sign tx: extract reading tx-signing message fields into helper function

docs/index.rst

@@ -1195,7 +1195,7 @@ A batch of 'tx_input' messages should be sent to Jade - one for each tx input.
  }
  }
 
-* 'script' and 'path' should be omitted if a signature for this input is not required.
+* 'is_witness', 'script' and 'path' should be omitted if a signature for this input is not required.
 * If provided, 'script' should be the script-sig/redeem-script required to satisfy the input utxo.
 * 'input_tx' should be the streamed bytes of the txn which output the utxo being spent.
 * NOTE: if this is the only input, and 'is_witness' is 'true', the 'input_tx' can (optionally) be replaced with a 'satoshi' element, eg: '"satoshi": 2200000'.
@@ -1637,7 +1637,7 @@ A batch of 'tx_input' messages should be sent to Jade - one for each tx input, a
  }
  }
 
-* 'script' and 'path' are as in sign_tx_legacy_input_request_.
+* 'is_witness', 'script' and 'path' are as in sign_tx_legacy_input_request_.
 * In addition, if a signature is required for this input and 'is_witness' is 'true', then the input utxo 'value_commitment' must be passed.
 * NOTE: no 'input_tx' is needed.
 

jadepy/jade.py

@@ -1330,18 +1330,19 @@ def sign_liquid_tx(self, network, txn, inputs, commitments, change, use_ae_signa
  The transaction to sign
 
  inputs : [dict]
- The tx inputs. Should contain keys:
+ The tx inputs.
+ If signing this input, should contain keys:
  is_witness, bool - whether this is a segwit input
- value_commitment, 33-bytes - The value commitment of ths input
-
- These are only required if signing this input:
  script, bytes- the redeem script
  path, [int] - the bip32 path to sign with
+ value_commitment, 33-bytes - The value commitment of ths input
 
  These are only required for Anti-Exfil signatures:
  ae_host_commitment, 32-bytes - The host-commitment for Anti-Exfil signatures
  ae_host_entropy, 32-bytes - The host-entropy for Anti-Exfil signatures
 
+ If not signing this input a null or an empty dict can be passed.
+
  commitments : [dict]
  An array sized for the number of outputs.
  Unblinded outputs should have a 'null' placeholder element.
@@ -1415,17 +1416,16 @@ def sign_tx(self, network, txn, inputs, change, use_ae_signatures=False):
 
  inputs : [dict]
  The tx inputs. Should contain keys:
- is_witness, bool - whether this is a segwit input
-
- These are only required if signing this input:
- script, bytes- the redeem script
- path, [int] - the bip32 path to sign with
-
  One of these is required:
  input_tx, bytes - The prior transaction which created the utxo of this input
  satoshi, int - The satoshi amount of this input - can be used in place of
  'input_tx' for a tx with a single segwit input
 
+ These are only required if signing this input:
+ is_witness, bool - whether this is a segwit input
+ script, bytes- the redeem script
+ path, [int] - the bip32 path to sign with
+
  These are only required for Anti-Exfil signatures:
  ae_host_commitment, 32-bytes - The host-commitment for Anti-Exfil signatures
  ae_host_entropy, 32-bytes - The host-entropy for Anti-Exfil signatures

main/process/process_utils.c

@@ -7,6 +7,7 @@
 #include "../utils/cbor_rpc.h"
 
 #include <sys/time.h>
+#include <wally_anti_exfil.h>
 #include <wally_script.h>
 
 #include "process_utils.h"
@@ -256,6 +257,56 @@ bool params_get_master_blindingkey(
  return true;
 }
 
