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/doca-sha-offload-engine

@a5736e4
by NVIDIA Corporationnvidia/skills3.5k stars
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Use this skill when wiring the DOCA SHA Offload Engine (an OpenSSL ENGINE) into an existing OpenSSL pipeline to offload one-shot SHA-1, SHA-256, or SHA-512 (EVP_Digest) onto DOCA SHA hardware without rewriting against doca-sha. Covers engine load mechanics (`openssl engine dynamic`, `set_pci_addr` ctrl, `-engine_impl`), the SHA-224 negative test that proves offload engaged, the message-size window where offload beats CPU SHA, and engine-vs-library selection. Trigger even when the user does not say "DOCA SHA Offload Engine" or "OpenSSL ENGINE" — typical implicit phrasings: "speed up openssl SHA on BlueField", "offload SHA without code changes", "is openssl using the accelerator or falling back to software", "prove DOCA SHA actually ran", "openssl dgst hashed but I'm not sure it was offloaded". Refuse and route elsewhere for new SHA pipelines (use doca-sha), MD5 / SHA-3 / SHA-224 / HMAC-SHA offload, incremental hashing via chained `EVP_DigestUpdate`, or OpenSSL PROVIDER authoring.

Use this Skill: https://skilld.dev/gh/nvidia/skills/doca-sha-offload-engine

This session only. Nothing lands on disk.

TASKS.md

≈5.3k tokens on demand. Your agent reads this file only when SKILL.md points to it.

DOCA SHA Offload Engine — Tasks

Where to start: The verbs that carry real workflow content are ## configure, ## build, ## run, ## test, ## debug, and ## use. The other verbs (install, modify) carry preconditions and a refuses-to-patch routing stub.

This file is loaded by SKILL.md after CAPABILITIES.md. It walks the agent through the task verbs every artifact in this bundle exposes (install / configure / build / modify / run / test / debug / use), then defers task verbs that do not belong here.

install

Goal: confirm the host has every precondition the engine's build + load + run sequence needs before any engine-specific work begins.

This skill does not own DOCA installation; that path lives in doca-setup. The doca-sha-offload-engine-specific preconditions:

  1. doca-sha.pc is present. Run pkg-config --modversion doca-sha. If the .pc does not resolve, the installed DOCA does not include doca-sha; route to ../../libs/doca-sha/SKILL.md and doca-setup.
  2. OpenSSL ≥ 1.1.1 is present per the shipped readme.md. Verify via openssl version. OpenSSL 3.x is supported via the legacy ENGINE code path per CAPABILITIES.md ## Version compatibility.
  3. libssl-dev (or distribution equivalent) is installed for the build host per the shipped test_cmdline_mode/readme.md. On Ubuntu: sudo apt install libssl-dev. On RHEL: sudo dnf install openssl-devel. The exact package name is distribution-specific; the agent does not invent it.
  4. DOCA SHA device is visible to DOCA. doca_caps --list-devs (per ../doca-caps/TASKS.md#run) reports a device whose PCIe address the operator plans to bind via set_pci_addr. The default PCIe address in the shipped source is 03:00.0; the operator must confirm this matches their hardware before relying on it.
  5. The application embedding the engine has access to OpenSSL's ENGINE API. For programmatic embedding, the app must link against libcrypto; for CLI embedding the openssl binary on the host is enough.

If any precondition fails, stop and route; engine-layer diagnosis against a missing OpenSSL, a missing libssl-dev, or an absent doca-sha install wastes time.

configure

Goal: pick the PCIe address of the DOCA SHA device, the load pattern (CLI vs programmatic), and the OpenSSL algorithm coverage the deployment needs.

