1 files changed, 657 insertions, 0 deletions
diff --git a/media/gmp-clearkey/0.1/ClearKeyUtils.cpp b/media/gmp-clearkey/0.1/ClearKeyUtils.cpp
new file mode 100644
index 0000000000..086283fb2e
--- /dev/null
+++ b/media/gmp-clearkey/0.1/ClearKeyUtils.cpp
@@ -0,0 +1,657 @@
+/*
+ * Copyright 2015, Mozilla Foundation and contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "ClearKeyUtils.h"
+
+#include <assert.h>
+#include <ctype.h>
+#include <memory.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <algorithm>
+#include <cctype>
+#include <memory>
+#include <sstream>
+#include <vector>
+
+#include "pk11pub.h"
+#include "prerror.h"
+#include "secmodt.h"
+
+#include "ArrayUtils.h"
+#include "BigEndian.h"
+#include "ClearKeyBase64.h"
+#include "mozilla/Sprintf.h"
+#include "psshparser/PsshParser.h"
+
+using namespace cdm;
+using std::string;
+using std::stringstream;
+using std::vector;
+
+struct DeleteHelper {
+  void operator()(PK11Context* value) { PK11_DestroyContext(value, true); }
+  void operator()(PK11SlotInfo* value) { PK11_FreeSlot(value); }
+  void operator()(PK11SymKey* value) { PK11_FreeSymKey(value); }
+};
+
+template <class T>
+struct MaybeDeleteHelper {
+  void operator()(T* ptr) {
+    if (ptr) {
+      DeleteHelper del;
+      del(ptr);
+    }
+  }
+};
+
+void CK_Log(const char* aFmt, ...) {
+  FILE* out = stdout;
+
+  if (getenv("CLEARKEY_LOG_FILE")) {
+    out = fopen(getenv("CLEARKEY_LOG_FILE"), "a");
+  }
+
+  va_list ap;
+
+  va_start(ap, aFmt);
+  const size_t len = 1024;
+  char buf[len];
+  VsprintfLiteral(buf, aFmt, ap);
+  va_end(ap);
+
+  fprintf(out, "%s\n", buf);
+  fflush(out);
+
+  if (out != stdout) {
+    fclose(out);
+  }
+}
+
+static bool PrintableAsString(const uint8_t* aBytes, uint32_t aLength) {
+  return std::all_of(aBytes, aBytes + aLength,
+                     [](uint8_t c) { return isprint(c) == 1; });
+}
+
+void CK_LogArray(const char* prepend, const uint8_t* aData,
+                 const uint32_t aDataSize) {
+  // If the data is valid ascii, use that. Otherwise print the hex
+  string data = PrintableAsString(aData, aDataSize)
+                    ? string(aData, aData + aDataSize)
+                    : ClearKeyUtils::ToHexString(aData, aDataSize);
+
+  CK_LOGD("%s%s", prepend, data.c_str());
+}
+
+/* static */
+bool ClearKeyUtils::DecryptCbcs(const vector<uint8_t>& aKey,
+                                const vector<uint8_t>& aIV,
+                                mozilla::Span<uint8_t> aSubsample,
+                                uint32_t aCryptByteBlock,
+                                uint32_t aSkipByteBlock) {
+  assert(aKey.size() == CENC_KEY_LEN);
+  assert(aIV.size() == CENC_KEY_LEN);
+  assert(aCryptByteBlock <= 0xFF);
+  assert(aSkipByteBlock <= 0xFF);
+
+  std::unique_ptr<PK11SlotInfo, MaybeDeleteHelper<PK11SlotInfo>> slot(
+      PK11_GetInternalKeySlot());
+
+  if (!slot.get()) {
+    CK_LOGE("Failed to get internal PK11 slot");
+    return false;
+  }
+
+  SECItem keyItem = {siBuffer, (unsigned char*)&aKey[0], CENC_KEY_LEN};
+  SECItem ivItem = {siBuffer, (unsigned char*)&aIV[0], CENC_KEY_LEN};
+
+  std::unique_ptr<PK11SymKey, MaybeDeleteHelper<PK11SymKey>> key(
+      PK11_ImportSymKey(slot.get(), CKM_AES_CBC, PK11_OriginUnwrap, CKA_DECRYPT,
+                        &keyItem, nullptr));
+
+  if (!key.get()) {
+    CK_LOGE("Failed to import sym key");
+    return false;
+  }
+
+  std::unique_ptr<PK11Context, MaybeDeleteHelper<PK11Context>> ctx(
+      PK11_CreateContextBySymKey(CKM_AES_CBC, CKA_DECRYPT, key.get(), &ivItem));
+
+  uint8_t* encryptedSubsample = &aSubsample[0];
+  const uint32_t BLOCK_SIZE = 16;
+  const uint32_t skipBytes = aSkipByteBlock * BLOCK_SIZE;
+  const uint32_t totalBlocks = aSubsample.Length() / BLOCK_SIZE;
+  uint32_t blocksProcessed = 0;
+
+  if (aSkipByteBlock == 0) {
+    // ISO/IEC 23001 - 7 Section 9.6.1
+    // 'When the fields default_crypt_byte_block and default_skip_byte_block in
+    // a version 1 Track Encryption Box('tenc') are non - zero numbers, pattern
+    // encryption SHALL be applied.'
