sign_tx: move sign_liquid_tx.c to sign_utils.c

diff --git a/main/amalgamated.c b/main/amalgamated.c
index 9810a2b..1fe2f29 100644
--- a/main/amalgamated.c
+++ b/main/amalgamated.c
@@ -107,10 +107,10 @@ void __wrap_abort(void);
 #include "./process/sign_attestation.c"
 #include "./process/sign_bip85_digest.c"
 #include "./process/sign_identity.c"
-#include "./process/sign_liquid_tx.c"
 #include "./process/sign_message.c"
 #include "./process/sign_psbt.c"
 #include "./process/sign_tx.c"
+#include "./process/sign_utils.c"
 #include "./process/update_pinserver.c"
 #ifdef CONFIG_ETH_USE_OPENETH
 #include "./qemu/qemu_display.c"
diff --git a/main/process/sign_liquid_tx.c b/main/process/sign_liquid_tx.c
deleted file mode 100644
index 1cf2f50..0000000
--- a/main/process/sign_liquid_tx.c
+++ /dev/null
@@ -1,649 +0,0 @@
-#ifndef AMALGAMATED_BUILD
-#include "../jade_assert.h"
-#include "../jade_wally_verify.h"
-#include "../ui/sign_tx.h"
-#include "../utils/cbor_rpc.h"
-#include "../utils/malloc_ext.h"
-#include "../utils/temporary_stack.h"
-#include "../utils/util.h"
-
-#include <sodium/utils.h>
-#include <wally_elements.h>
-
-#include "process_utils.h"
-
-static const char TX_TYPE_STR_SWAP[] = "swap";
-static const char TX_TYPE_STR_SEND_PAYMENT[] = "send_payment";
-
-// Map a txtype string to an enum value
-#define TX_TYPE_STR_MATCH(typestr) ((len == sizeof(typestr) - 1 && !strncmp(type, typestr, sizeof(typestr) - 1)))
-static bool rpc_get_txtype(jade_process_t* process, CborValue* value, TxType_t* txtype)
-{
-    const char* type = NULL;
-    size_t len = 0;
-    rpc_get_string_ptr("tx_type", value, &type, &len);
-    if (!type || !len) {
-        *txtype = TXTYPE_SEND_PAYMENT;
-        return true; // Not present, treat as a payment
-    }
-    if (TX_TYPE_STR_MATCH(TX_TYPE_STR_SWAP)) {
-        *txtype = TXTYPE_SWAP;
-        return true;
-    } else if (TX_TYPE_STR_MATCH(TX_TYPE_STR_SEND_PAYMENT)) {
-        *txtype = TXTYPE_SEND_PAYMENT;
-        return true;
-    }
-    return false; // Unknown tx_type
-}
-
-static void rpc_get_asset_summary(
-    jade_process_t* process, const char* field, const CborValue* value, asset_summary_t** data, size_t* written)
-{
-    JADE_ASSERT(field);
-    JADE_ASSERT(value);
-    JADE_INIT_OUT_PPTR(data);
-    JADE_INIT_OUT_SIZE(written);
-
-    CborValue result;
-    if (!rpc_get_array(field, value, &result)) {
-        return;
-    }
-
-    size_t num_array_items = 0;
-    CborError cberr = cbor_value_get_array_length(&result, &num_array_items);
-    if (cberr != CborNoError || !num_array_items) {
-        return;
-    }
-
-    CborValue arrayItem;
-    cberr = cbor_value_enter_container(&result, &arrayItem);
-    if (cberr != CborNoError || !cbor_value_is_valid(&arrayItem)) {
-        return;
-    }
-
-    asset_summary_t* const sums = JADE_CALLOC(num_array_items, sizeof(asset_summary_t));
-    jade_process_free_on_exit(process, sums);
-
-    for (size_t i = 0; i < num_array_items; ++i) {
-        JADE_ASSERT(!cbor_value_at_end(&arrayItem));
-        asset_summary_t* const item = sums + i;
-
-        if (!cbor_value_is_map(&arrayItem)
-            || !rpc_get_n_bytes("asset_id", &arrayItem, sizeof(item->asset_id), item->asset_id)
-            || !rpc_get_uint64_t("satoshi", &arrayItem, &item->value)) {
-            return;
-        }
-
-        cberr = cbor_value_advance(&arrayItem);
-        JADE_ASSERT(cberr == CborNoError);
-    }
-
-    cberr = cbor_value_leave_container(&result, &arrayItem);
-    if (cberr == CborNoError) {
-        *written = num_array_items;
-        *data = sums;
-    }
-}
-
-static bool validate_additional_info(jade_process_t* process, const struct wally_tx* tx, const TxType_t txtype,
-    const bool is_partial, const asset_summary_t* in_sums, const size_t num_in_sums, const asset_summary_t* out_sums,
-    const size_t num_out_sums)
-{
-    const char* errmsg = NULL;
-    // Shouldn't have pointers to empty arrays
-    JADE_ASSERT(!in_sums == !num_in_sums);
-    JADE_ASSERT(!out_sums == !num_out_sums);
-
-    // Validate tx type data
-    if (txtype == TXTYPE_SWAP) {
-        // Input and output summary must be present - they will be fully validated later
-        if (!in_sums || !out_sums) {
-            errmsg = "Swap tx missing input/output summary information";
-            goto done;
-        }
-
-        // Validate swap or proposal appears to have expected inputs and outputs
-        if (is_partial) {
-            // At this time the only 'partial swap' we accept is an initial proposal with exactly one
-            // input and exactly one output which is to self, and in a different asset to the input
-            if (tx->num_inputs != 1 || tx->num_outputs != 1 || num_in_sums != 1 || num_out_sums != 1
-                || !memcmp(in_sums[0].asset_id, out_sums[0].asset_id, sizeof(out_sums[0].asset_id))) {
-                errmsg = "Initial swap proposal must have single wallet input and output in different assets";
-                goto done;
-            }
-        } else {
-            // TODO: Ideally check total number of assets in our inputs and outputs
-            if (tx->num_inputs < 2 || tx->num_outputs < 2) {
-                errmsg = "Insufficient inputs/outputs for a swap tx";
-                goto done;
-            }
-        }
-    } else if (txtype != TXTYPE_SEND_PAYMENT) {
-        errmsg = "Unsupported tx-type in additional info";
-        goto done;
-    }
-done:
-    if (errmsg) {
-        jade_process_reject_message(process, CBOR_RPC_BAD_PARAMETERS, errmsg);
-        return false;
-    }
-    return true;
-}
-
-TxType_t rpc_get_additional_info(jade_process_t* process, CborValue* params, const struct wally_tx* tx,
-    TxType_t* txtype, bool* is_partial, asset_summary_t** in_sums, size_t* num_in_sums, asset_summary_t** out_sums,
-    size_t* num_out_sums)
-{
-    JADE_ASSERT(params);
-    JADE_ASSERT(tx);
-    JADE_ASSERT(txtype);
-    JADE_ASSERT(is_partial);
-    JADE_INIT_OUT_PPTR(in_sums);
-    JADE_INIT_OUT_SIZE(num_in_sums);
-    JADE_INIT_OUT_PPTR(out_sums);
-    JADE_INIT_OUT_SIZE(num_out_sums);
-
-    *is_partial = false;
-    *txtype = TXTYPE_SEND_PAYMENT;
-
-    // If no 'additional_data' passed, assume this is a a simple send-payment 'classic' tx
-    CborValue additional_info;
-    if (!rpc_get_map("additional_info", params, &additional_info)) {
-        return true;
-    }
-
-    // input/output summaries required for some complex txn types, eg. swaps
-    rpc_get_asset_summary(process, "wallet_input_summary", &additional_info, in_sums, num_in_sums);
-    rpc_get_asset_summary(process, "wallet_output_summary", &additional_info, out_sums, num_out_sums);
-
-    // 'partial' flag (defaults to false, set above)
-    rpc_get_boolean("is_partial", &additional_info, is_partial);
-
-    // Tx Type
-    if (!rpc_get_txtype(process, &additional_info, txtype)) {
-        return false;
-    }
-    if (!validate_additional_info(
-            process, tx, *txtype, *is_partial, *in_sums, *num_in_sums, *out_sums, *num_out_sums)) {
-        return false;
-    }
-    return true;
-}
-
