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Doca Aes Gcm
Use this skill when the user is doing hands-on DOCA AES-GCM work on a BlueField DPU or ConnectX NIC — configuring `doca_aes_gcm_task_encrypt` / `_task_decrypt`, querying `doca_aes_gcm_cap_*` for per-key-type (only `DOCA_AES_GCM_KEY_128` / `_256` — AES-192 not supported) and per-task support, sizing plaintext against the max-buf cap, setting source / destination mmap permissions, validating with a NIST GCMVS or RFC 5288 vector, or debugging DOCA_ERROR_* including the security-critical tag-verification-failed outcome on decrypt. Trigger even when the user does not explicitly mention "DOCA AES-GCM" or "AEAD" — typical implicit phrasings: "decrypt completion IO_FAILED", "auth tag isn't verifying", "NOT_PERMITTED on my encrypt buffer", "is AES-192-GCM on this BlueField" (no), or "encrypted record came back tampered". Refuse and route elsewhere for non-GCM AES modes (CBC / CTR / XTS — CPU OpenSSL), key management (KMS / HSM / rotation), SHA (doca-sha), or general AEAD background.
Archived 2026-10-23 · Source updated 2026-09-17 · License: Apache-2.0. Check the original repository for the latest version.
SKILL.md instructions
# DOCA AES-GCM **Where to start:** This skill assumes DOCA is already installed and the user is doing **hands-on AES-GCM-acceleration work** on a BlueField / ConnectX / host with DOCA. Open [`TASKS.md`](TASKS.md) if the user wants to *do* something (configure / build / modify / run / test / debug); open [`CAPABILITIES.md`](CAPABILITIES.md) when the question is *what can DOCA AES-GCM express* on this version. If the user has not installed DOCA yet, route to [`doca-setup`](../../doca-setup/SKILL.md) first. If the user is asking *"should I even use the accelerator for this encryption?"*, the path-selection rule in [`CAPABILITIES.md ## Capabilities and modes`](CAPABILITIES.md#capabilities-and-modes) is the first stop. If the user is treating AES-GCM as a confidentiality-only primitive (raw AES-CTR / AES-CBC style), stop and read the AEAD note in [`CAPABILITIES.md ## Safety policy`](CAPABILITIES.md#safety-policy) first — AES-GCM is authenticated encryption, and confusing the two is the most expensive failure mode this skill exists to prevent. ## Example questions this skill answers well The CLASSES of DOCA AES-GCM questions this skill is built to answer, each with one worked example. The agent should treat the *class* as the load-bearing piece — the worked example is a single instance. - **"Should I offload this AES-GCM encryption to DOCA AES-GCM, or just do it on the CPU with OpenSSL?"** — worked example: *"I am encrypting 4 KiB TLS records at line rate; is doca-aes-gcm worth the setup vs OpenSSL `EVP_aes_256_gcm` on the CPU?"*. Answered by the path-selection table in [`CAPABILITIES.md ## Capabilities and modes`](CAPABILITIES.md#capabilities-and-modes) + the *"when NOT to use doca-aes-gcm"* bullets in [`CAPABILITIES.md ## Safety policy`](CAPABILITIES.md#safety-policy). - **"Does my device support the AES-GCM key size I want?"** — worked example: *"is AES-256-GCM in the accelerator on this BlueField? And while we're here, is AES-192-GCM available?"* (Answer: the library exposes only `DOCA_AES_GCM_KEY_128` / `DOCA_AES_GCM_KEY_256`; AES-192 is not in the enum and is not supported. For the two real key types, gate on `doca_aes_gcm_cap_task_encrypt_is_key_type_supported(devinfo, key_type)` and the matching `_decrypt_is_key_type_supported`. AES-192 is not available — route to a CPU library.) Answered by the per-key-type capability queries and the per-task `doca_aes_gcm_cap_task_*_is_supported` queries in [`CAPABILITIES.md ## Capabilities and modes`](CAPABILITIES.md#capabilities-and-modes) + the discovery step in [`TASKS.md ## configure`](TASKS.md#configure). - **"How do I correctly decrypt an AES-GCM message and verify the auth tag?"** — worked example: *"my `doca_aes_gcm_task_decrypt` completion reports an error — is the plaintext output safe to use?"