+    // So if both are 0, then everything is encrypted. Similarly, if skip is 0
+    // and crypt is non-0, everything is encrypted.
+    // In this case we can just decrypt all the blocks in one call. This is the
+    // same outcome as decrypting them using smaller steps, as either way the
+    // CBC result should be the same.
+    MOZ_ASSERT(skipBytes == 0);
+    aCryptByteBlock = totalBlocks;
+  }
+
+  while (blocksProcessed < totalBlocks) {
+    uint32_t blocksToDecrypt = aCryptByteBlock <= totalBlocks - blocksProcessed
+                                   ? aCryptByteBlock
+                                   : totalBlocks - blocksProcessed;
+    uint32_t bytesToDecrypt = blocksToDecrypt * BLOCK_SIZE;
+    int outLen;
+    SECStatus rv;
+    rv = PK11_CipherOp(ctx.get(), encryptedSubsample, &outLen, bytesToDecrypt,
+                       encryptedSubsample, bytesToDecrypt);
+    if (rv != SECSuccess) {
+      CK_LOGE("PK11_CipherOp() failed");
+      return false;
+    }
+
+    encryptedSubsample += skipBytes + bytesToDecrypt;
+    blocksProcessed += aSkipByteBlock + blocksToDecrypt;
+  }
+
+  return true;
+}
+
+/* static */
+bool ClearKeyUtils::DecryptAES(const vector<uint8_t>& aKey,
+                               vector<uint8_t>& aData, vector<uint8_t>& aIV) {
+  assert(aIV.size() == CENC_KEY_LEN);
+  assert(aKey.size() == CENC_KEY_LEN);
+
+  PK11SlotInfo* slot = PK11_GetInternalKeySlot();
+  if (!slot) {
+    CK_LOGE("Failed to get internal PK11 slot");
+    return false;
+  }
+
+  SECItem keyItem = {siBuffer, (unsigned char*)&aKey[0], CENC_KEY_LEN};
+  PK11SymKey* key = PK11_ImportSymKey(slot, CKM_AES_CTR, PK11_OriginUnwrap,
+                                      CKA_ENCRYPT, &keyItem, nullptr);
+  PK11_FreeSlot(slot);
+  if (!key) {
+    CK_LOGE("Failed to import sym key");
+    return false;
+  }
+
+  CK_AES_CTR_PARAMS params;
+  params.ulCounterBits = 32;
+  memcpy(&params.cb, &aIV[0], CENC_KEY_LEN);
+  SECItem paramItem = {siBuffer, (unsigned char*)&params,
+                       sizeof(CK_AES_CTR_PARAMS)};
+
+  unsigned int outLen = 0;
+  auto rv = PK11_Decrypt(key, CKM_AES_CTR, &paramItem, &aData[0], &outLen,
+                         aData.size(), &aData[0], aData.size());
+
+  aData.resize(outLen);
+  PK11_FreeSymKey(key);
+
+  if (rv != SECSuccess) {
+    CK_LOGE("PK11_Decrypt() failed");
+    return false;
+  }
+
+  return true;
+}
+
+/**
+ * ClearKey expects all Key IDs to be base64 encoded with non-standard alphabet
+ * and padding.
+ */
+static bool EncodeBase64Web(vector<uint8_t> aBinary, string& aEncoded) {
+  const char sAlphabet[] =
+      "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_";
+  const uint8_t sMask = 0x3f;
+
+  aEncoded.resize((aBinary.size() * 8 + 5) / 6);
+
+  // Pad binary data in case there's rubbish past the last byte.
