[hmac, dv] Extend multistream TLT

Related to #23507.

Extends the multistream HMAC test so that:
* One-shot and streaming calls are mixed.
* Streaming calls are divided into random
number of message segments [1, 4].
* The order of test vectors is randomized.

Signed-off-by: Fatih Balli <[email protected]>

sw/device/tests/crypto/BUILD

@@ -473,6 +473,7 @@ opentitan_test(
         "//sw/device/lib/base:macros",
         "//sw/device/lib/crypto/impl:hash",
         "//sw/device/lib/crypto/impl:mac",
+        "//sw/device/lib/testing:rand_testutils",
         "//sw/device/lib/testing/test_framework:check",
         "//sw/device/lib/testing/test_framework:ottf_main",
     ],

sw/device/tests/crypto/hmac_multistream_functest.c

@@ -7,6 +7,7 @@
 #include "sw/device/lib/crypto/include/hash.h"
 #include "sw/device/lib/crypto/include/mac.h"
 #include "sw/device/lib/runtime/log.h"
+#include "sw/device/lib/testing/rand_testutils.h"
 #include "sw/device/lib/testing/test_framework/check.h"
 #include "sw/device/lib/testing/test_framework/ottf_main.h"
 
@@ -25,6 +26,123 @@ static_assert(sizeof(otcrypto_hash_context_t) ==
                   sizeof(otcrypto_hmac_context_t),
               "Hash and Hmac contexts are expected to be of the same length");
 
