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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/cbs.c
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Initial commit of BoringSSL for Android.
Diffstat (limited to 'src/crypto/bytestring/cbs.c')
-rw-r--r--src/crypto/bytestring/cbs.c388
1 files changed, 388 insertions, 0 deletions
diff --git a/src/crypto/bytestring/cbs.c b/src/crypto/bytestring/cbs.c
new file mode 100644
index 0000000..b417716
--- /dev/null
+++ b/src/crypto/bytestring/cbs.c
@@ -0,0 +1,388 @@
+/* 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/buf.h>
+#include <openssl/mem.h>
+#include <openssl/bytestring.h>
+
+#include <assert.h>
+#include <string.h>
+
+#include "internal.h"
+
+
+void CBS_init(CBS *cbs, const uint8_t *data, size_t len) {
+ cbs->data = data;
+ cbs->len = len;
+}
+
+static int cbs_get(CBS *cbs, const uint8_t **p, size_t n) {
+ if (cbs->len < n) {
+ return 0;
+ }
+
+ *p = cbs->data;
+ cbs->data += n;
+ cbs->len -= n;
+ return 1;
+}
+
+int CBS_skip(CBS *cbs, size_t len) {
+ const uint8_t *dummy;
+ return cbs_get(cbs, &dummy, len);
+}
+
+const uint8_t *CBS_data(const CBS *cbs) {
+ return cbs->data;
+}
+
+size_t CBS_len(const CBS *cbs) {
+ return cbs->len;
+}
+
+int CBS_stow(const CBS *cbs, uint8_t **out_ptr, size_t *out_len) {
+ if (*out_ptr != NULL) {
+ OPENSSL_free(*out_ptr);
+ *out_ptr = NULL;
+ }
+ *out_len = 0;
+
+ if (cbs->len == 0) {
+ return 1;
+ }
+ *out_ptr = BUF_memdup(cbs->data, cbs->len);
+ if (*out_ptr == NULL) {
+ return 0;
+ }
+ *out_len = cbs->len;
+ return 1;
+}
+
+int CBS_strdup(const CBS *cbs, char **out_ptr) {
+ if (*out_ptr != NULL) {
+ OPENSSL_free(*out_ptr);
+ }
+ *out_ptr = BUF_strndup((const char*)cbs->data, cbs->len);
+ return (*out_ptr != NULL);
+}
+
+int CBS_contains_zero_byte(const CBS *cbs) {
+ return memchr(cbs->data, 0, cbs->len) != NULL;
+}
+
+int CBS_mem_equal(const CBS *cbs, const uint8_t *data, size_t len) {
+ if (len != cbs->len)
+ return 0;
+ return CRYPTO_memcmp(cbs->data, data, len) == 0;
+}
+
+static int cbs_get_u(CBS *cbs, uint32_t *out, size_t len) {
+ uint32_t result = 0;
+ size_t i;
+ const uint8_t *data;
+
+ if (!cbs_get(cbs, &data, len)) {
+ return 0;
+ }
+ for (i = 0; i < len; i++) {
+ result <<= 8;
+ result |= data[i];
+ }
+ *out = result;
+ return 1;
+}
+
+int CBS_get_u8(CBS *cbs, uint8_t *out) {
+ const uint8_t *v;
+ if (!cbs_get(cbs, &v, 1)) {
+ return 0;
+ }
+ *out = *v;
+ return 1;
+}
+
+int CBS_get_u16(CBS *cbs, uint16_t *out) {
+ uint32_t v;
+ if (!cbs_get_u(cbs, &v, 2)) {
+ return 0;
+ }
+ *out = v;
+ return 1;
+}
+
+int CBS_get_u24(CBS *cbs, uint32_t *out) {
+ return cbs_get_u(cbs, out, 3);
+}
+