Steps the agent walks the user through, in order:

  1. Confirm the engine is the right surface. Walk CAPABILITIES.md ## Capabilities and modes engine-vs-library selection table. If the user is writing a new pipeline, route to ../../libs/doca-sha/SKILL.md; if the user needs SHA-224 or another non-covered algorithm, the engine is the wrong answer.
  2. Identify the DOCA SHA PCIe address. Run doca_caps --list-devs and pick the device the workload should bind. If the host's DOCA SHA device is at 03:00.0, the engine's build-time default works without override; otherwise the operator must either re-build with the alternative PCIe address (per the shipped test_cmdline_mode/readme.md edit- the-meson.build workflow) OR pass the PCIe address at load time via the set_pci_addr ctrl-cmd.
  3. Decide CLI vs programmatic load. For an openssl dgst / openssl speed driven pipeline, CLI is the right answer (no application change). For an application calling OpenSSL programmatically, the verified ENGINE_load_dynamic / ENGINE_by_id / ENGINE_ctrl_cmd_string / ENGINE_init / ENGINE_set_default_digests block from the shipped readme.md is the minimum source change.
  4. Decide whether to use -engine_impl. Per CAPABILITIES.md ## Observability, -engine_impl disables OpenSSL's software fallback. In production the operator may want fallback enabled (the engine fails open to software SHA when the device is unavailable); in verification the operator wants -engine_impl (so a missed offload surfaces as an error, not a silent software hash).
  5. For openssl speed perf characterization, decide the -async_jobs and -multi values. Per the shipped readmes, the engine's perf surface depends on the OpenSSL async pipeline; the agent surfaces this to the user before they ask for a "quick benchmark" that would not exercise the engine's actual scaling shape.
  6. Confirm the build inputs. PKG_CONFIG_PATH includes the install's pkgconfig directory; OpenSSL headers are visible to the meson build.

build

The engine is not pre-built under /opt/mellanox/doca/ on all install profiles; the user typically builds it from source under doca/tools/sha_offload_engine/ against the installed DOCA. The build pattern (per the shipped test_cmdline_mode/readme.md):

  1. (Optional) edit the build-time PCIe address. If the user's DOCA SHA device is not at 03:00.0, edit doca/tools/sha_offload_engine/meson.build to change the -DDOCA_ENGINE_PCI_ADDR="03:00.0" macro per the verified test_cmdline_mode/readme.md. The alternative is to leave the macro alone and pass the PCIe address at load time via set_pci_addr.
  2. Set the right PKG_CONFIG_PATH so pkg-config can find doca-sha.pc, doca-common.pc, and the OpenSSL .pc files. The DOCA pkgconfig directory is documented in doca-public-knowledge-map.
  3. Build under the DOCA top-level meson tree. Per test_cmdline_mode/readme.md: cd ${DOCA_DIR}; meson setup build; cd build; ninja. The engine's .so lands under the build tree at a path the shipped readme documents.
  4. Confirm the .so was produced. ls <build-dir>/.../libdoca_sha_offload_engine.so (or equivalent for the user's install layout).
  5. Confirm transitive dependencies. Run ldd <engine.so> and verify the OpenSSL and DOCA shared objects all resolve. Missing transitive dependencies are the most common cause of layer-1 load errors per CAPABILITIES.md ## Error taxonomy.

Routing for nearby "build" questions:

  • "I want to build a PROVIDER instead of an ENGINE for OpenSSL 3.x." → out of scope; the shipped artifact is an ENGINE, not a PROVIDER. Route to the OpenSSL upstream PROVIDERS migration guide via doca-public-knowledge-map.
  • "I want to author my own ENGINE wrapping a different doca library." → out of scope; route to doca-programming-guide TASKS.md ## build.

modify

Do not patch the shipped engine source tree. The shipped engine/doca_sha_offload_engine.c and lib/doca_sha_offload_lib.{c,h} are the verified worked example for this engine class; modifying them puts the user in contributor-to-DOCA territory.

What the agent does modify is the load + invocation environment — the PCIe address (either via the build-time macro or the run-time ctrl-cmd), the -async_jobs / -multi knobs on openssl speed, the inclusion of -engine_impl, the OpenSSL engines configuration in openssl.cnf for system-wide loads. Treat "modify the invocation, not the engine source" as the operating mode.