+/**
+ * This enum defines the different stages of a test vector during streaming
+ * or oneshot HMAC calls.
+ *
+ * Oneshot calls transition from `kHmacTestNotStarted` to `kHmacTestDone`.
+ *
+ * For streaming calls, the exact number of streaming segments can be up to 4.
+ * For fewer segments, a transition from `kHmacTestFeedSegmentX` to
+ * `kHmacTestFinalize` is allowed so long as all message bytes of the test is
+ * fed to HMAC core.
+ *
+ * The value of `kHmacTestFeedSegmentX` enum is arranged to match integer X,
+ * as it us used as an index to access `segment_idx` array defined in
+ * `hmac_extended_test_vector_t`.
+ */
+typedef enum hmac_test_progress {
+  /* The oneshot or streaming test has not been initialized.*/
+  kHmacTestNotStarted = 0,
+  /* The streaming test is initialized, but no message segment is fed.*/
+  kHmacTestFeedSegment1 = 1,
+  /* The streaming test is initialized and the first message segment is fed.*/
+  kHmacTestFeedSegment2 = 2,
+  /* The streaming test is initialized and the first two message segments are
+     fed.*/
+  kHmacTestFeedSegment3 = 3,
+  /* The streaming test is initialized and the first three message segments are
+     fed.*/
+  kHmacTestFeedSegment4 = 4,
+  /* All message bytes are fed but the final is not called.*/
+  kHmacTestFinalize = 5,
+  /* The test is completed and the result is verified.*/
+  kHmacTestDone = 6,
+} hmac_test_progress_t;
+
+/**
+ * Extend `hmac_test_vector_t` with metadata fields useful for streaming.
+ */
+typedef struct hmac_extended_test_vector {
+  /* The pointer to the test vector coming from the autogenerated C header. */
+  hmac_test_vector_t *hmac_test_vector;
+  /* The original index of this test vector in the autogenerated C header. */
+  size_t original_idx;
+  /* The number of update calls for a streaming test. */
+  size_t segment_count;
+  /* Randomly generated indices to break down the test message to segments. */
+  size_t segment_idx[4];
+  /* `progess` keeps track of how many message segments are streamed so far. */
+  hmac_test_progress_t progress;
+  /* `hash_ctx` is used to store context during streaming. */
+  otcrypto_hash_context_t hash_ctx;
+} hmac_extended_test_vector_t;
+
+static hmac_extended_test_vector_t
+    kHmacExtendedTestVectors[2 * ARRAYSIZE(kHmacTestVectors)];
+
+/**
+ * Populate `kHmacExtendedTestVectors` array with tests such that:
+ * i) There are mixture of oneshot and streaming HMAC operations.
+ * Each vector is run in 2 duplicates, one as a streaming and another
+ * as a oneshot call.
+ * ii) For streaming operations, messages are split into [1,4]
+ * segments with randomly chosen indices.
+ * iii) The order of tests is randomized.
+ */
+static void vectors_populate(void) {
+  hmac_extended_test_vector_t *cur_ext_vec;
+  hmac_test_vector_t *cur_vec;
+  // First add streaming calls to the test array.
+  for (size_t i = 0; i < ARRAYSIZE(kHmacTestVectors); i++) {
+    cur_ext_vec = &kHmacExtendedTestVectors[i];
+    cur_vec = &kHmacTestVectors[i];
+    cur_ext_vec->hmac_test_vector = cur_vec;