-bool asset_summary_update(asset_summary_t* sums, const size_t num_sums, const uint8_t* asset_id,
-    const size_t asset_id_len, const uint64_t value)
-{
-    if (!sums) {
-        return true; // Nothing to do
-    }
-    JADE_ASSERT(asset_id);
-    JADE_ASSERT(asset_id_len == sizeof(sums[0].asset_id));
-
-    // Add passed sats amount to the first record found with matching asset_id
-    for (size_t i = 0; i < num_sums; ++i) {
-        if (!memcmp(asset_id, sums[i].asset_id, sizeof(sums[i].asset_id))) {
-            sums[i].validated_value += value;
-            return true;
-        }
-    }
-    return false;
-}
-
-bool asset_summary_validate(asset_summary_t* sums, const size_t num_sums)
-{
-    JADE_ASSERT(!sums == !num_sums);
-
-    // Check every asset record (if any) has been fully validated
-    for (size_t i = 0; i < num_sums; ++i) {
-        if (sums[i].value != sums[i].validated_value) {
-            char* asset_id_hex = NULL;
-            wally_hex_from_bytes(sums[i].asset_id, sizeof(sums[i].asset_id), &asset_id_hex);
-            JADE_LOGW("Failed to validate input/output summary for %s", asset_id_hex);
-            JADE_WALLY_VERIFY(wally_free_string(asset_id_hex));
-            return false;
-        }
-    }
-    return true;
-}
-
-bool get_commitment_data(CborValue* item, commitment_t* commitment)
-{
-    JADE_ASSERT(item);
-    JADE_ASSERT(commitment);
-
-    commitment->content = COMMITMENTS_NONE;
-
-    // Need abf or asset_blind_proof
-    if (rpc_get_n_bytes("abf", item, sizeof(commitment->abf), commitment->abf)) {
-        commitment->content |= COMMITMENTS_ABF;
-    }
-
-    if (rpc_get_n_bytes(
-            "asset_blind_proof", item, sizeof(commitment->asset_blind_proof), commitment->asset_blind_proof)) {
-        commitment->content |= COMMITMENTS_ASSET_BLIND_PROOF;
-    }
-
-    if (!(commitment->content & (COMMITMENTS_ABF | COMMITMENTS_ASSET_BLIND_PROOF))) {
-        return false;
-    }
-
-    // Need vbf or value_blind_proof
-    if (rpc_get_n_bytes("vbf", item, sizeof(commitment->vbf), commitment->vbf)) {
-        commitment->content |= COMMITMENTS_VBF;
-    }
-
-    size_t written = 0;
-    rpc_get_bytes(
-        "value_blind_proof", sizeof(commitment->value_blind_proof), item, commitment->value_blind_proof, &written);
-    if (written && written <= sizeof(commitment->value_blind_proof)) {
-        commitment->value_blind_proof_len = written;
-        commitment->content |= COMMITMENTS_VALUE_BLIND_PROOF;
-    }
-
-    if (!(commitment->content & (COMMITMENTS_VBF | COMMITMENTS_VALUE_BLIND_PROOF))) {
-        return false;
-    }
-
-    if (!rpc_get_n_bytes("asset_id", item, sizeof(commitment->asset_id), commitment->asset_id)) {
-        return false;
-    }
-
-    if (!rpc_get_uint64_t("value", item, &commitment->value)) {
-        return false;
-    }
-
-    // Blinding key is optional in some scenarios
-    if (rpc_get_n_bytes("blinding_key", item, sizeof(commitment->blinding_key), commitment->blinding_key)) {
-        commitment->content |= COMMITMENTS_BLINDING_KEY;
-    }
-
-    // Actual commitments are optional - but must be both commitments or neither.
-    // If both are passed these will be copied into the tx and signed.
-    // If not passed, the above blinding factors/proofs must match what is already present in the transaction output.
-    // Must be both or neither - error if only one commitment passed.
-    if (rpc_has_field_data("asset_generator", item) || rpc_has_field_data("value_commitment", item)) {
-        if (!rpc_get_n_bytes(
-                "asset_generator", item, sizeof(commitment->asset_generator), commitment->asset_generator)) {
-            return false;
-        }
-
-        if (!rpc_get_n_bytes(
-                "value_commitment", item, sizeof(commitment->value_commitment), commitment->value_commitment)) {
-            return false;
-        }
-
-        // Set flag to show struct is fully populated/initialised, including commitments to sign.
-        commitment->content |= COMMITMENTS_INCLUDES_COMMITMENTS;
-    }
-
-    return true;
-}
-
-bool rpc_get_trusted_commitments(
-    jade_process_t* process, const CborValue* value, const struct wally_tx* tx, commitment_t** data)
-{
-    JADE_ASSERT(process);
-    JADE_ASSERT(value);
-    JADE_ASSERT(tx);
-    JADE_INIT_OUT_PPTR(data);
-
-    const char* errmsg = NULL;
-
-    CborValue result;
-    if (!rpc_get_array("trusted_commitments", value, &result)) {
-        errmsg = "Failed to extract trusted commitments from parameters";
-        goto cleanup;
-    }
-
-    // Expect one commitment element in the array for each output.
-    // (Can be null/zero's for unblinded outputs.)
-    size_t num_array_items = 0;
-    CborError cberr = cbor_value_get_array_length(&result, &num_array_items);
-    if (cberr != CborNoError || !num_array_items || num_array_items != tx->num_outputs) {
-        errmsg = "Unexpected number of trusted commitments for transaction";
-        goto cleanup;
-    }
-
-    CborValue arrayItem;
-    cberr = cbor_value_enter_container(&result, &arrayItem);
-    if (cberr != CborNoError || !cbor_value_is_valid(&arrayItem)) {
-        errmsg = "Invalid trusted commitments for transaction";
-        goto cleanup;
-    }
-
-    commitment_t* const commitments = JADE_CALLOC(num_array_items, sizeof(commitment_t));
-    jade_process_free_on_exit(process, commitments);
-
-    for (size_t i = 0; i < num_array_items; ++i) {
-        JADE_ASSERT(!cbor_value_at_end(&arrayItem));
-        commitments[i].content = COMMITMENTS_NONE;
-
-        if (cbor_value_is_null(&arrayItem)) {
-            CborError err = cbor_value_advance(&arrayItem);
-            JADE_ASSERT(err == CborNoError);
-            continue;
-        }
-
-        if (!cbor_value_is_map(&arrayItem)) {
-            errmsg = "Invalid trusted commitments for transaction";
-            goto cleanup;
-        }
-
-        size_t num_map_items = 0;
-        if (cbor_value_get_map_length(&arrayItem, &num_map_items) == CborNoError && num_map_items == 0) {
-            CborError err = cbor_value_advance(&arrayItem);
-            JADE_ASSERT(err == CborNoError);
-            continue;
-        }
-
-        // Populate commitments data
-        if (!get_commitment_data(&arrayItem, &commitments[i])) {
-            errmsg = "Invalid trusted commitments for transaction";
-            goto cleanup;
-        }
-
-        CborError err = cbor_value_advance(&arrayItem);
-        JADE_ASSERT(err == CborNoError);
-    }
-
-    cberr = cbor_value_leave_container(&result, &arrayItem);
-    if (cberr == CborNoError) {
-        *data = commitments;
-    } else {
-        errmsg = "Invalid trusted commitments for transaction";
-    }
-
-cleanup:
-    if (errmsg) {
-        jade_process_reject_message(process, CBOR_RPC_BAD_PARAMETERS, errmsg);
-        return false;
-    }
-    return true;
-}
-
-#ifdef CONFIG_SPIRAM
-// Workaround to run 'wally_explicit_surjectionproof_verify()' and 'wally_explicit_rangeproof_verify()'
-// on a temporary stack, as the underlying libsecp calls require over 50kb of stack space.
