Replace PST Report with buffer

Merge from Widevine repo of http://go/wvgerrit/23044

On some platforms, the compiler will not pack structures.  This CL
replaces the OECrypto_PST_Report packed structure with a simple buffer
of uint8_t.  This changes the signature of OEMCrypto_ReportUsage as
part of OEMCrypto v13.

There is also a new wrapper class that test code, the mock, and debug
code can use to access data in the report.

The old packed structure definition is moved to the level 3, where we
use a compiler that packs sructs when asked nicely.

arm/libwvlevel3.a  Level3 Library 4445 Jan 20 2017 11:29:15
x86/libwvlevel3.a  Level3 Library 4464 Jan 20 2017 11:10:49
mips/libwvlevel3.a  Level3 Library 4465 Jan 20 2017 10:56:08

b/32180083

Change-Id: Ie138f034cb12780a2f8636888cebf022c52169e5

libwvdrmengine/oemcrypto/include/OEMCryptoCENC.h

@@ -249,7 +249,12 @@ typedef enum OEMCrypto_Usage_Entry_Status {
 
 /*
  * OEMCrypto_PST_Report is used to report an entry from the Usage Table.
+ *
+ * Platforms that have compilers that support packed structures, may use the
+ * following definition.  Other platforms may use the header pst_report.h which
+ * defines a wrapper class.
  */
+#if 0  // If your compiler supports __attribute__((packed)).
 typedef struct {
   uint8_t signature[20];  //  -- HMAC SHA1 of the rest of the report.
   uint8_t status;  // current status of entry. (OEMCrypto_Usage_Entry_Status)
@@ -261,6 +266,7 @@ typedef struct {
   int64_t seconds_since_last_decrypt;      // now - time_of_last_decrypt
   uint8_t pst[];
 } __attribute__((packed)) OEMCrypto_PST_Report;
+#endif
 
 /*
  *  OEMCrypto_Clock_Security_Level.
@@ -2696,7 +2702,7 @@ OEMCryptoResult OEMCrypto_DeactivateUsageEntry(OEMCrypto_SESSION session,
 /* TODO(fredgc): copy text from http://go/wvgerrit/22887 */
 OEMCryptoResult OEMCrypto_ReportUsage(OEMCrypto_SESSION session,
                                       const uint8_t* pst, size_t pst_length,
-                                      OEMCrypto_PST_Report* buffer,
+                                      uint8_t* buffer,
                                       size_t* buffer_length);
 
 /*

libwvdrmengine/oemcrypto/include/level3.h

@@ -231,7 +231,7 @@ OEMCryptoResult Level3_DeactivateUsageEntry(OEMCrypto_SESSION session,
 OEMCryptoResult Level3_ReportUsage(OEMCrypto_SESSION session,
                                    const uint8_t *pst,
                                    size_t pst_length,
-                                   OEMCrypto_PST_Report *buffer,
+                                   uint8_t *buffer,
                                    size_t *buffer_length);
 OEMCryptoResult Level3_DeleteUsageEntry(OEMCrypto_SESSION session,
                                         const uint8_t* pst,

