Imported Upstream version 4.8.0.309

Former-commit-id: 5f9c6ae75f295e057a7d2971f3a6df4656fa8850

external/boringssl/crypto/bytestring/CMakeLists.txt

@@ -0,0 +1,25 @@
+include_directories(../../include)
+
+add_library(
+  bytestring
+
+  OBJECT
+
+  asn1_compat.c
+  ber.c
+  cbs.c
+  cbb.c
+)
+
+if(ENABLE_TESTS)
+add_executable(
+  bytestring_test
+
+  bytestring_test.cc
+
+  $<TARGET_OBJECTS:test_support>
+)
+
+target_link_libraries(bytestring_test crypto)
+add_dependencies(all_tests bytestring_test)
+endif()

external/boringssl/crypto/bytestring/asn1_compat.c

@@ -0,0 +1,51 @@
+/* Copyright (c) 2016, 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 <limits.h>
+#include <string.h>
+
+#include <openssl/mem.h>
+
+#include "internal.h"
+
+
+int CBB_finish_i2d(CBB *cbb, uint8_t **outp) {
+  assert(cbb->base->can_resize);
+
+  uint8_t *der;
+  size_t der_len;
+  if (!CBB_finish(cbb, &der, &der_len)) {
+    CBB_cleanup(cbb);
+    return -1;
+  }
+  if (der_len > INT_MAX) {
+    OPENSSL_free(der);
+    return -1;
+  }
+  if (outp != NULL) {
+    if (*outp == NULL) {
+      *outp = der;
+      der = NULL;
+    } else {
+      memcpy(*outp, der, der_len);
+      *outp += der_len;
+    }
+  }
+  OPENSSL_free(der);
+  return (int)der_len;
+}