-// NOTE: devices without SPIRAM do not have sufficient free memory to be able to do this verification,
-// so atm we exclude it for those devices.
-static bool verify_explicit_proofs(void* ctx)
-{
-    JADE_ASSERT(ctx);
-
-    const commitment_t* commitments = (const commitment_t*)ctx;
-    JADE_ASSERT(commitments->content & (COMMITMENTS_ASSET_BLIND_PROOF | COMMITMENTS_VALUE_BLIND_PROOF));
-    JADE_ASSERT(commitments->content & COMMITMENTS_INCLUDES_COMMITMENTS);
-
-    if (commitments->content & COMMITMENTS_ASSET_BLIND_PROOF) {
-        uint8_t reversed_asset_id[sizeof(commitments->asset_id)];
-        reverse(reversed_asset_id, commitments->asset_id, sizeof(commitments->asset_id));
-
-        // NOTE: Appears to require ~52kb of stack space
-        if (wally_explicit_surjectionproof_verify(commitments->asset_blind_proof,
-                sizeof(commitments->asset_blind_proof), reversed_asset_id, sizeof(reversed_asset_id),
-                commitments->asset_generator, sizeof(commitments->asset_generator))
-            != WALLY_OK) {
-            // Failed to verify explicit asset proof
-            return false;
-        }
-    }
-
-    if (commitments->content & COMMITMENTS_VALUE_BLIND_PROOF) {
-        // NOTE: Appears to require ~40kb of stack space
-        if (wally_explicit_rangeproof_verify(commitments->value_blind_proof, commitments->value_blind_proof_len,
-                commitments->value, commitments->value_commitment, sizeof(commitments->value_commitment),
-                commitments->asset_generator, sizeof(commitments->asset_generator))
-            != WALLY_OK) {
-            // Failed to verify explicit value proof
-            return false;
-        }
-    }
-
-    return true;
-}
-#endif // CONFIG_SPIRAM
-
-bool verify_commitment_consistent(const commitment_t* commitments, const char** errmsg)
-{
-    JADE_ASSERT(commitments);
-    JADE_INIT_OUT_PPTR(errmsg);
-
-    if (!(commitments->content & COMMITMENTS_INCLUDES_COMMITMENTS)) {
-        *errmsg = "Failed to extract final commitment values from commitments data";
-        return false;
-    }
-
-    if (!(commitments->content & (COMMITMENTS_ABF | COMMITMENTS_ASSET_BLIND_PROOF))
-        || !(commitments->content & (COMMITMENTS_VBF | COMMITMENTS_VALUE_BLIND_PROOF))) {
-        *errmsg = "Failed to extract blinding factors or proofs from commitments data";
-        return false;
-    }
-
-    // 1. Asset generator
-    // If passed the abf, check the blinded asset commitment can be reconstructed
-    // (ie. from the given reversed asset_id and abf)
-    if (commitments->content & COMMITMENTS_ABF) {
-        uint8_t reversed_asset_id[sizeof(commitments->asset_id)];
-        reverse(reversed_asset_id, commitments->asset_id, sizeof(commitments->asset_id));
-
-        uint8_t generator_tmp[sizeof(commitments->asset_generator)];
-        if (wally_asset_generator_from_bytes(reversed_asset_id, sizeof(reversed_asset_id), commitments->abf,
-                sizeof(commitments->abf), generator_tmp, sizeof(generator_tmp))
-                != WALLY_OK
-            || sodium_memcmp(commitments->asset_generator, generator_tmp, sizeof(generator_tmp)) != 0) {
-            *errmsg = "Failed to verify blinded asset generator from commitments data";
-            return false;
-        }
-    }
-
-    // 2. Value commitment
-    // If passed the vbf, check the blinded value commitment can be reconstructed
-    // (ie. from the given value, asset_generator and vbf)
-    if (commitments->content & COMMITMENTS_VBF) {
-        uint8_t commitment_tmp[sizeof(commitments->value_commitment)];
-        if (wally_asset_value_commitment(commitments->value, commitments->vbf, sizeof(commitments->vbf),
-                commitments->asset_generator, sizeof(commitments->asset_generator), commitment_tmp,
-                sizeof(commitment_tmp))
-                != WALLY_OK
-            || sodium_memcmp(commitments->value_commitment, commitment_tmp, sizeof(commitment_tmp)) != 0) {
-            *errmsg = "Failed to verify blinded value commitment from commitments data";
-            return false;
-        }
-    }
-
-    // Verify any blinded proofs
-    // NOTE: only a device with SPIRAM has sufficient memory to be able to do this verification.
-    if (commitments->content & (COMMITMENTS_ASSET_BLIND_PROOF | COMMITMENTS_VALUE_BLIND_PROOF)) {
-#ifdef CONFIG_SPIRAM
-        // Because the libsecp calls 'secp256k1_surjectionproof_verify()' and 'secp256k1_rangeproof_verify()'
-        // requires more stack space than is available to the main task, we run that function in a temporary task.
-        const size_t stack_size = 54 * 1024; // 54kb seems sufficient
-        if (!run_in_temporary_task(stack_size, verify_explicit_proofs, (void*)commitments)) {
-            *errmsg = "Failed to verify explicit asset/value commitment proofs";
-            return false;
-        }
-#else
-        *errmsg = "Devices without external SPIRAM are unable to verify explicit proofs";
-        return false;
-#endif // CONFIG_SPIRAM
-    }
-    return true;
-}
-
-static bool add_output_info(
-    commitment_t* commitments, const struct wally_tx_output* txoutput, output_info_t* outinfo, const char** errmsg)
-{
-    JADE_ASSERT(commitments);
-    JADE_ASSERT(txoutput);
-    JADE_ASSERT(outinfo);
-    JADE_INIT_OUT_PPTR(errmsg);
-
-    JADE_ASSERT(!(outinfo->flags & (OUTPUT_FLAG_CONFIDENTIAL | OUTPUT_FLAG_HAS_UNBLINDED)));
-    if (commitments->content != COMMITMENTS_NONE) {
-        // Output to be confidential/blinded, use the commitments data
-        outinfo->flags |= (OUTPUT_FLAG_CONFIDENTIAL | OUTPUT_FLAG_HAS_UNBLINDED);
-
-        // 1. Sanity checks
-        if (txoutput->asset_len != sizeof(commitments->asset_generator)) {
-            *errmsg = "Invalid asset generator in tx output";
-            return false;
-        }
-        if (txoutput->value_len != sizeof(commitments->value_commitment)) {
-            *errmsg = "Invalid value commitment in tx output";
-            return false;
-        }
-
-        // 2. If passed explicit commitments copy them into the transaction output ready for signing
-        // If not, copy the values from the tx into the commitment structure.