Routing for nearby "modify" questions:

  • "The engine should support SHA-224 / SHA-384 / SHA-3 / HMAC-SHA." → out of scope; that would be a source-level extension. The user can either (a) use doca-sha directly for those algorithms if the library supports them per ../../libs/doca-sha/CAPABILITIES.md, (b) use OpenSSL's software path for the non-covered algorithms, or (c) route to a different bundle that ships a customized engine.
  • "I want to enable the engine's debug logging." → the shipped source supports a PRINT_DEBUG_INFO compile-time macro and a debug_level ctrl-cmd; the user has to re-build with the macro to surface them.
  • "I need the engine to do incremental hashing across many EVP_DigestUpdate calls." → the verified engine is one-shot per the shipped readme.md. For true incremental hashing, route to ../../libs/doca-sha/ and the partial-hash task there.

run

The load + verify flow — every session goes through it. The detailed OpenSSL surface lives in the upstream OpenSSL documentation; this section names the shape of the flow, not the verbatim recipe.

Do-not-invent guard (openssl flag spellings). Real downstream agents have hallucinated an -engine-options flag for openssl dgst — it does not exist in upstream OpenSSL. The bundle's canonical pattern is two commands: first openssl engine dynamic -pre NO_VCHECK:1 -pre SO_PATH:<path> -pre LOAD -vvv -t -c to probe the engine, then openssl dgst -sha256 -engine <path> -engine_impl to run the digest through it. The bundle's exact spelling is -engine_impl with an underscore — not -engine-impl with a hyphen; some OpenSSL builds may accept both, but the bundle's verbatim form is the underscore. The engine ID is doca_sha_offload_engine; the install path of the .so is ${DOCA_DIR}/tools/doca_sha_offload_engine/ (per install_dir: 'tools/doca_sha_offload_engine' in tools/sha_offload_engine/meson.build and the shipped readme.md; NOT under ${DOCA_DIR}/infrastructure/). These names belong to different lifecycle stages: source is under doca/tools/sha_offload_engine/, Meson installs under tools/doca_sha_offload_engine/, and OpenSSL registers the engine ID doca_sha_offload_engine. Do not derive one spelling from another; inspect the installed .so path before loading it.

  1. Confirm the .so and the environment. Per ## install, ## configure, and ## build.
  2. Probe the engine load. Run the verified openssl engine dynamic -pre NO_VCHECK:1 -pre SO_PATH:<path-to-libdoca_sha_offload_engine.so> -pre LOAD -vvv -t -c invocation per the shipped readme.md. On success the output prints the engine name, the [SHA1, SHA256, SHA512] available digests, and the set_pci_addr ctrl-cmd. If the output is missing any of those, route to ## debug layer 1 or 2.
  3. Run the SHA-224 negative test first. Per the shipped test_cmdline_mode/readme.md, run openssl dgst -sha224 -engine <path> -engine_impl on a known input. The expected output is an error (Error setting digest); the error PROVES OpenSSL actually consulted the engine. If the call succeeds anyway, the engine is NOT being consulted — route to ## debug layer 4.
  4. Run a positive test. Run openssl dgst -sha256 -engine <path> -engine_impl on a known input. Expected: a correct SHA-256 hash and a stderr line matching engine "doca_sha_offload_engine" set. per the verified readme.md examples.
  5. For programmatic deployment, drop the verified load block into the application per the shipped readme.md:
    ENGINE *e;
    const char *doca_engine_path = "${DOCA_DIR}/tools/doca_sha_offload_engine/libdoca_sha_offload_engine.so";
    ENGINE_load_dynamic();
    e = ENGINE_by_id(doca_engine_path);
    ENGINE_ctrl_cmd_string(e, "set_pci_addr", doca_engine_pci_addr, 0);
    ENGINE_init(e);
    ENGINE_set_default_digests(e);
    Pair it with the verified unload sequence (ENGINE_unregister_digests → ENGINE_finish → ENGINE_free). Quote these verbatim from the shipped readme; do not invent alternative function names.
  6. Plan the perf-comparison run only after the verification is green. Per ## test the agent walks an openssl speed comparison with and without the engine.

When recording the run for downstream consumers, write down: pkg-config --modversion doca-sha, openssl version, host OS / kernel / NUMA, DOCA SHA device PCIe address, the engine load output (openssl engine dynamic -vvv -t -c), the SHA-224 negative test result, the positive test result, and the -engine_impl flag's presence / absence.

test

The engine's ## test verb covers TWO loops: (a) verification — did the engine actually run — and (b) performance characterization — for what message-size mix is the engine a win.