*. Answered by the auth-tag verification rule in [`CAPABILITIES.md ## Safety policy`](CAPABILITIES.md#safety-policy) (*do not use the plaintext if the auth tag did not verify*) + the decrypt completion-handling workflow in [`TASKS.md ## test`](TASKS.md#test) and [`TASKS.md ## debug`](TASKS.md#debug). - **"What permissions does the source / destination mmap need?"** — worked example: *"my `doca_aes_gcm_task_encrypt` returns `DOCA_ERROR_NOT_PERMITTED`"*. Answered by the permission matrix in [`CAPABILITIES.md ## Safety policy`](CAPABILITIES.md#safety-policy) + the mmap-set-permissions checklist in [`TASKS.md ## test`](TASKS.md#test). - **"Is this DOCA AES-GCM API available on my installed DOCA version?"** — worked example: *"is AES-192-GCM in the DOCA I have installed, on this device?"*. Answered by the version-compatibility overlay in [`CAPABILITIES.md ## Version compatibility`](CAPABILITIES.md#version-compatibility), which cross-links the canonical detection chain in [`doca-version`](../../doca-version/SKILL.md) and adds the AES-GCM-specific *"discover key sizes via cap query"* bullets. - **"What does this `DOCA_ERROR_*` from an AES-GCM call mean and which layer caused it?"** — worked example: *"`DOCA_ERROR_IO_FAILED` on the decrypt completion — is this a hardware bug or a tag mismatch?"*. Answered by the AES-GCM overlay on the cross-library taxonomy in [`CAPABILITIES.md ## Error taxonomy`](CAPABILITIES.md#error-taxonomy) + the layered ladder in [`TASKS.md ## debug`](TASKS.md#debug) that escalates to [`doca-debug`](../../doca-debug/SKILL.md). ## Audience This skill serves **external developers building applications that consume the DOCA AES-GCM library** — i.e., users whose code calls `doca_aes_gcm_*` (directly in C/C++, or through FFI/bindings from another language) to offload AES-GCM authenticated encryption / decryption onto a BlueField DPU or ConnectX accelerator. It is *not* for NVIDIA developers contributing to DOCA AES-GCM itself. **Language scope.** DOCA AES-GCM ships as a C library with `pkg-config` module name `doca-aes-gcm`. The shipped samples are written in C. C and C++ consumers are the canonical case and the worked examples in `TASKS.md` assume that path. Other-language consumers (Rust, Go, Python, …) consume the same `*.so` through FFI or language-specific bindings; the skill's contribution in that case is to keep the lifecycle, capability-discovery, permission, error-taxonomy, AEAD-semantics, and encrypt-vs-decrypt guidance language-neutral, and to route the agent to the public C ABI as the authoritative surface that any wrapper will eventually call. **Key handling is out of scope.** This skill teaches the agent how to *use* the DOCA AES-GCM library; it does not teach the user how to generate, store, rotate, or distribute AES-GCM keys. Key-management is the user's responsibility (a KMS, an HSM, a sealed file, an env var the user trusts). The skill's only key-handling rule is the operational one in [`CAPABILITIES.md ## Safety policy`](CAPABILITIES.md#safety-policy): do not log keys, do not commit them to source, and treat any key buffer the program holds as sensitive memory. ## When to load this skill Load this skill when the user is doing hands-on DOCA AES-GCM work, in any language. Concretely: - Initializing a `doca_aes_gcm` context on a `doca_dev` and configuring at least one task type (`doca_aes_gcm_task_encrypt` and/or `doca_aes_gcm_task_decrypt`) before `doca_ctx_start()`. - Choosing between **encrypt** (`doca_aes_gcm_task_encrypt` — takes key + IV + AAD + plaintext, produces ciphertext + auth tag) and **decrypt** (`doca_aes_gcm_task_decrypt` — takes key + IV + AAD + ciphertext + expected auth tag, produces plaintext *and verifies the tag*) for the user's data shape. - Setting permissions on `doca_mmap` correctly for the source buffer (`DOCA_ACCESS_FLAG_LOCAL_READ_ONLY` at minimum — the plaintext on encrypt or the ciphertext on decrypt) and the destination buffer (`DOCA_ACCESS_FLAG_LOCAL_READ_WRITE`). - Checking which AES-GCM key types (`DOCA_AES_GCM_KEY_128` / `DOCA_AES_GCM_KEY_256` — AES-192 is not in the library) the active device's accelerator advertises via `doca_aes_gcm_cap_task_encrypt_is_key_type_supported` / `doca_aes_gcm_cap_task_decrypt_is_key_type_supported`, and which task types via `doca_aes_gcm_cap_task_encrypt_is_supported` / `_task_decrypt_is_supported`. - Sizing the per-submission plaintext against `doca_aes_gcm_cap_task_encrypt_get_max_buf_size(devinfo)`. - Validating an encrypt + decrypt round-trip against a published AES-GCM test vector (NIST GCMVS, or RFC 5288 examples) before pushing any user data through the accelerator. - Handling the auth-tag verification result on decrypt completions *as a security-critical signal* — a tag-mismatch completion means the ciphertext was tampered with or corrupted, and the plaintext output of that task is poisoned and must not be consumed. - Debugging a `DOCA_ERROR_*` returned from an AES-GCM call (lifecycle vs. unsupported key size vs. permission vs. tag verification failure on decrypt) and the task-completion event on the progress engine. - Designing or extending non-C bindings (Rust, Go, Python, …) that wrap the AES-GCM C ABI — for the lifecycle, permission, capability, AEAD-semantics, and encrypt-vs-decrypt rules the wrapper must honor. Do **not** load this skill for general DOCA orientation, install of DOCA itself, AES modes that are not GCM (CBC / CTR / XTS — those are not in this library and CPU + OpenSSL is the right answer), SHA hashing on the same accelerator family (use [`doca-sha`](../doca-sha/SKILL.md)), or other DOCA libraries. For those, use [`doca-public-knowledge-map`](../../doca-public-knowledge-map/SKILL.md). ## What this skill provides This is a **thin loader**. The body keeps only the orientation needed to pick the right next file. The substantive AES-GCM-specific material lives in two companion files: - `CAPABILITIES.md` — what DOCA AES-GCM can express on this version: the two task types (encrypt and decrypt), the AEAD output shape (ciphertext + auth tag on encrypt; verified plaintext on decrypt), the AES-GCM key-type surface (only 128-bit and 256-bit — AES-192 is not in the enum, both cap-queried), the capability-query surface (`doca_aes_gcm_cap_*` for task presence, key-type support, and buffer sizing), the AES-GCM error taxonomy (mapped onto the cross-library `DOCA_ERROR_*` set, with explicit treatment of the tag-verification-failure outcome as security-critical), the observability surface (per-task completion events on the progress engine), the safety policy that gates source / destination mmap permission decisions and key-handling cautions, and the path-selection rule (when to use doca-aes-gcm versus CPU OpenSSL or a different DOCA crypto library). - `TASKS.md` — step-by-step workflows for the six in-scope AES-GCM verbs: `configure`, `build`, `modify`, `run`, `test`, `debug`. Plus a `Deferred task verbs` block that points out-of-scope questions at the right next skill. The skill assumes a host or BlueField where DOCA is already installed at the standard location and the user has the privileges their public install profile expects. It does not cover installing DOCA — that path goes through [`doca-setup`](../../doca-setup/SKILL.md). ## What this skill deliberately does not ship This skill is **agent guidance**, not a samples or templates bundle. To keep the boundary clean, it deliberately does not contain — and pull requests should not add: - **Pre-written DOCA AES-GCM application source code, in any language.** The verified AES-GCM source code is the shipped C samples at `/opt/mellanox/doca/samples/doca_aes_gcm/`. The agent's job is to route the user to those files and prescribe a minimum-diff modification on them via the universal modify-a-sample workflow in [`doca-programming-guide`](../../doca-programming-guide/SKILL.md), layered with the AES-GCM-specific overrides in [`TASKS.md ## modify`](TASKS.md#modify). - **Pre-computed AES-GCM test vectors.