Use ASCII chars in Content-Disposition filename parameter

Prior to this commit, gh-36328 avoided using RFC 2047 encoding for the
"filename" parameter and use ISO-8859-1 only. This change unfortunately
caused issues because some implementations might try and detect the
encoding automatically.

This commit restricts the filename parameter to ASCII encoding only by:
* transliterating characters to the closes ASCII character
("é"->"e", "ä"->"ae"...)
* falling back to "_" for other chacacters with non latin alphabet or
  emojis

Closes gh-37062
This commit is contained in:
Brian Clozel
2026-07-16 19:21:16 +02:00
parent a2feb9ffe6
commit 8fb2f72282
2 changed files with 382 additions and 305 deletions
@@ -19,6 +19,7 @@ package org.springframework.http;
import java.nio.charset.StandardCharsets;
import java.util.function.BiConsumer;
import org.junit.jupiter.api.Nested;
import org.junit.jupiter.api.Test;
import static org.assertj.core.api.Assertions.assertThat;
@@ -30,293 +31,10 @@ import static org.springframework.http.ContentDisposition.parse;
*
* @author Sebastien Deleuze
* @author Rossen Stoyanchev
* @author Brian Clozel
*/
class ContentDispositionTests {
@Test
void parseFilenameQuoted() {
assertThat(parse("form-data; name=\"foo\"; filename=\"foo.txt\""))
.isEqualTo(ContentDisposition.formData()
.name("foo")
.filename("foo.txt")
.build());
}
@Test
void parseFilenameUnquoted() {
assertThat(parse("form-data; filename=unquoted"))
.isEqualTo(ContentDisposition.formData()
.filename("unquoted")
.build());
}
@Test // SPR-16091
void parseFilenameWithSemicolon() {
assertThat(parse("attachment; filename=\"filename with ; semicolon.txt\""))
.isEqualTo(ContentDisposition.attachment()
.filename("filename with ; semicolon.txt")
.build());
}
@Test
void parseEncodedFilename() {
assertThat(parse("form-data; name=\"name\"; filename*=UTF-8''%E4%B8%AD%E6%96%87.txt"))
.isEqualTo(ContentDisposition.formData()
.name("name")
.filename("中文.txt", StandardCharsets.UTF_8)
.build());
}
@Test // gh-24112
void parseEncodedFilenameWithPaddedCharset() {
assertThat(parse("attachment; filename*= UTF-8''some-file.zip"))
.isEqualTo(ContentDisposition.attachment()
.filename("some-file.zip", StandardCharsets.UTF_8)
.build());
}
@Test // gh-26463
void parseBase64EncodedFilename() {
String input = "attachment; filename=\"=?UTF-8?B?5pel5pys6KqeLmNzdg==?=\"";
assertThat(parse(input).getFilename()).isEqualTo("日本語.csv");
}
@Test
void parseBase64EncodedFilenameMultipleSegments() {
String input =
"attachment; filename=\"=?utf-8?B?U3ByaW5n5qGG5p625Li65Z+65LqOSmF2YeeahOeOsOS7o+S8geS4muW6lA==?= " +
"=?utf-8?B?55So56iL5bqP5o+Q5L6b5LqG5YWo6Z2i55qE57yW56iL5ZKM6YWN572u5qih?= " +
"=?utf-8?B?5Z6LLnR4dA==?=\"";
assertThat(parse(input).getFilename()).isEqualTo("Spring框架为基于Java的现代企业应用程序提供了全面的编程和配置模型.txt");
}
@Test // gh-26463
void parseBase64EncodedShiftJISFilename() {
String input = "attachment; filename=\"=?SHIFT_JIS?B?k/qWe4zqLmNzdg==?=\"";
assertThat(parse(input).getFilename()).isEqualTo("日本語.csv");
}
@Test
void parseQuotedPrintableFilename() {
String input = "attachment; filename=\"=?UTF-8?Q?=E6=97=A5=E6=9C=AC=E8=AA=9E.csv?=\"";
