feat: eip-712 digest and calldata digest addition (WIP)

README.md

@@ -77,6 +77,7 @@ to quickly **build** your apps, **test** them on **Speculos** and **load** them
   - On Windows, install and launch [VcXsrv](https://sourceforge.net/projects/vcxsrv/)
     (make sure to configure it to disable access control).
 - Install [VScode](https://code.visualstudio.com/download) and add [Ledger's extension](https://marketplace.visualstudio.com/items?itemName=LedgerHQ.ledger-dev-tools).
+- Restart VSCode after installing the extension.
 - Open a terminal and clone `app-ethereum` with `git clone git@github.com:LedgerHQ/app-ethereum.git`.
 - Open the `app-ethereum` folder with VSCode.
 - Use Ledger extension's sidebar menu or open the tasks menu with `ctrl + shift + b`

src/features/sign_message_eip712/ui_logic.c

@@ -1335,7 +1335,7 @@ void ui_712_push_pairs(void) {
     // Initialize the pairs list
     nbPairs = flist_size((flist_node_t **) &ui_ctx->ui_pairs);
     if (N_storage.displayHash) {
-        nbPairs += 2;
+        nbPairs += 3;
     }
 
     ui_pairs_init(nbPairs);

src/features/sign_message_eip712_common/common_712.c

@@ -66,21 +66,52 @@ static char *format_hash(const uint8_t *hash, char *buffer, size_t buffer_size,
     return buffer + offset;
 }
 
+static void compute_eip712_digest(void) {
+    CX_ASSERT(cx_keccak_init_no_throw(&global_sha3, 256));
+    CX_ASSERT(cx_hash_no_throw((cx_hash_t *) &global_sha3,
+                               0,
+                               (uint8_t *) EIP_712_MAGIC,
+                               sizeof(EIP_712_MAGIC),
+                               NULL,
+                               0));
+    CX_ASSERT(cx_hash_no_throw((cx_hash_t *) &global_sha3,
+                               0,
+                               tmpCtx.messageSigningContext712.domainHash,
+                               sizeof(tmpCtx.messageSigningContext712.domainHash),
+                               NULL,
+                               0));
+    CX_ASSERT(cx_hash_no_throw((cx_hash_t *) &global_sha3,
+                               CX_LAST,
+                               tmpCtx.messageSigningContext712.messageHash,
+                               sizeof(tmpCtx.messageSigningContext712.messageHash),
+                               tmpCtx.messageSigningContext712.eip712Digest,
+                               sizeof(tmpCtx.messageSigningContext712.eip712Digest)));
+}
+
 void eip712_format_hash(uint8_t index) {
     if ((g_pairs == NULL) || (g_pairsList == NULL) || (index >= g_pairsList->nbPairs)) {
         return;
     }
+
+    compute_eip712_digest();
+
+    g_pairs[index].item = "EIP-712 Digest";
+    g_pairs[index].value = format_hash(tmpCtx.messageSigningContext712.eip712Digest,
+                                       strings.tmp.tmp,
+                                       sizeof(strings.tmp.tmp),
+                                       0);
+    index++;
     g_pairs[index].item = "Domain hash";
     g_pairs[index].value = format_hash(tmpCtx.messageSigningContext712.domainHash,
                                        strings.tmp.tmp,
                                        sizeof(strings.tmp.tmp),
-                                       0);
+                                       70);
     index++;
     g_pairs[index].item = "Message hash";
     g_pairs[index].value = format_hash(tmpCtx.messageSigningContext712.messageHash,
                                        strings.tmp.tmp,
                                        sizeof(strings.tmp.tmp),
-                                       70);
+                                       140);
 }
 