+    cur_ext_vec->original_idx = i;
+    cur_ext_vec->segment_count = rand_testutils_gen32_range(1, 4);
+    // Pick three indicies to break down message into 4 parts, but we only
+    // use the first `segment_count` of them. The indices of a message
+    // looks like below:
+    // ix[0] = 0 ... idx[1] ... idx[2] ... idx[3] ...  message_len-1
+    cur_ext_vec->segment_idx[0] = 0;
+    cur_ext_vec->segment_idx[2] =
+        rand_testutils_gen32_range(0, cur_vec->message.len);
+    cur_ext_vec->segment_idx[1] =
+        rand_testutils_gen32_range(0, cur_ext_vec->segment_idx[2]);
+    cur_ext_vec->segment_idx[3] = rand_testutils_gen32_range(
+        cur_ext_vec->segment_idx[2], cur_vec->message.len);
+    cur_ext_vec->progress = kHmacTestNotStarted;
+  }
+
+  // Add oneshot calls of the same vectors.
+  for (size_t i = 0; i < ARRAYSIZE(kHmacTestVectors); i++) {
+    cur_ext_vec = &kHmacExtendedTestVectors[ARRAYSIZE(kHmacTestVectors) + i];
+    cur_vec = &kHmacTestVectors[i];
+    cur_ext_vec->hmac_test_vector = cur_vec;
+    cur_ext_vec->original_idx = i;
+    cur_ext_vec->segment_count = 0;
+    cur_ext_vec->progress = kHmacTestNotStarted;
+  }
+
+  // Now we shuffle the order of vectors and print
+  // how the new order maps to the original order from the test file.
+  rand_testutils_shuffle(kHmacExtendedTestVectors,
+                         sizeof(hmac_extended_test_vector_t),
+                         ARRAYSIZE(kHmacExtendedTestVectors));
+  for (size_t i = 0; i < ARRAYSIZE(kHmacExtendedTestVectors); i++) {
+    cur_ext_vec = &kHmacExtendedTestVectors[i];
+    cur_vec = cur_ext_vec->hmac_test_vector;
+    LOG_INFO("Vector order = %d, original_vector_id = %d", i,
+             cur_ext_vec->original_idx);
+    LOG_INFO(
+        "segment_count = %d, segment_idx = [%d, %d, %d, %d], message_len = %d",
+        cur_ext_vec->segment_count, cur_ext_vec->segment_idx[0],
+        cur_ext_vec->segment_idx[1], cur_ext_vec->segment_idx[2],
+        cur_ext_vec->segment_idx[3],
+        cur_ext_vec->hmac_test_vector->message.len);
+  }
+}
+
 /**
  * Determines `hash_mode` for given SHA-2 test vectors.
  *
@@ -72,8 +190,6 @@ static status_t ctx_init(otcrypto_hash_context_t *hash_ctx,
     case kHmacTestOperationSha384:
       OT_FALLTHROUGH_INTENDED;
     case kHmacTestOperationSha512:
-      LOG_INFO("Invoking hash_init for %s.",
-               current_test_vector->vector_identifier);
       TRY(get_hash_mode(current_test_vector, &hash_mode));
       TRY(otcrypto_hash_init(hash_ctx, hash_mode));
       break;
@@ -82,8 +198,6 @@ static status_t ctx_init(otcrypto_hash_context_t *hash_ctx,
     case kHmacTestOperationHmacSha384:
       OT_FALLTHROUGH_INTENDED;
     case kHmacTestOperationHmacSha512:
-      LOG_INFO("Invoking hmac_init for %s.",
-               current_test_vector->vector_identifier);
       TRY(otcrypto_hmac_init((otcrypto_hmac_context_t *)hash_ctx,
                              &current_test_vector->key));
       break;
@@ -93,6 +207,55 @@ static status_t ctx_init(otcrypto_hash_context_t *hash_ctx,
   return OTCRYPTO_OK;
 }
 