+  aBinary.push_back(0);
+
+  // Number of bytes not consumed in the previous character
+  uint32_t shift = 0;
+
+  auto out = aEncoded.begin();
+  auto data = aBinary.begin();
+  for (string::size_type i = 0; i < aEncoded.length(); i++) {
+    if (shift) {
+      out[i] = (*data << (6 - shift)) & sMask;
+      data++;
+    } else {
+      out[i] = 0;
+    }
+
+    out[i] += (*data >> (shift + 2)) & sMask;
+    shift = (shift + 2) % 8;
+
+    // Cast idx to size_t before using it as an array-index,
+    // to pacify clang 'Wchar-subscripts' warning:
+    size_t idx = static_cast<size_t>(out[i]);
+
+    // out of bounds index for 'sAlphabet'
+    assert(idx < MOZ_ARRAY_LENGTH(sAlphabet));
+    out[i] = sAlphabet[idx];
+  }
+
+  return true;
+}
+
+/* static */
+void ClearKeyUtils::MakeKeyRequest(const vector<KeyId>& aKeyIDs,
+                                   string& aOutRequest,
+                                   SessionType aSessionType) {
+  assert(!aKeyIDs.empty() && aOutRequest.empty());
+
+  aOutRequest.append("{\"kids\":[");
+  for (size_t i = 0; i < aKeyIDs.size(); i++) {
+    if (i) {
+      aOutRequest.append(",");
+    }
+    aOutRequest.append("\"");
+
+    string base64key;
+    EncodeBase64Web(aKeyIDs[i], base64key);
+    aOutRequest.append(base64key);
+
+    aOutRequest.append("\"");
+  }
+  aOutRequest.append("],\"type\":");
+
+  aOutRequest.append("\"");
+  aOutRequest.append(SessionTypeToString(aSessionType));
+  aOutRequest.append("\"}");
+}
+
+#define EXPECT_SYMBOL(CTX, X)                     \
+  do {                                            \
+    if (GetNextSymbol(CTX) != (X)) {              \
+      CK_LOGE("Unexpected symbol in JWK parser"); \
+      return false;                               \
+    }                                             \
+  } while (false)
+
+struct ParserContext {
+  const uint8_t* mIter;
+  const uint8_t* mEnd;
+};
+
+static uint8_t PeekSymbol(ParserContext& aCtx) {
+  for (; aCtx.mIter < aCtx.mEnd; (aCtx.mIter)++) {
+    if (!isspace(*aCtx.mIter)) {
+      return *aCtx.mIter;
+    }
+  }
+
+  return 0;
+}
+
+static uint8_t GetNextSymbol(ParserContext& aCtx) {
+  uint8_t sym = PeekSymbol(aCtx);
+  aCtx.mIter++;
+  return sym;
+}
+
+static bool SkipToken(ParserContext& aCtx);
+
+static bool SkipString(ParserContext& aCtx) {
+  EXPECT_SYMBOL(aCtx, '"');
+  for (uint8_t sym = GetNextSymbol(aCtx); sym; sym = GetNextSymbol(aCtx)) {
+    if (sym == '\\') {
+      sym = GetNextSymbol(aCtx);
+      if (!sym) {
+        return false;
+      }
+    } else if (sym == '"') {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+/**
+ * Skip whole object and values it contains.
+ */
+static bool SkipObject(ParserContext& aCtx) {
+  EXPECT_SYMBOL(aCtx, '{');
+
+  if (PeekSymbol(aCtx) == '}') {
+    GetNextSymbol(aCtx);
+    return true;
+  }
+
+  while (true) {
+    if (!SkipString(aCtx)) return false;
+    EXPECT_SYMBOL(aCtx, ':');
+    if (!SkipToken(aCtx)) return false;
+
+    if (PeekSymbol(aCtx) == '}') {
+      GetNextSymbol(aCtx);
+      return true;
+    }
+    EXPECT_SYMBOL(aCtx, ',');
+  }
+
+  return false;
+}
+
+/**
+ * Skip array value and the values it contains.
+ */
+static bool SkipArray(ParserContext& aCtx) {
+  EXPECT_SYMBOL(aCtx, '[');
+
+  if (PeekSymbol(aCtx) == ']') {
+    GetNextSymbol(aCtx);
+    return true;
+  }
+
+  while (SkipToken(aCtx)) {
+    if (PeekSymbol(aCtx) == ']') {
+      GetNextSymbol(aCtx);
+      return true;
+    }
+    EXPECT_SYMBOL(aCtx, ',');
+  }
+
+  return false;
+}
+
+/**
+ * Skip unquoted literals like numbers, |true|, and |null|.
