Fix ClearKey Drm base64 en/decoding to use base64url.

ClearKey's base64  en/decoding should use '-' and '_'
instead of '+' and '/' (web safe coding). Add support
for base64url coding in libstagefright foundation library
and update ClearKey plugins.

Test: CTS - ClearSystemTests
  ANDROID_BUILD_droid-cts/tools/cts-tradefed run cts -m
  CtsMediaTestCases --test android.media.cts.ClearKeySystemTest

Test: CTS - NativeClearSystemTests
  ANDROID_BUILD_droid-cts/tools/cts-tradefed run cts -m
  CtsMediaTestCases --test android.media.cts.NativeClearKeySystemTest

Test: libstagefright/foundation/tests/Base64_test
  adb shell /data/nativetest64/sf_foundation_test/sf_foundation_test

Test: ClearKeyDrmUnitTest
  adb shell LD_LIBRARY_PATH="/vendor/lib/mediadrm"
  /data/nativetest/ClearKeyDrmUnitTest/ClearKeyDrmUnitTest

Test: Vts
  vts-tradefed run commandAndExit vts -m VtsHalDrmV1_0Target
  --primary-abi-only -l VERBOSE

bug: 64388098
Change-Id: Ic08515fd491f15e088600c64603149401c117f4a
diff --git a/drm/mediadrm/plugins/clearkey/InitDataParser.cpp b/drm/mediadrm/plugins/clearkey/InitDataParser.cpp
index 6a4f8d5..caff393 100644
--- a/drm/mediadrm/plugins/clearkey/InitDataParser.cpp
+++ b/drm/mediadrm/plugins/clearkey/InitDataParser.cpp
@@ -136,7 +136,7 @@
     AString encodedId;
     for (size_t i = 0; i < keyIds.size(); ++i) {
         encodedId.clear();
-        android::encodeBase64(keyIds[i], kKeyIdSize, &encodedId);
+        android::encodeBase64Url(keyIds[i], kKeyIdSize, &encodedId);
         if (i != 0) {
             request.append(",");
         }
diff --git a/drm/mediadrm/plugins/clearkey/tests/InitDataParserUnittest.cpp b/drm/mediadrm/plugins/clearkey/tests/InitDataParserUnittest.cpp
index 84ed242..8c49656 100644
--- a/drm/mediadrm/plugins/clearkey/tests/InitDataParserUnittest.cpp
+++ b/drm/mediadrm/plugins/clearkey/tests/InitDataParserUnittest.cpp
@@ -59,7 +59,7 @@
                   (size_t)requestString.find(kRequestSuffix));
         for (size_t i = 0; i < expectedKeys.size(); ++i) {
             AString encodedIdAString;
-            android::encodeBase64(expectedKeys[i], kKeyIdSize,
+            android::encodeBase64Url(expectedKeys[i], kKeyIdSize,
                                   &encodedIdAString);
             String8 encodedId(encodedIdAString.c_str());
             encodedId.removeAll(kBase64Padding);
@@ -231,5 +231,4 @@
 
     attemptParseExpectingFailure(initData, kCencMimeType);
 }
-
 }  // namespace clearkeydrm
diff --git a/drm/mediadrm/plugins/clearkey/tests/JsonWebKeyUnittest.cpp b/drm/mediadrm/plugins/clearkey/tests/JsonWebKeyUnittest.cpp
index c3b0d84..d9f3ea6 100644
--- a/drm/mediadrm/plugins/clearkey/tests/JsonWebKeyUnittest.cpp
+++ b/drm/mediadrm/plugins/clearkey/tests/JsonWebKeyUnittest.cpp
@@ -284,14 +284,14 @@
                 "\"keys\":"
                     "[{"
                         "\"kid\":\"Y2xlYXJrZXlrZXlpZDAx\""
-                        "\"k\":\"SGVsbG8gRnJpZW5kISE\""
+                        "\"k\":\"SGVsbG8gRnJpZW5kICE-Pw\""
                         "\"kty\":\"oct\""
                         "\"alg\":\"A128KW1\""
                     "}"
                     "{"
                         "\"kty\":\"oct\""
                         "\"alg\":\"A128KW2\""
-                        "\"k\":\"SGVsbG8gRnJpZW5kIQ\""
+                        "\"k\":\"SGVsbG8gRnJpZW5kICE_\""
                         "\"kid\":\"Y2xlYXJrZXlrZXlpZDAy\""
                     "}"
                     "{"
@@ -303,7 +303,7 @@
                     "{"
                         "\"alg\":\"A128KW3\""
                         "\"kid\":\"Y2xlYXJrZXlrZXlpZDAz\""
-                        "\"k\":\"R29vZCBkYXkh\""
+                        "\"k\":\"SGVsbG8gPz4-IEZyaWVuZCA_Pg\""
                         "\"kty\":\"oct\""
                     "}]"
             "}");
@@ -313,8 +313,8 @@
     EXPECT_TRUE(keys.size() == 3);
 
