1/*
2 * Copyright (C) 2007 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <parser_dcf.h>
18#include <svc_drm.h>
19
20static int32_t drm_parseUintVar(uint8_t * buffer, uint8_t * len)
21{
22    int32_t i;
23    int32_t byteLen;
24    int32_t sum;
25
26    if (NULL == buffer)
27        return DRM_UINT_VAR_ERR;
28
29    byteLen = 0;
30    while ((buffer[byteLen] & UINT_VAR_FLAG) > 0 && byteLen < MAX_UINT_VAR_BYTE) /* UINT_VAR_FLAG == 0x80 */
31        byteLen++;
32
33    if (byteLen >= MAX_UINT_VAR_BYTE) /* MAX_UINT_VAR_BYTE == 5 */
34        return DRM_UINT_VAR_ERR; /* The var int is too large, and that is impossible */
35
36    *len = (uint8_t)(byteLen + 1);
37    sum = buffer[byteLen];
38    for (i = byteLen - 1; i >= 0; i--)
39        sum += ((buffer[i] & UINT_VAR_DATA) << 7 * (byteLen - i)); /* UINT_VAR_DATA == 0x7F */
40
41    return sum;
42}
43
44/* See parser_dcf.h */
45int32_t drm_dcfParser(uint8_t *buffer, int32_t bufferLen, T_DRM_DCF_Info *pDcfInfo,
46                      uint8_t **ppEncryptedData)
47{
48    uint8_t *tmpBuf;
49    uint8_t *pStart, *pEnd;
50    uint8_t *pHeader, *pData;
51    uint8_t varLen;
52
53    if (NULL == buffer || bufferLen <= 0 || NULL == pDcfInfo)
54        return FALSE;
55
56    tmpBuf = buffer;
57    /* 1. Parse the version, content-type and content-url */
58    pDcfInfo->Version = *(tmpBuf++);
59    if (0x01 != pDcfInfo->Version) /* Because it is OMA DRM v1.0, the vension must be 1 */
60        return FALSE;
61    pDcfInfo->ContentTypeLen = *(tmpBuf++);
62    pDcfInfo->ContentURILen = *(tmpBuf++);
63    strncpy((char *)pDcfInfo->ContentType, (char *)tmpBuf, pDcfInfo->ContentTypeLen);
64    tmpBuf += pDcfInfo->ContentTypeLen;
65    strncpy((char *)pDcfInfo->ContentURI, (char *)tmpBuf, pDcfInfo->ContentURILen);
66    tmpBuf += pDcfInfo->ContentURILen;
67
68    /* 2. Get the headers length and data length */
69    pDcfInfo->HeadersLen = drm_parseUintVar(tmpBuf, &varLen);
70    if (DRM_UINT_VAR_ERR == pDcfInfo->HeadersLen)
71        return FALSE;
72    tmpBuf += varLen;
73    pDcfInfo->DecryptedDataLen = DRM_UNKNOWN_DATA_LEN;
74    pDcfInfo->EncryptedDataLen = drm_parseUintVar(tmpBuf, &varLen);
75    if (DRM_UINT_VAR_ERR == pDcfInfo->EncryptedDataLen)
76        return FALSE;
77    tmpBuf += varLen;
78    pHeader = tmpBuf;
79    tmpBuf += pDcfInfo->HeadersLen;
80    pData = tmpBuf;
81
82    /* 3. Parse the headers */
83    pStart = pHeader;
84    while (pStart < pData) {
85        pEnd = pStart;
86        while ('\r' != *pEnd && pEnd < pData)
87            pEnd++;
88
89        if (0 == strncmp((char *)pStart, HEADER_ENCRYPTION_METHOD, HEADER_ENCRYPTION_METHOD_LEN))
90            strncpy((char *)pDcfInfo->Encryption_Method,
91                         (char *)(pStart + HEADER_ENCRYPTION_METHOD_LEN),
92                         pEnd - pStart - HEADER_ENCRYPTION_METHOD_LEN);
93        else if (0 == strncmp((char *)pStart, HEADER_RIGHTS_ISSUER, HEADER_RIGHTS_ISSUER_LEN))
94            strncpy((char *)pDcfInfo->Rights_Issuer,
95                         (char *)(pStart + HEADER_RIGHTS_ISSUER_LEN),
96                         pEnd - pStart - HEADER_RIGHTS_ISSUER_LEN);
97        else if (0 == strncmp((char *)pStart, HEADER_CONTENT_NAME, HEADER_CONTENT_NAME_LEN))
98            strncpy((char *)pDcfInfo->Content_Name,
99                         (char *)(pStart + HEADER_CONTENT_NAME_LEN),
100                         pEnd - pStart - HEADER_CONTENT_NAME_LEN);
101        else if (0 == strncmp((char *)pStart, HEADER_CONTENT_DESCRIPTION, HEADER_CONTENT_DESCRIPTION_LEN))
102            strncpy((char *)pDcfInfo->ContentDescription,
103                         (char *)(pStart + HEADER_CONTENT_DESCRIPTION_LEN),
104                         pEnd - pStart - HEADER_CONTENT_DESCRIPTION_LEN);
105        else if (0 == strncmp((char *)pStart, HEADER_CONTENT_VENDOR, HEADER_CONTENT_VENDOR_LEN))
106            strncpy((char *)pDcfInfo->ContentVendor,
107                         (char *)(pStart + HEADER_CONTENT_VENDOR_LEN),
108                         pEnd - pStart - HEADER_CONTENT_VENDOR_LEN);
109        else if (0 == strncmp((char *)pStart, HEADER_ICON_URI, HEADER_ICON_URI_LEN))
110            strncpy((char *)pDcfInfo->Icon_URI,
111                         (char *)(pStart + HEADER_ICON_URI_LEN),
112                         pEnd - pStart - HEADER_ICON_URI_LEN);
113
114        if ('\n' == *(pEnd + 1))
115            pStart = pEnd + 2;  /* Two bytes: a '\r' and a '\n' */
116        else
117            pStart = pEnd + 1;
118    }
119
120    /* 4. Give out the location of encrypted data */
121    if (NULL != ppEncryptedData)
122        *ppEncryptedData = pData;
123
124    return TRUE;
125}
126