external/boringssl/crypto/bytestring/ber.c

@@ -0,0 +1,263 @@
+/* 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 "internal.h"
+
+
+/* kMaxDepth is a just a sanity limit. The code should be such that the length
+ * of the input being processes always decreases. None the less, a very large
+ * input could otherwise cause the stack to overflow. */
+static const unsigned kMaxDepth = 2048;
+
+/* is_string_type returns one if |tag| is a string type and zero otherwise. It
+ * ignores the constructed bit. */
+static int is_string_type(unsigned tag) {
+  if ((tag & 0xc0) != 0) {
+    return 0;
+  }
+  switch (tag & 0x1f) {
+    case CBS_ASN1_BITSTRING:
+    case CBS_ASN1_OCTETSTRING:
+    case CBS_ASN1_UTF8STRING:
+    case CBS_ASN1_NUMERICSTRING:
+    case CBS_ASN1_PRINTABLESTRING:
+    case CBS_ASN1_T16STRING:
+    case CBS_ASN1_VIDEOTEXSTRING:
+    case CBS_ASN1_IA5STRING:
+    case CBS_ASN1_GRAPHICSTRING:
+    case CBS_ASN1_VISIBLESTRING:
+    case CBS_ASN1_GENERALSTRING:
+    case CBS_ASN1_UNIVERSALSTRING:
+    case CBS_ASN1_BMPSTRING:
+      return 1;
+    default:
+      return 0;
+  }
+}
+
+/* cbs_find_ber walks an ASN.1 structure in |orig_in| and sets |*ber_found|
+ * depending on whether an indefinite length element or constructed string was
+ * found. The value of |orig_in| is not changed. It returns one on success (i.e.
+ * |*ber_found| was set) and zero on error. */
+static int cbs_find_ber(const CBS *orig_in, char *ber_found, unsigned depth) {
+  CBS in;
+
+  if (depth > kMaxDepth) {
+    return 0;
+  }
+
+  CBS_init(&in, CBS_data(orig_in), CBS_len(orig_in));
+  *ber_found = 0;
+
+  while (CBS_len(&in) > 0) {
+    CBS contents;
+    unsigned tag;
+    size_t header_len;
+
+    if (!CBS_get_any_ber_asn1_element(&in, &contents, &tag, &header_len)) {
+      return 0;
+    }
+    if (CBS_len(&contents) == header_len &&
+        header_len > 0 &&
+        CBS_data(&contents)[header_len-1] == 0x80) {
+      /* Found an indefinite-length element. */
+      *ber_found = 1;
+      return 1;
+    }
+    if (tag & CBS_ASN1_CONSTRUCTED) {
+      if (is_string_type(tag)) {
+        /* Constructed strings are only legal in BER and require conversion. */
+        *ber_found = 1;
+        return 1;
+      }
+      if (!CBS_skip(&contents, header_len) ||
+          !cbs_find_ber(&contents, ber_found, depth + 1)) {
+        return 0;
+      }
+    }
+  }
+
+  return 1;
+}
+
+/* is_eoc returns true if |header_len| and |contents|, as returned by
+ * |CBS_get_any_ber_asn1_element|, indicate an "end of contents" (EOC) value. */
+static char is_eoc(size_t header_len, CBS *contents) {
+  return header_len == 2 && CBS_len(contents) == 2 &&
+         memcmp(CBS_data(contents), "\x00\x00", 2) == 0;
+}
+
+/* cbs_convert_ber reads BER data from |in| and writes DER data to |out|. If
+ * |string_tag| is non-zero, then all elements must match |string_tag| up to the
+ * constructed bit and primitive element bodies are written to |out| without
+ * element headers. This is used when concatenating the fragments of a
+ * constructed string. If |looking_for_eoc| is set then any EOC elements found
+ * will cause the function to return after consuming it. It returns one on
+ * success and zero on error. */
+static int cbs_convert_ber(CBS *in, CBB *out, unsigned string_tag,
+                           char looking_for_eoc, unsigned depth) {
+  assert(!(string_tag & CBS_ASN1_CONSTRUCTED));
+
+  if (depth > kMaxDepth) {
+    return 0;
+  }
+
+  while (CBS_len(in) > 0) {
+    CBS contents;
+    unsigned tag, child_string_tag = string_tag;
+    size_t header_len;
+    CBB *out_contents, out_contents_storage;
+
+    if (!CBS_get_any_ber_asn1_element(in, &contents, &tag, &header_len)) {
+      return 0;
+    }
+
+    if (is_eoc(header_len, &contents)) {
+      return looking_for_eoc;
+    }
+
+    if (string_tag != 0) {
+      /* This is part of a constructed string. All elements must match
+       * |string_tag| up to the constructed bit and get appended to |out|
+       * without a child element. */
+      if ((tag & ~CBS_ASN1_CONSTRUCTED) != string_tag) {
+        return 0;
+      }
+      out_contents = out;
+    } else {
+      unsigned out_tag = tag;
+      if ((tag & CBS_ASN1_CONSTRUCTED) && is_string_type(tag)) {
+        /* If a constructed string, clear the constructed bit and inform
+         * children to concatenate bodies. */
+        out_tag &= ~CBS_ASN1_CONSTRUCTED;
+        child_string_tag = out_tag;
+      }
+      if (!CBB_add_asn1(out, &out_contents_storage, out_tag)) {
+        return 0;
+      }
+      out_contents = &out_contents_storage;
+    }
+
+    if (CBS_len(&contents) == header_len && header_len > 0 &&
+        CBS_data(&contents)[header_len - 1] == 0x80) {
+      /* This is an indefinite length element. */
+      if (!cbs_convert_ber(in, out_contents, child_string_tag,
+                           1 /* looking for eoc */, depth + 1) ||
+          !CBB_flush(out)) {
+        return 0;
+      }
+      continue;
+    }
+
+    if (!CBS_skip(&contents, header_len)) {
+      return 0;
+    }
+
+    if (tag & CBS_ASN1_CONSTRUCTED) {
+      /* Recurse into children. */
+      if (!cbs_convert_ber(&contents, out_contents, child_string_tag,
+                           0 /* not looking for eoc */, depth + 1)) {
+        return 0;
+      }
+    } else {
+      /* Copy primitive contents as-is. */
+      if (!CBB_add_bytes(out_contents, CBS_data(&contents),
+                         CBS_len(&contents))) {
+        return 0;
+      }
+    }
+
+    if (!CBB_flush(out)) {
+      return 0;
+    }
+  }
+
+  return looking_for_eoc == 0;
+}
+
+int CBS_asn1_ber_to_der(CBS *in, uint8_t **out, size_t *out_len) {
+  CBB cbb;
+
+  /* First, do a quick walk to find any indefinite-length elements. Most of the
+   * time we hope that there aren't any and thus we can quickly return. */
+  char conversion_needed;
+  if (!cbs_find_ber(in, &conversion_needed, 0)) {
+    return 0;
+  }
+
+  if (!conversion_needed) {
+    *out = NULL;
+    *out_len = 0;
+    return 1;
+  }
+
+  if (!CBB_init(&cbb, CBS_len(in)) ||
+      !cbs_convert_ber(in, &cbb, 0, 0, 0) ||
+      !CBB_finish(&cbb, out, out_len)) {
+    CBB_cleanup(&cbb);
+    return 0;
+  }
+
+  return 1;
+}
+
+int CBS_get_asn1_implicit_string(CBS *in, CBS *out, uint8_t **out_storage,
+                                 unsigned outer_tag, unsigned inner_tag) {
+  assert(!(outer_tag & CBS_ASN1_CONSTRUCTED));
+  assert(!(inner_tag & CBS_ASN1_CONSTRUCTED));
+  assert(is_string_type(inner_tag));
+
+  if (CBS_peek_asn1_tag(in, outer_tag)) {
+    /* Normal implicitly-tagged string. */
+    *out_storage = NULL;
+    return CBS_get_asn1(in, out, outer_tag);
+  }
+
+  /* Otherwise, try to parse an implicitly-tagged constructed string.
+   * |CBS_asn1_ber_to_der| is assumed to have run, so only allow one level deep
+   * of nesting. */
+  CBB result;
+  CBS child;
+  if (!CBB_init(&result, CBS_len(in)) ||
+      !CBS_get_asn1(in, &child, outer_tag | CBS_ASN1_CONSTRUCTED)) {
+    goto err;
+  }
+
+  while (CBS_len(&child) > 0) {
+    CBS chunk;
+    if (!CBS_get_asn1(&child, &chunk, inner_tag) ||
+        !CBB_add_bytes(&result, CBS_data(&chunk), CBS_len(&chunk))) {
+      goto err;
+    }
+  }
+
+  uint8_t *data;
+  size_t len;
+  if (!CBB_finish(&result, &data, &len)) {
+    goto err;
+  }
+
+  CBS_init(out, data, len);
+  *out_storage = data;
+  return 1;
+
+err:
+  CBB_cleanup(&result);
+  return 0;
+}