+ * (XXX and anything else that matches /([:alnum:]|[+-.])+/)
+ */
+static bool SkipLiteral(ParserContext& aCtx) {
+  for (; aCtx.mIter < aCtx.mEnd; aCtx.mIter++) {
+    if (!isalnum(*aCtx.mIter) && *aCtx.mIter != '.' && *aCtx.mIter != '-' &&
+        *aCtx.mIter != '+') {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+static bool SkipToken(ParserContext& aCtx) {
+  uint8_t startSym = PeekSymbol(aCtx);
+  if (startSym == '"') {
+    CK_LOGD("JWK parser skipping string");
+    return SkipString(aCtx);
+  } else if (startSym == '{') {
+    CK_LOGD("JWK parser skipping object");
+    return SkipObject(aCtx);
+  } else if (startSym == '[') {
+    CK_LOGD("JWK parser skipping array");
+    return SkipArray(aCtx);
+  } else {
+    CK_LOGD("JWK parser skipping literal");
+    return SkipLiteral(aCtx);
+  }
+
+  return false;
+}
+
+static bool GetNextLabel(ParserContext& aCtx, string& aOutLabel) {
+  EXPECT_SYMBOL(aCtx, '"');
+
+  const uint8_t* start = aCtx.mIter;
+  for (uint8_t sym = GetNextSymbol(aCtx); sym; sym = GetNextSymbol(aCtx)) {
+    if (sym == '\\') {
+      GetNextSymbol(aCtx);
+      continue;
+    }
+
+    if (sym == '"') {
+      aOutLabel.assign(start, aCtx.mIter - 1);
+      return true;
+    }
+  }
+
+  return false;
+}
+
+static bool ParseKeyObject(ParserContext& aCtx, KeyIdPair& aOutKey) {
+  EXPECT_SYMBOL(aCtx, '{');
+
+  // Reject empty objects as invalid licenses.
+  if (PeekSymbol(aCtx) == '}') {
+    GetNextSymbol(aCtx);
+    return false;
+  }
+
+  string keyId;
+  string key;
+
+  while (true) {
+    string label;
+    string value;
+
+    if (!GetNextLabel(aCtx, label)) {
+      return false;
+    }
+
+    EXPECT_SYMBOL(aCtx, ':');
+    if (label == "kty") {
+      if (!GetNextLabel(aCtx, value)) return false;
+      // By spec, type must be "oct".
+      if (value != "oct") return false;
+    } else if (label == "k" && PeekSymbol(aCtx) == '"') {
+      // if this isn't a string we will fall through to the SkipToken() path.
+      if (!GetNextLabel(aCtx, key)) return false;
+    } else if (label == "kid" && PeekSymbol(aCtx) == '"') {
+      if (!GetNextLabel(aCtx, keyId)) return false;
+    } else {
+      if (!SkipToken(aCtx)) return false;
+    }
+
+    uint8_t sym = PeekSymbol(aCtx);
+    if (!sym || sym == '}') {
+      break;
+    }
+    EXPECT_SYMBOL(aCtx, ',');
+  }
+
+  return !key.empty() && !keyId.empty() &&
+         DecodeBase64(keyId, aOutKey.mKeyId) &&
+         DecodeBase64(key, aOutKey.mKey) && GetNextSymbol(aCtx) == '}';
+}
+
+static bool ParseKeys(ParserContext& aCtx, vector<KeyIdPair>& aOutKeys) {
+  // Consume start of array.
+  EXPECT_SYMBOL(aCtx, '[');
+
+  while (true) {
+    KeyIdPair key;
+    if (!ParseKeyObject(aCtx, key)) {
+      CK_LOGE("Failed to parse key object");
+      return false;
+    }
+
+    assert(!key.mKey.empty() && !key.mKeyId.empty());
+    aOutKeys.push_back(key);
+
+    uint8_t sym = PeekSymbol(aCtx);
+    if (!sym || sym == ']') {
+      break;
+    }
+
+    EXPECT_SYMBOL(aCtx, ',');
+  }
+
+  return GetNextSymbol(aCtx) == ']';
+}
+
+/* static */
+bool ClearKeyUtils::ParseJWK(const uint8_t* aKeyData, uint32_t aKeyDataSize,
+                             vector<KeyIdPair>& aOutKeys,
+                             SessionType aSessionType) {
+  ParserContext ctx;
+  ctx.mIter = aKeyData;
+  ctx.mEnd = aKeyData + aKeyDataSize;
+
+  // Consume '{' from start of object.
