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fix: declare c2pa XML namespace on SVG root, not manifest tag #2113

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fix: declare c2pa XML namespace on SVG root, not manifest tag #2113

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c05af03
fix: declare c2pa XML namespace on SVG root, not manifest tag
ak-singh May 2, 2026
ea1d4c8
Merge branch 'main' into fix/svg-namespace-on-root
tmathern May 4, 2026
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138 changes: 132 additions & 6 deletions sdk/src/asset_handlers/svg_io.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -19,7 +19,7 @@ use std::{
};

use quick_xml::{
events::{BytesText, Event},
events::{BytesStart, BytesText, Event},
Reader, Writer,
};

Expand Down Expand Up @@ -174,15 +174,13 @@ fn create_manifest_tag(data: &[u8], with_meta: bool) -> Result<Event<'_>> {
.write_inner_content(|writer| {
writer
.create_element(MANIFEST)
.with_attribute((MANIFEST_NS, MANIFEST_NS_VAL))
.write_text_content(BytesText::from_escaped(&encoded))?;
Ok(())
})
.map_err(|_e| Error::XmlWriteError)?;
} else {
writer
.create_element(MANIFEST)
.with_attribute((MANIFEST_NS, MANIFEST_NS_VAL))
.write_text_content(BytesText::from_escaped(&encoded))
.map_err(|_e| Error::XmlWriteError)?;
}
Expand All @@ -194,6 +192,16 @@ fn create_manifest_tag(data: &[u8], with_meta: bool) -> Result<Event<'_>> {
Ok(event)
}

fn add_c2pa_namespace_if_missing(start: &mut BytesStart) {
let already_declared = start
.attributes()
.filter_map(|attr| attr.ok())
.any(|attr| attr.key.as_ref() == MANIFEST_NS.as_bytes());
if !already_declared {
start.push_attribute((MANIFEST_NS, MANIFEST_NS_VAL));
}
}

enum DetectedTagsDepth {
Metadata,
Manifest,
Expand Down Expand Up @@ -414,10 +422,15 @@ impl CAIWriter for SvgIO {
// add manifest case
loop {
match reader.read_event_into(&mut buf) {
Ok(Event::Start(e)) => {
Ok(Event::Start(mut e)) => {
let name = String::from_utf8_lossy(e.name().into_inner()).into_owned();
xml_path.push(name);

// Ensure xmlns:c2pa is declared in the SVG root.
if xml_path.len() == 1 && xml_path[0] == SVG {
add_c2pa_namespace_if_missing(&mut e);
}

// writes the event to the writer
writer
.write_event(Event::Start(e))
Expand Down Expand Up @@ -450,10 +463,15 @@ impl CAIWriter for SvgIO {

loop {
match reader.read_event_into(&mut buf) {
Ok(Event::Start(e)) => {
Ok(Event::Start(mut e)) => {
let name = String::from_utf8_lossy(e.name().into_inner()).into_owned();
xml_path.push(name);

// Ensure xmlns:c2pa is declared in the SVG root.
if xml_path.len() == 1 && xml_path[0] == SVG {
add_c2pa_namespace_if_missing(&mut e);
}

// writes the event to the writer
writer
.write_event(Event::Start(e))
Expand Down Expand Up @@ -492,10 +510,15 @@ impl CAIWriter for SvgIO {
//add metadata & manifest case
loop {
match reader.read_event_into(&mut buf) {
Ok(Event::Start(e)) => {
Ok(Event::Start(mut e)) => {
let name = String::from_utf8_lossy(e.name().into_inner()).into_owned();
xml_path.push(name);

// Ensure xmlns:c2pa is declared in the SVG root.
if xml_path.len() == 1 && xml_path[0] == SVG {
add_c2pa_namespace_if_missing(&mut e);
}

// writes the event to the writer
writer
.write_event(Event::Start(e))
Expand Down Expand Up @@ -772,6 +795,32 @@ pub mod tests {
test::{fixture_path, temp_dir_path},
};

fn assert_c2pa_namespace_on_svg_root(xml: &str) {
let svg_idx = xml.find("<svg").expect("SVG root tag missing");
let svg_open_end = svg_idx
+ xml[svg_idx..]
.find('>')
.expect("malformed SVG: <svg> tag not closed");
let svg_open_tag = &xml[svg_idx..=svg_open_end];
assert!(
svg_open_tag.contains("xmlns:c2pa=\"http://c2pa.org/manifest\""),
"xmlns:c2pa should be on <svg> root, got: {svg_open_tag}"
);
}

fn assert_no_c2pa_namespace_on_manifest(xml: &str) {
let manifest_idx = xml.find("<c2pa:manifest").expect("manifest tag missing");
let manifest_open_end = manifest_idx
+ xml[manifest_idx..]
.find('>')
.expect("malformed: <c2pa:manifest> tag not closed");
let manifest_open_tag = &xml[manifest_idx..=manifest_open_end];
assert!(
!manifest_open_tag.contains("xmlns:c2pa"),
"xmlns:c2pa should not be on <c2pa:manifest>, got: {manifest_open_tag}"
);
}

