Fuzzers for libkeymint_support

Plugin Design Considerations

The fuzzer plugins for libkeymint_support are designed based on the understanding of the source code and try 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 fuzzers.

Maximize utilization of input data

The plugins feed the entire input data to the module. This ensures that the plugins tolerate any kind of input (empty, huge, malformed, etc) and dont exit() on any input and thereby increasing the chance of identifying vulnerabilities.

Table of contents

• keymint_attestation_fuzzer
• keymint_authSet_fuzzer
• keymint_remote_prov_fuzzer
• keymint_rkpsupport_fuzzer

Fuzzer for KeyMintAttestation

KeyMintAttestation supports the following parameters:

1. PaddingMode(parameter name: "padding")
2. Digest(parameter name: "digest")
3. Index(parameter name: "idx")
4. Timestamp(parameter name: "timestamp")
5. AuthSet(parameter name: "authSet")
6. IssuerSubjectName(parameter name: "issuerSubjectName")
7. AttestationChallenge(parameter name: "challenge")
8. AttestationApplicationId(parameter name: "id")
9. EcCurve(parameter name: "ecCurve")
10. BlockMode(parameter name: "blockmode")
11. minMacLength(parameter name: "minMacLength")
12. macLength(parameter name: "macLength")

Steps to run

1. Build the fuzzer

$ mm -j$(nproc) keymint_attestation_fuzzer

2. Run on device

$ adb sync data
$ adb shell /data/fuzz/arm64/keymint_attestation_fuzzer/keymint_attestation_fuzzer

Fuzzer for KeyMintAuthSet

KeyMintAuthSet supports the following parameters:

1. AuthorizationSet(parameter name: "authSet")
2. AuthorizationSet(parameter name: "params")
3. KeyParameters(parameter name: "numKeyParam")
4. Tag(parameter name: "tag")

Steps to run

1. Build the fuzzer

$ mm -j$(nproc) keymint_authSet_fuzzer

2. Run on device

$ adb sync data
$ adb shell /data/fuzz/arm64/keymint_authSet_fuzzer/keymint_authSet_fuzzer

Fuzzer for KeyMintRemoteProv

KeyMintRemoteProv supports the following parameters:

1. ChallengeSize(parameter name: "challengeSize")
2. Challenge(parameter name: "challenge")
3. NumKeys(parameter name: "numKeys")

Steps to run

1. Build the fuzzer

$ mm -j$(nproc) keymint_remote_prov_fuzzer

2. Run on device

$ adb sync data
$ adb shell /data/fuzz/arm64/keymint_remote_prov_fuzzer/keymint_remote_prov_fuzzer

Fuzzer for KeyMintRemoteKeyProvSupport

KeyMintRemoteKeyProvSupport supports the following parameters:

1. SupportedEekCurve(parameter name: "supportedEekCurve")
2. Length(parameter name: "length")
3. SerialNumberProp(parameter name: "serialNoProp")
4. InstanceName(parameter name: "instanceName")
5. Value(parameter name: "value")

Steps to run

1. Build the fuzzer

$ mm -j$(nproc) keymint_rkpsupport_fuzzer

2. Run on device

$ adb sync data
$ adb shell /data/fuzz/arm64/keymint_rkpsupport_fuzzer/keymint_rkpsupport_fuzzer