-        // ie. so in any case commitment struct is complete, and reflects what is in the tx output
-        if (commitments->content & COMMITMENTS_INCLUDES_COMMITMENTS) {
-            memcpy(txoutput->asset, commitments->asset_generator, sizeof(commitments->asset_generator));
-            memcpy(txoutput->value, commitments->value_commitment, sizeof(commitments->value_commitment));
-        } else {
-            memcpy(commitments->asset_generator, txoutput->asset, sizeof(commitments->asset_generator));
-            memcpy(commitments->value_commitment, txoutput->value, sizeof(commitments->value_commitment));
-            commitments->content |= COMMITMENTS_INCLUDES_COMMITMENTS;
-        }
-
-        // 3. Check the asset generator and value commitment can be reconstructed
-        if (!verify_commitment_consistent(commitments, errmsg)) {
-            // errmsg populated by call if failure
-            return false;
-        }
-
-        // 4. Fetch the asset_id, value, and optional blinding_key into the info struct
-        JADE_STATIC_ASSERT(sizeof(outinfo->asset_id) == sizeof(commitments->asset_id));
-        memcpy(outinfo->asset_id, commitments->asset_id, sizeof(commitments->asset_id));
-        outinfo->value = commitments->value;
-
-        if (commitments->content & COMMITMENTS_BLINDING_KEY) {
-            JADE_STATIC_ASSERT(sizeof(outinfo->blinding_key) == sizeof(commitments->blinding_key));
-            memcpy(outinfo->blinding_key, commitments->blinding_key, sizeof(commitments->blinding_key));
-            outinfo->flags |= OUTPUT_FLAG_HAS_BLINDING_KEY;
-        }
-    } else if (txoutput->asset[0] != WALLY_TX_ASSET_CT_EXPLICIT_PREFIX
-        || txoutput->value[0] != WALLY_TX_ASSET_CT_EXPLICIT_PREFIX) {
-        // No blinding info for blinded output - may not be an issue if we're
-        // not interested in this output.  Just set flags appropriately.
-        outinfo->flags |= OUTPUT_FLAG_CONFIDENTIAL;
-
-        // NOTE: This is not valid if this output has been validated as belonging to this wallet
-        if (outinfo->flags & OUTPUT_FLAG_VALIDATED) {
-            *errmsg = "Missing blinding information for wallet output";
-            return false;
-        }
-    } else {
-        // unconfidential, take directly from the tx
-        outinfo->flags |= OUTPUT_FLAG_HAS_UNBLINDED;
-
-        // Copy the asset ID without the leading unconfidential tag byte
-        // NOTE: we reverse the asset-id bytes to the 'display' order
-        reverse(outinfo->asset_id, txoutput->asset + 1, sizeof(outinfo->asset_id));
-
-        JADE_WALLY_VERIFY(
-            wally_tx_confidential_value_to_satoshi(txoutput->value, txoutput->value_len, &outinfo->value));
-    }
-
-    return true;
-}
-
-bool validate_elements_outputs(jade_process_t* process, const network_t network_id, const struct wally_tx* tx,
-    const TxType_t txtype, commitment_t* commitments, output_info_t* output_info, asset_summary_t* in_sums,
-    const size_t num_in_sums, asset_summary_t* out_sums, const size_t num_out_sums, uint64_t* fees)
-{
-    JADE_ASSERT(tx);
-    JADE_ASSERT(commitments);
-    JADE_ASSERT(output_info);
-    JADE_ASSERT(fees);
-
-    const char* errmsg = NULL;
-    *fees = 0;
-
-    uint8_t policy_asset[ASSET_TAG_LEN];
-    network_to_policy_asset(network_id, policy_asset, sizeof(policy_asset));
-
-    // Check the trusted commitments: expect one element in the array for each output.
-    // Can be null for unblinded outputs as we will skip them.
-    // Populate an `output_index` -> (blinding_key, asset, value) map
-
-    // NOTE: some advanced tx types permit some outputs to be blind (ie blinded, without unblinding info/proofs)
-    // By default/in the basic 'send payment' case all outputs must have unconfidential/unblinded.
-    const bool allow_blind_outputs = txtype == TXTYPE_SWAP; // swaps allow 'other wallets' blind outputs
-
-    // Save fees for the final confirmation screen
-    for (size_t i = 0; i < tx->num_outputs; ++i) {
-        // Gather the (unblinded) output info for user confirmation
-        output_info_t* outinfo = output_info + i;
-        if (!add_output_info(&commitments[i], &tx->outputs[i], outinfo, &errmsg)) {
-            goto done;
-        }
-
-        // If are not allowing blinded outputs, check each confidential output has unblinding info
-        if (!allow_blind_outputs && outinfo->flags & OUTPUT_FLAG_CONFIDENTIAL) {
-            if (!(outinfo->flags & OUTPUT_FLAG_HAS_UNBLINDED) || !(outinfo->flags & OUTPUT_FLAG_HAS_BLINDING_KEY)) {
-                errmsg = "Missing commitments data for blinded output";
-                goto done;
-            }
-        }
-
-        // Collect fees (ie. outputs with no script)
-        // NOTE: fees must be unconfidential, and must be denominated in the policy asset
-        if (!tx->outputs[i].script) {
-            if (outinfo->flags & OUTPUT_FLAG_CONFIDENTIAL) {
-                errmsg = "Fee output (without script) cannot be blinded";
-                goto done;
-            }
-            if (memcmp(outinfo->asset_id, policy_asset, sizeof(policy_asset))) {
-                errmsg = "Unexpected fee output (without script) asset-id";
-                goto done;
-            }
-            if (!outinfo->value) {
-                errmsg = "Fee output (without script) cannot be 0";
-                goto done;
-            }
-            if (*fees) {
-                errmsg = "Unexpected multiple fee outputs (without script)";
-                goto done;
-            }
-            *fees += outinfo->value;
-        }
-
-        // If the output has been verified as belonging to this wallet, we can
-        // use it to validate some part of any passed input- or output- summary.
-        if (outinfo->flags & OUTPUT_FLAG_VALIDATED) {
-            JADE_ASSERT(outinfo->flags & OUTPUT_FLAG_HAS_UNBLINDED);
-
-            if (outinfo->flags & OUTPUT_FLAG_CHANGE) {
-                // NOTE: change outputs are subtracted from the relevant 'input summary'.