assertThat(parse(input).getFilename()).isEqualTo("日本語.csv");
}
@Test
void parseQuotedPrintableFilenameMultipleSegments() {
String input =
"attachment; filename=\"=?utf-8?Q?Spring=E6=A1=86=E6=9E=B6=E4=B8=BA=E5=9F=BA=E4=BA=8E?=" +
"=?utf-8?Q?Java=E7=9A=84=E7=8E=B0=E4=BB=A3=E4=BC=81=E4=B8=9A=E5=BA=94?=" +
"=?utf-8?Q?=E7=94=A8=E7=A8=8B=E5=BA=8F=E6=8F=90=E4=BE=9B=E4=BA=86=E5=85=A8?=" +
"=?utf-8?Q?=E9=9D=A2=E7=9A=84=E7=BC=96=E7=A8=8B=E5=92=8C=E9=85=8D=E7=BD=AE?=" +
"=?utf-8?Q?=E6=A8=A1=E5=9E=8B.txt?=\"";
assertThat(parse(input).getFilename()).isEqualTo("Spring框架为基于Java的现代企业应用程序提供了全面的编程和配置模型.txt");
}
@Test
void parseQuotedPrintableShiftJISFilename() {
String input = "attachment; filename=\"=?SHIFT_JIS?Q?=93=FA=96{=8C=EA.csv?=\"";
assertThat(parse(input).getFilename()).isEqualTo("日本語.csv");
}
@Test
void parseEncodedFilenameWithoutCharset() {
assertThat(parse("form-data; name=\"name\"; filename*=test.txt"))
.isEqualTo(ContentDisposition.formData()
.name("name")
.filename("test.txt")
.build());
}
@Test
void parseEncodedFilenameWithInvalidCharset() {
assertThatIllegalArgumentException()
.isThrownBy(() -> parse("form-data; name=\"name\"; filename*=UTF-16''test.txt"));
}
@Test
void parseEncodedFilenameWithInvalidName() {
assertThatIllegalArgumentException()
.isThrownBy(() -> parse("form-data; name=\"name\"; filename*=UTF-8''%A"));
assertThatIllegalArgumentException()
.isThrownBy(() -> parse("form-data; name=\"name\"; filename*=UTF-8''%A.txt"));
}
@Test
void parseBackslash() {
String s = "form-data; name=\"foo\"; filename=\"foo\\\\bar \\\"baz\\\" qux \\\\\\\" quux.txt\"";
ContentDisposition cd = ContentDisposition.parse(
s);
assertThat(cd.getName()).isEqualTo("foo");
assertThat(cd.getFilename()).isEqualTo("foo\\bar \"baz\" qux \\\" quux.txt");
assertThat(cd.toString()).isEqualTo(s);
}
@Test
void parseBackslashInLastPosition() {
ContentDisposition cd = ContentDisposition.parse("form-data; name=\"foo\"; filename=\"bar\\\"");
assertThat(cd.getName()).isEqualTo("foo");
assertThat(cd.getFilename()).isEqualTo("bar\\");
assertThat(cd.toString()).isEqualTo("form-data; name=\"foo\"; filename=\"bar\\\\\"");
}
@Test
void parseWindowsPath() {
ContentDisposition cd = ContentDisposition.parse("form-data; name=\"foo\"; filename=\"D:\\foo\\bar.txt\"");
assertThat(cd.getName()).isEqualTo("foo");
assertThat(cd.getFilename()).isEqualTo("D:\\foo\\bar.txt");
assertThat(cd.toString()).isEqualTo("form-data; name=\"foo\"; filename=\"D:\\\\foo\\\\bar.txt\"");
}
@Test
void parseWithExtraSemicolons() {
assertThat(parse("form-data; name=\"foo\";; ; filename=\"foo.txt\";"))
.isEqualTo(ContentDisposition.formData()
.name("foo")
.filename("foo.txt")
.build());
}
@Test
void parseAttributesCaseInsensitively() {
ContentDisposition cd = ContentDisposition.parse("form-data; Name=\"foo\"; FileName=\"bar.txt\"");
assertThat(cd.getName()).isEqualTo("foo");
assertThat(cd.getFilename()).isEqualTo("bar.txt");
assertThat(cd.toString()).isEqualTo("form-data; name=\"foo\"; filename=\"bar.txt\"");
}
@Test
void parseEmpty() {
assertThatIllegalArgumentException().isThrownBy(() -> parse(""));
}
@Test
void parseNoType() {
assertThatIllegalArgumentException().isThrownBy(() -> parse(";"));