** The skill tells the agent to use a *published* test vector (e.g. NIST GCMVS, RFC 5288 AES-GCM examples) as the known-vector smoke; it does not ship a vector bank of its own. The agent must cite the vector source so the user can audit it. - **Pre-baked AES-GCM keys, IVs, or AAD strings.** A key in this repo is a key in every customer's repo — by construction, it must not be there. The skill teaches the *shape* of the inputs; the user supplies the actual bytes from their own key-management system. - **Standalone build manifests** (`meson.build`, `CMakeLists.txt`, `Cargo.toml`, …) parked inside the skill. The agent constructs the build manifest *in the user's project directory* against the user's installed DOCA, where `pkg-config --modversion doca-aes-gcm` is the source of truth. - **A `samples/`, `bindings/`, or `reference/` subtree** of any kind. A mock or incomplete artifact in this skill's tree, even one labeled "reference", is misleading: users will read it as buildable. ## Loading order 1. Read this `SKILL.md` first to confirm the user's question is in scope. 2. **For the AES-GCM capability matrix, task types, key-size surface, capability-query rules, permission matrix, AEAD semantics, error taxonomy, observability, and safety / path-selection policy, see [CAPABILITIES.md](CAPABILITIES.md).** 3. **For step-by-step workflows — configure, build, modify, run, test, debug — see [TASKS.md](TASKS.md).** Both companion files cross-link to each other, [`doca-version`](../../doca-version/SKILL.md) for the canonical version-handling rules, and [`doca-public-knowledge-map`](../../doca-public-knowledge-map/SKILL.md) whenever the right answer is "look it up in the public docs or the installed package layout" rather than "AES-GCM-specific guidance". ## Related skills - [`doca-public-knowledge-map`](../../doca-public-knowledge-map/SKILL.md) — the routing table for every public DOCA documentation source and the on-disk layout of an installed DOCA package. The DOCA AES-GCM page lives at `docs.nvidia.com/doca/sdk/DOCA-AES-GCM/`; it is a member of the DOCA Crypto Acceleration family alongside [`doca-sha`](../doca-sha/SKILL.md). - [`doca-setup`](../../doca-setup/SKILL.md) — env preparation, install verification, and the *I have no install yet* path with the public NGC DOCA container. This skill assumes its preconditions are satisfied. - [`doca-version`](../../doca-version/SKILL.md) — canonical DOCA version-handling rules. This skill's [`## Version compatibility`](CAPABILITIES.md#version-compatibility) cross-links the four-way match rule and adds only the AES-GCM-specific *"discover key sizes + task presence via cap query"* overlay. - [`doca-structured-tools-contract`](../../doca-structured-tools-contract/SKILL.md) — the bundle's structured-tools precedence rule (detect / prefer / fall back / report). The Command appendix in [TASKS.md](TASKS.md) honors this contract. - [`doca-programming-guide`](../../doca-programming-guide/SKILL.md) — general DOCA programming patterns shared by every library: the canonical `pkg-config` + meson build pattern, the universal modify-a-shipped-sample first-app workflow, the universal lifecycle, the cross-library `DOCA_ERROR_*` taxonomy, and the program-side debug order. This skill layers AES-GCM specifics on top. - [`doca-sha`](../doca-sha/SKILL.md) — the sibling library in the DOCA Crypto Acceleration family for hardware-accelerated SHA hashing. Load alongside this skill when the user's flow is authenticated-encryption *with a separate keyed hash* (rare — AES-GCM already provides authentication via its tag) or when the user is comparing offload paths between the two. - [`doca-debug`](../../doca-debug/SKILL.md) — the cross-cutting debug ladder (install / version / build / link / runtime / program / driver). AES-GCM-specific debug (key-size-not-supported, oversized input, tag-verification failure on decrypt) overlays on top of that ladder.