diff options
| author | Taras Madan <tarasmadan@google.com> | 2025-01-22 16:07:17 +0100 |
|---|---|---|
| committer | Taras Madan <tarasmadan@google.com> | 2025-01-23 10:42:36 +0000 |
| commit | 7b4377ad9d8a7205416df8d6217ef2b010f89481 (patch) | |
| tree | e6fec4fd12ff807a16d847923f501075bf71d16c /vendor/github.com/google/safehtml/template/error.go | |
| parent | 475a4c203afb8b7d3af51c4fd32bb170ff32a45e (diff) | |
vendor: delete
Diffstat (limited to 'vendor/github.com/google/safehtml/template/error.go')
| -rw-r--r-- | vendor/github.com/google/safehtml/template/error.go | 280 |
1 files changed, 0 insertions, 280 deletions
diff --git a/vendor/github.com/google/safehtml/template/error.go b/vendor/github.com/google/safehtml/template/error.go deleted file mode 100644 index fe7821433..000000000 --- a/vendor/github.com/google/safehtml/template/error.go +++ /dev/null @@ -1,280 +0,0 @@ -// Copyright 2017 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package template - -import ( - "fmt" - "text/template/parse" -) - -// Error describes a problem encountered during template Escaping. -type Error struct { - // ErrorCode describes the kind of error. - ErrorCode ErrorCode - // Node is the node that caused the problem, if known. - // If not nil, it overrides Name and Line. - Node parse.Node - // Name is the name of the template in which the error was encountered. - Name string - // Line is the line number of the error in the template source or 0. - Line int - // Description is a human-readable description of the problem. - Description string -} - -// ErrorCode is a code for a kind of error. -type ErrorCode int - -// We define codes for each error that manifests while escaping templates, but -// escaped templates may also fail at runtime. -// -// Output: "ZgotmplZ" -// Example: -// <img src="{{.X}}"> -// where {{.X}} evaluates to `javascript:...` -// Discussion: -// "ZgotmplZ" is a special value that indicates that unsafe content reached a -// CSS or URL context at runtime. The output of the example will be -// <img src="#ZgotmplZ"> -// If the data comes from a trusted source, use content types to exempt it -// from filtering: URL(`javascript:...`). -const ( - // OK indicates the lack of an error. - OK ErrorCode = iota - - // ErrAmbigContext: "... appears in an ambiguous context within a URL" - // Example: - // <a href=" - // {{if .C}} - // /path/ - // {{else}} - // /search?q= - // {{end}} - // {{.X}} - // "> - // Discussion: - // {{.X}} is in an ambiguous URL context since, depending on {{.C}}, - // it may be either a URL suffix or a query parameter. - // Moving {{.X}} into the condition removes the ambiguity: - // <a href="{{if .C}}/path/{{.X}}{{else}}/search?q={{.X}}"> - ErrAmbigContext - - // ErrBadHTML: "expected space, attr name, or end of tag, but got ...", - // "... in unquoted attr", "... in attribute name" - // Example: - // <a href = /search?q=foo> - // <href=foo> - // <form na<e=...> - // <option selected< - // Discussion: - // This is often due to a typo in an HTML element, but some runes - // are banned in tag names, attribute names, and unquoted attribute - // values because they can tickle parser ambiguities. - // Quoting all attributes is the best policy. - ErrBadHTML - - // ErrBranchEnd: "{{if}} branches end in different contexts" - // Example: - // {{if .C}}<a href="{{end}}{{.X}} - // Discussion: - // Package html/template statically examines each path through an - // {{if}}, {{range}}, or {{with}} to escape any following pipelines. - // The example is ambiguous since {{.X}} might be an HTML text node, - // or a URL prefix in an HTML attribute. The context of {{.X}} is - // used to figure out how to escape it, but that context depends on - // the run-time value of {{.C}} which is not statically known. - // - // The problem is usually something like missing quotes or angle - // brackets, or can be avoided by refactoring to put the two contexts - // into different branches of an if, range or with. If the problem - // is in a {{range}} over a collection that should never be empty, - // adding a dummy {{else}} can help. - ErrBranchEnd - - // ErrEndContext: "... ends in a non-text context: ..." - // Examples: - // <div - // <div title="no close quote> - // <script>f() - // Discussion: - // Executed templates should produce a DocumentFragment of HTML. - // Templates that end without closing tags will trigger this error. - // Templates that should not be used in an HTML context or that - // produce incomplete Fragments should not be executed directly. - // - // {{define "main"}} <script>{{template "helper"}}</script> {{end}} - // {{define "helper"}} document.write(' <div title=" ') {{end}} - // - // "helper" does not produce a valid document fragment, so should - // not be Executed directly. - ErrEndContext - - // ErrNoSuchTemplate: "no such template ..." - // Examples: - // {{define "main"}}<div {{template "attrs"}}>{{end}} - // {{define "attrs"}}href="{{.URL}}"{{end}} - // Discussion: - // Package html/template looks through template calls to compute the - // context. - // Here the {{.URL}} in "attrs" must be treated as a URL when called - // from "main", but you will get this error if "attrs" is not defined - // when "main" is parsed. - ErrNoSuchTemplate - - // ErrOutputContext: "cannot compute output context for template ..." - // Examples: - // {{define "t"}}{{if .T}}{{template "t" .T}}{{end}}{{.H}}",{{end}} - // Discussion: - // A recursive template does not end in the same context in which it - // starts, and a reliable output context cannot be computed. - // Look for typos in the named template. - // If the template should not be called in the named start context, - // look for calls to that template in unexpected contexts. - // Maybe refactor recursive templates to not be recursive. - ErrOutputContext - - // ErrPartialCharset: "unfinished JS regexp charset in ..." - // Example: - // <script>var pattern = /foo[{{.Chars}}]/</script> - // Discussion: - // Package html/template does not support interpolation into regular - // expression literal character sets. - ErrPartialCharset - - // ErrPartialEscape: "unfinished escape sequence in ..." - // Example: - // <script>alert("\{{.X}}")</script> - // Discussion: - // Package html/template does not support actions following a - // backslash. - // This is usually an error and there are better solutions; for - // example - // <script>alert("{{.X}}")</script> - // should work, and if {{.X}} is a partial escape sequence such as - // "xA0", mark the whole sequence as safe content: JSStr(`\xA0`) - ErrPartialEscape - - // ErrRangeLoopReentry: "on range loop re-entry: ..." - // Example: - // <script>var x = [{{range .