From: Aki Tuomi <aki.tuomi@open-xchange.com>
Date: Thu, 21 May 2026 08:00:56 +0000 (+0300)
Subject: [PATCH 4/6] lib-var-expand: Change escape func signature to return int with error_r
X-Git-Tag: archive/raspbian/1%2.4.1+dfsg1-6+rpi1+deb13u7^2~80
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=42f88afe333ea25df2a35cadba9a91a647b24b6e;p=dovecot.git

[PATCH 4/6] lib-var-expand: Change escape func signature to return int with error_r

Wire error propagation in var_expand_program_execute_one_real() so a
failing escape function causes the expansion to return -1.

Update all implementations (passdb-sql, userdb-sql, db-ldap, dict-ldap,
auth-request-var-expand) and replace the unsafe auth_request_escape_func_t
cast in auth-request-var-expand.c with a proper bridge wrapper.

Gbp-Pq: Name 0004-lib-var-expand-Change-escape-func-signature-to-retur.patch
---

diff --git a/src/auth/auth-request-var-expand.c b/src/auth/auth-request-var-expand.c
index e101c8d..410ec0b 100644
--- a/src/auth/auth-request-var-expand.c
+++ b/src/auth/auth-request-var-expand.c
@@ -55,6 +55,15 @@ escape_none(const char *string,
 	return string;
 }
 
+static int
+auth_request_escape_wrapper(const char *input, const char **output_r,
+			    void *context, const char **error_r ATTR_UNUSED)
+{
+	const struct auth_request_var_expand_ctx *ctx = context;
+	*output_r = ctx->escape_func(input, ctx->auth_request);
+	return 0;
+}
+
 const char *
 auth_request_str_escape(const char *string,
 			const struct auth_request *request ATTR_UNUSED)
@@ -242,9 +251,9 @@ int auth_request_var_expand_with_table(string_t *dest, const char *str,
 	const struct var_expand_params params = {
 		.table = table,
 		.providers = auth_request_var_expand_providers,
-		.escape_func = (var_expand_escape_func_t *)ctx.escape_func,
+		.escape_func = auth_request_escape_wrapper,
 		.context = &ctx,
-		.escape_context = (void *)auth_request,
+		.escape_context = &ctx,
 		.event = auth_request->event,
 	};
 
diff --git a/src/auth/db-ldap.c b/src/auth/db-ldap.c
index 8eda924..9bf7998 100644
--- a/src/auth/db-ldap.c
+++ b/src/auth/db-ldap.c
@@ -1138,7 +1138,8 @@ void db_ldap_get_attribute_names(pool_t pool,
 		*sensitive_r = array_front(&sensitive_attr_names);
 }
 
-const char *ldap_escape(const char *input, void *context ATTR_UNUSED)
+int ldap_escape(const char *input, const char **output_r,
+		void *context ATTR_UNUSED, const char **error_r ATTR_UNUSED)
 {
 	/* This function escapes both LDAP filters and LDAP DNs. This works,
 	   because both allow using the method of escaping any characters.
@@ -1195,8 +1196,10 @@ const char *ldap_escape(const char *input, void *context ATTR_UNUSED)
 			   (required by DN) */
 			if (pos > 0 && input[pos - 1] == ' ')
 				pos--;
-			else
-				return input;
+			else {
+				*output_r = input;
+				return 0;
+			}
 		}
 	}
 
@@ -1211,7 +1214,8 @@ const char *ldap_escape(const char *input, void *context ATTR_UNUSED)
 			pos--;
 	} while (pos < input_len);
 	str_append_data(str, input, pos);
-	return str_c(str);
+	*output_r = str_c(str);
+	return 0;
 }
 
 static bool
diff --git a/src/auth/db-ldap.h b/src/auth/db-ldap.h
index a6aac02..3686ab8 100644
--- a/src/auth/db-ldap.h
+++ b/src/auth/db-ldap.h
@@ -169,8 +169,8 @@ void db_ldap_connect_delayed(struct ldap_connection *conn);
 
 void db_ldap_enable_input(struct ldap_connection *conn, bool enable);
 