+  EXPECT_SYMBOL(ctx, '{');
+
+  while (true) {
+    string label;
+    // Consume member key.
+    if (!GetNextLabel(ctx, label)) return false;
+    EXPECT_SYMBOL(ctx, ':');
+
+    if (label == "keys") {
+      // Parse "keys" array.
+      if (!ParseKeys(ctx, aOutKeys)) return false;
+    } else if (label == "type") {
+      // Consume type string.
+      string type;
+      if (!GetNextLabel(ctx, type)) return false;
+      if (type != SessionTypeToString(aSessionType)) {
+        return false;
+      }
+    } else {
+      SkipToken(ctx);
+    }
+
+    // Check for end of object.
+    if (PeekSymbol(ctx) == '}') {
+      break;
+    }
+
+    // Consume ',' between object members.
+    EXPECT_SYMBOL(ctx, ',');
+  }
+
+  // Consume '}' from end of object.
+  EXPECT_SYMBOL(ctx, '}');
+
+  return true;
+}
+
+static bool ParseKeyIds(ParserContext& aCtx, vector<KeyId>& aOutKeyIds) {
+  // Consume start of array.
+  EXPECT_SYMBOL(aCtx, '[');
+
+  while (true) {
+    string label;
+    vector<uint8_t> keyId;
+    if (!GetNextLabel(aCtx, label) || !DecodeBase64(label, keyId)) {
+      return false;
+    }
+    if (!keyId.empty() && keyId.size() <= kMaxKeyIdsLength) {
+      aOutKeyIds.push_back(keyId);
+    }
+
+    uint8_t sym = PeekSymbol(aCtx);
+    if (!sym || sym == ']') {
+      break;
+    }
+
+    EXPECT_SYMBOL(aCtx, ',');
+  }
+
+  return GetNextSymbol(aCtx) == ']';
+}
+
+/* static */
+bool ClearKeyUtils::ParseKeyIdsInitData(const uint8_t* aInitData,
+                                        uint32_t aInitDataSize,
+                                        vector<KeyId>& aOutKeyIds) {
+  ParserContext ctx;
+  ctx.mIter = aInitData;
+  ctx.mEnd = aInitData + aInitDataSize;
+
+  // Consume '{' from start of object.
+  EXPECT_SYMBOL(ctx, '{');
+
+  while (true) {
+    string label;
+    // Consume member kids.
+    if (!GetNextLabel(ctx, label)) return false;
+    EXPECT_SYMBOL(ctx, ':');
+
+    if (label == "kids") {
+      // Parse "kids" array.
+      if (!ParseKeyIds(ctx, aOutKeyIds) || aOutKeyIds.empty()) {
+        return false;
+      }
+    } else {
+      SkipToken(ctx);
+    }
+
+    // Check for end of object.
+    if (PeekSymbol(ctx) == '}') {
+      break;
+    }
+
+    // Consume ',' between object members.
+    EXPECT_SYMBOL(ctx, ',');
+  }
+
+  // Consume '}' from end of object.
+  EXPECT_SYMBOL(ctx, '}');
+
+  return true;
+}
+
+/* static */ const char* ClearKeyUtils::SessionTypeToString(
+    SessionType aSessionType) {
+  switch (aSessionType) {
+    case SessionType::kTemporary:
+      return "temporary";
+    case SessionType::kPersistentLicense:
+      return "persistent-license";
+    default: {
+      // We don't support any other license types.
+      assert(false);
+      return "invalid";
+    }
+  }
+}
+
+/* static */
+bool ClearKeyUtils::IsValidSessionId(const char* aBuff, uint32_t aLength) {
+  if (aLength > 10) {
+    // 10 is the max number of characters in UINT32_MAX when
+    // represented as a string; ClearKey session ids are integers.
+    return false;
+  }
+  for (uint32_t i = 0; i < aLength; i++) {
+    if (!isdigit(aBuff[i])) {
+      return false;
+    }
+  }
+  return true;
+}
+
+string ClearKeyUtils::ToHexString(const uint8_t* aBytes, uint32_t aLength) {
+  stringstream ss;
+  ss << std::showbase << std::uppercase << std::hex;
+  for (uint32_t i = 0; i < aLength; ++i) {
+    ss << std::hex << static_cast<uint32_t>(aBytes[i]);
+    ss << " ";
+  }
+
+  return ss.str();
+}