 /**

src/features/sign_tx/eth_ustream.c

@@ -28,6 +28,7 @@
 #include "shared_context.h"  // tmpContent
 #include "read.h"            // read_u64_be
 #include "network.h"         // get_tx_chain_id
+#include "app_mem_utils.h"   // APP_MEM_FREE_AND_NULL
 
 static bool check_fields(txContext_t *context, const char *name, uint32_t length) {
     UNUSED(name);  // Just for the case where DEBUG is not enabled
@@ -109,6 +110,17 @@ bool copy_tx_data(txContext_t *context, uint8_t *out, uint32_t length) {
             return false;
         }
     }
+    // Feed calldata bytes into the calldata digest hash (includes single-byte fields)
+    if (context->calldata_sha3 != NULL) {
+        if (cx_hash_no_throw((cx_hash_t *) context->calldata_sha3,
+                             0,
+                             context->workBuffer,
+                             length,
+                             NULL,
+                             0) != CX_OK) {
+            return false;
+        }
+    }
     context->workBuffer += length;
     context->commandLength -= length;
     if (context->processingField) {
@@ -350,6 +362,19 @@ static bool process_data(txContext_t *context) {
     }
     if (context->currentFieldPos == context->currentFieldLength) {
         PRINTF("incrementing field\n");
+        // Finalize calldata digest if we were hashing
+        if (context->calldata_sha3 != NULL) {
+            if (cx_hash_no_throw((cx_hash_t *) context->calldata_sha3,
+                                 CX_LAST,
+                                 NULL,
+                                 0,
+                                 context->calldataDigest,
+                                 sizeof(context->calldataDigest)) != CX_OK) {
+                return false;
+            }
+            context->calldataDigestValid = context->content->dataPresent;
+            APP_MEM_FREE_AND_NULL((void **) &context->calldata_sha3);
+        }
         context->currentField++;
         context->processingField = false;
     }

src/features/sign_tx/eth_ustream.h

@@ -143,6 +143,9 @@ typedef struct txContext_t {
     uint8_t batch_nb_tx;
     uint8_t current_batch_size;
     uint8_t selector_bytes[CALLDATA_SELECTOR_SIZE];
+    cx_sha3_t *calldata_sha3;
+    uint8_t calldataDigest[INT256_LENGTH];
+    bool calldataDigestValid;
 } txContext_t;
 
 bool init_tx(txContext_t *context, cx_sha3_t *sha3, txContent_t *content, bool store_calldata);

src/features/sign_tx/logic_sign_tx.c

@@ -37,13 +37,47 @@ static uint32_t split_binary_parameter_part(char *result, size_t result_size, ui
     }
 }
 
+static bool init_calldata_digest(txContext_t *context) {
+    uint8_t len_buf[INT256_LENGTH];
+
+    if (APP_MEM_CALLOC((void **) &context->calldata_sha3, sizeof(cx_sha3_t)) == false) {
+        return false;
+    }
+    if (cx_keccak_init_no_throw(context->calldata_sha3, 256) != CX_OK) {
+        APP_MEM_FREE_AND_NULL((void **) &context->calldata_sha3);
+        return false;
+    }
+    // Hash uint256(len(calldata)) as big-endian length prefix
+    explicit_bzero(len_buf, sizeof(len_buf));
+    len_buf[28] = (context->currentFieldLength >> 24) & 0xFF;
+    len_buf[29] = (context->currentFieldLength >> 16) & 0xFF;
+    len_buf[30] = (context->currentFieldLength >> 8) & 0xFF;
+    len_buf[31] = context->currentFieldLength & 0xFF;
+    if (cx_hash_no_throw((cx_hash_t *) context->calldata_sha3,
+                         0,
+                         len_buf,
+                         sizeof(len_buf),
+                         NULL,
+                         0) != CX_OK) {
+        APP_MEM_FREE_AND_NULL((void **) &context->calldata_sha3);
+        return false;
+    }
+    return true;
+}
+
 customStatus_e custom_processor(txContext_t *context) {
     if (((context->txType == LEGACY && context->currentField == LEGACY_RLP_DATA) ||
          (context->txType == EIP2930 && context->currentField == EIP2930_RLP_DATA) ||
          (context->txType == EIP1559 && context->currentField == EIP1559_RLP_DATA) ||
          (context->txType == EIP7702 && context->currentField == EIP7702_RLP_DATA)) &&
         (context->currentFieldLength != 0)) {
         context->content->dataPresent = true;
+        // Initialize calldata digest hashing at the start of the DATA field
+        if (context->currentFieldPos == 0 && context->calldata_sha3 == NULL) {
+            if (!init_calldata_digest(context)) {
+                return CUSTOM_FAULT;
+            }
+        }
         // If handling a new contract rather than a function call, abort immediately
         if (tmpContent.txContent.destinationLength == 0) {
             return CUSTOM_NOT_HANDLED;
@@ -134,6 +168,19 @@ customStatus_e custom_processor(txContext_t *context) {
 