-                asset_summary_update(
-                    in_sums, num_in_sums, outinfo->asset_id, sizeof(outinfo->asset_id), (0 - outinfo->value));
-            } else {
-                asset_summary_update(
-                    out_sums, num_out_sums, outinfo->asset_id, sizeof(outinfo->asset_id), outinfo->value);
-            }
-        }
-    }
-done:
-    if (errmsg) {
-        jade_process_reject_message(process, CBOR_RPC_BAD_PARAMETERS, errmsg);
-        return false;
-    }
-    return true;
-}
-
-bool show_elements_fee_confirmation_activity(const network_t network_id, const struct wally_tx* tx,
-    const output_info_t* outinfo, const script_flavour_t aggregate_inputs_scripts_flavour, const uint64_t fees,
-    const TxType_t txtype, const bool is_partial)
-{
-    JADE_ASSERT(network_id != NETWORK_NONE);
-    JADE_ASSERT(tx);
-    JADE_ASSERT(outinfo);
-
-    const char* const warning_msg
-        = aggregate_inputs_scripts_flavour == SCRIPT_FLAVOUR_MIXED ? WARN_MSG_MIXED_INPUTS : NULL;
-    const char* title = (txtype == TXTYPE_SWAP) ? (is_partial ? "Swap Proposal" : "Complete Swap") : "Send Transaction";
-
-    // Return whether the user accepts or declines
-    return show_elements_final_confirmation_activity(network_id, title, fees, warning_msg);
-}
-#endif // AMALGAMATED_BUILD
diff --git a/main/process/sign_utils.c b/main/process/sign_utils.c
new file mode 100644
index 0000000..1cf2f50
--- /dev/null
+++ b/main/process/sign_utils.c
@@ -0,0 +1,649 @@
+#ifndef AMALGAMATED_BUILD
+#include "../jade_assert.h"
+#include "../jade_wally_verify.h"
+#include "../ui/sign_tx.h"
+#include "../utils/cbor_rpc.h"
+#include "../utils/malloc_ext.h"
+#include "../utils/temporary_stack.h"
+#include "../utils/util.h"
+
+#include <sodium/utils.h>
+#include <wally_elements.h>
+
+#include "process_utils.h"
+
+static const char TX_TYPE_STR_SWAP[] = "swap";
+static const char TX_TYPE_STR_SEND_PAYMENT[] = "send_payment";
+
+// Map a txtype string to an enum value
+#define TX_TYPE_STR_MATCH(typestr) ((len == sizeof(typestr) - 1 && !strncmp(type, typestr, sizeof(typestr) - 1)))
+static bool rpc_get_txtype(jade_process_t* process, CborValue* value, TxType_t* txtype)
+{
+    const char* type = NULL;
+    size_t len = 0;
+    rpc_get_string_ptr("tx_type", value, &type, &len);
+    if (!type || !len) {
+        *txtype = TXTYPE_SEND_PAYMENT;
+        return true; // Not present, treat as a payment
+    }
+    if (TX_TYPE_STR_MATCH(TX_TYPE_STR_SWAP)) {
+        *txtype = TXTYPE_SWAP;
+        return true;
+    } else if (TX_TYPE_STR_MATCH(TX_TYPE_STR_SEND_PAYMENT)) {
+        *txtype = TXTYPE_SEND_PAYMENT;
+        return true;
+    }
+    return false; // Unknown tx_type
+}
+
+static void rpc_get_asset_summary(
+    jade_process_t* process, const char* field, const CborValue* value, asset_summary_t** data, size_t* written)
+{
+    JADE_ASSERT(field);
+    JADE_ASSERT(value);
+    JADE_INIT_OUT_PPTR(data);
+    JADE_INIT_OUT_SIZE(written);
+
+    CborValue result;
+    if (!rpc_get_array(field, value, &result)) {
+        return;
+    }
+
+    size_t num_array_items = 0;
+    CborError cberr = cbor_value_get_array_length(&result, &num_array_items);
+    if (cberr != CborNoError || !num_array_items) {
+        return;
+    }
+
+    CborValue arrayItem;
+    cberr = cbor_value_enter_container(&result, &arrayItem);
+    if (cberr != CborNoError || !cbor_value_is_valid(&arrayItem)) {
+        return;
+    }
+
+    asset_summary_t* const sums = JADE_CALLOC(num_array_items, sizeof(asset_summary_t));
+    jade_process_free_on_exit(process, sums);
+
+    for (size_t i = 0; i < num_array_items; ++i) {
+        JADE_ASSERT(!cbor_value_at_end(&arrayItem));
+        asset_summary_t* const item = sums + i;
+
+        if (!cbor_value_is_map(&arrayItem)
+            || !rpc_get_n_bytes("asset_id", &arrayItem, sizeof(item->asset_id), item->asset_id)
+            || !rpc_get_uint64_t("satoshi", &arrayItem, &item->value)) {
+            return;
+        }
+
+        cberr = cbor_value_advance(&arrayItem);
+        JADE_ASSERT(cberr == CborNoError);
+    }
+
+    cberr = cbor_value_leave_container(&result, &arrayItem);
+    if (cberr == CborNoError) {
+        *written = num_array_items;
+        *data = sums;
+    }
+}
+
+static bool validate_additional_info(jade_process_t* process, const struct wally_tx* tx, const TxType_t txtype,
+    const bool is_partial, const asset_summary_t* in_sums, const size_t num_in_sums, const asset_summary_t* out_sums,
+    const size_t num_out_sums)
+{
+    const char* errmsg = NULL;
+    // Shouldn't have pointers to empty arrays
+    JADE_ASSERT(!in_sums == !num_in_sums);
+    JADE_ASSERT(!out_sums == !num_out_sums);
+
+    // Validate tx type data
+    if (txtype == TXTYPE_SWAP) {
+        // Input and output summary must be present - they will be fully validated later
+        if (!in_sums || !out_sums) {
+            errmsg = "Swap tx missing input/output summary information";
+            goto done;
+        }
+
+        // Validate swap or proposal appears to have expected inputs and outputs
+        if (is_partial) {
+            // At this time the only 'partial swap' we accept is an initial proposal with exactly one
+            // input and exactly one output which is to self, and in a different asset to the input
+            if (tx->num_inputs != 1 || tx->num_outputs != 1 || num_in_sums != 1 || num_out_sums != 1
+                || !memcmp(in_sums[0].asset_id, out_sums[0].asset_id, sizeof(out_sums[0].asset_id))) {
+                errmsg = "Initial swap proposal must have single wallet input and output in different assets";
+                goto done;
+            }
+        } else {
+            // TODO: Ideally check total number of assets in our inputs and outputs
+            if (tx->num_inputs < 2 || tx->num_outputs < 2) {
+                errmsg = "Insufficient inputs/outputs for a swap tx";
+                goto done;
+            }
+        }
+    } else if (txtype != TXTYPE_SEND_PAYMENT) {
+        errmsg = "Unsupported tx-type in additional info";
+        goto done;
+    }
+done:
+    if (errmsg) {
+        jade_process_reject_message(process, CBOR_RPC_BAD_PARAMETERS, errmsg);
+        return false;
+    }
+    return true;
+}
+
+TxType_t rpc_get_additional_info(jade_process_t* process, CborValue* params, const struct wally_tx* tx,
+    TxType_t* txtype, bool* is_partial, asset_summary_t** in_sums, size_t* num_in_sums, asset_summary_t** out_sums,
+    size_t* num_out_sums)
+{
+    JADE_ASSERT(params);
+    JADE_ASSERT(tx);
+    JADE_ASSERT(txtype);
+    JADE_ASSERT(is_partial);
+    JADE_INIT_OUT_PPTR(in_sums);
+    JADE_INIT_OUT_SIZE(num_in_sums);
+    JADE_INIT_OUT_PPTR(out_sums);
+    JADE_INIT_OUT_SIZE(num_out_sums);
+
+    *is_partial = false;
+    *txtype = TXTYPE_SEND_PAYMENT;
+
+    // If no 'additional_data' passed, assume this is a a simple send-payment 'classic' tx
+    CborValue additional_info;
+    if (!rpc_get_map("additional_info", params, &additional_info)) {
+        return true;
+    }
+
+    // input/output summaries required for some complex txn types, eg. swaps
+    rpc_get_asset_summary(process, "wallet_input_summary", &additional_info, in_sums, num_in_sums);
+    rpc_get_asset_summary(process, "wallet_output_summary", &additional_info, out_sums, num_out_sums);
+
+    // 'partial' flag (defaults to false, set above)
+    rpc_get_boolean("is_partial", &additional_info, is_partial);
