BoringCrypto

Certificate

Approved Algorithms (33)

Derived Review-Risk Graph (review prompts, not findings)

flowchart LR
  %% Deterministic review-risk graph for BoringCrypto
  %% Review prompts and evidence gaps, NOT vulnerability findings.
  subgraph CMVP["CMVP-disclosed clues"]
    C3["[low] Self-test / status surface<br/>(referenced in text)<br/><i>Status Output<br/>Self-Test<br/>Show Status</i>"]
    C5["[low] Protocol / secure-channel<br/>references (may be KDF<br/>names, not a live channel)<br/><i>TLS<br/>HTTPS<br/>library named: boringssl</i>"]
    C6["[low] Operating system / runtime<br/>referenced (boundary<br/>membership not asserted)<br/><i>operating system<br/>linux<br/>application</i>"]
  end
  subgraph Inference["Derived inference"]
    I3["Possible only, some<br/>services may process input<br/>before, or without,<br/>operator authentication."]
    I5["Possible only, a protocol<br/>is referenced, but whether<br/>it is a live channel or<br/>only a KDF/algorithm name<br/>is unconfirmed."]
    I6["Possible only, a<br/>runtime/OS is referenced,<br/>but its membership in the<br/>cryptographic boundary is<br/>not established."]
  end
  subgraph Risk["Reviewer question"]
    R3["Can unauthenticated<br/>services leak state,<br/>consume resources, or<br/>transition security state?"]
    R5["If a live TLS/SSH/IKE<br/>channel exists, could<br/>library CVEs apply, or is<br/>this only a<br/>KDF/documentation name?"]
    R6["If the OS/runtime is<br/>in-boundary, could its<br/>CVEs be hidden by<br/>firmware-only versioning?"]
  end
  subgraph Evidence["Evidence needed to close"]
    E3["confirm the disclosure<br/>itself (keyword hit,<br/>context unverified) ·<br/>pre-auth reachability<br/>matrix · rate limits and<br/>output redaction ·<br/>abuse-case tests"]
    E5["confirm the disclosure<br/>itself (keyword hit,<br/>context unverified) ·<br/>library identity and<br/>version ·<br/>certificate-validation<br/>behaviour · protocol-CVE<br/>disposition"]
    E6["confirm the disclosure<br/>itself (keyword hit,<br/>context unverified) ·<br/>runtime identity and<br/>config · kernel/runtime<br/>hardening profile ·<br/>patch/backport manifest"]
  end
  C3 --> I3 --> R3 --> E3
  C5 --> I5 --> R5 --> E5
  C6 --> I6 --> R6 --> E6
  classDef clue fill:#eef3f9,stroke:#6f7f91,color:#1f3a5f;
  classDef infer fill:#fff7e6,stroke:#b98500,color:#6b4e00;
  classDef risk fill:#fbe9e9,stroke:#b02a2a,color:#7a1f1f;
  classDef evidence fill:#e6f4ea,stroke:#1e7d34,color:#14532d;
  class C3,C5,C6 clue;
  class I3,I5,I6 infer;
  class R3,R5,R6 risk;
  class E3,E5,E6 evidence;

flowchart LR
  %% Deterministic clue tier for BoringCrypto
  %% confidence: high = structured record field; medium = structured but soft; low (dashed) = bare keyword hit, context unverified
  subgraph CMVP["CMVP-disclosed clues (deterministic)"]
    C3["[low] Self-test / status surface (referenced in text)<br/><i>Status Output<br/>Self-Test<br/>Show Status</i><br/>src: text:keyword"]
    C5["[low] Protocol / secure-channel references (may be KDF names, not a live channel)<br/><i>TLS<br/>HTTPS<br/>library named: boringssl</i><br/>src: text:keyword"]
    C6["[low] Operating system / runtime referenced (boundary membership not asserted)<br/><i>operating system<br/>linux<br/>application</i><br/>src: text:keyword"]
  end
  classDef clueHigh fill:#eef3f9,stroke:#2f6fb0,stroke-width:2px,color:#1f3a5f;
  classDef clueMedium fill:#eef3f9,stroke:#6f7f91,color:#1f3a5f;
  classDef clueLow fill:#f7f7f7,stroke:#999,stroke-dasharray:4 4,color:#444;
  class C3,C5,C6 clueLow;

Security Policy, page by page

Google, LLC. BoringCrypto Software Version: 2023042800 Date: January 10, 2025 Public Material – May be reproduced only in its original entirety (without revision).

