psasim: add support for psa_generate_random()

Signed-off-by: Tom Cosgrove <tom.cosgrove@arm.com>

tests/psa-client-server/psasim/src/psa_functions_codes.h

@@ -25,6 +25,7 @@ enum {
     PSA_AEAD_UPDATE_AD,
     PSA_AEAD_VERIFY,
     PSA_DESTROY_KEY,
+    PSA_GENERATE_RANDOM,
     PSA_GET_KEY_ATTRIBUTES,
     PSA_HASH_ABORT,
     PSA_HASH_CLONE,

tests/psa-client-server/psasim/src/psa_sim_crypto_client.c

@@ -1191,6 +1191,69 @@ fail:
 }
 
 
+psa_status_t psa_generate_random(
+    uint8_t *output, size_t  output_size
+    )
+{
+    uint8_t *params = NULL;
+    uint8_t *result = NULL;
+    size_t result_length;
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    size_t needed = psasim_serialise_begin_needs() +
+                    psasim_serialise_buffer_needs(output, output_size);
+
+    params = malloc(needed);
+    if (params == NULL) {
+        status = PSA_ERROR_INSUFFICIENT_MEMORY;
+        goto fail;
+    }
+
+    uint8_t *pos = params;
+    size_t remaining = needed;
+    int ok;
+    ok = psasim_serialise_begin(&pos, &remaining);
+    if (!ok) {
+        goto fail;
+    }
+    ok = psasim_serialise_buffer(&pos, &remaining, output, output_size);
+    if (!ok) {
+        goto fail;
+    }
+
+    ok = psa_crypto_call(PSA_GENERATE_RANDOM,
+                         params, (size_t) (pos - params), &result, &result_length);
+    if (!ok) {
+        printf("PSA_GENERATE_RANDOM server call failed\n");
+        goto fail;
+    }
+
+    uint8_t *rpos = result;
+    size_t rremain = result_length;
+
+    ok = psasim_deserialise_begin(&rpos, &rremain);
+    if (!ok) {
+        goto fail;
+    }
+
+    ok = psasim_deserialise_psa_status_t(&rpos, &rremain, &status);
+    if (!ok) {
+        goto fail;
+    }
+
+    ok = psasim_deserialise_return_buffer(&rpos, &rremain, output, output_size);
+    if (!ok) {
+        goto fail;
+    }
+
+fail:
+    free(params);
+    free(result);
+
+    return status;
+}
+
+
 psa_status_t psa_get_key_attributes(
     mbedtls_svc_key_id_t key,
     psa_key_attributes_t *attributes

tests/psa-client-server/psasim/src/psa_sim_crypto_server.c

@@ -1324,6 +1324,80 @@ fail:
     return 0;       // This shouldn't happen!
 }
 
+// Returns 1 for success, 0 for failure
+int psa_generate_random_wrapper(
+    uint8_t *in_params, size_t in_params_len,
+    uint8_t **out_params, size_t *out_params_len)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    uint8_t *output = NULL;
+    size_t output_size;
+
+    uint8_t *pos = in_params;
+    size_t remaining = in_params_len;
+    uint8_t *result = NULL;
+    int ok;
+
+    ok = psasim_deserialise_begin(&pos, &remaining);
+    if (!ok) {
+        goto fail;
+    }
+
+    ok = psasim_deserialise_buffer(&pos, &remaining, &output, &output_size);
+    if (!ok) {
+        goto fail;
+    }
+
+    // Now we call the actual target function
+
+    status = psa_generate_random(
+        output, output_size
+        );
+
+    // NOTE: Should really check there is no overflow as we go along.
+    size_t result_size =
+        psasim_serialise_begin_needs() +
+        psasim_serialise_psa_status_t_needs(status) +
+        psasim_serialise_buffer_needs(output, output_size);
+
+    result = malloc(result_size);
+    if (result == NULL) {
+        goto fail;
+    }
+
+    uint8_t *rpos = result;
+    size_t rremain = result_size;
+
+    ok = psasim_serialise_begin(&rpos, &rremain);
+    if (!ok) {
+        goto fail;
+    }
+
+    ok = psasim_serialise_psa_status_t(&rpos, &rremain, status);
+    if (!ok) {
+        goto fail;
+    }
+
+    ok = psasim_serialise_buffer(&rpos, &rremain, output, output_size);
+    if (!ok) {
+        goto fail;
+    }
+
+    *out_params = result;
+    *out_params_len = result_size;
+
+    free(output);
+
+    return 1;   // success
+
+fail:
+    free(result);
+
+    free(output);
+
+    return 0;       // This shouldn't happen!
+}
+
 // Returns 1 for success, 0 for failure
 int psa_get_key_attributes_wrapper(
     uint8_t *in_params, size_t in_params_len,
@@ -2252,6 +2326,10 @@ psa_status_t psa_crypto_call(psa_msg_t msg)
             ok = psa_destroy_key_wrapper(in_params, in_params_len,
                                          &out_params, &out_params_len);
             break;
+        case PSA_GENERATE_RANDOM:
+            ok = psa_generate_random_wrapper(in_params, in_params_len,
+                                             &out_params, &out_params_len);
+            break;
         case PSA_GET_KEY_ATTRIBUTES:
             ok = psa_get_key_attributes_wrapper(in_params, in_params_len,
                                                 &out_params, &out_params_len);

tests/psa-client-server/psasim/src/psa_sim_generate.pl

@@ -2371,3 +2371,30 @@ psa_status_t psa_get_key_attributes(mbedtls_svc_key_id_t key,
  *         results in this error code.
  */
 psa_status_t psa_destroy_key(mbedtls_svc_key_id_t key);
+
+/**
+ * \brief Generate random bytes.
+ *
+ * \warning This function **can** fail! Callers MUST check the return status
+ *          and MUST NOT use the content of the output buffer if the return
+ *          status is not #PSA_SUCCESS.
+ *
+ * \note    To generate a key, use psa_generate_key() instead.
+ *
+ * \param[out] output       Output buffer for the generated data.
+ * \param output_size       Number of bytes to generate and output.
+ *
+ * \retval #PSA_SUCCESS \emptydescription
+ * \retval #PSA_ERROR_NOT_SUPPORTED \emptydescription
+ * \retval #PSA_ERROR_INSUFFICIENT_ENTROPY \emptydescription
+ * \retval #PSA_ERROR_INSUFFICIENT_MEMORY \emptydescription
+ * \retval #PSA_ERROR_COMMUNICATION_FAILURE \emptydescription
+ * \retval #PSA_ERROR_HARDWARE_FAILURE \emptydescription
+ * \retval #PSA_ERROR_CORRUPTION_DETECTED \emptydescription
+ * \retval #PSA_ERROR_BAD_STATE
+ *         The library has not been previously initialized by psa_crypto_init().
+ *         It is implementation-dependent whether a failure to initialize
+ *         results in this error code.
+ */
+psa_status_t psa_generate_random(uint8_t *output,
+                                 size_t output_size);