     const String8 clearKeys[] =
-            { String8("Hello Friend!!"), String8("Hello Friend!"),
-              String8("Good day!") };
+            { String8("Hello Friend !>?"), String8("Hello Friend !?"),
+              String8("Hello ?>> Friend ?>") };
     verifyKeys(keys, clearKeys);
 }
 
diff --git a/media/libstagefright/foundation/base64.cpp b/media/libstagefright/foundation/base64.cpp
index cc89064..8f32582 100644
--- a/media/libstagefright/foundation/base64.cpp
+++ b/media/libstagefright/foundation/base64.cpp
@@ -23,6 +23,7 @@
 
 sp<ABuffer> decodeBase64(const AString &s) {
     size_t n = s.size();
+
     if ((n % 4) != 0) {
         return NULL;
     }
@@ -45,7 +46,6 @@
     size_t outLen = (n / 4) * 3 - padding;
 
     sp<ABuffer> buffer = new ABuffer(outLen);
-
     uint8_t *out = buffer->data();
     if (out == NULL || buffer->size() < outLen) {
         return NULL;
@@ -61,9 +61,9 @@
             value = 26 + c - 'a';
         } else if (c >= '0' && c <= '9') {
             value = 52 + c - '0';
-        } else if (c == '+') {
+        } else if (c == '+' || c == '-') {
             value = 62;
-        } else if (c == '/') {
+        } else if (c == '/' || c == '_') {
             value = 63;
         } else if (c != '=') {
             return NULL;
@@ -144,4 +144,26 @@
     }
 }
 
+void encodeBase64Url(
+        const void *_data, size_t size, AString *out) {
+    encodeBase64(_data, size, out);
+
+    if ((-1 != out->find("+")) || (-1 != out->find("/"))) {
+        size_t outLen = out->size();
+        char *base64url = new char[outLen];
+        for (size_t i = 0; i < outLen; ++i) {
+            if (out->c_str()[i] == '+')
+                base64url[i] = '-';
+            else if (out->c_str()[i] == '/')
+                base64url[i] = '_';
+            else
+                base64url[i] = out->c_str()[i];
+        }
+
+        out->setTo(base64url, outLen);
+        delete[] base64url;
+    }
+}
+
+
 }  // namespace android
diff --git a/media/libstagefright/foundation/include/media/stagefright/foundation/base64.h b/media/libstagefright/foundation/include/media/stagefright/foundation/base64.h
index e340b89..abc95e0 100644
--- a/media/libstagefright/foundation/include/media/stagefright/foundation/base64.h
+++ b/media/libstagefright/foundation/include/media/stagefright/foundation/base64.h
@@ -28,6 +28,8 @@
 sp<ABuffer> decodeBase64(const AString &s);
 void encodeBase64(const void *data, size_t size, AString *out);
 
+void encodeBase64Url(const void *data, size_t size, AString *out);
+
 }  // namespace android
 
 #endif  // BASE_64_H_
diff --git a/media/libstagefright/foundation/tests/Android.mk b/media/libstagefright/foundation/tests/Android.mk
index d741c6f..a9e3c76 100644
--- a/media/libstagefright/foundation/tests/Android.mk
+++ b/media/libstagefright/foundation/tests/Android.mk
@@ -9,11 +9,13 @@
 
 LOCAL_SRC_FILES := \
 	AData_test.cpp \
+	Base64_test.cpp \
 	Flagged_test.cpp \
 	TypeTraits_test.cpp \
 	Utils_test.cpp \
 