}
@Test
void parseInvalidParameter() {
assertThatIllegalArgumentException().isThrownBy(() -> parse("foo;bar"));
}
@Test
void format() {
assertThat(
ContentDisposition.formData()
.name("foo")
.filename("foo.txt")
.build().toString())
.isEqualTo("form-data; name=\"foo\"; filename=\"foo.txt\"");
}
@Test
void formatWithEncodedFilename() {
assertThat(
ContentDisposition.formData()
.name("name")
.filename("中文.txt", StandardCharsets.UTF_8)
.build().toString())
.isEqualTo("form-data; name=\"name\"; " +
"filename=\"__.txt\"; " +
"filename*=UTF-8''%E4%B8%AD%E6%96%87.txt");
}
@Test
void formatWithEncodedFilenameUsingUsAscii() {
assertThat(
ContentDisposition.formData()
.name("name")
.filename("test.txt", StandardCharsets.US_ASCII)
.build()
.toString())
.isEqualTo("form-data; name=\"name\"; filename=\"test.txt\"");
}
@Test // gh-24220
void formatWithFilenameWithQuotes() {
BiConsumer<String, String> tester = (input, output) -> {
assertThat(ContentDisposition.formData().filename(input).build().toString())
.isEqualTo("form-data; filename=\"" + output + "\"");
assertThat(ContentDisposition.formData().filename(input, StandardCharsets.US_ASCII).build().toString())
.isEqualTo("form-data; filename=\"" + output + "\"");
};
String filename = "\"foo.txt";
tester.accept(filename, "\\\"foo.txt");
filename = "\\\"foo.txt";
tester.accept(filename, "\\\\\\\"foo.txt");
filename = "\\\\\"foo.txt";
tester.accept(filename, "\\\\\\\\\\\"foo.txt");
filename = "\\\\\\\"foo.txt";
tester.accept(filename, "\\\\\\\\\\\\\\\"foo.txt");
filename = "\\\\\\\\\"foo.txt";
tester.accept(filename, "\\\\\\\\\\\\\\\\\\\"foo.txt");
tester.accept("\"\"foo.txt", "\\\"\\\"foo.txt");
tester.accept("\"\"\"foo.txt", "\\\"\\\"\\\"foo.txt");
tester.accept("foo.txt\\", "foo.txt\\\\");
tester.accept("foo.txt\\\\", "foo.txt\\\\\\\\");
tester.accept("foo.txt\\\\\\", "foo.txt\\\\\\\\\\\\");
}
@Test
void formatWithUtf8FilenameWithQuotes() {
String filename = "\"中文.txt";
assertThat(ContentDisposition.formData().filename(filename, StandardCharsets.UTF_8).build().toString())
.isEqualTo("form-data; filename=\"\\\"__.txt\"; filename*=UTF-8''%22%E4%B8%AD%E6%96%87.txt");
}
@Test
void formatWithEncodedFilenameUsingInvalidCharset() {
assertThatIllegalArgumentException().isThrownBy(() ->
ContentDisposition.formData()
.name("name")
.filename("test.txt", StandardCharsets.UTF_16)
.build()
.toString());
}
@Test
void parseFormatted() {
ContentDisposition cd = ContentDisposition.builder("form-data")
.name("foo")
.filename("foo\\bar \"baz\" qux \\\" quux.txt").build();
ContentDisposition parsed = ContentDisposition.parse(cd.toString());
assertThat(parsed).isEqualTo(cd);
assertThat(parsed.toString()).isEqualTo(cd.toString());
}
@Test // gh-30252
void parseFormattedWithQuestionMark() {
String filename = "filename with ?问号.txt";
ContentDisposition cd = ContentDisposition.attachment()
.filename(filename, StandardCharsets.UTF_8)
.build();
String result = cd.toString();
assertThat(result).isEqualTo("attachment; " +
"filename=\"filename with ?__.txt\"; " +
"filename*=UTF-8''filename%20with%20%3F%E9%97%AE%E5%8F%B7.txt");
String[] parts = result.split("; ");