+
+    // Tx Type
+    if (!rpc_get_txtype(process, &additional_info, txtype)) {
+        return false;
+    }
+    if (!validate_additional_info(
+            process, tx, *txtype, *is_partial, *in_sums, *num_in_sums, *out_sums, *num_out_sums)) {
+        return false;
+    }
+    return true;
+}
+
+bool asset_summary_update(asset_summary_t* sums, const size_t num_sums, const uint8_t* asset_id,
+    const size_t asset_id_len, const uint64_t value)
+{
+    if (!sums) {
+        return true; // Nothing to do
+    }
+    JADE_ASSERT(asset_id);
+    JADE_ASSERT(asset_id_len == sizeof(sums[0].asset_id));
+
+    // Add passed sats amount to the first record found with matching asset_id
+    for (size_t i = 0; i < num_sums; ++i) {
+        if (!memcmp(asset_id, sums[i].asset_id, sizeof(sums[i].asset_id))) {
+            sums[i].validated_value += value;
+            return true;
+        }
+    }
+    return false;
+}
+
+bool asset_summary_validate(asset_summary_t* sums, const size_t num_sums)
+{
+    JADE_ASSERT(!sums == !num_sums);
+
+    // Check every asset record (if any) has been fully validated
+    for (size_t i = 0; i < num_sums; ++i) {
+        if (sums[i].value != sums[i].validated_value) {
+            char* asset_id_hex = NULL;
+            wally_hex_from_bytes(sums[i].asset_id, sizeof(sums[i].asset_id), &asset_id_hex);
+            JADE_LOGW("Failed to validate input/output summary for %s", asset_id_hex);
+            JADE_WALLY_VERIFY(wally_free_string(asset_id_hex));
+            return false;
+        }
+    }
+    return true;
+}
+
+bool get_commitment_data(CborValue* item, commitment_t* commitment)
+{
+    JADE_ASSERT(item);
+    JADE_ASSERT(commitment);
+
+    commitment->content = COMMITMENTS_NONE;
+
+    // Need abf or asset_blind_proof
+    if (rpc_get_n_bytes("abf", item, sizeof(commitment->abf), commitment->abf)) {
+        commitment->content |= COMMITMENTS_ABF;
+    }
+
+    if (rpc_get_n_bytes(
+            "asset_blind_proof", item, sizeof(commitment->asset_blind_proof), commitment->asset_blind_proof)) {
+        commitment->content |= COMMITMENTS_ASSET_BLIND_PROOF;
+    }
+
+    if (!(commitment->content & (COMMITMENTS_ABF | COMMITMENTS_ASSET_BLIND_PROOF))) {
+        return false;
+    }
+
+    // Need vbf or value_blind_proof
+    if (rpc_get_n_bytes("vbf", item, sizeof(commitment->vbf), commitment->vbf)) {
+        commitment->content |= COMMITMENTS_VBF;
+    }
+
+    size_t written = 0;
+    rpc_get_bytes(
+        "value_blind_proof", sizeof(commitment->value_blind_proof), item, commitment->value_blind_proof, &written);
+    if (written && written <= sizeof(commitment->value_blind_proof)) {
+        commitment->value_blind_proof_len = written;
+        commitment->content |= COMMITMENTS_VALUE_BLIND_PROOF;
+    }
+
+    if (!(commitment->content & (COMMITMENTS_VBF | COMMITMENTS_VALUE_BLIND_PROOF))) {
+        return false;
+    }
+
+    if (!rpc_get_n_bytes("asset_id", item, sizeof(commitment->asset_id), commitment->asset_id)) {
+        return false;
+    }
+
+    if (!rpc_get_uint64_t("value", item, &commitment->value)) {
+        return false;
+    }
+
+    // Blinding key is optional in some scenarios
+    if (rpc_get_n_bytes("blinding_key", item, sizeof(commitment->blinding_key), commitment->blinding_key)) {
+        commitment->content |= COMMITMENTS_BLINDING_KEY;
+    }
+
+    // Actual commitments are optional - but must be both commitments or neither.
+    // If both are passed these will be copied into the tx and signed.
+    // If not passed, the above blinding factors/proofs must match what is already present in the transaction output.
+    // Must be both or neither - error if only one commitment passed.
+    if (rpc_has_field_data("asset_generator", item) || rpc_has_field_data("value_commitment", item)) {
+        if (!rpc_get_n_bytes(
+                "asset_generator", item, sizeof(commitment->asset_generator), commitment->asset_generator)) {
+            return false;
+        }
+
+        if (!rpc_get_n_bytes(
+                "value_commitment", item, sizeof(commitment->value_commitment), commitment->value_commitment)) {
+            return false;
+        }
+
+        // Set flag to show struct is fully populated/initialised, including commitments to sign.
+        commitment->content |= COMMITMENTS_INCLUDES_COMMITMENTS;
+    }
+
+    return true;
+}
+
+bool rpc_get_trusted_commitments(
+    jade_process_t* process, const CborValue* value, const struct wally_tx* tx, commitment_t** data)
+{
+    JADE_ASSERT(process);
+    JADE_ASSERT(value);
+    JADE_ASSERT(tx);
+    JADE_INIT_OUT_PPTR(data);
+
+    const char* errmsg = NULL;
+
+    CborValue result;
+    if (!rpc_get_array("trusted_commitments", value, &result)) {
+        errmsg = "Failed to extract trusted commitments from parameters";
+        goto cleanup;
+    }
+
+    // Expect one commitment element in the array for each output.
+    // (Can be null/zero's for unblinded outputs.)
+    size_t num_array_items = 0;
+    CborError cberr = cbor_value_get_array_length(&result, &num_array_items);
+    if (cberr != CborNoError || !num_array_items || num_array_items != tx->num_outputs) {
+        errmsg = "Unexpected number of trusted commitments for transaction";
+        goto cleanup;
+    }
+
+    CborValue arrayItem;
+    cberr = cbor_value_enter_container(&result, &arrayItem);
+    if (cberr != CborNoError || !cbor_value_is_valid(&arrayItem)) {
+        errmsg = "Invalid trusted commitments for transaction";
+        goto cleanup;
+    }
+
+    commitment_t* const commitments = JADE_CALLOC(num_array_items, sizeof(commitment_t));
+    jade_process_free_on_exit(process, commitments);
+
+    for (size_t i = 0; i < num_array_items; ++i) {
+        JADE_ASSERT(!cbor_value_at_end(&arrayItem));
+        commitments[i].content = COMMITMENTS_NONE;
+
+        if (cbor_value_is_null(&arrayItem)) {
+            CborError err = cbor_value_advance(&arrayItem);
+            JADE_ASSERT(err == CborNoError);
+            continue;
+        }
+
+        if (!cbor_value_is_map(&arrayItem)) {
+            errmsg = "Invalid trusted commitments for transaction";
+            goto cleanup;
+        }
+
+        size_t num_map_items = 0;
+        if (cbor_value_get_map_length(&arrayItem, &num_map_items) == CborNoError && num_map_items == 0) {
+            CborError err = cbor_value_advance(&arrayItem);
+            JADE_ASSERT(err == CborNoError);
+            continue;
+        }
+
+        // Populate commitments data
+        if (!get_commitment_data(&arrayItem, &commitments[i])) {
+            errmsg = "Invalid trusted commitments for transaction";
+            goto cleanup;
+        }
+
+        CborError err = cbor_value_advance(&arrayItem);
+        JADE_ASSERT(err == CborNoError);
+    }
+
+    cberr = cbor_value_leave_container(&result, &arrayItem);
+    if (cberr == CborNoError) {
+        *data = commitments;
+    } else {
+        errmsg = "Invalid trusted commitments for transaction";
+    }
+
+cleanup:
+    if (errmsg) {
+        jade_process_reject_message(process, CBOR_RPC_BAD_PARAMETERS, errmsg);
+        return false;
+    }
+    return true;
+}
+
+#ifdef CONFIG_SPIRAM
+// Workaround to run 'wally_explicit_surjectionproof_verify()' and 'wally_explicit_rangeproof_verify()'
+// on a temporary stack, as the underlying libsecp calls require over 50kb of stack space.