+// Get the common parameters required when signing an tx input
+bool params_tx_input_signing_data(const bool use_ae_signatures, CborValue* params, bool* is_witness,
+ signing_data_t* sig_data, const uint8_t** ae_host_commitment, size_t* ae_host_commitment_len,
+ const uint8_t** script, size_t* script_len, script_flavour_t* aggregate_script_flavour, const char** errmsg)
+{
+ JADE_ASSERT(params);
+ JADE_ASSERT(is_witness);
+ JADE_ASSERT(sig_data);
+ JADE_INIT_OUT_PPTR(ae_host_commitment);
+ JADE_INIT_OUT_SIZE(ae_host_commitment_len);
+ JADE_INIT_OUT_PPTR(script);
+ JADE_INIT_OUT_SIZE(script_len);
+ JADE_ASSERT(aggregate_script_flavour);
+ JADE_ASSERT(errmsg);
+
+ if (!rpc_get_boolean("is_witness", params, is_witness)) {
+ *errmsg = "Failed to extract is_witness from parameters";
+ return false;
+ }
+
+ const size_t max_path_len = sizeof(sig_data->path) / sizeof(sig_data->path[0]);
+ if (!rpc_get_bip32_path("path", params, sig_data->path, max_path_len, &sig_data->path_len)
+ || sig_data->path_len == 0) {
+ *errmsg = "Failed to extract valid path from parameters";
+ return false;
+ }
+
+ // If required, read anti-exfil host commitment data
+ if (use_ae_signatures) {
+ rpc_get_bytes_ptr("ae_host_commitment", params, ae_host_commitment, ae_host_commitment_len);
+ if (!*ae_host_commitment || *ae_host_commitment_len != WALLY_HOST_COMMITMENT_LEN) {
+ *errmsg = "Failed to extract valid host commitment from parameters";
+ return false;
+ }
+ }
+
+ // Get prevout script - required for signing inputs
+ rpc_get_bytes_ptr("script", params, script, script_len);
+ if (!*script || *script_len == 0) {
+ *errmsg = "Failed to extract script from parameters";
+ return false;
+ }
+
+ // Track the types of the input prevout scripts
+ const script_flavour_t script_flavour = get_script_flavour(*script, *script_len);
+ update_aggregate_scripts_flavour(script_flavour, aggregate_script_flavour);
+
+ return true;
+}
+
 // For now just return 'single-sig' or 'other'.
 // In future may extend to inlcude eg. 'green', 'other-multisig', etc.
 script_flavour_t get_script_flavour(const uint8_t* script, const size_t script_len)
@@ -284,4 +335,4 @@ void update_aggregate_scripts_flavour(
  // As soon as we see something differet, set to 'mixed'
  *aggregate_scripts_flavour = SCRIPT_FLAVOUR_MIXED;
  }
-}
+}

main/process/process_utils.h

@@ -112,6 +112,10 @@ bool params_multisig_pubkeys(bool is_change, CborValue* params, multisig_data_t*
 bool params_get_master_blindingkey(
  CborValue* params, uint8_t* master_blinding_key, size_t master_blinding_key_len, const char** errmsg);
 
+bool params_tx_input_signing_data(const bool use_ae_signatures, CborValue* params, bool* is_witness,
+ signing_data_t* sig_data, const uint8_t** ae_host_commitment, size_t* ae_host_commitment_len,
+ const uint8_t** script, size_t* script_len, script_flavour_t* aggregate_script_flavour, const char** errmsg);
+
 // Track the types of the input prevout scripts
 script_flavour_t get_script_flavour(const uint8_t* script, const size_t script_len);
 void update_aggregate_scripts_flavour(script_flavour_t new_script_flavour, script_flavour_t* aggregate_scripts_flavour);

main/process/sign_liquid_tx.c

@@ -540,6 +540,7 @@ void sign_liquid_tx_process(void* process_ptr)
  // txn input as expected - get input parameters
  GET_MSG_PARAMS(process);
 
+ bool is_witness = false;
  size_t script_len = 0;
  const uint8_t* script = NULL;
 
@@ -555,47 +556,16 @@ void sign_liquid_tx_process(void* process_ptr)
  rpc_get_id(&process->ctx.value, sig_data->id, sizeof(sig_data->id), &written);
  JADE_ASSERT(written != 0);
 