libwvdrmengine/oemcrypto/include/pst_report.h

@@ -0,0 +1,146 @@
+// Copyright 2017 Google Inc. All Rights Reserved.
+
+/*********************************************************************
+ * pst_report.h
+ *
+ * Reference APIs needed to support Widevine's crypto algorithms.
+ *********************************************************************/
+
+#ifndef PST_REPORT_H_
+#define PST_REPORT_H_
+
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+
+#include "OEMCryptoCENC.h"
+#include "string_conversions.h"  // needed for htonll64.
+
+namespace wvcdm {
+
+class Unpacked_PST_Report {
+ public:
+  // This object does not own the buffer, and does not check that buffer
+  // is not null.
+  Unpacked_PST_Report(uint8_t *buffer) : buffer_(buffer) {}
+
+  // Copy and move semantics of this class is like that of a pointer.
+  Unpacked_PST_Report(const Unpacked_PST_Report& other) :
+      buffer_(other.buffer_) {}
+
+  Unpacked_PST_Report& operator=(const Unpacked_PST_Report& other) {
+    buffer_ = other.buffer_;
+    return *this;
+  }
+
+  size_t report_size() const {
+    return pst_length() + kraw_pst_report_size;
+  }
+
+  static size_t report_size(size_t pst_length) {
+    return pst_length + kraw_pst_report_size;
+  }
+
+  uint8_t status() const {
+    return static_cast<uint8_t>(* (buffer_ +  kstatus_offset));
+  }
+
+  void set_status(uint8_t value)  {
+    buffer_[kstatus_offset] = value;
+  }
+
+  uint8_t* signature()  {
+    return buffer_ + ksignature_offset;
+  }
+
+  uint8_t clock_security_level() const {
+    return static_cast<uint8_t>(* (buffer_ +  kclock_security_level_offset));
+  }
+
+  void set_clock_security_level(uint8_t value)  {
+    buffer_[kclock_security_level_offset] = value;
+  }
+
+  uint8_t pst_length() const {
+    return static_cast<uint8_t>(* (buffer_ +  kpst_length_offset));
+  }
+
+  void set_pst_length(uint8_t value)  {
+    buffer_[kpst_length_offset] = value;
+  }
+
+  uint8_t padding() const {
+    return static_cast<uint8_t>(* (buffer_ +  kpadding_offset));
+  }
+
+  void set_padding(uint8_t value)  {
+    buffer_[kpadding_offset] = value;
+  }
+
+  // In host byte order.
+  int64_t seconds_since_license_received() const {
+    int64_t time;
+    memcpy(&time, buffer_ +  kseconds_since_license_received_offset,
+           sizeof(int64_t));
+    return wvcdm::ntohll64(time);
+  }
+
+  // Parameter time is in host byte order.
+  void set_seconds_since_license_received(int64_t time) const {
+    time = wvcdm::ntohll64(time);
+    memcpy(buffer_ +  kseconds_since_license_received_offset, &time,
+           sizeof(int64_t));
+  }
+
+  // In host byte order.
+  int64_t seconds_since_first_decrypt() const {
+    int64_t time;
+    memcpy(&time, buffer_ +  kseconds_since_first_decrypt_offset,
+           sizeof(int64_t));
+    return wvcdm::ntohll64(time);
+  }
+
+  // Parameter time is in host byte order.
+  void set_seconds_since_first_decrypt(int64_t time) const {
+    time = wvcdm::ntohll64(time);
+    memcpy(buffer_ +  kseconds_since_first_decrypt_offset, &time,
+           sizeof(int64_t));
+  }
+
+  // In host byte order.
+  int64_t seconds_since_last_decrypt() const {
+    int64_t time;
+    memcpy(&time, buffer_ +  kseconds_since_last_decrypt_offset,
+           sizeof(int64_t));
+    return wvcdm::ntohll64(time);
+  }
+
+  // Parameter time is in host byte order.
+  void set_seconds_since_last_decrypt(int64_t time) const {
+    time = wvcdm::ntohll64(time);
+    memcpy(buffer_ +  kseconds_since_last_decrypt_offset, &time,
+           sizeof(int64_t));
+  }
+
+  uint8_t* pst() {
+    return  (buffer_ +  kpst_offset);
+  }
+
+ private:
+  uint8_t *buffer_;
+
+  // Size of the PST_Report without the pst string.
+  static const size_t kraw_pst_report_size = 48;
+  static const size_t ksignature_offset  = 0;
+  static const size_t kstatus_offset  = 20;
+  static const size_t kclock_security_level_offset = 21;
+  static const size_t kpst_length_offset = 22;
+  static const size_t kpadding_offset = 23;
+  static const size_t kseconds_since_license_received_offset = 24;
+  static const size_t kseconds_since_first_decrypt_offset = 32;
+  static const size_t kseconds_since_last_decrypt_offset = 40;
+  static const size_t kpst_offset = 48;
+};
+}  // namespace wvcdm
+
+#endif  // PST_REPORT_H_