}}'{{.}},{{end}}]</script> - // Discussion: - // If an iteration through a range would cause it to end in a - // different context than an earlier pass, there is no single context. - // In the example, there is missing a quote, so it is not clear - // whether {{.}} is meant to be inside a JS string or in a JS value - // context. The second iteration would produce something like - // - // <script>var x = ['firstValue,'secondValue]</script> - ErrRangeLoopReentry - - // ErrSlashAmbig: '/' could start a division or regexp. - // Example: - // <script> - // {{if .C}}var x = 1{{end}} - // /-{{.N}}/i.test(x) ? doThis : doThat(); - // </script> - // Discussion: - // The example above could produce `var x = 1/-2/i.test(s)...` - // in which the first '/' is a mathematical division operator or it - // could produce `/-2/i.test(s)` in which the first '/' starts a - // regexp literal. - // Look for missing semicolons inside branches, and maybe add - // parentheses to make it clear which interpretation you intend. - ErrSlashAmbig - - // ErrPredefinedEscaper: "predefined escaper ... disallowed in template" - // Example: - // <div class={{. | html}}>Hello<div> - // Discussion: - // Package html/template already contextually escapes all pipelines to - // produce HTML output safe against code injection. Manually escaping - // pipeline output using the predefined escapers "html" or "urlquery" is - // unnecessary, and may affect the correctness or safety of the escaped - // pipeline output in Go 1.8 and earlier. - // - // In most cases, such as the given example, this error can be resolved by - // simply removing the predefined escaper from the pipeline and letting the - // contextual autoescaper handle the escaping of the pipeline. In other - // instances, where the predefined escaper occurs in the middle of a - // pipeline where subsequent commands expect escaped input, e.g. - // {{.X | html | makeALink}} - // where makeALink does - // return `<a href="`+input+`">link</a>` - // consider refactoring the surrounding template to make use of the - // contextual autoescaper, i.e. - // <a href="{{.X}}">link</a> - // - // To ease migration to Go 1.9 and beyond, "html" and "urlquery" will - // continue to be allowed as the last command in a pipeline. However, if the - // pipeline occurs in an unquoted attribute value context, "html" is - // disallowed. Avoid using "html" and "urlquery" entirely in new templates. - ErrPredefinedEscaper - - // ErrEscapeAction: "cannot escape action ..." - // Discussion: - // Error returned while escaping an action using EscaperForContext. - // Refer to error message for more details. - // TODO: remove this error type and replace it with more informative sanitization errors. - ErrEscapeAction - - // ErrCSPCompatibility: `"javascript:" URI disallowed for CSP compatibility`, - // "inline event handler ... is disallowed for CSP compatibility - // Examples: - // <span onclick="doThings();">A thing.</span> - // <a href="javascript:linkClicked()">foo</a> - // Discussion: - // Inline event handlers (onclick="...", onerror="...") and - // <a href="javascript:..."> links can be used to run scripts, - // so an attacker who finds an XSS bug could inject such HTML - // and execute malicious JavaScript. These patterns must be - // refactored into safer alternatives for compatibility with - // Content Security Policy (CSP). - // - // For example, the following HTML that contains an inline event handler: - // <script> function doThings() { ... } </script> - // <span onclick="doThings();">A thing.</span> - // can be refactored into: - // <span id="things">A thing.</span> - // <script nonce="${nonce}"> - // document.addEventListener('DOMContentLoaded', function () { - // document.getElementById('things') - // .addEventListener('click', function doThings() { ... }); - // }); - // </script> - // - // Likewise, the following HTML containng a javascript: URI: - // <a href="javascript:linkClicked()">foo</a> - // can be refactored into: - // <a id="foo">foo</a> - // <script nonce="${nonce}"> - // document.addEventListener('DOMContentLoaded', function () { - // document.getElementById('foo') - // .addEventListener('click', linkClicked); - // }); - // </script> - ErrCSPCompatibility - // All JS templates inside script literals have to be balanced; otherwise a concatenation such as - // <script>alert(`x{{.data}}`</script> can contain XSS if data contains user-controlled escaped strings (e.g. as JSON). - ErrUnbalancedJsTemplate -) - -func (e *Error) Error() string { - switch { - case e.Node != nil: - loc, _ := (*parse.Tree)(nil).ErrorContext(e.Node) - return fmt.Sprintf("html/template:%s: %s", loc, e.Description) - case e.Line != 0: - return fmt.Sprintf("html/template:%s:%d: %s", e.Name, e.Line, e.Description) - case e.Name != "": - return fmt.Sprintf("html/template:%s: %s", e.Name, e.Description) - } - return "html/template: " + e.Description -} - -// errorf creates an error given a format string f and args. -// The template Name still needs to be supplied. -func errorf(k ErrorCode, node parse.Node, line int, f string, args ...interface{}) *Error { - return &Error{k, node, "", line, fmt.Sprintf(f, args...)} -} |