Introduction Federal Information Processing Standards Publication 140-3 — Security Requirements for Cryptographic Modules specifies requirements for cryptographic modules to be deployed in a Sensitive but Unclassified environment. The National Institute of Standards and Technology (NIST) and Canadian Centre for Cyber Security (CCCS) Cryptographic Module Validation Program (CMVP) run the FIPS 140 program. The NVLAP accredits independent testing labs to perform FIPS 140 testing; the CMVP validates modules meeting FIPS

140 validation. Validated is the term given to a module that is documented and tested against the FIPS

Additional information is available on the CMVP website at: https://csrc.nist.gov/projects/cryptographic-module-validation-program About this Document This non-proprietary Cryptographic Module Security Policy for BoringCrypto from Google, LLC provides an overview of the product and a high-level description of how it meets the overall Level 1 security requirements of FIPS 140-3. The BoringCrypto module is also referenced in this document as the “module”. Disclaimer The contents of this document are subject to revision without notice due to continued progress in methodology, design, and manufacturing. Google, LLC. shall have no liability for any error or damages of any kind resulting from the use of this document. Notices This document may be freely reproduced and distributed in its entirety without modification. Public Material – May be reproduced only in its original entirety (without revision).

List of Figures Public Material – May be reproduced only in its original entirety (without revision).

This document describes the cryptographic module Security Policy (SP) for the Google, LLC. BoringCrypto (Software version: 2023042800) cryptographic module (also referred to as the “module” hereafter). It contains specification of the security rules under which the cryptographic module operates, including the security rules derived from the requirements of the FIPS 140-3 standard. The module meets the overall Level 1 security requirements of FIPS 140-3. The following table lists the level of validation for each area in FIPS 140-3: Public Material – May be reproduced only in its original entirety (without revision).

2. Cryptographic Module Specification Google, LLC BoringCrypto module is an open-source, general-purpose cryptographic library which provides FIPS 140-3 approved cryptographic algorithms to serve BoringSSL and other user-space applications. The boundary of the module is defined as a single object file, bcm.o, and its instantiation in memory. The module version is: 2023042800. The module was tested on the following operational environments: Table 2 - Tested Operational Environments The cryptographic module is also supported on the following operational environments for which operational testing and algorithm testing was not performed: Table 3 - Vendor Affirmed Operational Environments Public Material – May be reproduced only in its original entirety (without revision).

HMAC key lengths < 112 bits are disallowed by SP 800-131Ar2. Public Material – May be reproduced only in its original entirety (without revision).

Algorithm CKG [IG D.H]

Caveat

Use / Function Cryptographic key generation per SP 800- 133rev2 and IG D.I * Generation of asymmetric keys for signature generation per [133] section 5.1. * Generation of asymmetric keys for key establishment per [133] section 5.2. * Symmetric key derivation for industry

Table 4

• Approved Algorithms No part of the TLS protocol, other than the approved cryptographic algorithms and the KDFs, have been tested by the CAVP and CMVP. Public Material
• May be reproduced only in its original entirety (without revision).

standard protocols from a key agreement shared secret per [133] section 6.2.1.

Table 5

• Vendor Affirmed Algorithms The module does not implement any Non-Approved Algorithms Allowed in the Approved Mode of Operation. (SP 800-140B tables ‘Non-Approved Algorithms Allowed in the Approved Mode of Operation’ has been omitted) The module does not implement any Non-Approved Algorithms Allowed in the Approved Mode of Operation with No Security Claimed. (SP 800-140B tables ‘Non-Approved Algorithms Allowed in the Approved Mode of Operation with No Security Claimed’ has been omitted) Table 6
• Non-Approved Algorithms Not Allowed in the Approved Mode of Operation Public Material
• May be reproduced only in its original entirety (without revision).

KTS

KTS

SP 800-38F. AES-KW, AES- KWP

128, 192, 256-bit keys with 128, 192, or 256- bit encryption strength

AES-KW/A4687 AES-KWP/A4687

Table 7

• Security Function Implementation (SFI) Figure 1
• BoringCrypto cryptographic boundary Public Material
• May be reproduced only in its original entirety (without revision).