#[test]
fn test_write_svg_no_meta() {
let more_data = "some more test data".as_bytes();
Expand All @@ -785,6 +834,9 @@ pub mod tests {
let svg_io = SvgIO::new("svg");

if let Ok(()) = svg_io.save_cai_store(&output, more_data) {
let xml = std::fs::read_to_string(&output).unwrap();
assert_c2pa_namespace_on_svg_root(&xml);
assert_no_c2pa_namespace_on_manifest(&xml);
if let Ok(read_test_data) = svg_io.read_cai_store(&output) {
assert!(vec_compare(more_data, &read_test_data));
success = true;
Expand All @@ -808,6 +860,9 @@ pub mod tests {
let svg_io = SvgIO::new("svg");

if let Ok(()) = svg_io.save_cai_store(&output, more_data) {
let xml = std::fs::read_to_string(&output).unwrap();
assert_c2pa_namespace_on_svg_root(&xml);
assert_no_c2pa_namespace_on_manifest(&xml);
if let Ok(read_test_data) = svg_io.read_cai_store(&output) {
assert!(vec_compare(more_data, &read_test_data));
success = true;
Expand All @@ -831,6 +886,11 @@ pub mod tests {
let svg_io = SvgIO::new("svg");

if let Ok(()) = svg_io.save_cai_store(&output, more_data) {
let xml = std::fs::read_to_string(&output).unwrap();
assert_c2pa_namespace_on_svg_root(&xml);
// sample3's <c2pa:manifest> has inline xmlns:c2pa from a prior
// signing. By design we don't strip it on resign.
// This test intentionally omits the assert_no_c2pa_namespace_on_manifest check.
if let Ok(read_test_data) = svg_io.read_cai_store(&output) {
assert!(vec_compare(more_data, &read_test_data));
success = true;
Expand All @@ -841,6 +901,72 @@ pub mod tests {
assert!(success)
}

#[test]
fn test_write_svg_no_metadata_element() {
let more_data = "some more test data".as_bytes();
let source = fixture_path("sample5.svg");

let mut success = false;
if let Ok(temp_dir) = tempdirectory() {
let output = temp_dir_path(&temp_dir, "sample5.svg");

if let Ok(_size) = std::fs::copy(source, &output) {
let svg_io = SvgIO::new("svg");

if let Ok(()) = svg_io.save_cai_store(&output, more_data) {
let xml = std::fs::read_to_string(&output).unwrap();
assert_c2pa_namespace_on_svg_root(&xml);
assert_no_c2pa_namespace_on_manifest(&xml);
if let Ok(read_test_data) = svg_io.read_cai_store(&output) {
assert!(vec_compare(more_data, &read_test_data));
success = true;
}
}
}
}
assert!(success)
}

#[test]
fn test_write_svg_namespace_idempotent() {
let more_data = "some more test data".as_bytes();
let new_manifest_data = "new manifest data".as_bytes();
let source = fixture_path("sample1.svg");

let mut success = false;
if let Ok(temp_dir) = tempdirectory() {
let output = temp_dir_path(&temp_dir, "sample1.svg");

if let Ok(_size) = std::fs::copy(source, &output) {
let svg_io = SvgIO::new("svg");

if let Ok(()) = svg_io.save_cai_store(&output, more_data) {
if let Ok(()) = svg_io.save_cai_store(&output, new_manifest_data) {
let xml = std::fs::read_to_string(&output).unwrap();

let svg_idx = xml.find("<svg").expect("SVG root tag missing");
let svg_open_end = svg_idx
+ xml[svg_idx..]
.find('>')
.expect("malformed SVG: <svg> tag not closed");
let svg_open_tag = &xml[svg_idx..=svg_open_end];
let count = svg_open_tag.matches("xmlns:c2pa").count();
assert_eq!(
count, 1,
"expected xmlns:c2pa exactly once on <svg> root, got {count}: {svg_open_tag}"
);

if let Ok(read_test_data) = svg_io.read_cai_store(&output) {
assert!(vec_compare(new_manifest_data, &read_test_data));
success = true;
}
}
}
}
}
assert!(success)
}

#[test]
fn test_patch_write_svg() {
let test_data = "some test data".as_bytes();
Expand Down