+int CBS_get_u32(CBS *cbs, uint32_t *out) {
+ return cbs_get_u(cbs, out, 4);
+}
+
+int CBS_get_bytes(CBS *cbs, CBS *out, size_t len) {
+ const uint8_t *v;
+ if (!cbs_get(cbs, &v, len)) {
+ return 0;
+ }
+ CBS_init(out, v, len);
+ return 1;
+}
+
+static int cbs_get_length_prefixed(CBS *cbs, CBS *out, size_t len_len) {
+ uint32_t len;
+ if (!cbs_get_u(cbs, &len, len_len)) {
+ return 0;
+ }
+ return CBS_get_bytes(cbs, out, len);
+}
+
+int CBS_get_u8_length_prefixed(CBS *cbs, CBS *out) {
+ return cbs_get_length_prefixed(cbs, out, 1);
+}
+
+int CBS_get_u16_length_prefixed(CBS *cbs, CBS *out) {
+ return cbs_get_length_prefixed(cbs, out, 2);
+}
+
+int CBS_get_u24_length_prefixed(CBS *cbs, CBS *out) {
+ return cbs_get_length_prefixed(cbs, out, 3);
+}
+
+int CBS_get_any_asn1_element(CBS *cbs, CBS *out, unsigned *out_tag,
+ size_t *out_header_len) {
+ uint8_t tag, length_byte;
+ CBS header = *cbs;
+ CBS throwaway;
+
+ if (out == NULL) {
+ out = &throwaway;
+ }
+
+ if (!CBS_get_u8(&header, &tag) ||
+ !CBS_get_u8(&header, &length_byte)) {
+ return 0;
+ }
+
+ if ((tag & 0x1f) == 0x1f) {
+ /* Long form tags are not supported. */
+ return 0;
+ }
+
+ if (out_tag != NULL) {
+ *out_tag = tag;
+ }
+
+ size_t len;
+ if ((length_byte & 0x80) == 0) {
+ /* Short form length. */
+ len = ((size_t) length_byte) + 2;
+ if (out_header_len != NULL) {
+ *out_header_len = 2;
+ }
+ } else {
+ /* Long form length. */
+ const size_t num_bytes = length_byte & 0x7f;
+ uint32_t len32;
+
+ if ((tag & CBS_ASN1_CONSTRUCTED) != 0 && num_bytes == 0) {
+ /* indefinite length */
+ *out_header_len = 2;
+ return CBS_get_bytes(cbs, out, 2);
+ }
+
+ if (num_bytes == 0 || num_bytes > 4) {
+ return 0;
+ }
+ if (!cbs_get_u(&header, &len32, num_bytes)) {
+ return 0;
+ }
+ if (len32 < 128) {
+ /* Length should have used short-form encoding. */
+ return 0;
+ }
+ if ((len32 >> ((num_bytes-1)*8)) == 0) {
+ /* Length should have been at least one byte shorter. */
+ return 0;
+ }
+ len = len32;
+ if (len + 2 + num_bytes < len) {
+ /* Overflow. */
+ return 0;
+ }
+ len += 2 + num_bytes;
+ if (out_header_len != NULL) {
+ *out_header_len = 2 + num_bytes;
+ }
+ }
+
+ return CBS_get_bytes(cbs, out, len);
+}
+
+static int cbs_get_asn1(CBS *cbs, CBS *out, unsigned tag_value,
+ int skip_header) {
+ size_t header_len;
+ unsigned tag;
+ CBS throwaway;
+
+ if (out == NULL) {
+ out = &throwaway;
+ }
+
+ if (!CBS_get_any_asn1_element(cbs, out, &tag, &header_len) ||
+ tag != tag_value ||
+ (header_len > 0 &&
+ /* This ensures that the tag is either zero length or
+ * indefinite-length. */
+ CBS_len(out) == header_len &&
+ CBS_data(out)[header_len - 1] == 0x80)) {
+ return 0;
+ }
+
+ if (skip_header && !CBS_skip(out, header_len)) {