3. Cryptographic Module Interfaces functions. The module does not implement a power input interface or a control output interface. Table 8

• Ports and Interfaces As a software module, control of the physical ports is outside the module scope. However, when the module is performing self-tests, or is in an error state, all output on the module’s logical data output interfaces is inhibited. Public Material
• May be reproduced only in its original entirety (without revision).

4. Roles, services, and authentication

The cryptographic module only implements a Crypto Officer (CO) role. The CO role is implicitly assumed by the entity accessing services implemented by the module. An operator is considered the owner of the thread that instantiates the module and, therefore, only one concurrent operator is allowed. The module does not support operator authentication. Table 9 – Roles and Authentication

The Approved services supported by the module and access rights within services accessible over the module’s public interface are listed in the table below: Table 10

• Roles, Service Commands, Input and Output Public Material
• May be reproduced only in its original entirety (without revision).

Approved services are listed in Table 11

• Approved Services. The SSPs listed in the table indicate the access required using below notation: G = Generate: The module generates or derives the SSP. R = Read: The SSP is read from the module (e.g., the SSP is output). W = Write: The SSP is updated, imported, or written to the module. E = Execute: The module uses the SSP in performing a cryptographic operation. Z = Zeroize: The module zeroizes the SSP. The indicator is provided as part of the API and is not a separate call. When a call is made to the module to perform an action using an algorithm, the response contains the indicator as part of the return value automatically. There is not a separate call just to determine the indicator status other than the general status parameter as to whether the entire module is in the approved state or not. Public Material
• May be reproduced only in its original entirety (without revision).

G, E W, E E Public Material – May be reproduced only in its original entirety (without revision).

E Table 11

• Approved Services Non-Approved Services are listed in the Table 12 below: Public Material
• May be reproduced only in its original entirety (without revision).

Table 12 - Non-Approved Services Public Material – May be reproduced only in its original entirety (without revision).

5. Software/Firmware Security The pre-operational integrity test is performed using HMAC-SHA-256. The integrity test can be executed on demand by power-cycling the host platform and reloading the module. The module does not support software loading.

The form of the module is a single object file, bcm.o.

6. Operational Environment The module runs on a GPC, which is a modifiable operational environment, running one of the operating systems specified in Table
7. Each tested operating system manages processes and threads in a logically separated manner. The module’s user is considered the owner of the calling application that instantiates the module. No special configuration of the operating system is required. The module is designed to ensure that the power-up tests are initiated automatically when the module is loaded.
8. Physical Security As a software module, the physical security requirements are not applicable.
9. Non-invasive Security The module does not claim any non-invasive security measures. Public Material – May be reproduced only in its original entirety (without revision).

9. Sensitive Security Parameter Management Public Material – May be reproduced only in its original entirety (without revision).

Module only wraps or unwraps the key, transporting the key would be performed by the calling application. Public Material – May be reproduced only in its original entirety (without revision).

Public Material – May be reproduced only in its original entirety (without revision).

Public Material – May be reproduced only in its original entirety (without revision).

Public Material – May be reproduced only in its original entirety (without revision).

Public Material – May be reproduced only in its original entirety (without revision).

Public Material – May be reproduced only in its original entirety (without revision).

Public Material – May be reproduced only in its original entirety (without revision).

Table 13

• SSP’s Table 14
• Non-Deterministic Random Number Generation Specification Public Material
• May be reproduced only in its original entirety (without revision).

10. Self-tests FIPS 140-3 requires the module to perform self-tests to ensure the integrity of the module and the correctness of the cryptographic functionality. Some functions also require conditional tests during normal operation of the module. Self-tests can be requested on demand by power cycling the host platform. The module has a single error state, just called the error state. The failure of a self-test will cause the module to enter the error state. The module indicates this error state by providing the output status “Aborted”. The module can be recovered by terminating execution of the host program and reclamation by the host operating system. The supported tests are listed and described in this section.

Pre-operational self-tests are run upon the initialization of the module. The CAST (Cryptographic Algorithm Self-Test) for HMAC-SHA2-256 is performed before the integrity test. Self-tests do not require operator intervention to run. If any of the tests fail, the module will not initialize and enter an error state where no services can be accessed. The module implements the following pre-operational self-tests: Table 15 – Pre-operational Self-tests

Conditional cryptographic algorithm self-tests (CAST) are run prior to the first use of the cryptographic algorithm. CASTs do not require operator intervention to run. If any of the tests fail, the module will enter an error state and no services can be accessed. The module implements the following CASTs: Public Material – May be reproduced only in its original entirety (without revision).

