Add DMA support for remaining AES modes by Frauschi · Pull Request #282 · wolfSSL/wolfHSM

Frauschi · 2026-02-05T16:13:19Z

This PR adds DMA support for the three remaining AES modes:

ECB
CBC
CTR

The implementations are very similar to the existing AES-GCM DMA implementation. For CBC, there is #225 already, which is superseded by this PR (#225 seems stalled and doesn't pass tests). @JacobBarthelmeh if you are fine with it, you may close #225 once this is merged.

I added new message request/response structures for these AES DMA operations, as mapping them to the existing whMessageCrypto_AesDmaRequest/whMessageCrypto_AesGcmDmaResponse structures would increase complexity and also the number of transmitted bytes unnecessarily (although they seemed to be intended for all modes).

All the new implementations are tested in the unit tests and also executed in the benchmark.

I also did some minor cleanup work for non-DMA implementations (e.g. around CBC IV handling) and, most importantly, removed the IV handling for non-DMA ECB mode, as ECB does not use IV at all. This previous handling in code hasn't caused any bugs or problems, but for clarity I assumed the removal is beneficial anyway.

JacobBarthelmeh

Initially was going to keep all AES operations under one "message" struct. I can see the merit in having separate ones for each mode though.

Copilot

Pull request overview

This pull request adds DMA (Direct Memory Access) support for three additional AES cipher modes: ECB, CBC, and CTR. The implementation follows the existing AES-GCM DMA pattern and includes proper cleanup of IV handling for ECB mode (which doesn't use IVs). The PR also refactors the existing AES-GCM DMA message structures for better clarity by renaming them from generic AesDmaRequest/Response to mode-specific AesGcmDmaRequest/Response.

Changes:

Added DMA support for AES-ECB, AES-CBC, and AES-CTR modes with new message request/response structures and translation functions
Removed unnecessary IV handling from ECB mode in both DMA and non-DMA implementations
Added comprehensive benchmark coverage for all new DMA operations

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated 11 comments.

Show a summary per file

File	Description
wolfhsm/wh_message_crypto.h	Added new DMA request/response structures for ECB, CBC, and CTR; renamed AES-GCM DMA structures for clarity; removed IV from ECB request structure
wolfhsm/wh_client_crypto.h	Added function declarations and documentation for new DMA operations
test/wh_test_crypto.c	Removed DMA exclusions for CTR and CBC tests; corrected ECB IV handling to use NULL
src/wh_server_crypto.c	Implemented DMA handlers for ECB, CBC, and CTR; removed IV handling from ECB; added default cases to switch statements; updated GCM handler to use renamed structures
src/wh_message_crypto.c	Added translation functions for new DMA structures; renamed GCM translation functions
src/wh_client_cryptocb.c	Added crypto callback handlers for new DMA cipher types
src/wh_client_crypto.c	Implemented client-side DMA functions for ECB, CBC, and CTR; removed IV handling from non-DMA ECB
benchmark/wh_bench_ops.h	Increased MAX_BENCH_OPS to accommodate new benchmark operations
benchmark/wh_bench.c	Added benchmark module entries for all new DMA operations
benchmark/bench_modules/wh_bench_mod_all.h	Added function declarations for new benchmark modules
benchmark/bench_modules/wh_bench_mod_aes.c	Implemented benchmark functions for all new DMA operations; added IV reset for CBC benchmarks

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Copilot · 2026-02-05T21:51:37Z

src/wh_server_crypto.c

+{
+    int                               ret = 0;
+    whMessageCrypto_AesCtrDmaRequest  req;
+    whMessageCrypto_AesCtrDmaResponse res;


The response structure 'res' is not initialized. This could lead to undefined behavior if dmaAddrStatus fields are accessed when no error occurs. Consider initializing the structure with memset(&res, 0, sizeof(res)) after declaration.

Copilot · 2026-02-05T21:51:38Z

src/wh_server_crypto.c

+{
+    int                               ret = 0;
+    whMessageCrypto_AesEcbDmaRequest  req;
+    whMessageCrypto_AesEcbDmaResponse res;


The response structure 'res' is not initialized. This could lead to undefined behavior if dmaAddrStatus fields are accessed when no error occurs. Consider initializing the structure with memset(&res, 0, sizeof(res)) after declaration.

Copilot · 2026-02-05T21:51:38Z

src/wh_server_crypto.c

+{
+    int                               ret = 0;
+    whMessageCrypto_AesCbcDmaRequest  req;
+    whMessageCrypto_AesCbcDmaResponse res;


The response structure 'res' is not initialized. This could lead to undefined behavior if dmaAddrStatus fields are accessed when no error occurs. Consider initializing the structure with memset(&res, 0, sizeof(res)) after declaration.

Copilot · 2026-02-05T21:51:38Z

src/wh_server_crypto.c

+    (void)inSize;
+    (void)seq;
+


Missing input size validation. The function should check that inSize is at least sizeof(whMessageCrypto_AesEcbDmaRequest) before proceeding, similar to how _HandleAesCtrDma does at line 2447. Currently inSize is cast to void, which means no validation is performed.

Suggested change

(void)inSize;

(void)seq;

(void)seq;

if (inSize < (uint16_t)sizeof(whMessageCrypto_AesEcbDmaRequest)) {

return WH_ERROR_BADARGS;

}

Copilot · 2026-02-05T21:51:39Z

src/wh_server_crypto.c

+    whKeyId  keyId;
+    uint32_t keyLen;
+
+    (void)inSize;


Missing input size validation. The function should check that inSize is at least sizeof(whMessageCrypto_AesCbcDmaRequest) before proceeding, similar to how _HandleAesCtrDma does at line 2447. Currently inSize is cast to void, which means no validation is performed.