+// NOTE: devices without SPIRAM do not have sufficient free memory to be able to do this verification,
+// so atm we exclude it for those devices.
+static bool verify_explicit_proofs(void* ctx)
+{
+    JADE_ASSERT(ctx);
+
+    const commitment_t* commitments = (const commitment_t*)ctx;
+    JADE_ASSERT(commitments->content & (COMMITMENTS_ASSET_BLIND_PROOF | COMMITMENTS_VALUE_BLIND_PROOF));
+    JADE_ASSERT(commitments->content & COMMITMENTS_INCLUDES_COMMITMENTS);
+
+    if (commitments->content & COMMITMENTS_ASSET_BLIND_PROOF) {
+        uint8_t reversed_asset_id[sizeof(commitments->asset_id)];
+        reverse(reversed_asset_id, commitments->asset_id, sizeof(commitments->asset_id));
+
+        // NOTE: Appears to require ~52kb of stack space
+        if (wally_explicit_surjectionproof_verify(commitments->asset_blind_proof,
+                sizeof(commitments->asset_blind_proof), reversed_asset_id, sizeof(reversed_asset_id),
+                commitments->asset_generator, sizeof(commitments->asset_generator))
+            != WALLY_OK) {
+            // Failed to verify explicit asset proof
+            return false;
+        }
+    }
+
+    if (commitments->content & COMMITMENTS_VALUE_BLIND_PROOF) {
+        // NOTE: Appears to require ~40kb of stack space
+        if (wally_explicit_rangeproof_verify(commitments->value_blind_proof, commitments->value_blind_proof_len,
+                commitments->value, commitments->value_commitment, sizeof(commitments->value_commitment),
+                commitments->asset_generator, sizeof(commitments->asset_generator))
+            != WALLY_OK) {
+            // Failed to verify explicit value proof
+            return false;
+        }
+    }
+
+    return true;
+}
+#endif // CONFIG_SPIRAM
+
+bool verify_commitment_consistent(const commitment_t* commitments, const char** errmsg)
+{
+    JADE_ASSERT(commitments);
+    JADE_INIT_OUT_PPTR(errmsg);
+
+    if (!(commitments->content & COMMITMENTS_INCLUDES_COMMITMENTS)) {
+        *errmsg = "Failed to extract final commitment values from commitments data";
+        return false;
+    }
+
+    if (!(commitments->content & (COMMITMENTS_ABF | COMMITMENTS_ASSET_BLIND_PROOF))
+        || !(commitments->content & (COMMITMENTS_VBF | COMMITMENTS_VALUE_BLIND_PROOF))) {
+        *errmsg = "Failed to extract blinding factors or proofs from commitments data";
+        return false;
+    }
+
+    // 1. Asset generator
+    // If passed the abf, check the blinded asset commitment can be reconstructed
+    // (ie. from the given reversed asset_id and abf)
+    if (commitments->content & COMMITMENTS_ABF) {
+        uint8_t reversed_asset_id[sizeof(commitments->asset_id)];
+        reverse(reversed_asset_id, commitments->asset_id, sizeof(commitments->asset_id));
+
+        uint8_t generator_tmp[sizeof(commitments->asset_generator)];
+        if (wally_asset_generator_from_bytes(reversed_asset_id, sizeof(reversed_asset_id), commitments->abf,
+                sizeof(commitments->abf), generator_tmp, sizeof(generator_tmp))
+                != WALLY_OK
+            || sodium_memcmp(commitments->asset_generator, generator_tmp, sizeof(generator_tmp)) != 0) {
+            *errmsg = "Failed to verify blinded asset generator from commitments data";
+            return false;
+        }
+    }
+
+    // 2. Value commitment
+    // If passed the vbf, check the blinded value commitment can be reconstructed
+    // (ie. from the given value, asset_generator and vbf)
+    if (commitments->content & COMMITMENTS_VBF) {
+        uint8_t commitment_tmp[sizeof(commitments->value_commitment)];
+        if (wally_asset_value_commitment(commitments->value, commitments->vbf, sizeof(commitments->vbf),
+                commitments->asset_generator, sizeof(commitments->asset_generator), commitment_tmp,
+                sizeof(commitment_tmp))
+                != WALLY_OK
+            || sodium_memcmp(commitments->value_commitment, commitment_tmp, sizeof(commitment_tmp)) != 0) {
+            *errmsg = "Failed to verify blinded value commitment from commitments data";
+            return false;
+        }
+    }
+
+    // Verify any blinded proofs
+    // NOTE: only a device with SPIRAM has sufficient memory to be able to do this verification.
+    if (commitments->content & (COMMITMENTS_ASSET_BLIND_PROOF | COMMITMENTS_VALUE_BLIND_PROOF)) {
+#ifdef CONFIG_SPIRAM
+        // Because the libsecp calls 'secp256k1_surjectionproof_verify()' and 'secp256k1_rangeproof_verify()'
+        // requires more stack space than is available to the main task, we run that function in a temporary task.
+        const size_t stack_size = 54 * 1024; // 54kb seems sufficient
+        if (!run_in_temporary_task(stack_size, verify_explicit_proofs, (void*)commitments)) {
+            *errmsg = "Failed to verify explicit asset/value commitment proofs";
+            return false;
+        }
+#else
+        *errmsg = "Devices without external SPIRAM are unable to verify explicit proofs";
+        return false;
+#endif // CONFIG_SPIRAM
+    }
+    return true;
+}
+
+static bool add_output_info(
+    commitment_t* commitments, const struct wally_tx_output* txoutput, output_info_t* outinfo, const char** errmsg)
+{
+    JADE_ASSERT(commitments);
+    JADE_ASSERT(txoutput);
+    JADE_ASSERT(outinfo);
+    JADE_INIT_OUT_PPTR(errmsg);
+
+    JADE_ASSERT(!(outinfo->flags & (OUTPUT_FLAG_CONFIDENTIAL | OUTPUT_FLAG_HAS_UNBLINDED)));
+    if (commitments->content != COMMITMENTS_NONE) {
+        // Output to be confidential/blinded, use the commitments data
+        outinfo->flags |= (OUTPUT_FLAG_CONFIDENTIAL | OUTPUT_FLAG_HAS_UNBLINDED);
+
+        // 1. Sanity checks
+        if (txoutput->asset_len != sizeof(commitments->asset_generator)) {
+            *errmsg = "Invalid asset generator in tx output";
+            return false;
+        }
+        if (txoutput->value_len != sizeof(commitments->value_commitment)) {
+            *errmsg = "Invalid value commitment in tx output";
+            return false;
+        }
+
+        // 2. If passed explicit commitments copy them into the transaction output ready for signing
+        // If not, copy the values from the tx into the commitment structure.
