Add in function to read a mnemonic from stdin

Author: sangbida

common/Makefile

@@ -46,6 +46,7 @@ COMMON_SRC_NOGEN :=				\
 	common/hmac.c				\
 	common/hsm_capable.c			\
 	common/hsm_encryption.c			\
+	common/hsm_secret.c			\
 	common/htlc_state.c			\
 	common/htlc_trim.c			\
 	common/htlc_tx.c			\

common/hsm_secret.c

@@ -440,6 +440,48 @@ const char *read_stdin_pass(const tal_t *ctx, enum hsm_secret_error *err)
 	return passphrase;
 }
 
+/* Add this function to hsm_secret.c */
+const char *read_stdin_mnemonic(const tal_t *ctx, enum hsm_secret_error *err)
+{
+	*err = HSM_SECRET_OK;
+
+	printf("Introduce your BIP39 word list separated by space (at least 12 words):\n");
+	fflush(stdout);
+
+	char *line = NULL;
+	size_t size = 0;
+	if (getline(&line, &size, stdin) < 0) {
+		free(line);
+		*err = HSM_SECRET_ERR_INVALID_FORMAT;
+		return NULL;
+	}
+
+	/* Strip newline */
+	size_t len = strlen(line);
+	if (len > 0 && line[len - 1] == '\n')
+		line[len - 1] = '\0';
+
+	/* Validate mnemonic */
+	struct words *words;
+	if (bip39_get_wordlist("en", &words) != WALLY_OK) {
+		free(line);
+		*err = HSM_SECRET_ERR_WORDLIST_FAILED;
+		return NULL;
+	}
+
+	if (bip39_mnemonic_validate(words, line) != WALLY_OK) {
+		free(line);
+		*err = HSM_SECRET_ERR_INVALID_MNEMONIC;
+		return NULL;
+	}
+
+	/* Convert to tal string */
+	char *mnemonic = tal_strdup(ctx, line);
+	free(line);
+
+	return mnemonic;
+}
+
 
 
 

common/hsm_secret.h

@@ -143,4 +143,14 @@ enum hsm_secret_type detect_hsm_secret_type(const u8 *hsm_secret, size_t len);
  */
 bool validate_mnemonic_passphrase(const u8 *hsm_secret, size_t len, const char *passphrase);
 
+/**
+ * Reads a BIP39 mnemonic from stdin with validation.
+ * Returns a newly allocated string on success, NULL on error.
+ * @ctx - tal context for allocation
+ * @err - optional pointer to set error code on failure
+ * 
+ * Returns tal-allocated mnemonic string or NULL on error.
+ */
+const char *read_stdin_mnemonic(const tal_t *ctx, enum hsm_secret_error *err);
+
 #endif /* LIGHTNING_COMMON_HSM_SECRET_H */

tools/hsmtool.c

@@ -451,64 +451,25 @@ static int guess_to_remote(const char *address, struct node_id *node_id,
 	return 1;
 }
 
-static char *get_mnemonic(void) {
-	char *line = NULL;
-	size_t line_size = 0;
-
-	printf("Introduce your BIP39 word list separated by space (at least 12 words):\n");
-	fflush(stdout);
-	size_t characters = getline(&line, &line_size, stdin);
-	if (characters < 0)
-		errx(ERROR_USAGE, "Could not read line from stdin.");
-	line[characters-1] = '\0';
-	return line;
-}
-
-static char *read_mnemonic(void) {
-	char *mnemonic;
-	struct words *words;
-
-	/* Get English wordlist */
-	if (bip39_get_wordlist("en", &words) != WALLY_OK)
-		errx(ERROR_LIBWALLY, "Could not load English wordlist");
-
-	/* Get mnemonic from user */
-	mnemonic = get_mnemonic();
-
-	/* Validate mnemonic */
-	if (bip39_mnemonic_validate(words, mnemonic) != WALLY_OK) {
-		errx(ERROR_USAGE, "Invalid mnemonic: \"%s\"", mnemonic);
-	}
-	return mnemonic;
-}
-
 static int generate_hsm(const char *hsm_secret_path)
 {
-	char *mnemonic;
-	const char *passphrase;
-	struct words *words;
-	enum hsm_secret_error pass_err;
-
-	/* Get English wordlist */
-	if (bip39_get_wordlist("en", &words) != WALLY_OK)
-		errx(ERROR_LIBWALLY, "Could not load English wordlist");
-
-	/* Get mnemonic from user */
-	mnemonic = get_mnemonic();
+	const char *mnemonic, *passphrase;
+	enum hsm_secret_error err;
 
-	/* Validate mnemonic */
-	if (bip39_mnemonic_validate(words, mnemonic) != WALLY_OK)
-		errx(ERROR_USAGE, "Invalid mnemonic: \"%s\"", mnemonic);
+	/* Get mnemonic from user using consistent interface */
+	mnemonic = read_stdin_mnemonic(tmpctx, &err);
+	if (!mnemonic)
+		errx(EXITCODE_ERROR_HSM_FILE, "Could not read mnemonic: %s", hsm_secret_error_str(err));
 