external/boringssl/crypto/bytestring/cbb.c

@@ -0,0 +1,445 @@
+/* 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>
+
+
+void CBB_zero(CBB *cbb) {
+  memset(cbb, 0, sizeof(CBB));
+}
+
+static int cbb_init(CBB *cbb, uint8_t *buf, size_t cap) {
+  /* This assumes that |cbb| has already been zeroed. */
+  struct cbb_buffer_st *base;
+
+  base = OPENSSL_malloc(sizeof(struct cbb_buffer_st));
+  if (base == NULL) {
+    return 0;
+  }
+
+  base->buf = buf;
+  base->len = 0;
+  base->cap = cap;
+  base->can_resize = 1;
+
+  cbb->base = base;
+  cbb->is_top_level = 1;
+  return 1;
+}
+
+int CBB_init(CBB *cbb, size_t initial_capacity) {
+  CBB_zero(cbb);
+
+  uint8_t *buf = OPENSSL_malloc(initial_capacity);
+  if (initial_capacity > 0 && buf == NULL) {
+    return 0;
+  }
+
+  if (!cbb_init(cbb, buf, initial_capacity)) {
+    OPENSSL_free(buf);
+    return 0;
+  }
+
+  return 1;
+}
+
+int CBB_init_fixed(CBB *cbb, uint8_t *buf, size_t len) {
+  CBB_zero(cbb);
+
+  if (!cbb_init(cbb, buf, len)) {
+    return 0;
+  }
+
+  cbb->base->can_resize = 0;
+  return 1;
+}
+
+void CBB_cleanup(CBB *cbb) {
+  if (cbb->base) {
+    /* Only top-level |CBB|s are cleaned up. Child |CBB|s are non-owning. They
+     * are implicitly discarded when the parent is flushed or cleaned up. */
+    assert(cbb->is_top_level);
+
+    if (cbb->base->can_resize) {
+      OPENSSL_free(cbb->base->buf);
+    }
+    OPENSSL_free(cbb->base);
+  }
+  cbb->base = NULL;
+}
+
+static int cbb_buffer_reserve(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;
+  }
+
+  return 1;
+}
+
+static int cbb_buffer_add(struct cbb_buffer_st *base, uint8_t **out,
+                          size_t len) {
+  if (!cbb_buffer_reserve(base, out, len)) {
+    return 0;
+  }
+  /* This will not overflow or |cbb_buffer_reserve| would have failed. */
+  base->len += len;
+  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->child->pending_len_len == 0) {
+    return 1;
+  }
+
+  child_start = cbb->child->offset + cbb->child->pending_len_len;
+
+  if (!CBB_flush(cbb->child) ||
+      child_start < cbb->child->offset ||
+      cbb->base->len < child_start) {
+    return 0;
+  }
+
+  len = cbb->base->len - child_start;
+
+  if (cbb->child->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->child->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->child->offset++] = initial_length_byte;
+    cbb->child->pending_len_len = len_len - 1;
+  }
+
+  for (i = cbb->child->pending_len_len - 1; i < cbb->child->pending_len_len;
+       i--) {
+    cbb->base->buf[cbb->child->offset + i] = len;
+    len >>= 8;
+  }
+  if (len != 0) {
+    return 0;
+  }
+
+  cbb->child->base = NULL;
+  cbb->child = NULL;
+
+  return 1;
+}
+
+const uint8_t *CBB_data(const CBB *cbb) {
+  assert(cbb->child == NULL);
+  return cbb->base->buf + cbb->offset + cbb->pending_len_len;
+}
+
+size_t CBB_len(const CBB *cbb) {
+  assert(cbb->child == NULL);
+  assert(cbb->offset + cbb->pending_len_len <= cbb->base->len);
+
+  return cbb->base->len - cbb->offset - cbb->pending_len_len;
+}
+
+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;
+  }
+
+  size_t 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->child->offset = offset;
+  cbb->child->pending_len_len = len_len;
+  cbb->child->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 ((tag & 0x1f) == 0x1f) {
+    /* Long form identifier octets are not supported. */
+    return 0;
+  }
+
+  if (!CBB_flush(cbb) ||
+      !CBB_add_u8(cbb, tag)) {
+    return 0;
+  }
+
+  size_t 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->child->offset = offset;
+  cbb->child->pending_len_len = 1;
+  cbb->child->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_reserve(CBB *cbb, uint8_t **out_data, size_t len) {
+  if (!CBB_flush(cbb) ||
+      !cbb_buffer_reserve(cbb->base, out_data, len)) {
+    return 0;
+  }
+  return 1;
+}
+
+int CBB_did_write(CBB *cbb, size_t len) {
+  size_t newlen = cbb->base->len + len;
+  if (cbb->child != NULL ||
+      newlen < cbb->base->len ||
+      newlen > cbb->base->cap) {
+    return 0;
+  }
+  cbb->base->len = newlen;
+  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);
+}
+
+void CBB_discard_child(CBB *cbb) {
+  if (cbb->child == NULL) {
+    return;
+  }
+
+  cbb->base->len = cbb->child->offset;
+
+  cbb->child->base = NULL;
+  cbb->child = NULL;
+}
+
+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);
+}