Suggested change

(void)inSize;

if (inSize < (uint16_t)sizeof(whMessageCrypto_AesCbcDmaRequest)) {

return WH_ERROR_BAD_ARGS;

}

Copilot · 2026-02-05T21:51:39Z

src/wh_server_crypto.c

+
+    /* Set response */
+    res.outSz = outSz;
+    *outSize  = sizeof(whMessageCrypto_AesEcbResponse);


The outSize is being set to the wrong response type. It should be sizeof(whMessageCrypto_AesEcbDmaResponse) instead of sizeof(whMessageCrypto_AesEcbResponse).

Suggested change

*outSize = sizeof(whMessageCrypto_AesEcbResponse);

*outSize = sizeof(whMessageCrypto_AesEcbDmaResponse);

Copilot · 2026-02-05T21:51:40Z

src/wh_server_crypto.c

+
+    /* Set response */
+    res.outSz = outSz;
+    *outSize  = sizeof(whMessageCrypto_AesCbcResponse);


The outSize is being set to the wrong response type. It should be sizeof(whMessageCrypto_AesCbcDmaResponse) instead of sizeof(whMessageCrypto_AesCbcResponse).

Suggested change

*outSize = sizeof(whMessageCrypto_AesCbcResponse);

*outSize = sizeof(whMessageCrypto_AesCbcDmaResponse);

Copilot · 2026-02-05T21:51:40Z

src/wh_client_crypto.c

+
+    /* Send request and receive response */
+    reqLen = sizeof(whMessageCrypto_GenericRequestHeader) + sizeof(*req);
+    WH_DEBUG_VERBOSE_HEXDUMP("[client] AESCBC DMA req packet: \n",


The debug message says "AESCBC DMA req packet" but this is in the wh_Client_AesEcbDma function. It should say "AESECB DMA req packet" instead.

Suggested change

WH_DEBUG_VERBOSE_HEXDUMP("[client] AESCBC DMA req packet: \n",

WH_DEBUG_VERBOSE_HEXDUMP("[client] AESECB DMA req packet: \n",

Copilot · 2026-02-05T21:51:40Z

src/wh_client_crypto.c

+
+        if (ret == WH_ERROR_OK) {
+            /* Get response */
+            whMessageCrypto_AesCbcDmaResponse* res;


The response type is incorrect. This function is wh_Client_AesEcbDma but it's using whMessageCrypto_AesCbcDmaResponse. It should be whMessageCrypto_AesEcbDmaResponse.

Suggested change

whMessageCrypto_AesCbcDmaResponse* res;

whMessageCrypto_AesEcbDmaResponse* res;

Copilot · 2026-02-05T21:51:40Z

benchmark/bench_modules/wh_bench_mod_aes.c

+            goto exit;
+        }
+        if (ret != 0) {
+            WH_BENCH_PRINTF("Failed to wh_Client_AesCbcDma %d\n", ret);


The error message is incorrect. This function is _benchAesEcbDma and is calling wc_AesEcbEncrypt/wc_AesEcbDecrypt, but the error message says "Failed to wh_Client_AesCbcDma". It should say "Failed to wc_AesEcb" or similar.

Suggested change

WH_BENCH_PRINTF("Failed to wh_Client_AesCbcDma %d\n", ret);

WH_BENCH_PRINTF("Failed to wc_AesEcb %d\n", ret);

Frauschi added 3 commits February 5, 2026 16:57

Add DMA support for AES-CTR

249cf8c

Add DMA support for AES-CBC

88b409a

Add DMA support for AES-ECB

d8f3885

Frauschi requested a review from bigbrett February 5, 2026 16:37

JacobBarthelmeh self-assigned this Feb 5, 2026

JacobBarthelmeh approved these changes Feb 5, 2026

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JacobBarthelmeh requested a review from Copilot February 5, 2026 21:46

JacobBarthelmeh removed their assignment Feb 5, 2026

Copilot started reviewing on behalf of JacobBarthelmeh February 5, 2026 21:46 View session

Copilot AI reviewed Feb 5, 2026

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Add DMA support for remaining AES modes#282

Add DMA support for remaining AES modes#282
Frauschi wants to merge 3 commits intowolfSSL:mainfrom
Frauschi:aes_dma

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-    (void)inSize;
+    if (inSize < (uint16_t)sizeof(whMessageCrypto_AesCbcDmaRequest)) {
+        return WH_ERROR_BAD_ARGS;
+    }

	*outSize = sizeof(whMessageCrypto_AesEcbResponse);
	*outSize = sizeof(whMessageCrypto_AesEcbDmaResponse);

	*outSize = sizeof(whMessageCrypto_AesCbcResponse);
	*outSize = sizeof(whMessageCrypto_AesCbcDmaResponse);

	WH_DEBUG_VERBOSE_HEXDUMP("[client] AESCBC DMA req packet: \n",
	WH_DEBUG_VERBOSE_HEXDUMP("[client] AESECB DMA req packet: \n",

	whMessageCrypto_AesCbcDmaResponse* res;
	whMessageCrypto_AesEcbDmaResponse* res;

	WH_BENCH_PRINTF("Failed to wh_Client_AesCbcDma %d\n", ret);
	WH_BENCH_PRINTF("Failed to wc_AesEcb %d\n", ret);

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