-const char *ldap_dn_escape(const char *str, void *context);
-const char *ldap_escape(const char *str, void *context);
+int ldap_dn_escape(const char *str, const char **output_r, void *context, const char **error_r);
+int ldap_escape(const char *str, const char **output_r, void *context, const char **error_r);
 const char *ldap_get_error(struct ldap_connection *conn);
 
 struct db_ldap_result_iterate_context *
diff --git a/src/auth/passdb-sql.c b/src/auth/passdb-sql.c
index ec160e3..3745942 100644
--- a/src/auth/passdb-sql.c
+++ b/src/auth/passdb-sql.c
@@ -167,10 +167,12 @@ static void sql_query_callback(struct sql_result *result,
 	auth_request_unref(&auth_request);
 }
 
-static const char *passdb_sql_escape(const char *str, void *context)
+static int passdb_sql_escape(const char *str, const char **output_r,
+			     void *context, const char **error_r ATTR_UNUSED)
 {
 	struct sql_db *db = context;
-	return sql_escape_string(db, str);
+	*output_r = sql_escape_string(db, str);
+	return 0;
 }
 
 static void sql_lookup_pass(struct passdb_sql_request *sql_request)
diff --git a/src/auth/test-auth-request-var-expand.c b/src/auth/test-auth-request-var-expand.c
index 851e365..75236bb 100644
--- a/src/auth/test-auth-request-var-expand.c
+++ b/src/auth/test-auth-request-var-expand.c
@@ -70,6 +70,14 @@ test_escape(const char *string, const struct auth_request *request)
 	return dest;
 }
 
+static int
+test_escape_varexpand(const char *string, const char **output_r,
+		      void *context, const char **error_r ATTR_UNUSED)
+{
+	*output_r = test_escape(string, context);
+	return 0;
+}
+
 static bool test_empty_request(string_t *str, const char *input)
 {
 	const struct var_expand_params params = {
@@ -102,7 +110,7 @@ static void test_auth_request_var_expand_keys(void)
 
 	const struct var_expand_params params = {
 		.table = auth_request_get_var_expand_table(&test_request),
-		.escape_func = (var_expand_escape_func_t *)test_escape,
+		.escape_func = test_escape_varexpand,
 		.escape_context = &test_request,
 	};
 
@@ -129,7 +137,7 @@ static void test_auth_request_var_expand_flags(void)
 
 	struct var_expand_params params = {
 		.table = auth_request_get_var_expand_table(&test_request),
-		.escape_func = (var_expand_escape_func_t *)test_escape,
+		.escape_func = test_escape_varexpand,
 		.escape_context = &test_request
 	};
 	test_assert(var_expand(str, test_input, &params, &error) == 0);
@@ -169,7 +177,7 @@ static void test_auth_request_var_expand_long(void)
 
 	const struct var_expand_params params = {
 		.table = auth_request_get_var_expand_table(&test_request),
-		.escape_func = (var_expand_escape_func_t *)test_escape,
+		.escape_func = test_escape_varexpand,
 		.escape_context = &test_request,
 	};
 
@@ -200,7 +208,7 @@ static void test_auth_request_var_expand_usernames(void)
 		test_request.fields.user = t_strdup_noconst(tests[i].username);
 		const struct var_expand_params params = {
 			.table = auth_request_get_var_expand_table(&test_request),
-			.escape_func = (var_expand_escape_func_t *)test_escape,
+			.escape_func = test_escape_varexpand,
 			.escape_context = &test_request,
 		};
 		str_truncate(str, 0);
diff --git a/src/auth/test-ldap.c b/src/auth/test-ldap.c
index cd9904a..4557306 100644
--- a/src/auth/test-ldap.c
+++ b/src/auth/test-ldap.c
@@ -25,8 +25,9 @@ static void test_ldap_escape(void)
 	};
 	test_begin("ldap_escape()");
 	for (unsigned int i = 0; i < N_ELEMENTS(tests); i++) {
-		test_assert_strcmp_idx(ldap_escape(tests[i].input, NULL),
-				       tests[i].output, i);
+		const char *output, *error;
+		test_assert(ldap_escape(tests[i].input, &output, NULL, &error) == 0);
+		test_assert_strcmp_idx(output, tests[i].output, i);
 	}
 	test_end();
 }
diff --git a/src/auth/userdb-sql.c b/src/auth/userdb-sql.c
index 09bac48..39caf38 100644
--- a/src/auth/userdb-sql.c
+++ b/src/auth/userdb-sql.c
@@ -112,10 +112,12 @@ static void sql_query_callback(struct sql_result *sql_result,
 	i_free(sql_request);
 }
 