Table 16

• Conditional Algorithm Self-tests Conditional self-tests are run during the module’s operation. If any of these tests fail, the module will enter an error state, where no services can be accessed by the operators. The module can be reinitialized to clear the error and resume approved mode of operation. The module implements the following addition conditional self-tests: Table 17
• Conditional Self-tests Public Material
• May be reproduced only in its original entirety (without revision).

11. Life-Cycle Assurance The cryptographic module is initialized by loading the module before any cryptographic functionality is available. In User Space the operating system is responsible for the initialization process and loading of the library. General guidance about the module can be found at https://boringssl.googlesource.com/boringssl. This includes information about the APIs, building and specific information related to FIPS can be found at https://boringssl.googlesource.com/boringssl.git/+/refs/heads/fips20230428/crypto/fipsmodule/FIPS.md (note this still mentions 140-2, but the information there is the same).

The source code for the module is maintained in a git repository. While in development, work on the code is maintained internally, before eventually being released externally. BoringCrypto is released publicly to https://boringssl.googlesource.com/boringssl (this is the generic version, available under the Building for Linux instructions). The version number is determined by the developer releasing the version, though git attaches hashes to every single file and branch in the repository. The Android version of the module is also maintained in a git repository. Once the generic version is available, it is imported into the Android repository. As with the generic version, while development on the port is performed, it is handled in an internal git repository. Once it is ready for release it is published publicly to https://ci.android.com. The version number is determined by the Android repository build number (the numeric part of the manifest filename). Only the Android version of the module is released as a pre-compiled version (as opposed to a selfcompiled version. The Android manifest specifies all the configuration information needed to duplicate the build. Documentation that isn’t included in text files stored in git is maintained in Google Docs. All documents (whether spreadsheets, documents, presentations or anything else) are automatically version tracked along with the owner. Like git, Docs uses access control lists to control access to the design documentation for the module. All internal systems (both git and Google Docs) utilize the Google ID for login and access control over the repositories.

The module is open source. A Linux workstation with the following tools is required to build and compile the module: Public Material – May be reproduced only in its original entirety (without revision).

• ninja build system version 1.11.1 (https://github.com/ninja- build/ninja/releases)
• cmake version 3.27.4 (https://cmake.org/download/)

The necessary Android build tools that are configured as part of the manifest. Running the envsetup.sh script will ensure that the proper environment is set to build the library for Android. Download the manifest from https://ci.android.com/builds/submitted/10050109/aosp_cf_arm64_phone-userdebug/latest by clicking the Download button. Verify the manifest using the following command: sha256sum ~/manifest_10050109.xml Manually validate that the output from the final command indicates the following expected hash values for this file: 5f8701016e3c39503e26c81e0facb6ab386319b94f5d2508288907e652060d92 manifest_10050109.xml The module can be obtained by issuing the following commands: mkdir aosp cd aosp ~/repo init -u https://android.googlesource.com/platform/manifest --depth 1 ~/repo init -m ~/manifest_10050109.xml ~/repo sync -q -c -j 50 To build the correct test tools (the test_fips components below, not the module), the following additional steps need to be followed: cd external/boringssl git fetch https://android.googlesource.com/platform/external/boringssl refs/changes/99/2775199/2 && git cherry-pick FETCH_HEAD git fetch https://android.googlesource.com/platform/external/boringssl refs/changes/28/2778328/2 && git cherry-pick FETCH_HEAD cd src/util/fipstools nano break-kat.go Change the first line of the file to be: //go:build ignore Save and exit Once downloaded, the module and testing components can be built using the following commands: croot . build/envsetup.sh lunch aosp_arm64-eng m clean m test_fips Public Material – May be reproduced only in its original entirety (without revision).