String quotedPrintableFilename = parts[0] + "; " + parts[1];
assertThat(ContentDisposition.parse(quotedPrintableFilename).getFilename())
.isEqualTo("filename with ?__.txt");
String rfc5987Filename = parts[0] + "; " + parts[2];
assertThat(ContentDisposition.parse(rfc5987Filename).getFilename())
.isEqualTo(filename);
}
@Test
void attachmentType(){
ContentDisposition attachment = ContentDisposition.attachment().build();
@@ -341,4 +59,307 @@ class ContentDispositionTests {
assertThat(inline.isInline()).isTrue();
}
@Nested
class ParsingTests {
@Test
void parseFilenameQuoted() {
assertThat(parse("form-data; name=\"foo\"; filename=\"foo.txt\""))
.isEqualTo(ContentDisposition.formData()
.name("foo")
.filename("foo.txt")
.build());
}
@Test
void parseFilenameUnquoted() {
assertThat(parse("form-data; filename=unquoted"))
.isEqualTo(ContentDisposition.formData()
.filename("unquoted")
.build());
}
@Test // SPR-16091
void parseFilenameWithSemicolon() {
assertThat(parse("attachment; filename=\"filename with ; semicolon.txt\""))
.isEqualTo(ContentDisposition.attachment()
.filename("filename with ; semicolon.txt")
.build());
}
@Test
void parseEncodedFilename() {
assertThat(parse("form-data; name=\"name\"; filename*=UTF-8''%E4%B8%AD%E6%96%87.txt"))
.isEqualTo(ContentDisposition.formData()
.name("name")
.filename("中文.txt", StandardCharsets.UTF_8)
.build());
}
@Test // gh-24112
void parseEncodedFilenameWithPaddedCharset() {
assertThat(parse("attachment; filename*= UTF-8''some-file.zip"))
.isEqualTo(ContentDisposition.attachment()
.filename("some-file.zip", StandardCharsets.UTF_8)
.build());
}
@Test // gh-26463
void parseBase64EncodedFilename() {
String input = "attachment; filename=\"=?UTF-8?B?5pel5pys6KqeLmNzdg==?=\"";
assertThat(parse(input).getFilename()).isEqualTo("日本語.csv");
}
@Test
void parseBase64EncodedFilenameMultipleSegments() {
String input =
"attachment; filename=\"=?utf-8?B?U3ByaW5n5qGG5p625Li65Z+65LqOSmF2YeeahOeOsOS7o+S8geS4muW6lA==?= " +
"=?utf-8?B?55So56iL5bqP5o+Q5L6b5LqG5YWo6Z2i55qE57yW56iL5ZKM6YWN572u5qih?= " +
"=?utf-8?B?5Z6LLnR4dA==?=\"";
assertThat(parse(input).getFilename()).isEqualTo("Spring框架为基于Java的现代企业应用程序提供了全面的编程和配置模型.txt");
}
@Test // gh-26463
void parseBase64EncodedShiftJISFilename() {
String input = "attachment; filename=\"=?SHIFT_JIS?B?k/qWe4zqLmNzdg==?=\"";
assertThat(parse(input).getFilename()).isEqualTo("日本語.csv");
}
@Test
void parseQuotedPrintableFilename() {
String input = "attachment; filename=\"=?UTF-8?Q?=E6=97=A5=E6=9C=AC=E8=AA=9E.csv?=\"";
assertThat(parse(input).getFilename()).isEqualTo("日本語.csv");
}
@Test
void parseQuotedPrintableFilenameMultipleSegments() {
String input =
"attachment; filename=\"=?utf-8?Q?Spring=E6=A1=86=E6=9E=B6=E4=B8=BA=E5=9F=BA=E4=BA=8E?=" +
"=?utf-8?Q?Java=E7=9A=84=E7=8E=B0=E4=BB=A3=E4=BC=81=E4=B8=9A=E5=BA=94?=" +
"=?utf-8?Q?=E7=94=A8=E7=A8=8B=E5=BA=8F=E6=8F=90=E4=BE=9B=E4=BA=86=E5=85=A8?=" +
"=?utf-8?Q?=E9=9D=A2=E7=9A=84=E7=BC=96=E7=A8=8B=E5=92=8C=E9=85=8D=E7=BD=AE?=" +
"=?utf-8?Q?=E6=A8=A1=E5=9E=8B.txt?=\"";
assertThat(parse(input).getFilename()).isEqualTo("Spring框架为基于Java的现代企业应用程序提供了全面的编程和配置模型.txt");
}
@Test
void parseQuotedPrintableShiftJISFilename() {