+/**
+ * Run the test given by `current_test_vector` as oneshot operation.
+ *
+ * @param current_test_vector Pointer to the test vector.
+ * @return The result of the operation.
+ */
+static status_t hmac_oneshot(hmac_test_vector_t *current_test_vector) {
+  // Populate `checksum` and `config.security_level` fields.
+  current_test_vector->key.checksum =
+      integrity_blinded_checksum(&current_test_vector->key);
+
+  // The test vectors already have the correct digest sizes hardcoded.
+  size_t digest_len = current_test_vector->digest.len;
+  // Allocate the buffer for the maximum digest size (which comes from SHA-512).
+  uint32_t act_tag[kSha512DigestWords];
+  otcrypto_word32_buf_t tag_buf = {
+      .data = act_tag,
+      .len = digest_len,
+  };
+  otcrypto_hash_digest_t hash_digest = {
+      // .mode is to be determined below in switch-case block.
+      .data = act_tag,
+      .len = digest_len,
+  };
+  switch (current_test_vector->test_operation) {
+    case kHmacTestOperationSha256:
+      OT_FALLTHROUGH_INTENDED;
+    case kHmacTestOperationSha384:
+      OT_FALLTHROUGH_INTENDED;
+    case kHmacTestOperationSha512:
+      TRY(get_hash_mode(current_test_vector, &hash_digest.mode));
+      TRY(otcrypto_hash(current_test_vector->message, hash_digest));
+      break;
+    case kHmacTestOperationHmacSha256:
+      OT_FALLTHROUGH_INTENDED;
+    case kHmacTestOperationHmacSha384:
+      OT_FALLTHROUGH_INTENDED;
+    case kHmacTestOperationHmacSha512:
+      TRY(otcrypto_hmac(&current_test_vector->key, current_test_vector->message,
+                        tag_buf));
+      break;
+    default:
+      return OTCRYPTO_BAD_ARGS;
+  }
+  LOG_INFO("Comparing result for %s.", current_test_vector->vector_identifier);
+  CHECK_ARRAYS_EQ(act_tag, current_test_vector->digest.data, digest_len);
+  return OTCRYPTO_OK;
+}
+
 /**
  * Feed messages to the streaming hash/hmac operation with context `hash_ctx`.
  * `current_test_vector` is used to determine message bytes to be used.
@@ -102,31 +265,18 @@ static status_t ctx_init(otcrypto_hash_context_t *hash_ctx,
  *
  * @param hash_ctx Corresponding context for given `current_test_vector`.
  * @param current_test_vector Pointer to the hardcoded test vector.
- * @param segment_index Determines whether the first or the second half of the
- * message to be used to update the context.
+ * @param segment_start The starting index of the chosen segment.
+ * @param segment_len The byte length of the chosen segment.
+ * @return The result of the operation.
  */
 static status_t feed_msg(otcrypto_hash_context_t *hash_ctx,
                          hmac_test_vector_t *current_test_vector,
-                         size_t segment_index) {
-  size_t segment_start;
-  size_t segment_length;
-  if (segment_index == 0) {
-    segment_start = 0;
-    segment_length = current_test_vector->message.len / 2;
-  } else if (segment_index == 1) {
-    segment_start = current_test_vector->message.len / 2;
-    segment_length =
-        current_test_vector->message.len - current_test_vector->message.len / 2;
-  } else {
-    return OTCRYPTO_BAD_ARGS;
-  }
-
+                         size_t segment_start, size_t segment_len) {
   otcrypto_const_byte_buf_t msg = {
       .data = &current_test_vector->message.data[segment_start],
-      .len = segment_length,
+      .len = segment_len,
   };
-  LOG_INFO("Feeding message part %d for %s.", segment_index,
-           current_test_vector->vector_identifier);
+
   switch (current_test_vector->test_operation) {
     case kHmacTestOperationSha256:
       OT_FALLTHROUGH_INTENDED;
@@ -154,6 +304,7 @@ static status_t feed_msg(otcrypto_hash_context_t *hash_ctx,
  *
  * @param hash_ctx Corresponding context for given `current_test_vector`.
  * @param current_test_vector Pointer to the hardcoded test vector.
+ * @return The result of the operation.
  */
 static status_t hmac_finalize(otcrypto_hash_context_t *hash_ctx,
                               hmac_test_vector_t *current_test_vector) {
@@ -170,8 +321,6 @@ static status_t hmac_finalize(otcrypto_hash_context_t *hash_ctx,
       .data = act_tag,
       .len = digest_len,
   };
-  LOG_INFO("Invoking final call for %s.",
-           current_test_vector->vector_identifier);
   switch (current_test_vector->test_operation) {
     case kHmacTestOperationSha256:
       OT_FALLTHROUGH_INTENDED;
@@ -192,32 +341,111 @@ static status_t hmac_finalize(otcrypto_hash_context_t *hash_ctx,
       return OTCRYPTO_BAD_ARGS;
   }
   LOG_INFO("Comparing result for %s.", current_test_vector->vector_identifier);
-  TRY_CHECK_ARRAYS_EQ(act_tag, current_test_vector->digest.data, digest_len);
+  CHECK_ARRAYS_EQ(act_tag, current_test_vector->digest.data, digest_len);
   return OTCRYPTO_OK;
 }
 
