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diff --git a/fuzzer/README.md b/fuzzer/README.md new file mode 100644 index 0000000..b8cc260 --- /dev/null +++ b/fuzzer/README.md @@ -0,0 +1,150 @@ +# Fuzzer for libFraunhoferAAC decoder + +## Plugin Design Considerations +The fuzzer plugin for aac decoder is designed based on the understanding of the +codec and tries to achieve the following: + +##### Maximize code coverage + +This fuzzer makes use of the following config parameters: +1. Transport type (parameter name: `TRANSPORT_TYPE`) + +| Parameter| Valid Values| Configured Value| +|------------- |-------------| ----- | +| `TRANSPORT_TYPE` | 0.`TT_UNKNOWN ` 1.`TT_MP4_RAW ` 2.`TT_MP4_ADIF ` 3.`TT_MP4_ADTS ` 4.`TT_MP4_LATM_MCP1 ` 5.`TT_MP4_LATM_MCP0 ` 6.`TT_MP4_LOAS ` 7.`TT_DRM ` | `TT_MP4_ADIF ` | + +Note: Value of `TRANSPORT_TYPE` could be set to any of these values. +It is set to `TT_MP4_ADIF` in the fuzzer plugin. + +##### Maximize utilization of input data +The plugin feeds the entire input data to the codec using a loop. + * If the decode operation was successful, the input is advanced by an + offset calculated using valid bytes. + * If the decode operation was un-successful, the input is advanced by 1 byte + till it reaches a valid frame or end of stream. + +This ensures that the plugin tolerates any kind of input (empty, huge, +malformed, etc) and doesnt `exit()` on any input and thereby increasing the +chance of identifying vulnerabilities. + +## Build + +This describes steps to build aac_dec_fuzzer binary. + +## Android + +### Steps to build +Build the fuzzer +``` + $ mm -j$(nproc) aac_dec_fuzzer +``` + +### Steps to run +Create a directory CORPUS_DIR and copy some aac files to that folder. +Push this directory to device. + +To run on device +``` + $ adb sync data + $ adb shell /data/fuzz/arm64/aac_dec_fuzzer/aac_dec_fuzzer CORPUS_DIR +``` +To run on host +``` + $ $ANDROID_HOST_OUT/fuzz/x86_64/aac_dec_fuzzer/aac_dec_fuzzer CORPUS_DIR +``` + +# Fuzzer for libFraunhoferAAC encoder + +## Plugin Design Considerations +The fuzzer plugin for aac encoder is designed based on the understanding of the +codec and tries to achieve the following: + +##### Maximize code coverage + +The configuration parameters are not hardcoded, but instead selected based on +incoming data. This ensures more code paths are reached by the fuzzer. + +Following arguments are passed to aacEncoder_SetParam to set the respective AACENC_PARAM parameter: + +| AACENC_PARAM param| Valid Values| Configured Value| +|-------------| ----- |----- | +|`AACENC_SBR_MODE` | `-1 ` `0 ` `1 ` `2 ` | Calculated using first byte of data | +|`AACENC_AOT` |`AOT_NONE ` `AOT_NULL_OBJECT ` `AOT_AAC_MAIN ` `AOT_AAC_LC ` `AOT_AAC_SSR ` `AOT_AAC_LTP ` `AOT_SBR ` `AOT_AAC_SCAL ` `AOT_TWIN_VQ ` `AOT_CELP ` `AOT_HVXC ` `AOT_RSVD_10 ` `AOT_RSVD_11 ` `AOT_TTSI ` `AOT_MAIN_SYNTH ` `AOT_WAV_TAB_SYNTH ` `AOT_GEN_MIDI ` `AOT_ALG_SYNTH_AUD_FX ` `AOT_ER_AAC_LC ` `AOT_RSVD_18 ` `AOT_ER_AAC_LTP ` `AOT_ER_AAC_SCAL ` `AOT_ER_TWIN_VQ ` `AOT_ER_BSAC ` `AOT_ER_AAC_LD ` `AOT_ER_CELP ` `AOT_ER_HVXC ` `AOT_ER_HILN ` `AOT_ER_PARA ` `AOT_RSVD_28 ` `AOT_PS ` `AOT_MPEGS ` `AOT_ESCAPE ` `AOT_MP3ONMP4_L1 ` `AOT_MP3ONMP4_L2 ` `AOT_MP3ONMP4_L3 ` `AOT_RSVD_35 ` `AOT_RSVD_36 ` `AOT_AAC_SLS ` `AOT_SLS ` `AOT_ER_AAC_ELD ` `AOT_USAC ` `AOT_SAOC ` `AOT_LD_MPEGS ` `AOT_MP2_AAC_LC ` `AOT_MP2_SBR ` `AOT_DRM_AAC ` `AOT_DRM_SBR ` `AOT_DRM_MPEG_PS ` `AOT_DRM_SURROUND ` `AOT_DRM_USAC ` | Calculated using second byte of data | +|`AACENC_SAMPLERATE` | `8000 ` `11025 ` `12000 ` `16000 ` `22050 ` `24000 ` `32000 ` `44100 ` `48000 ` `64000 ` `88200 ` `96000 `| Calculated using third byte of data | +|`AACENC_BITRATE` | In range `8000 ` to `960000 ` | Calculated using fourth, fifth and sixth byte of data | +|`AACENC_CHANNELMODE` | `MODE_1 ` `MODE_2 ` `MODE_1_2 ` `MODE_1_2_1 ` `MODE_1_2_2 ` `MODE_1_2_2_1 ` `MODE_1_2_2_2_1 ` `MODE_6_1 ` `MODE_7_1_BACK ` `MODE_7_1_TOP_FRONT ` `MODE_7_1_REAR_SURROUND ` `MODE_7_1_FRONT_CENTER ` `MODE_212 ` | Calculated using seventh byte of data | +|`AACENC_TRANSMUX` | `TT_MP4_RAW ` `TT_MP4_ADIF ` `TT_MP4_ADTS ` `TT_MP4_LATM_MCP1 ` `TT_MP4_LATM_MCP0 ` `TT_MP4_LOAS ` `TT_DRM ` | Calculated using eight byte of data |`AACENC_SBR_RATIO` |`-1 ` `0 ` `1 ` `2 ` | Calculated using ninth byte of data | +|`AACENC_BITRATEMODE` |`AACENC_BR_MODE_INVALID ` `AACENC_BR_MODE_CBR ` `AACENC_BR_MODE_VBR_1 ` `AACENC_BR_MODE_VBR_2 ` `AACENC_BR_MODE_VBR_3 ` `AACENC_BR_MODE_VBR_4 ` `AACENC_BR_MODE_VBR_5 ` `AACENC_BR_MODE_FF ` `AACENC_BR_MODE_SFR ` | Calculated using thirty-fourth byte of data | +|`AACENC_GRANULE_LENGTH` |`120 ` `128 ` `240 ` `256 ` `480 ` `512 ` `1024 ` | Calculated using thirty-fifth byte of data | +|`AACENC_CHANNELORDER` |`CH_ORDER_MPEG ` `CH_ORDER_WAV ` | Calculated using thirty-sixth byte of data | +|`AACENC_AFTERBURNER` |`0 ` `1 ` | Calculated using thirty-seventh byte of data | +|`AACENC_BANDWIDTH` |`0 ` `1` | Calculated using thirty-eigth byte of data | +|` AACENC_IDX_PEAK_BITRATE` | In range `8000 ` to `960000 ` | Calculated using thirty-ninth byte of data | +|` AACENC_HEADER_PERIOD` |In range `0 ` to `255 ` | Calculated using fortieth byte of data | +|` AACENC_SIGNALING_MODE` |`-1 ` `0 ` `1 ` `2 ` `3 ` | Calculated using forty-first byte of data | +|` AACENC_TPSUBFRAMES` |In range `0 ` to `255 ` | Calculated using forty-second byte of data | +|` AACENC_AUDIOMUXVER` |`-1 ` `0 ` `1 ` `2 ` | Calculated using forty-third byte of data | +|` AACENC_PROTECTION` |`0 ` `1 ` | Calculated using forty-fourth of data | +|`AACENC_ANCILLARY_BITRATE` |In range `0 ` to `960000 `| Calculated using forty-fifth byte of data | +|`AACENC_METADATA_MODE ` |`0 ` `1 ` `2 ` `3 ` | Calculated using forty-sixth byte of data | + +Following values are configured to set up the meta data represented by the class variable `mMetaData ` : + +| Variable name| Possible Values| Configured Value| +|------------- | ----- |----- | +| `drc_profile` | `AACENC_METADATA_DRC_NONE ` `AACENC_METADATA_DRC_FILMSTANDARD ` `AACENC_METADATA_DRC_FILMLIGHT ` `AACENC_METADATA_DRC_MUSICSTANDARD ` `AACENC_METADATA_DRC_MUSICLIGHT ` `AACENC_METADATA_DRC_SPEECH ` `AACENC_METADATA_DRC_NOT_PRESENT ` | Calculated using tenth