String input = "attachment; filename=\"=?SHIFT_JIS?Q?=93=FA=96{=8C=EA.csv?=\"";
assertThat(parse(input).getFilename()).isEqualTo("日本語.csv");
}
@Test
void parseEncodedFilenameWithoutCharset() {
assertThat(parse("form-data; name=\"name\"; filename*=test.txt"))
.isEqualTo(ContentDisposition.formData()
.name("name")
.filename("test.txt")
.build());
}
@Test
void parseEncodedFilenameWithInvalidCharset() {
assertThatIllegalArgumentException()
.isThrownBy(() -> parse("form-data; name=\"name\"; filename*=UTF-16''test.txt"));
}
@Test
void parseEncodedFilenameWithInvalidName() {
assertThatIllegalArgumentException()
.isThrownBy(() -> parse("form-data; name=\"name\"; filename*=UTF-8''%A"));
assertThatIllegalArgumentException()
.isThrownBy(() -> parse("form-data; name=\"name\"; filename*=UTF-8''%A.txt"));
}
@Test
void parseBackslash() {
String s = "form-data; name=\"foo\"; filename=\"foo\\\\bar \\\"baz\\\" qux \\\\\\\" quux.txt\"";
ContentDisposition cd = ContentDisposition.parse(s);
assertThat(cd.getName()).isEqualTo("foo");
assertThat(cd.getFilename()).isEqualTo("foo\\bar \"baz\" qux \\\" quux.txt");
}
@Test
void parseBackslashInLastPosition() {
ContentDisposition cd = ContentDisposition.parse("form-data; name=\"foo\"; filename=\"bar\\\"");
assertThat(cd.getName()).isEqualTo("foo");
assertThat(cd.getFilename()).isEqualTo("bar\\");
assertThat(cd.toString()).isEqualTo("form-data; name=\"foo\"; filename=\"bar\\\\\"");
}
@Test
void parseWindowsPath() {
ContentDisposition cd = ContentDisposition.parse("form-data; name=\"foo\"; filename=\"D:\\foo\\bar.txt\"");
assertThat(cd.getName()).isEqualTo("foo");
assertThat(cd.getFilename()).isEqualTo("D:\\foo\\bar.txt");
assertThat(cd.toString()).isEqualTo("form-data; name=\"foo\"; filename=\"D:\\\\foo\\\\bar.txt\"");
}
@Test
void parseWithExtraSemicolons() {
assertThat(parse("form-data; name=\"foo\";; ; filename=\"foo.txt\";"))
.isEqualTo(ContentDisposition.formData()
.name("foo")
.filename("foo.txt")
.build());
}
@Test
void parseAttributesCaseInsensitively() {
ContentDisposition cd = ContentDisposition.parse("form-data; Name=\"foo\"; FileName=\"bar.txt\"");
assertThat(cd.getName()).isEqualTo("foo");
assertThat(cd.getFilename()).isEqualTo("bar.txt");
assertThat(cd.toString()).isEqualTo("form-data; name=\"foo\"; filename=\"bar.txt\"");
}
@Test
void parseEmpty() {
assertThatIllegalArgumentException().isThrownBy(() -> parse(""));
}
@Test
void parseNoType() {
assertThatIllegalArgumentException().isThrownBy(() -> parse(";"));
}
@Test
void parseInvalidParameter() {
assertThatIllegalArgumentException().isThrownBy(() -> parse("foo;bar"));
}
@Test
void parseFormatted() {
ContentDisposition cd = ContentDisposition.builder("form-data")
.name("foo")
.filename("foo\\bar \"baz\" qux \\\" quux.txt").build();
ContentDisposition parsed = ContentDisposition.parse(cd.toString());
assertThat(parsed).isEqualTo(cd);
assertThat(parsed.toString()).isEqualTo(cd.toString());
}
@Test // gh-30252
void parseFormattedWithQuestionMark() {
String filename = "filename with ?问号.txt";
ContentDisposition cd = ContentDisposition.attachment()
.filename(filename, StandardCharsets.UTF_8)
