5 files changed, 38 insertions, 14 deletions
diff --git a/src/crypto/bytestring/CMakeLists.txt b/src/crypto/bytestring/CMakeLists.txt
index cbbacf2..3462aee 100644
--- a/src/crypto/bytestring/CMakeLists.txt
+++ b/src/crypto/bytestring/CMakeLists.txt
@@ -1,4 +1,4 @@
-include_directories(. .. ../../include)
+include_directories(../../include)
 
 add_library(
   bytestring
diff --git a/src/crypto/bytestring/bytestring_test.cc b/src/crypto/bytestring/bytestring_test.cc
index 66e9c1e..e987e1b 100644
--- a/src/crypto/bytestring/bytestring_test.cc
+++ b/src/crypto/bytestring/bytestring_test.cc
@@ -109,7 +109,7 @@ static bool TestGetASN1() {
   static const uint8_t kData2[] = {0x30, 3, 1, 2};
   static const uint8_t kData3[] = {0x30, 0x80};
   static const uint8_t kData4[] = {0x30, 0x81, 1, 1};
-  static const uint8_t kData5[] = {0x30, 0x82, 0, 1, 1};
+  static const uint8_t kData5[4 + 0x80] = {0x30, 0x82, 0, 0x80};
   static const uint8_t kData6[] = {0xa1, 3, 0x4, 1, 1};
   static const uint8_t kData7[] = {0xa1, 3, 0x4, 2, 1};
   static const uint8_t kData8[] = {0xa1, 3, 0x2, 1, 1};
@@ -649,6 +649,14 @@ static bool TestASN1Uint64() {
   return true;
 }
 
+static int TestZero() {
+  CBB cbb;
+  CBB_zero(&cbb);
+  // Calling |CBB_cleanup| on a zero-state |CBB| must not crash.
+  CBB_cleanup(&cbb);
+  return 1;
+}
+
 int main(void) {
   CRYPTO_library_init();
 
@@ -665,7 +673,8 @@ int main(void) {
       !TestCBBASN1() ||
       !TestBerConvert() ||
       !TestASN1Uint64() ||
-      !TestGetOptionalASN1Bool()) {
+      !TestGetOptionalASN1Bool() ||
+      !TestZero()) {
     return 1;
   }
 
diff --git a/src/crypto/bytestring/cbb.c b/src/crypto/bytestring/cbb.c
index f1e09a2..1da6a21 100644
--- a/src/crypto/bytestring/cbb.c
+++ b/src/crypto/bytestring/cbb.c
@@ -20,6 +20,10 @@
 #include <openssl/mem.h>
 
 
+void CBB_zero(CBB *cbb) {
+  memset(cbb, 0, sizeof(CBB));
+}
+
 static int cbb_init(CBB *cbb, uint8_t *buf, size_t cap) {
   struct cbb_buffer_st *base;
 
@@ -243,6 +247,11 @@ int CBB_flush(CBB *cbb) {
   return 1;
 }
 
+size_t CBB_len(const CBB *cbb) {
+  assert(cbb->child == NULL);
+
+  return cbb->base->len;
+}
 
 static int cbb_add_length_prefixed(CBB *cbb, CBB *out_contents,
                                    size_t len_len) {
diff --git a/src/crypto/bytestring/cbs.c b/src/crypto/bytestring/cbs.c
index b8caedd..5e0c538 100644
--- a/src/crypto/bytestring/cbs.c
+++ b/src/crypto/bytestring/cbs.c
@@ -137,6 +137,15 @@ int CBS_get_bytes(CBS *cbs, CBS *out, size_t len) {
   return 1;
 }
 
+int CBS_copy_bytes(CBS *cbs, uint8_t *out, size_t len) {
+  const uint8_t *v;
+  if (!cbs_get(cbs, &v, len)) {
+    return 0;
+  }
+  memcpy(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)) {
@@ -320,14 +329,19 @@ int CBS_get_asn1_uint64(CBS *cbs, uint64_t *out) {
 }
 
 int CBS_get_optional_asn1(CBS *cbs, CBS *out, int *out_present, unsigned tag) {
+  int present = 0;
+
   if (CBS_peek_asn1_tag(cbs, tag)) {
     if (!CBS_get_asn1(cbs, out, tag)) {
       return 0;
     }
-    *out_present = 1;
-  } else {
-    *out_present = 0;
+    present = 1;
+  }
+
+  if (out_present != NULL) {
+    *out_present = present;
   }
+
   return 1;
 }
 
diff --git a/src/crypto/bytestring/internal.h b/src/crypto/bytestring/internal.h
index 391ad19..b4ea7e5 100644
--- a/src/crypto/bytestring/internal.h
+++ b/src/crypto/bytestring/internal.h
@@ -38,14 +38,6 @@ extern "C" {
  * It returns one on success and zero otherwise. */
 OPENSSL_EXPORT int CBS_asn1_ber_to_der(CBS *in, uint8_t **out, size_t *out_len);
 
-/* CBS_get_any_ber_asn1_element acts the same as |CBS_get_any_asn1_element| but
- * also allows indefinite-length elements to be returned. In that case,
- * |*out_header_len| and |CBS_len(out)| will both be two as only the header is
- * returned. */
-OPENSSL_EXPORT int CBS_get_any_ber_asn1_element(CBS *cbs, CBS *out,
-                                                unsigned *out_tag,
-                                                size_t *out_header_len);
-
 
 #if defined(__cplusplus)
 }  /* extern C */