+        // ie. so in any case commitment struct is complete, and reflects what is in the tx output
+        if (commitments->content & COMMITMENTS_INCLUDES_COMMITMENTS) {
+            memcpy(txoutput->asset, commitments->asset_generator, sizeof(commitments->asset_generator));
+            memcpy(txoutput->value, commitments->value_commitment, sizeof(commitments->value_commitment));
+        } else {
+            memcpy(commitments->asset_generator, txoutput->asset, sizeof(commitments->asset_generator));
+            memcpy(commitments->value_commitment, txoutput->value, sizeof(commitments->value_commitment));
+            commitments->content |= COMMITMENTS_INCLUDES_COMMITMENTS;
+        }
+
+        // 3. Check the asset generator and value commitment can be reconstructed
+        if (!verify_commitment_consistent(commitments, errmsg)) {
+            // errmsg populated by call if failure
+            return false;
+        }
+
+        // 4. Fetch the asset_id, value, and optional blinding_key into the info struct
+        JADE_STATIC_ASSERT(sizeof(outinfo->asset_id) == sizeof(commitments->asset_id));
+        memcpy(outinfo->asset_id, commitments->asset_id, sizeof(commitments->asset_id));
+        outinfo->value = commitments->value;
+
+        if (commitments->content & COMMITMENTS_BLINDING_KEY) {
+            JADE_STATIC_ASSERT(sizeof(outinfo->blinding_key) == sizeof(commitments->blinding_key));
+            memcpy(outinfo->blinding_key, commitments->blinding_key, sizeof(commitments->blinding_key));
+            outinfo->flags |= OUTPUT_FLAG_HAS_BLINDING_KEY;
+        }
+    } else if (txoutput->asset[0] != WALLY_TX_ASSET_CT_EXPLICIT_PREFIX
+        || txoutput->value[0] != WALLY_TX_ASSET_CT_EXPLICIT_PREFIX) {
+        // No blinding info for blinded output - may not be an issue if we're
+        // not interested in this output.  Just set flags appropriately.
+        outinfo->flags |= OUTPUT_FLAG_CONFIDENTIAL;
+
+        // NOTE: This is not valid if this output has been validated as belonging to this wallet
+        if (outinfo->flags & OUTPUT_FLAG_VALIDATED) {
+            *errmsg = "Missing blinding information for wallet output";
+            return false;
+        }
+    } else {
+        // unconfidential, take directly from the tx
+        outinfo->flags |= OUTPUT_FLAG_HAS_UNBLINDED;
+
+        // Copy the asset ID without the leading unconfidential tag byte
+        // NOTE: we reverse the asset-id bytes to the 'display' order
+        reverse(outinfo->asset_id, txoutput->asset + 1, sizeof(outinfo->asset_id));
+
+        JADE_WALLY_VERIFY(
+            wally_tx_confidential_value_to_satoshi(txoutput->value, txoutput->value_len, &outinfo->value));
+    }
+
+    return true;
+}
+
+bool validate_elements_outputs(jade_process_t* process, const network_t network_id, const struct wally_tx* tx,
+    const TxType_t txtype, commitment_t* commitments, output_info_t* output_info, asset_summary_t* in_sums,
+    const size_t num_in_sums, asset_summary_t* out_sums, const size_t num_out_sums, uint64_t* fees)
+{
+    JADE_ASSERT(tx);
+    JADE_ASSERT(commitments);
+    JADE_ASSERT(output_info);
+    JADE_ASSERT(fees);
+
+    const char* errmsg = NULL;
+    *fees = 0;
+
+    uint8_t policy_asset[ASSET_TAG_LEN];
+    network_to_policy_asset(network_id, policy_asset, sizeof(policy_asset));
+
+    // Check the trusted commitments: expect one element in the array for each output.
+    // Can be null for unblinded outputs as we will skip them.
+    // Populate an `output_index` -> (blinding_key, asset, value) map
+
+    // NOTE: some advanced tx types permit some outputs to be blind (ie blinded, without unblinding info/proofs)
+    // By default/in the basic 'send payment' case all outputs must have unconfidential/unblinded.
+    const bool allow_blind_outputs = txtype == TXTYPE_SWAP; // swaps allow 'other wallets' blind outputs
+
+    // Save fees for the final confirmation screen
+    for (size_t i = 0; i < tx->num_outputs; ++i) {
+        // Gather the (unblinded) output info for user confirmation
+        output_info_t* outinfo = output_info + i;
+        if (!add_output_info(&commitments[i], &tx->outputs[i], outinfo, &errmsg)) {
+            goto done;
+        }
+
+        // If are not allowing blinded outputs, check each confidential output has unblinding info
+        if (!allow_blind_outputs && outinfo->flags & OUTPUT_FLAG_CONFIDENTIAL) {
+            if (!(outinfo->flags & OUTPUT_FLAG_HAS_UNBLINDED) || !(outinfo->flags & OUTPUT_FLAG_HAS_BLINDING_KEY)) {
+                errmsg = "Missing commitments data for blinded output";
+                goto done;
+            }
+        }
+
+        // Collect fees (ie. outputs with no script)
+        // NOTE: fees must be unconfidential, and must be denominated in the policy asset
+        if (!tx->outputs[i].script) {
+            if (outinfo->flags & OUTPUT_FLAG_CONFIDENTIAL) {
+                errmsg = "Fee output (without script) cannot be blinded";
+                goto done;
+            }
+            if (memcmp(outinfo->asset_id, policy_asset, sizeof(policy_asset))) {
+                errmsg = "Unexpected fee output (without script) asset-id";
+                goto done;
+            }
+            if (!outinfo->value) {
+                errmsg = "Fee output (without script) cannot be 0";
+                goto done;
+            }
+            if (*fees) {
+                errmsg = "Unexpected multiple fee outputs (without script)";
+                goto done;
+            }
+            *fees += outinfo->value;
+        }
+
+        // If the output has been verified as belonging to this wallet, we can
+        // use it to validate some part of any passed input- or output- summary.
+        if (outinfo->flags & OUTPUT_FLAG_VALIDATED) {
+            JADE_ASSERT(outinfo->flags & OUTPUT_FLAG_HAS_UNBLINDED);
+
+            if (outinfo->flags & OUTPUT_FLAG_CHANGE) {
+                // NOTE: change outputs are subtracted from the relevant 'input summary'.
+                asset_summary_update(
+                    in_sums, num_in_sums, outinfo->asset_id, sizeof(outinfo->asset_id), (0 - outinfo->value));
+            } else {
+                asset_summary_update(
+                    out_sums, num_out_sums, outinfo->asset_id, sizeof(outinfo->asset_id), outinfo->value);
+            }
+        }
+    }
+done:
+    if (errmsg) {
+        jade_process_reject_message(process, CBOR_RPC_BAD_PARAMETERS, errmsg);
+        return false;
+    }
+    return true;
+}
+
+bool show_elements_fee_confirmation_activity(const network_t network_id, const struct wally_tx* tx,
+    const output_info_t* outinfo, const script_flavour_t aggregate_inputs_scripts_flavour, const uint64_t fees,
+    const TxType_t txtype, const bool is_partial)
+{
+    JADE_ASSERT(network_id != NETWORK_NONE);
+    JADE_ASSERT(tx);
+    JADE_ASSERT(outinfo);
+
+    const char* const warning_msg
+        = aggregate_inputs_scripts_flavour == SCRIPT_FLAVOUR_MIXED ? WARN_MSG_MIXED_INPUTS : NULL;
+    const char* title = (txtype == TXTYPE_SWAP) ? (is_partial ? "Swap Proposal" : "Complete Swap") : "Send Transaction";
+
+    // Return whether the user accepts or declines
+    return show_elements_final_confirmation_activity(network_id, title, fees, warning_msg);
+}
+#endif // AMALGAMATED_BUILD