- bool is_witness = false;
- ret = rpc_get_boolean("is_witness", &params, &is_witness);
- if (!ret) {
- jade_process_reject_message(
- process, CBOR_RPC_BAD_PARAMETERS, "Failed to extract is_witness from parameters", NULL);
- goto cleanup;
- }
-
  // Path node can be omitted if we don't want to sign this input
  // (But if passed must be valid - empty/root path is not allowed for signing)
  const bool has_path = rpc_has_field_data("path", &params);
  if (has_path) {
- const size_t max_path_len = sizeof(sig_data->path) / sizeof(sig_data->path[0]);
- if (!rpc_get_bip32_path("path", &params, sig_data->path, max_path_len, &sig_data->path_len)
- || sig_data->path_len == 0) {
- jade_process_reject_message(
- process, CBOR_RPC_BAD_PARAMETERS, "Failed to extract valid path from parameters", NULL);
+ // Get all common tx-signing input fields which must be present if a path is given
+ if (!params_tx_input_signing_data(use_ae_signatures, &params, &is_witness, sig_data, &ae_host_commitment,
+ &ae_host_commitment_len, &script, &script_len, &aggregate_inputs_scripts_flavour, &errmsg)) {
+ jade_process_reject_message(process, CBOR_RPC_BAD_PARAMETERS, errmsg, NULL);
  goto cleanup;
  }
-
- // If required, read anti-exfil host commitment data
- if (use_ae_signatures) {
- rpc_get_bytes_ptr("ae_host_commitment", &params, &ae_host_commitment, &ae_host_commitment_len);
- if (!ae_host_commitment || ae_host_commitment_len != WALLY_HOST_COMMITMENT_LEN) {
- jade_process_reject_message(process, CBOR_RPC_BAD_PARAMETERS,
- "Failed to extract valid host commitment from parameters", NULL);
- goto cleanup;
- }
- }
-
- // Get prevout script - required for signing inputs
- rpc_get_bytes_ptr("script", &params, &script, &script_len);
- if (!script || script_len == 0) {
- jade_process_reject_message(
- process, CBOR_RPC_BAD_PARAMETERS, "Failed to extract script from parameters", NULL);
- goto cleanup;
- }
-
- // Track the types of the input prevout scripts
- const script_flavour_t script_flavour = get_script_flavour(script, script_len);
- update_aggregate_scripts_flavour(script_flavour, &aggregate_inputs_scripts_flavour);
  }
 
  size_t value_len = 0;

main/process/sign_tx.c

@@ -430,6 +430,7 @@ void sign_tx_process(void* process_ptr)
  // txn input as expected - get input parameters
  GET_MSG_PARAMS(process);
 
+ bool is_witness = false;
  size_t script_len = 0;
  const uint8_t* script = NULL;
  uint64_t input_satoshi = 0;
@@ -448,47 +449,16 @@ void sign_tx_process(void* process_ptr)
  rpc_get_id(&process->ctx.value, sig_data->id, sizeof(sig_data->id), &written);
  JADE_ASSERT(written != 0);
 
- bool is_witness = false;
- ret = rpc_get_boolean("is_witness", &params, &is_witness);
- if (!ret) {
- jade_process_reject_message(
- process, CBOR_RPC_BAD_PARAMETERS, "Failed to extract is_witness from parameters", NULL);
- goto cleanup;
- }
-
  // Path node can be omitted if we don't want to sign this input
  // (But if passed must be valid - empty/root path is not allowed for signing)
  const bool has_path = rpc_has_field_data("path", &params);
  if (has_path) {
- const size_t max_path_len = sizeof(sig_data->path) / sizeof(sig_data->path[0]);
- if (!rpc_get_bip32_path("path", &params, sig_data->path, max_path_len, &sig_data->path_len)
- || sig_data->path_len == 0) {
- jade_process_reject_message(
- process, CBOR_RPC_BAD_PARAMETERS, "Failed to extract valid path from parameters", NULL);
+ // Get all common tx-signing input fields which must be present if a path is given
+ if (!params_tx_input_signing_data(use_ae_signatures, &params, &is_witness, sig_data, &ae_host_commitment,
+ &ae_host_commitment_len, &script, &script_len, &aggregate_inputs_scripts_flavour, &errmsg)) {
+ jade_process_reject_message(process, CBOR_RPC_BAD_PARAMETERS, errmsg, NULL);
  goto cleanup;
  }
-
- // If required, read anti-exfil host commitment data
- if (use_ae_signatures) {
- rpc_get_bytes_ptr("ae_host_commitment", &params, &ae_host_commitment, &ae_host_commitment_len);
- if (!ae_host_commitment || ae_host_commitment_len != WALLY_HOST_COMMITMENT_LEN) {
- jade_process_reject_message(process, CBOR_RPC_BAD_PARAMETERS,
- "Failed to extract valid host commitment from parameters", NULL);
- goto cleanup;
- }
- }
-
- // Get prevout script - required for signing inputs
- rpc_get_bytes_ptr("script", &params, &script, &script_len);
- if (!script || script_len == 0) {
- jade_process_reject_message(
- process, CBOR_RPC_BAD_PARAMETERS, "Failed to extract script from parameters", NULL);
- goto cleanup;
- }
-
- // Track the types of the input prevout scripts
- const script_flavour_t script_flavour = get_script_flavour(script, script_len);
- update_aggregate_scripts_flavour(script_flavour, &aggregate_inputs_scripts_flavour);
  }
 
  // Full input tx can be omitted for transactions with only one single witness