Once the above tools have been obtained, issue the following command to create a CMake toolchain file to specify the use of Clang: printf "set(CMAKE_C_COMPILER \"clang\")\nset(CMAKE_CXX_COMPILER \"clang++\")\n" > ${HOME}/toolchain The FIPS 140-3 validated release of the module can be obtained by downloading the tarball containing the source code at the following location: https://commondatastorage.googleapis.com/chromium-boringssl-fips/boringssla430310d6563c0734ddafca7731570dfb683dc19.tar.xz or by issuing the following command: wget https://commondatastorage.googleapis.com/chromium-boringssl-fips/boringssla430310d6563c0734ddafca7731570dfb683dc19.tar.xz The set of files specified in the archive constitutes the complete set of source files of the validated module. There shall be no additions, deletions, or alterations of this set as used during module build. The downloaded tarball file can be verified using the below SHA-256 digest value: 2d5339b756dbf1ceb4fdc4b1c8f19e32ded055292dc57827a6592f15ca9d359f By issuing the following command: sha256sum boringssl-a430310d6563c0734ddafca7731570dfb683dc19.tar.xz The tarball can be extracted using the following command: tar xJ < boringssl-a430310d6563c0734ddafca7731570dfb683dc19.tar.xz After the tarball has been extracted, the following commands will compile the module: cd boringssl mkdir build && cd build && cmake -GNinja -DCMAKE_TOOLCHAIN_FILE=${HOME}/toolchain -DFIPS=1 DCMAKE_BUILD_TYPE=Release .. ninja && ninja run_tests Retrieving Module name and version The following methods will provide the module name and versions:

• FIPS_module_name()
• BoringCrypto
• FIPS_version()
• 2023042800 Public Material
• May be reproduced only in its original entirety (without revision).

In the case of AES-GCM, the IV generation method is user-selectable, and the value can be computed in more than one manner. In the context of the TLS protocol version 1.3, AES-GCM encryption and decryption is used compliant to Scenario 5 in FIPS 140-3 IG C.H. The module is compliant with NIST SP800-52rev2 and the mechanism for IV generation is compliant with RFC 8446. The module ensures that it is strictly increasing and thus cannot repeat. When the IV exhausts the maximum number of possible values for a given session key, the first party (client or server) to encounter this condition may either send a TLS 1.3 KeyUpdate message to establish a new encryption key, or fail. In either case, the module prevents any IV duplication and thus enforces the security property. In the context of the TLS protocol version 1.2, AES-GCM encryption and decryption is used compliant to Scenario 1 in FIPS 140-3 IG C.H. The module is compatible with TLS protocol version 1.2 using AES-GCM ciphersuites as specified in NIST SP800-52rev2, Section 3.3.1, and the mechanism for IV generation is compliant with RFC 5288. The module ensures that it is strictly increasing and thus cannot repeat. When the IV exhausts the maximum number of possible values for a given session key, the first party (client or server) to encounter this condition may either trigger a handshake to establish a new encryption key in accordance with RFC 5246 or fail. In either case, the module prevents any IV duplication and thus enforces the security property. The module’s IV is generated internally by the module’s Approved DRBG, which is internal to the module’s boundary. The IV is 96 bits in length per NIST SP 800-38D, Section 8.2.2 and FIPS 140-3 IG C.H scenario 2. The selection of the IV construction method is the responsibility of the user of this cryptographic module. In approved mode, only internally generated IVs are considered compliant for use. Per IG C.H, in the event module power is lost and restored, the consuming application must ensure that any of its AES-GCM keys used for encryption or decryption are re-distributed.

The module allows the use of 1024-bit RSA keys for legacy purposes including signature generation, which is disallowed in Approved mode as per NIST SP 800-131A. Therefore, the cryptographic operations with the Non-Approved key sizes will result in the module operating in Non-Approved mode. The elliptic curves utilized shall be the validated NIST-recommended curves and shall provide a minimum of 112 bits of encryption strength.

Non-Approved cryptographic algorithms shall not share the same key or CSP as an approved algorithm. As such, Approved algorithms shall not use the keys generated by the module’s Non-Approved key generation methods or the converse. Public Material – May be reproduced only in its original entirety (without revision).

The module supports two modes of operation: Approved and Non-approved. The module will be in approved mode when all power up self-tests have completed successfully, and only Approved algorithms are invoked. See Table 4 above for a list of the supported Approved algorithms. The nonApproved mode is entered when a non-Approved algorithm is invoked. See Table 6 for a list of nonApproved algorithms. 12. Mitigation of Other Attacks The module is not designed to mitigate against attacks that are outside of the scope of FIPS 140-3. Public Material – May be reproduced only in its original entirety (without revision).

13. References and Standards The following Standards are referenced in this Security Policy: Table 19 – References and Standards
14. Acronyms Public Material – May be reproduced only in its original entirety (without revision).

Public Material – May be reproduced only in its original entirety (without revision).

Table 20

• Acronyms Public Material
• May be reproduced only in its original entirety (without revision).