Verification loop

The SHA-224 negative test is mandatory. Without it, the operator cannot tell whether DOCA SHA ran or whether OpenSSL silently used its software path. Per CAPABILITIES.md ## Observability prove-offload pattern:

  1. Run openssl dgst -sha224 -engine <path> -engine_impl <some-input>. Expected: error (Error setting digest per the shipped readme). If the call succeeds with a hash, OpenSSL is silently using software SHA — the engine is not being consulted. Route to ## debug layer 4.
  2. Run openssl dgst -sha256 -engine <path> -engine_impl <some-input>. Expected: a correct SHA-256 hash and a stderr line engine "doca_sha_offload_engine" set.. If this fails, route to ## debug layer 2 or 3.
  3. Repeat (2) for -sha1 and -sha512. All three should succeed.
  4. Only after all four steps pass is the engine verified.

Performance-characterization loop

Per the shipped test_cmdline_mode/readme.md and readme.md, openssl speed is the documented surface. The eval-loop overlay:

Iteration trigger What it looks like What changes next iteration
openssl speed -evp sha1 -bytes 10000 -elapsed without the engine completes; the same command with --engine and no -async_jobs is slower or about equal Round-trip cost dominates for small messages without async batching Add -async_jobs 256 and re-run; the engine's async surface is what changes the picture.
Engine with -async_jobs 256 wins comfortably; engine without -async_jobs does not Workload's deployment must enable async to benefit The agent's recommendation is "deploy with async enabled, or move to the doca-sha library directly for finer-grained control of the parallelism shape".
Engine wins at 100 KB but not at 10 KB The crossover point is between those sizes for this platform Capture the message-size mix the production workload actually uses; if it is dominantly below the crossover, the engine is not a win for that pipeline.
Engine wins on synchronous openssl dgst for a single large message The single-call path is doca-sha's natural shape Quote the result alongside the message size; do NOT extrapolate to a workload with many small messages.
Same invocation produces different numbers across two hosts at the same DOCA version DOCA SHA device, firmware, or NUMA delta below DOCA Capture the (DOCA + OpenSSL + device + firmware + NUMA) tuple on both hosts; route through doca-version TASKS.md ## test.
Same invocation produces different numbers on the same host across DOCA versions Regression signal Cross-link both baselines, name the changed fields, route to doca-version TASKS.md ## debug.

The agent's rule: every change to the OpenSSL invocation re-opens the loop. Re-running with -multi 8 without re-walking the -async_jobs knob first is exactly the failure mode this loop replaces.

Baseline-capture rule. When the goal is a baseline, the captured artifact must include pkg-config --modversion doca-sha, openssl version, the device PCIe address, the openssl speed command lines (engine on and engine off), the -async_jobs and -multi values, and the host's CPU SHA-NI status (for the CPU baseline).

debug

When the engine fails to load, register, or engage, walk the CAPABILITIES.md ## Error taxonomy layers in order:

  1. Load-layer. openssl engine dynamic -pre LOAD -vvv fails or the verbose output does not list the engine. Confirm the SO_PATH is the verified ${DOCA_DIR}/tools/doca_sha_offload_engine/libdoca_sha_offload_engine.so; run ldd <engine.so> to surface missing transitive dependencies; confirm OpenSSL on the host matches what the engine was built against.
  2. Register-layer. Engine loaded but the [SHA1, SHA256, SHA512] digests are not listed, or set_pci_addr is rejected, or ENGINE_set_default_digests returns 0. Confirm the PCIe address is a valid DOCA SHA device via doca_caps --list-devs; route to ../doca-caps/TASKS.md#run.
  3. Runtime-layer. Engine registered, but a digest call fails. Confirm the message size against doca_sha_cap_get_max_src_buf_size per ../../libs/doca-sha/CAPABILITIES.md; raise DOCA_LOG_LEVEL to surface the engine's internal logging.
  4. Engine-not-engaged. The openssl dgst call completed and produced a hash, but the SHA-224 negative test from ## test shows OpenSSL silently used the software path. Common causes: the engine was loaded but ENGINE_set_default_digests was not called; the application was started before the engine was registered; the OpenSSL engines config does not actually include the engine. Re-walk ## run steps 2 and 3.
  5. Version. Cross-cutting partial-install / mixed-version. Walk doca-version TASKS.md ## debug end-to-end; confirm OpenSSL and the engine were built against compatible toolchains.
  6. Cross-cutting. Cause is below DOCA. Hand off to doca-debug TASKS.md ## debug and doca-setup TASKS.md ## debug.