byte of data | +| `comp_profile` | `AACENC_METADATA_DRC_NONE ` `AACENC_METADATA_DRC_FILMSTANDARD ` `AACENC_METADATA_DRC_FILMLIGHT ` `AACENC_METADATA_DRC_MUSICSTANDARD ` `AACENC_METADATA_DRC_MUSICLIGHT ` `AACENC_METADATA_DRC_SPEECH ` `AACENC_METADATA_DRC_NOT_PRESENT ` | Calculated using eleventh byte of data | +| `drc_TargetRefLevel` | In range `0 ` to `255 ` | Calculated using twelfth byte of data | +| `comp_TargetRefLevel` | In range `0 ` to `255 ` | Calculated using thirteenth byte of data | +| `prog_ref_level_present` | `0 ` `1 ` | Calculated using fourteenth byte of data | +| `prog_ref_level` | In range `0 ` to `255 ` | Calculated using fifteenth byte of data | +| `PCE_mixdown_idx_present` | `0 ` `1 ` | Calculated using sixteenth byte of data | +| `ETSI_DmxLvl_present` | `0 ` `1 ` | Calculated using seventeenth byte of data | +| `centerMixLevel` | In range `0 ` to `7 ` | Calculated using eighteenth byte of data | +| `surroundMixLevel` | In range `0 ` to `7 ` | Calculated using nineteenth byte of data | +| `dolbySurroundMode` | In range `0 ` to `2 ` | Calculated using twentieth byte of data | +| `drcPresentationMode` | In range `0 ` to `2 ` | Calculated using twenty-first byte of data | +| `extAncDataEnable` | `0 ` `1 ` | Calculated using twenty-second byte of data | +| `extDownmixLevelEnable` | `0 ` `1 ` | Calculated using twenty-third byte of data | +| `extDownmixLevel_A` | In range `0 ` to `7 ` | Calculated using twenty-fourth byte of data | +| `extDownmixLevel_B` | In range `0 ` to `7 ` | Calculated using twenty-fifth byte of data | +| `dmxGainEnable` | `0 ` `1 ` | Calculated using twenty-sixth byte of data | +| `dmxGain5` | In range `0 ` to `255 ` | Calculated using twenty-seventh byte of data | +| `dmxGain2` | In range `0 ` to `255 ` | Calculated using twenty-eighth byte of data | +| `lfeDmxEnable` | `0 ` `1 ` | Calculated using twenty-ninth byte of data | +| `lfeDmxLevel` | In range `0 ` to `15 ` | Calculated using thirtieth byte of data | + +Indexes `mInBufferIdx_1`, `mInBufferIdx_2` and `mInBufferIdx_3`(in range `0 ` to `2`) are calculated using the thirty-first, thirty-second and thirty-third byte respectively. + +##### Maximize utilization of input data +The plugin feeds the entire input data to the codec and continues with the encoding even on a failure. This ensures that the plugin tolerates any kind of input (empty, huge, malformed, etc) and doesnt `exit()` on any input and thereby increasing the chance of identifying vulnerabilities. + +## Build + +This describes steps to build aac_enc_fuzzer binary. + +## Android + +### Steps to build +Build the fuzzer +``` + $ mm -j$(nproc) aac_enc_fuzzer +``` + +### Steps to run +Create a directory CORPUS_DIR and copy some raw files to that folder. +Push this directory to device. + +To run on device +``` + $ adb sync data + $ adb shell /data/fuzz/arm64/aac_enc_fuzzer/aac_enc_fuzzer CORPUS_DIR +``` +To run on host +``` + $ $ANDROID_HOST_OUT/fuzz/x86_64/aac_enc_fuzzer/aac_enc_fuzzer CORPUS_DIR +``` + +## References: + * http://llvm.org/docs/LibFuzzer.html + * https://github.com/google/oss-fuzz |