.build();
String result = cd.toString();
assertThat(result).isEqualTo("attachment; " +
"filename=\"filename with ?__.txt\"; " +
"filename*=UTF-8''filename%20with%20%3F%E9%97%AE%E5%8F%B7.txt");
String[] parts = result.split("; ");
String quotedPrintableFilename = parts[0] + "; " + parts[1];
assertThat(ContentDisposition.parse(quotedPrintableFilename).getFilename())
.isEqualTo("filename with ?__.txt");
String rfc5987Filename = parts[0] + "; " + parts[2];
assertThat(ContentDisposition.parse(rfc5987Filename).getFilename())
.isEqualTo(filename);
}
}
@Nested
class FormattingTests {
@Test
void format() {
assertThat(
ContentDisposition.formData()
.name("foo")
.filename("foo.txt")
.build().toString())
.isEqualTo("form-data; name=\"foo\"; filename=\"foo.txt\"");
}
@Test
void formatWithEncodedFilename() {
assertThat(
ContentDisposition.formData()
.name("name")
.filename("Äsprïngö.txt", StandardCharsets.UTF_8)
.build().toString())
.isEqualTo("form-data; name=\"name\"; " +
"filename=\"Aespringoe.txt\"; " +
"filename*=UTF-8''%C3%84spr%C3%AFng%C3%B6.txt");
}
@Test
void formatWithUnmappableCharacters() {
assertThat(
ContentDisposition.formData()
.name("name")
.filename("中文.txt", StandardCharsets.UTF_8)
.build().toString())
.isEqualTo("form-data; name=\"name\"; " +
"filename=\"__.txt\"; " +
"filename*=UTF-8''%E4%B8%AD%E6%96%87.txt");
}
@Test
void formatWithEncodedFilenameUsingUsAscii() {
assertThat(
ContentDisposition.formData()
.name("name")
.filename("test.txt", StandardCharsets.US_ASCII)
.build()
.toString())
.isEqualTo("form-data; name=\"name\"; filename=\"test.txt\"");
}
@Test // gh-24220
void formatWithFilenameWithQuotes() {
BiConsumer<String, String> tester = (input, output) -> {
assertThat(ContentDisposition.formData().filename(input).build().toString())
.isEqualTo("form-data; filename=\"" + output + "\"");
assertThat(ContentDisposition.formData().filename(input, StandardCharsets.US_ASCII).build().toString())
.isEqualTo("form-data; filename=\"" + output + "\"");
};
String filename = "\"foo.txt";
tester.accept(filename, "\\\"foo.txt");
filename = "\\\"foo.txt";
tester.accept(filename, "\\\\\\\"foo.txt");
filename = "\\\\\"foo.txt";
tester.accept(filename, "\\\\\\\\\\\"foo.txt");
filename = "\\\\\\\"foo.txt";
tester.accept(filename, "\\\\\\\\\\\\\\\"foo.txt");
filename = "\\\\\\\\\"foo.txt";
tester.accept(filename, "\\\\\\\\\\\\\\\\\\\"foo.txt");
tester.accept("\"\"foo.txt", "\\\"\\\"foo.txt");
tester.accept("\"\"\"foo.txt", "\\\"\\\"\\\"foo.txt");
tester.accept("foo.txt\\", "foo.txt\\\\");
tester.accept("foo.txt\\\\", "foo.txt\\\\\\\\");
tester.accept("foo.txt\\\\\\", "foo.txt\\\\\\\\\\\\");
}
@Test
void formatWithUtf8FilenameWithQuotes() {
String filename = "\"中文.txt";
assertThat(ContentDisposition.formData().filename(filename, StandardCharsets.UTF_8).build().toString())
.isEqualTo("form-data; filename=\"\\\"__.txt\"; filename*=UTF-8''%22%E4%B8%AD%E6%96%87.txt");
}
@Test
void formatWithEncodedFilenameUsingInvalidCharset() {
assertThatIllegalArgumentException().isThrownBy(() ->
ContentDisposition.formData()
.name("name")
.filename("test.txt", StandardCharsets.UTF_16)
.build()
.toString());
}
}
}