+ assert(0);
+ return 0;
+ }
+
+ return 1;
+}
+
+int CBS_get_asn1(CBS *cbs, CBS *out, unsigned tag_value) {
+ return cbs_get_asn1(cbs, out, tag_value, 1 /* skip header */);
+}
+
+int CBS_get_asn1_element(CBS *cbs, CBS *out, unsigned tag_value) {
+ return cbs_get_asn1(cbs, out, tag_value, 0 /* include header */);
+}
+
+int CBS_peek_asn1_tag(const CBS *cbs, unsigned tag_value) {
+ if (CBS_len(cbs) < 1) {
+ return 0;
+ }
+ return CBS_data(cbs)[0] == tag_value;
+}
+
+int CBS_get_asn1_uint64(CBS *cbs, uint64_t *out) {
+ CBS bytes;
+ const uint8_t *data;
+ size_t i, len;
+
+ if (!CBS_get_asn1(cbs, &bytes, CBS_ASN1_INTEGER)) {
+ return 0;
+ }
+
+ *out = 0;
+ data = CBS_data(&bytes);
+ len = CBS_len(&bytes);
+
+ if (len == 0) {
+ /* An INTEGER is encoded with at least one octet. */
+ return 0;
+ }
+
+ if ((data[0] & 0x80) != 0) {
+ /* negative number */
+ return 0;
+ }
+
+ for (i = 0; i < len; i++) {
+ if ((*out >> 56) != 0) {
+ /* Too large to represent as a uint64_t. */
+ return 0;
+ }
+ *out <<= 8;
+ *out |= data[i];
+ }
+
+ return 1;
+}
+
+int CBS_get_optional_asn1(CBS *cbs, CBS *out, int *out_present, unsigned tag) {
+ if (CBS_peek_asn1_tag(cbs, tag)) {
+ if (!CBS_get_asn1(cbs, out, tag)) {
+ return 0;
+ }
+ *out_present = 1;
+ } else {
+ *out_present = 0;
+ }
+ return 1;
+}
+
+int CBS_get_optional_asn1_octet_string(CBS *cbs, CBS *out, int *out_present,
+ unsigned tag) {
+ CBS child;
+ int present;
+ if (!CBS_get_optional_asn1(cbs, &child, &present, tag)) {
+ return 0;
+ }
+ if (present) {
+ if (!CBS_get_asn1(&child, out, CBS_ASN1_OCTETSTRING) ||
+ CBS_len(&child) != 0) {
+ return 0;
+ }
+ } else {
+ CBS_init(out, NULL, 0);
+ }
+ if (out_present) {
+ *out_present = present;
+ }
+ return 1;
+}
+
+int CBS_get_optional_asn1_uint64(CBS *cbs, uint64_t *out, unsigned tag,
+ uint64_t default_value) {
+ CBS child;
+ int present;
+ if (!CBS_get_optional_asn1(cbs, &child, &present, tag)) {
+ return 0;
+ }
+ if (present) {
+ if (!CBS_get_asn1_uint64(&child, out) ||
+ CBS_len(&child) != 0) {
+ return 0;
+ }
+ } else {
+ *out = default_value;
+ }
+ return 1;
+}
+
+int CBS_get_optional_asn1_bool(CBS *cbs, int *out, unsigned tag,
+ int default_value) {
+ CBS child, child2;
+ int present;
+ if (!CBS_get_optional_asn1(cbs, &child, &present, tag)) {
+ return 0;
+ }
+ if (present) {
+ uint8_t boolean;
+
+ if (!CBS_get_asn1(&child, &child2, CBS_ASN1_BOOLEAN) ||
+ CBS_len(&child2) != 1 ||
+ CBS_len(&child) != 0) {
+ return 0;
+ }
+
+ boolean = CBS_data(&child2)[0];
+ if (boolean == 0) {
+ *out = 0;
+ } else if (boolean == 0xff) {
+ *out = 1;
+ } else {
+ return 0;
+ }
+ } else {
+ *out = default_value;
+ }
+ return 1;
+}