         if (context->currentFieldPos == context->currentFieldLength) {
             PRINTF("\n\nIncrementing one\n");
+            // Finalize calldata digest if we were hashing
+            if (context->calldata_sha3 != NULL) {
+                if (cx_hash_no_throw((cx_hash_t *) context->calldata_sha3,
+                                     CX_LAST,
+                                     NULL,
+                                     0,
+                                     context->calldataDigest,
+                                     sizeof(context->calldataDigest)) != CX_OK) {
+                    return CUSTOM_FAULT;
+                }
+                context->calldataDigestValid = context->content->dataPresent;
+                APP_MEM_FREE_AND_NULL((void **) &context->calldata_sha3);
+            }
             context->currentField++;
             context->processingField = false;
         }
@@ -505,6 +552,7 @@ __attribute__((noinline)) static uint16_t finalize_parsing_helper(const txContex
     }
 end:
     APP_MEM_FREE_AND_NULL((void **) &g_tx_hash_ctx);
+    APP_MEM_FREE_AND_NULL((void **) &txContext.calldata_sha3);
     return error;
 }
 

src/nbgl/ui_approve_tx.c

@@ -234,6 +234,20 @@ static bool setTagValuePairs(bool displayNetwork, bool fromPlugin) {
                 nbPairs++;
             }
         }
+
+        // Display the Calldata Digest
+        // ----------------------------
+        if (txContext.calldataDigestValid) {
+            strlcpy(strings.common.calldata_digest, "0x", 3);
+            if (bytes_to_lowercase_hex(strings.common.calldata_digest + 2,
+                                       sizeof(strings.common.calldata_digest) - 2,
+                                       txContext.calldataDigest,
+                                       INT256_LENGTH) >= 0) {
+                g_pairs[nbPairs].item = "Calldata Digest";
+                g_pairs[nbPairs].value = strings.common.calldata_digest;
+                nbPairs++;
+            }
+        }
     }
     return true;
 }
@@ -290,6 +304,10 @@ static uint8_t getNbPairs(bool displayNetwork, bool fromPlugin) {
         if ((N_storage.displayHash) || (tmpContent.txContent.dataPresent)) {
             nbPairs++;
         }
+        // Count the Calldata Digest
+        if (txContext.calldataDigestValid) {
+            nbPairs++;
+        }
     }
     return nbPairs;
 }

src/nbgl/ui_sign_712.c

@@ -98,8 +98,8 @@ uint16_t ui_sign_712_v0(void) {
         return sw;
     }
 
-    // Initialize the buffers
-    if (!ui_pairs_init(2)) {
+    // Initialize the buffers (3 pairs: EIP-712 Digest, Domain Hash, Message Hash)
+    if (!ui_pairs_init(3)) {
         // Initialization failed, cleanup and return
         return SWO_INSUFFICIENT_MEMORY;
     }

src/shared_context.h

@@ -98,6 +98,7 @@ typedef struct messageSigningContext712_t {
     bip32_path_t bip32;
     uint8_t domainHash[INT256_LENGTH];
     uint8_t messageHash[INT256_LENGTH];
+    uint8_t eip712Digest[INT256_LENGTH];
 } messageSigningContext712_t;
 
 typedef struct authSigningContext7702_t {
@@ -145,6 +146,7 @@ typedef struct txStringProperties_s {
     char nonce[8];  // 10M tx per account ought to be enough for everybody
     char network_name[NETWORK_STRING_MAX_SIZE + 1];
     char tx_hash[2 + (INT256_LENGTH * 2) + 1];
+    char calldata_digest[2 + (INT256_LENGTH * 2) + 1];
 } txStringProperties_t;
 
 #define SHARED_CTX_FIELD_1_SIZE 380