 	/* Get optional passphrase */
 	printf("Warning: remember that different passphrases yield different "
 	       "bitcoin wallets.\n");
 	printf("If left empty, no password is used (echo is disabled).\n");
 	printf("Enter your passphrase: \n");
 	fflush(stdout);
-	passphrase = read_stdin_pass(tmpctx, &pass_err);
+	passphrase = read_stdin_pass(tmpctx, &err);
 	if (!passphrase)
-		errx(EXITCODE_ERROR_HSM_FILE, "Could not read passphrase: %s", hsm_secret_error_str(pass_err));
+		errx(EXITCODE_ERROR_HSM_FILE, "Could not read passphrase: %s", hsm_secret_error_str(err));
 	if (strlen(passphrase) == 0) {
 		passphrase = NULL;
 	}
@@ -549,8 +510,7 @@ static int generate_hsm(const char *hsm_secret_path)
 		printf("Remember your passphrase - it's required to use this hsm_secret!\n");
 	}
 
-	free(mnemonic);
-	/* passphrase will be automatically cleaned up by tmpctx */
+	/* passphrase and mnemonic will be automatically cleaned up by tmpctx */
 	return 0;
 }
 
@@ -617,39 +577,55 @@ static int dumponchaindescriptors(const char *hsm_secret_path,
 
 static int check_hsm(const char *hsm_secret_path)
 {
-	char *mnemonic;
-	struct secret hsm_secret;
+	struct secret file_secret, derived_secret;
 	u8 bip32_seed[BIP39_SEED_LEN_512];
 	size_t bip32_seed_len;
-	const char *passphrase;
-	enum hsm_secret_error pass_err;
+	const char *passphrase, *mnemonic;
+	enum hsm_secret_error err;
 
-	get_hsm_seed(&hsm_secret, hsm_secret_path);
+	/* Check what type of hsm_secret we're dealing with */
+	u8 *contents = grab_file(tmpctx, hsm_secret_path);
+	if (!contents)
+		errx(EXITCODE_ERROR_HSM_FILE, "Reading hsm_secret");
+	tal_resize(&contents, tal_bytelen(contents) - 1);
+	
+	enum hsm_secret_type type = detect_hsm_secret_type(contents, tal_bytelen(contents));
 
+	/* Get the actual seed from the file */
+	get_hsm_seed(&file_secret, hsm_secret_path);
+
+	/* Ask user for their BIP39 backup passphrase */
 	printf("Warning: remember that different passphrases yield different "
 	       "bitcoin wallets.\n");
 	printf("If left empty, no password is used (echo is disabled).\n");
 	printf("Enter your passphrase: \n");
 	fflush(stdout);
-	passphrase = read_stdin_pass(tmpctx, &pass_err);
+	passphrase = read_stdin_pass(tmpctx, &err);
 	if (!passphrase)
-		errx(EXITCODE_ERROR_HSM_FILE, "Could not read passphrase: %s", hsm_secret_error_str(pass_err));
+		errx(EXITCODE_ERROR_HSM_FILE, "Could not read passphrase: %s", hsm_secret_error_str(err));
 	if (strlen(passphrase) == 0) {
 		passphrase = NULL;
 	}
 
-	mnemonic = read_mnemonic();
+	/* Ask user for their backup mnemonic using consistent interface */
+	mnemonic = read_stdin_mnemonic(tmpctx, &err);
+	if (!mnemonic)
+		errx(EXITCODE_ERROR_HSM_FILE, "Could not read mnemonic: %s", hsm_secret_error_str(err));
+	
+	/* Derive seed from user's backup mnemonic + passphrase */
 	if (bip39_mnemonic_to_seed(mnemonic, passphrase, bip32_seed, sizeof(bip32_seed), &bip32_seed_len) != WALLY_OK)
 		errx(ERROR_LIBWALLY, "Unable to derive BIP32 seed from BIP39 mnemonic");
 
-	/* We only use first 32 bytes */
-	if (memcmp(bip32_seed, hsm_secret.data, sizeof(hsm_secret.data)) != 0)
+	/* Copy first 32 bytes to our secret for comparison */
+	memcpy(derived_secret.data, bip32_seed, sizeof(derived_secret.data));
+
+	/* Compare the seeds - this works for all formats */
+	if (memcmp(derived_secret.data, file_secret.data, sizeof(file_secret.data)) != 0)
 		errx(ERROR_KEYDERIV, "resulting hsm_secret did not match");
 
 	printf("OK\n");
 
-	free(mnemonic);
-	/* passphrase will be automatically cleaned up by tmpctx */
+	/* passphrase and mnemonic will be automatically cleaned up by tmpctx */
 	return 0;
 }