_prefixed(CBB *cbb, CBB *out_contents) {
+ return cbb_add_length_prefixed(cbb, out_contents, 1);
+}
+
+int CBB_add_u16_length_prefixed(CBB *cbb, CBB *out_contents) {
+ return cbb_add_length_prefixed(cbb, out_contents, 2);
+}
+
+int CBB_add_u24_length_prefixed(CBB *cbb, CBB *out_contents) {
+ return cbb_add_length_prefixed(cbb, out_contents, 3);
+}
+
+int CBB_add_asn1(CBB *cbb, CBB *out_contents, uint8_t tag) {
+ if (!CBB_flush(cbb) ||
+ !CBB_add_u8(cbb, tag)) {
+ return 0;
+ }
+
+ cbb->offset = cbb->base->len;
+ if (!CBB_add_u8(cbb, 0)) {
+ return 0;
+ }
+
+ memset(out_contents, 0, sizeof(CBB));
+ out_contents->base = cbb->base;
+ cbb->child = out_contents;
+ cbb->pending_len_len = 1;
+ cbb->pending_is_asn1 = 1;
+
+ return 1;
+}
+
+int CBB_add_bytes(CBB *cbb, const uint8_t *data, size_t len) {
+ uint8_t *dest;
+
+ if (!CBB_flush(cbb) ||
+ !cbb_buffer_add(cbb->base, &dest, len)) {
+ return 0;
+ }
+ memcpy(dest, data, len);
+ return 1;
+}
+
+int CBB_add_space(CBB *cbb, uint8_t **out_data, size_t len) {
+ if (!CBB_flush(cbb) ||
+ !cbb_buffer_add(cbb->base, out_data, len)) {
+ return 0;
+ }
+ return 1;
+}
+
+int CBB_add_u8(CBB *cbb, uint8_t value) {
+ if (!CBB_flush(cbb)) {
+ return 0;
+ }
+
+ return cbb_buffer_add_u(cbb->base, value, 1);
+}
+
+int CBB_add_u16(CBB *cbb, uint16_t value) {
+ if (!CBB_flush(cbb)) {
+ return 0;
+ }
+
+ return cbb_buffer_add_u(cbb->base, value, 2);
+}
+
+int CBB_add_u24(CBB *cbb, uint32_t value) {
+ if (!CBB_flush(cbb)) {
+ return 0;
+ }
+
+ return cbb_buffer_add_u(cbb->base, value, 3);
+}
+
+int CBB_add_asn1_uint64(CBB *cbb, uint64_t value) {
+ CBB child;
+ size_t i;
+ int started = 0;
+
+ if (!CBB_add_asn1(cbb, &child, CBS_ASN1_INTEGER)) {
+ return 0;
+ }
+
+ for (i = 0; i < 8; i++) {
+ uint8_t byte = (value >> 8*(7-i)) & 0xff;
+ if (!started) {
+ if (byte == 0) {
+ /* Don't encode leading zeros. */
+ continue;
+ }
+ /* If the high bit is set, add a padding byte to make it
+ * unsigned. */
+ if ((byte & 0x80) && !CBB_add_u8(&child, 0)) {
+ return 0;
+ }
+ started = 1;
+ }
+ if (!CBB_add_u8(&child, byte)) {
+ return 0;
+ }
+ }
+
+ /* 0 is encoded as a single 0, not the empty string. */
+ if (!started && !CBB_add_u8(&child, 0)) {
+ return 0;
+ }
+
+ return CBB_flush(cbb);
+}