In every case: quote what OpenSSL and the engine reported. Do not paraphrase the load output; do not collapse the SHA-224 test into "the engine works".

use

Goal: turn a verified engine + perf characterization into an integration decision — "do I deploy this engine or rewrite to doca-sha?".

The decision shape this skill teaches:

  1. Confirm verification. The SHA-224 negative test from ## test is the gate; an unverified engine deployment is a deployment that silently falls back to software SHA on a moment's notice.
  2. Quote the win alongside the message-size mix. "The engine wins at 100 KB with -async_jobs 256; at 4 KB the CPU wins" is a defensible deployment recommendation; "the engine is faster" is not.
  3. For deployments where the workload's message-size mix is below the crossover, the right answer is NOT the engine. It may be doca-sha directly with a custom batching strategy, or the host's SHA-NI path, or a redesign that batches more aggressively before hashing.
  4. For deployments where the application code is fixed and cannot adopt doca-sha directly, the engine is the right answer even when the win is small — the alternative is no offload at all.
  5. Plan the deprecation path on OpenSSL 3.x. The ENGINE API is deprecated in OpenSSL 3.x in favor of PROVIDERS; the engine still works via the legacy code path per CAPABILITIES.md ## Version compatibility, but a deployment that wants to be future-proof should plan a doca-sha-direct rewrite (or wait for a PROVIDER artifact if one ships in a future DOCA release).
  6. Per-release re-verification. Every DOCA upgrade AND every OpenSSL upgrade requires re-running the SHA-224 verification AND the openssl speed characterization. The agent does not assume a known-good deployment survives version bumps without re-testing.

Deferred task verbs

The verbs below are not doca-sha-offload-engine work and should be routed out:

  • install DOCA ⇒ doca-setup TASKS.md.
  • author a new SHA pipeline against doca-sha directly ⇒ ../../libs/doca-sha/SKILL.md.
  • offload algorithms the engine does not cover (SHA-224, SHA-3, MD5, HMAC-SHA) ⇒ ../../libs/doca-sha/CAPABILITIES.md for the library's coverage; for genuine non-coverage, route to OpenSSL's software path or to a different bundle.
  • OpenSSL PROVIDER authoring (OpenSSL 3.x long-term) ⇒ out of scope; route via doca-public-knowledge-map to the OpenSSL upstream PROVIDERS migration docs on openssl.org.
  • hardware-touching changes underneath (firmware burn on the DOCA SHA device, BFB reflash) ⇒ doca-hardware-safety.

Source: SKILL.md on GitHub

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    The doca-sha-offload-engine skill is a documentation-only resource providing verified instructions for using the NVIDIA DOCA SHA Offload Engine with OpenSSL. It guides users through installation, configuration, building, and performance testing of the engine. All referenced tools and URLs belong to trusted or well-known sources (NVIDIA, OpenSSL), and no malicious patterns such as prompt injection, obfuscation, or unauthorized data exfiltration were detected.

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Signed by skilld at a5736e4. This ties the file your Agent reads to that commit on GitHub. It does not review the instructions.

Last checked against GitHub yesterday.

Activeupdated 2 months ago
metadata
{
  "kind": "tool"
}
Other metadata
compatibility
Requires DOCA SDK installed at /opt/mellanox/doca on Linux (Ubuntu 22.04/24.04 or RHEL/SLES) with a BlueField DPU or ConnectX NIC attached, plus OpenSSL ≥ 1.1.1 and libssl-dev (or distro equivalent) on the build host. The engine ships under /opt/mellanox/doca/tools/doca_sha_offload_engine/ as libdoca_sha_offload_engine.so; reads the user's local install via `pkg-config doca-sha` and inspects /opt/mellanox/doca/{lib,include,samples,applications}.

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