external/boringssl/crypto/bytestring/cbs.c

@@ -0,0 +1,440 @@
+/* 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) {
+  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_last_u8(CBS *cbs, uint8_t *out) {
+  if (cbs->len == 0) {
+    return 0;
+  }
+  *out = cbs->data[cbs->len - 1];
+  cbs->len--;
+  return 1;
+}
+
+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;
+}
+
+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)) {
+    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);
+}
+
+static int cbs_get_any_asn1_element(CBS *cbs, CBS *out, unsigned *out_tag,
+                                    size_t *out_header_len, int ber_ok) {
+  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;
+  }
+
+  /* ITU-T X.690 section 8.1.2.3 specifies the format for identifiers with a tag
+   * number no greater than 30.
+   *
+   * If the number portion is 31 (0x1f, the largest value that fits in the
+   * allotted bits), then the tag is more than one byte long and the
+   * continuation bytes contain the tag number. This parser only supports tag
+   * numbers less than 31 (and thus single-byte tags). */
+  if ((tag & 0x1f) == 0x1f) {
+    return 0;
+  }
+
+  if (out_tag != NULL) {
+    *out_tag = tag;
+  }
+
+  size_t len;
+  /* The format for the length encoding is specified in ITU-T X.690 section
+   * 8.1.3. */
+  if ((length_byte & 0x80) == 0) {
+    /* Short form length. */
+    len = ((size_t) length_byte) + 2;
+    if (out_header_len != NULL) {
+      *out_header_len = 2;
+    }
+  } else {
+    /* The high bit indicate that this is the long form, while the next 7 bits
+     * encode the number of subsequent octets used to encode the length (ITU-T
+     * X.690 clause 8.1.3.5.b). */
+    const size_t num_bytes = length_byte & 0x7f;
+    uint32_t len32;
+
+    if (ber_ok && (tag & CBS_ASN1_CONSTRUCTED) != 0 && num_bytes == 0) {
+      /* indefinite length */
+      if (out_header_len != NULL) {
+        *out_header_len = 2;
+      }
+      return CBS_get_bytes(cbs, out, 2);
+    }
+
+    /* ITU-T X.690 clause 8.1.3.5.c specifies that the value 0xff shall not be
+     * used as the first byte of the length. If this parser encounters that
+     * value, num_bytes will be parsed as 127, which will fail the check below.
+     */
+    if (num_bytes == 0 || num_bytes > 4) {
+      return 0;
+    }
+    if (!cbs_get_u(&header, &len32, num_bytes)) {
+      return 0;
+    }
+    /* ITU-T X.690 section 10.1 (DER length forms) requires encoding the length
+     * with the minimum number of octets. */
+    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);
+}
+
+int CBS_get_any_asn1_element(CBS *cbs, CBS *out, unsigned *out_tag,
+                                    size_t *out_header_len) {
+  return cbs_get_any_asn1_element(cbs, out, out_tag, out_header_len,
+                                  0 /* DER only */);
+}
+
+int CBS_get_any_ber_asn1_element(CBS *cbs, CBS *out, unsigned *out_tag,
+                                 size_t *out_header_len) {
+  return cbs_get_any_asn1_element(cbs, out, out_tag, out_header_len,
+                                  1 /* BER allowed */);
+}
+
+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) {
+    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;
+  }
+
+  if (data[0] == 0 && len > 1 && (data[1] & 0x80) == 0) {
+    /* Extra leading zeros. */
+    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) {
+  int present = 0;
+
+  if (CBS_peek_asn1_tag(cbs, tag)) {
+    if (!CBS_get_asn1(cbs, out, tag)) {
+      return 0;
+    }
+    present = 1;
+  }
+
+  if (out_present != NULL) {
+    *out_present = present;
+  }
+
+  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;
+}