 /**
- * Run all vectors specified in `kHmacTestVectors` in parallel. Namely:
- * i) Each stream is instantiated (by init call).
- * ii) Each stream receives the first half its message.
- * iii) Each stream receives the second half of its message.
- * iv) Each stream is concluded with a final call and the digest result is
- * compared with the expected valud.
+ * Process a message segment for the given test vector.
+ *
+ * If the given test vector is already run and completed, this function
+ * simply returns.
+ *
+ * If the given test vector is a oneshot call, then it is run and the
+ * result is compared. The process of the vector is already update to done.
+ *
+ * If the given test vector is a starming call, then this function calls
+ * the necessary init, update or final call. In the final call, the result
+ * is compared with the expected result.
+ *
+ * @param test_ext_vec The test vector to run.
+ * @return The result of the operation.
+ *
  */
-static status_t run_test(void) {
-  // hash_contexts are also used as hmac_contexts, since their size is equal.
-  otcrypto_hash_context_t hash_contexts[ARRAYSIZE(kHmacTestVectors)];
-  for (size_t i = 0; i < ARRAYSIZE(kHmacTestVectors); i++) {
-    TRY(ctx_init(&hash_contexts[i], &kHmacTestVectors[i]));
+static status_t process_segment(hmac_extended_test_vector_t *test_ext_vec) {
+  // If `test_ext_vec` is done, simply return.
+  if (test_ext_vec->progress == kHmacTestDone) {
+    return OTCRYPTO_OK;
   }
-  for (size_t i = 0; i < ARRAYSIZE(kHmacTestVectors); i++) {
-    TRY(feed_msg(&hash_contexts[i], &kHmacTestVectors[i], /*segment_index=*/0));
+
+  // If `test_ext_vec` is one-shot, we need to call one-shot API.
+  if (test_ext_vec->segment_count == 0 &&
+      test_ext_vec->progress == kHmacTestNotStarted) {
+    LOG_INFO("Invoking oneshot HMAC for vector #%d",
+             test_ext_vec->original_idx);
+    hmac_oneshot(test_ext_vec->hmac_test_vector);
+    // Mark this test as complete
+    test_ext_vec->progress = kHmacTestDone;
+    return OTCRYPTO_OK;
   }
-  for (size_t i = 0; i < ARRAYSIZE(kHmacTestVectors); i++) {
-    TRY(feed_msg(&hash_contexts[i], &kHmacTestVectors[i], /*segment_index=*/1));
+
+  // A sanity check: oneshot calls should not arrive here and `segment_count`
+  // should be valid.
+  if (test_ext_vec->segment_count == 0 || test_ext_vec->segment_count > 4) {
+    return OTCRYPTO_BAD_ARGS;
   }
-  for (size_t i = 0; i < ARRAYSIZE(kHmacTestVectors); i++) {
-    TRY(hmac_finalize(&hash_contexts[i], &kHmacTestVectors[i]));
+
+  // If `test_ext_vec` is streaming, and this is the first call, then call init.
+  if (test_ext_vec->progress == kHmacTestNotStarted) {
+    LOG_INFO("Initializing HMAC stream for vector #%d",
+             test_ext_vec->original_idx);
+    ctx_init(&test_ext_vec->hash_ctx, test_ext_vec->hmac_test_vector);
+    test_ext_vec->progress = kHmacTestFeedSegment1;
+    return OTCRYPTO_OK;
+  }
+
+  if (test_ext_vec->progress == kHmacTestFinalize) {
+    LOG_INFO("Finalizing HMAC stream for vector #%d",
+             test_ext_vec->original_idx);
+    hmac_finalize(&test_ext_vec->hash_ctx, test_ext_vec->hmac_test_vector);
+    test_ext_vec->progress = kHmacTestDone;
+    return OTCRYPTO_OK;
+  }
+
+  // Handle the last message specially
+  if (test_ext_vec->progress == test_ext_vec->segment_count) {
+    size_t segment_start =
+        test_ext_vec->segment_idx[test_ext_vec->progress - 1];
+    size_t segment_len =
+        test_ext_vec->hmac_test_vector->message.len - segment_start;
+    // Sanity check
+    if (segment_start > test_ext_vec->hmac_test_vector->message.len) {
+      return OTCRYPTO_BAD_ARGS;
+    }
+    LOG_INFO("Streaming the last segment #%d of vector #%d.",
+             test_ext_vec->progress, test_ext_vec->original_idx);
+    feed_msg(&test_ext_vec->hash_ctx, test_ext_vec->hmac_test_vector,
+             segment_start, segment_len);
+    test_ext_vec->progress = kHmacTestFinalize;
+    return OTCRYPTO_OK;
+  }
+
+  if (test_ext_vec->progress < test_ext_vec->segment_count) {
+    size_t segment_start =
+        test_ext_vec->segment_idx[test_ext_vec->progress - 1];
+    size_t segment_len =
+        test_ext_vec->segment_idx[test_ext_vec->progress] - segment_start;
+    LOG_INFO("Streaming segment #%d of vector #%d.", test_ext_vec->progress,
+             test_ext_vec->original_idx);
+    feed_msg(&test_ext_vec->hash_ctx, test_ext_vec->hmac_test_vector,
+             segment_start, segment_len);
+    test_ext_vec->progress++;
+    return OTCRYPTO_OK;
+  }
+  return OTCRYPTO_BAD_ARGS;
+}
+
+/**
+ * Run all vectors specified in `kHmacExtendedTestVectors` in parallel step
+ * by step.
+ */
+static status_t run_test(void) {
+  vectors_populate();
+
+  for (size_t i = kHmacTestNotStarted; i < kHmacTestDone; i++) {
+    for (size_t j = 0; j < ARRAYSIZE(kHmacExtendedTestVectors); j++) {
+      TRY(process_segment(&kHmacExtendedTestVectors[j]));
+    }
   }
   return OTCRYPTO_OK;
 }