 LOCAL_SHARED_LIBRARIES := \
+	liblog \
 	libstagefright_foundation \
 	libutils \
 
diff --git a/media/libstagefright/foundation/tests/Base64_test.cpp b/media/libstagefright/foundation/tests/Base64_test.cpp
new file mode 100644
index 0000000..7a4289e
--- /dev/null
+++ b/media/libstagefright/foundation/tests/Base64_test.cpp
@@ -0,0 +1,155 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * 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 <utils/Log.h>
+
+#include "gtest/gtest.h"
+
+#include <media/stagefright/foundation/ABuffer.h>
+#include <media/stagefright/foundation/AString.h>
+#include <media/stagefright/foundation/AStringUtils.h>
+#include <media/stagefright/foundation/base64.h>
+
+#include <utils/RefBase.h>
+#include <utils/String8.h>
+
+namespace {
+const android::String8 kBase64Padding("=");
+};
+
+namespace android {
+
+class Base64Test : public ::testing::Test {
+};
+
+void verifyDecode(const AString* expected, const AString* in) {
+    size_t numTests = 0;
+    while (!expected[numTests].empty())
+        ++numTests;
+
+    for (size_t i = 0; i < numTests; ++i) {
+        // Since android::decodeBase64() requires padding characters,
+        // add them so length of encoded text is exactly a multiple of 4.
+        int remainder = in[i].size() % 4;
+        String8 paddedText(in[i].c_str());
+        if (remainder > 0) {
+            for (int i = 0; i < 4 - remainder; ++i) {
+                paddedText.append(kBase64Padding);
+            }
+        }
+        sp<ABuffer> result = decodeBase64(AString(paddedText.string()));
+
+        ASSERT_EQ(AStringUtils::Compare(expected[i].c_str(),
+                reinterpret_cast<char*>(result->data()),
+                expected[i].size(), false), 0);
+    }
+}
+
+void verifyEncode(const AString* expected, const AString* in) {
+    size_t numTests = 0;
+    while (!expected[numTests].empty())
+        ++numTests;
+
+    AString out = AString("");
+    for (size_t i = 0; i < numTests; ++i) {
+        encodeBase64Url(in[i].c_str(), in[i].size(), &out);
+
+        ASSERT_EQ(AStringUtils::Compare(expected[i].c_str(), out.c_str(),
+                expected[i].size(), false), 0);
+    }
+}
+
+TEST_F(Base64Test, TestDecodeBase64) {
+    const AString base64[] = {
+        AString("SGVsbG8gRnJpZW5kIQ"),
+        AString("R29vZCBkYXkh"),
+        AString("")  // string to signal end of array
+    };
+
+    const AString clearText[] = {
+        AString("Hello Friend!"),
+        AString("Good day!"),
+        AString("")
+    };
+
+    verifyDecode(clearText, base64);
+}
+
+TEST_F(Base64Test, TestDecodeBase64Url) {
+    const AString base64Url[] = {
+        AString("SGVsbG8gRnJpZW5kICE-Pw"),
+        AString("SGVsbG8gRnJpZW5kICE_"),
+        AString("SGVsbG8gPz4-IEZyaWVuZCA_Pg"),
+        AString("")
+    };
+
+    const AString clearText[] = {
+        AString("Hello Friend !>?"),
+        AString("Hello Friend !?"),
+        AString("Hello ?>> Friend ?>"),
+        AString("")
+    };
+
+    verifyDecode(clearText, base64Url);
+}
+
+TEST_F(Base64Test, TestDecodeMalformedBase64) {
+    const AString base64Url[] = {
+        AString("1?GawgguFyGrWKav7AX4VKUg"),  // fail on parsing
+        AString("GawgguFyGrWKav7AX4V???"),    // fail on length not multiple of 4
+        AString("GawgguFyGrWKav7AX4VKUg"),    // ditto
+    };
+
+    for (size_t i = 0; i < 3; ++i) {
+        sp<ABuffer> result = decodeBase64(AString(base64Url[i]));
+        EXPECT_TRUE(result == nullptr);
+    }
+}
+
+TEST_F(Base64Test, TestEncodeBase64) {
+    const AString clearText[] = {
+        AString("Hello Friend!"),
+        AString("Good day!"),
+        AString("")
+    };
+
+    const AString base64[] = {
+        AString("SGVsbG8gRnJpZW5kIQ=="),
+        AString("R29vZCBkYXkh"),
+        AString("")
+    };
+
+    verifyEncode(base64, clearText);
+}
+
+TEST_F(Base64Test, TestEncodeBase64Url) {
+    const AString clearText[] = {
+        AString("Hello Friend !>?"),
+        AString("Hello Friend !?"),
+        AString("Hello ?>> Friend ?>"),
+        AString("")
+    };
+
+    const AString base64Url[] = {
+        AString("SGVsbG8gRnJpZW5kICE-Pw=="),
+        AString("SGVsbG8gRnJpZW5kICE_"),
+        AString("SGVsbG8gPz4-IEZyaWVuZCA_Pg"),
+        AString("")
+    };
+
+    verifyEncode(base64Url, clearText);
+}
+
+} // namespace android