external/boringssl/crypto/bytestring/internal.h

@@ -0,0 +1,75 @@
+/* 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. */
+
+#ifndef OPENSSL_HEADER_BYTESTRING_INTERNAL_H
+#define OPENSSL_HEADER_BYTESTRING_INTERNAL_H
+
+#include <openssl/base.h>
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+
+/* CBS_asn1_ber_to_der reads a BER element from |in|. If it finds
+ * indefinite-length elements or constructed strings then it converts the BER
+ * data to DER and sets |*out| and |*out_length| to describe a malloced buffer
+ * containing the DER data. Additionally, |*in| will be advanced over the BER
+ * element.
+ *
+ * If it doesn't find any indefinite-length elements or constructed strings then
+ * it sets |*out| to NULL and |*in| is unmodified.
+ *
+ * This function should successfully process any valid BER input, however it
+ * will not convert all of BER's deviations from DER. BER is ambiguous between
+ * implicitly-tagged SEQUENCEs of strings and implicitly-tagged constructed
+ * strings. Implicitly-tagged strings must be parsed with
+ * |CBS_get_ber_implicitly_tagged_string| instead of |CBS_get_asn1|. The caller
+ * must also account for BER variations in the contents of a primitive.
+ *
+ * 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_asn1_implicit_string parses a BER string of primitive type
+ * |inner_tag| implicitly-tagged with |outer_tag|. It sets |out| to the
+ * contents. If concatenation was needed, it sets |*out_storage| to a buffer
+ * which the caller must release with |OPENSSL_free|. Otherwise, it sets
+ * |*out_storage| to NULL.
+ *
+ * This function does not parse all of BER. It requires the string be
+ * definite-length. Constructed strings are allowed, but all children of the
+ * outermost element must be primitive. The caller should use
+ * |CBS_asn1_ber_to_der| before running this function.
+ *
+ * It returns one on success and zero otherwise. */
+OPENSSL_EXPORT int CBS_get_asn1_implicit_string(CBS *in, CBS *out,
+                                                uint8_t **out_storage,
+                                                unsigned outer_tag,
+                                                unsigned inner_tag);
+
+/* CBB_finish_i2d calls |CBB_finish| on |cbb| which must have been initialized
+ * with |CBB_init|. If |outp| is not NULL then the result is written to |*outp|
+ * and |*outp| is advanced just past the output. It returns the number of bytes
+ * in the result, whether written or not, or a negative value on error. On
+ * error, it calls |CBB_cleanup| on |cbb|.
+ *
+ * This function may be used to help implement legacy i2d ASN.1 functions. */
+int CBB_finish_i2d(CBB *cbb, uint8_t **outp);
+
+
+#if defined(__cplusplus)
+}  /* extern C */
+#endif
+
+#endif  /* OPENSSL_HEADER_BYTESTRING_INTERNAL_H */