-static const char *userdb_sql_escape(const char *str, void *context)
+static int userdb_sql_escape(const char *str, const char **output_r,
+			     void *context, const char **error_r ATTR_UNUSED)
 {
 	struct sql_db *db = context;
-	return sql_escape_string(db, str);
+	*output_r = sql_escape_string(db, str);
+	return 0;
 }
 
 static void userdb_sql_lookup(struct auth_request *auth_request,
diff --git a/src/lib-dict-backend/dict-ldap.c b/src/lib-dict-backend/dict-ldap.c
index 81eed29..c3420f8 100644
--- a/src/lib-dict-backend/dict-ldap.c
+++ b/src/lib-dict-backend/dict-ldap.c
@@ -139,7 +139,8 @@ int dict_ldap_connect(struct ldap_dict *dict, const char **error_r)
 #define IS_LDAP_ESCAPED_CHAR(c) \
 	((((unsigned char)(c)) & 0x80) != 0 || strchr(LDAP_ESCAPE_CHARS, (c)) != NULL)
 
-static const char *ldap_escape(const char *str, void *context ATTR_UNUSED)
+static int ldap_escape(const char *str, const char **output_r,
+		       void *context ATTR_UNUSED, const char **error_r ATTR_UNUSED)
 {
 	string_t *ret = NULL;
 
@@ -154,7 +155,8 @@ static const char *ldap_escape(const char *str, void *context ATTR_UNUSED)
 			str_append_c(ret, *p);
 	}
 
-	return ret == NULL ? str : str_c(ret);
+	*output_r = ret == NULL ? str : str_c(ret);
+	return 0;
 }
 
 static
diff --git a/src/lib-var-expand/expansion-program.c b/src/lib-var-expand/expansion-program.c
index 6a05bc3..7fc591d 100644
--- a/src/lib-var-expand/expansion-program.c
+++ b/src/lib-var-expand/expansion-program.c
@@ -142,9 +142,11 @@ int var_expand_program_execute(string_t *dest, const struct var_expand_program *
 		if (state.transfer_set) {
 			if (!program->only_literal && !state.transfer_safe &&
 			    params->escape_func != NULL) {
-				str_append(state.result,
-					   params->escape_func(str_c(state.transfer),
-							       params->escape_context));
+				const char *escaped;
+				if (params->escape_func(str_c(state.transfer), &escaped,
+							params->escape_context, error_r) < 0)
+					return -1;
+				str_append(state.result, escaped);
 			} else
 				str_append_str(state.result, state.transfer);
 		} else {
diff --git a/src/lib-var-expand/test-var-expand.c b/src/lib-var-expand/test-var-expand.c
index 3fa9c68..a66b3e8 100644
--- a/src/lib-var-expand/test-var-expand.c
+++ b/src/lib-var-expand/test-var-expand.c
@@ -586,7 +586,8 @@ static void test_var_expand_tables_arr(void)
 	test_end();
 }
 
-static const char *test_escape(const char *str, void *context)
+static int test_escape(const char *str, const char **output_r,
+		       void *context, const char **error_r ATTR_UNUSED)
 {
 	const char *escape_chars = context;
 	string_t *dest = t_str_new(strlen(str) + 2);
@@ -601,7 +602,8 @@ static const char *test_escape(const char *str, void *context)
 		}
 	}
 	str_append_c(dest, '\'');
-	return str_c(dest);
+	*output_r = str_c(dest);
+	return 0;
 }
 
 static void test_var_expand_escape(void)
diff --git a/src/lib-var-expand/var-expand.h b/src/lib-var-expand/var-expand.h
index 58aea4e..1633025 100644
--- a/src/lib-var-expand/var-expand.h
+++ b/src/lib-var-expand/var-expand.h
@@ -11,9 +11,10 @@
 */
 typedef int value_provider_func_t(const char *key, const char **value_r,
 				  void *context, const char **error_r);
-/* Used for escaping values, gets given string to escape and context,
-   must return escaped string. */
-typedef const char *var_expand_escape_func_t(const char *str, void *context);
+/* Used for escaping values. On success sets output_r and returns 0.
+   On failure sets error_r and returns -1. */
+typedef int var_expand_escape_func_t(const char *input, const char **output_r,
+				     void *context, const char **error_r);
 
 struct var_expand_parser_state;
 struct var_expand_program;