Merge pull request #20 from ucan-wg/v1-fuzz-match-and-simple-glob

Rewrite simple glob match + FuzzMatch

capability/policy/glob.go

@@ -0,0 +1,79 @@
+package policy
+
+import "fmt"
+
+type glob string
+
+// parseGlob ensures that the pattern conforms to the spec: only '*' and escaped '\*' are allowed.
+func parseGlob(pattern string) (glob, error) {
+	for i := 0; i < len(pattern); i++ {
+		if pattern[i] == '*' {
+			continue
+		}
+		if pattern[i] == '\\' && i+1 < len(pattern) && pattern[i+1] == '*' {
+			i++ // skip the escaped '*'
+			continue
+		}
+		if pattern[i] == '\\' && i+1 < len(pattern) {
+			i++ // skip the escaped character
+			continue
+		}
+		if pattern[i] == '\\' {
+			return "", fmt.Errorf("invalid escape sequence")
+		}
+	}
+
+	return glob(pattern), nil
+}
+
+func mustParseGlob(pattern string) glob {
+	g, err := parseGlob(pattern)
+	if err != nil {
+		panic(err)
+	}
+	return g
+}
+
+// Match matches a string against the glob pattern with * wildcards, handling escaped '\*' literals.
+func (pattern glob) Match(str string) bool {
+	// i is the index for the pattern
+	// j is the index for the string
+	var i, j int
+
+	// starIdx keeps track of the position of the last * in the pattern.
+	// matchIdx keeps track of the position in the string where the last * matched.
+	var starIdx, matchIdx int = -1, -1
+
+	for j < len(str) {
+		if i < len(pattern) && (pattern[i] == str[j] || pattern[i] == '\\' && i+1 < len(pattern) && pattern[i+1] == str[j]) {
+			// characters match or if there's an escaped character that matches
+			if pattern[i] == '\\' {
+				// skip the escape character
+				i++
+			}
+			i++
+			j++
+		} else if i < len(pattern) && pattern[i] == '*' {
+			// there's a * wildcard in the pattern
+			starIdx = i
+			matchIdx = j
+			i++
+		} else if starIdx != -1 {
+			// there's a previous * wildcard, backtrack
+			i = starIdx + 1
+			matchIdx++
+			j = matchIdx
+		} else {
+			// no match found
+			return false
+		}
+	}
+
+	// check for remaining characters in the pattern
+	for i < len(pattern) && pattern[i] == '*' {
+		i++
+	}
+
+	// the entire pattern is processed, it's a match
+	return i == len(pattern)
+}

capability/policy/glob_test.go

@@ -0,0 +1,73 @@
+package policy
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestSimpleGlobMatch(t *testing.T) {
+	tests := []struct {
+		pattern string
+		str     string
+		matches bool
+	}{
+		// Basic matching
+		{"*", "anything", true},
+		{"a*", "abc", true},
+		{"*c", "abc", true},
+		{"a*c", "abc", true},
+		{"a*c", "abxc", true},
+		{"a*c", "ac", true},
+		{"a*c", "a", false},
+		{"a*c", "ab", false},
+
+		// Escaped characters
+		{"a\\*c", "a*c", true},
+		{"a\\*c", "abc", false},
+
+		// Mixed wildcards and literals
+		{"a*b*c", "abc", true},
+		{"a*b*c", "aXbYc", true},
+		{"a*b*c", "aXbY", false},
+		{"a*b*c", "abYc", true},
+		{"a*b*c", "aXbc", true},
+		{"a*b*c", "aXbYcZ", false},
+
+		// Edge cases
+		{"", "", true},
+		{"", "a", false},
+		{"*", "", true},
+		{"*", "a", true},
+		{"\\*", "*", true},
+		{"\\*", "a", false},
+
+		// Specified test cases
+		{"Alice\\*, Bob*, Carol.", "Alice*, Bob, Carol.", true},
+		{"Alice\\*, Bob*, Carol.", "Alice*, Bob, Dan, Erin, Carol.", true},
+		{"Alice\\*, Bob*, Carol.", "Alice*, Bob  , Carol.", true},
+		{"Alice\\*, Bob*, Carol.", "Alice*, Bob*, Carol.", true},
+		{"Alice\\*, Bob*, Carol.", "Alice*, Bob, Carol", false},
+		{"Alice\\*, Bob*, Carol.", "Alice*, Bob*, Carol!", false},
+		{"Alice\\*, Bob*, Carol.", "Alice, Bob, Carol.", false},
+		{"Alice\\*, Bob*, Carol.", "Alice Cooper, Bob, Carol.", false},
+		{"Alice\\*, Bob*, Carol.", " Alice*, Bob, Carol. ", false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.pattern+"_"+tt.str, func(t *testing.T) {
+			g, err := parseGlob(tt.pattern)
+			require.NoError(t, err)
+			require.Equal(t, tt.matches, g.Match(tt.str))
+		})
+	}
+}
+
+func BenchmarkGlob(b *testing.B) {
+	b.ReportAllocs()
+
+	for i := 0; i < b.N; i++ {
+		g := mustParseGlob("Alice\\*, Bob*, Carol.")
+		g.Match("Alice*, Bob*, Carol!")
+	}
+}

capability/policy/ipld.go

@@ -232,7 +232,7 @@ func statementToIPLD(statement Statement) (datamodel.Node, error) {
 		if err != nil {
 			return nil, err
 		}
-		err = listBuilder.AssembleValue().AssignString(statement.pattern)
+		err = listBuilder.AssembleValue().AssignString(string(statement.pattern))
 		if err != nil {
 			return nil, err
 		}

capability/policy/match.go

@@ -112,7 +112,7 @@ func matchStatement(statement Statement, node ipld.Node) bool {
 			if err != nil {
 				return false
 			}
-			return s.glob.Match(v)
+			return s.pattern.Match(v)
 		}
 	case KindAll:
 		if s, ok := statement.(quantifier); ok {

capability/policy/match_test.go

@@ -490,3 +490,52 @@ func TestPolicyExamples(t *testing.T) {
 		require.True(t, evaluate(`["any", ".a", ["==", ".b", 2]]`, data))
 	})
 }
+
+func FuzzMatch(f *testing.F) {
+	// Policy + Data examples
+	f.Add([]byte(`[["==", ".status", "draft"]]`), []byte(`{"status": "draft"}`))
+	f.Add([]byte(`[["all", ".reviewer", ["like", ".email", "*@example.com"]]]`), []byte(`{"reviewer": [{"email": "[email protected]"}, {"email": "[email protected]"}]}`))
+	f.Add([]byte(`[["any", ".tags", ["or", [["==", ".", "news"], ["==", ".", "press"]]]]]`), []byte(`{"tags": ["news", "press"]}`))
+	f.Add([]byte(`[["==", ".name", "Alice"]]`), []byte(`{"name": "Alice"}`))
+	f.Add([]byte(`[[">", ".age", 30]]`), []byte(`{"age": 31}`))
+	f.Add([]byte(`[["<=", ".height", 180]]`), []byte(`{"height": 170}`))
+	f.Add([]byte(`[["not", ["==", ".status", "inactive"]]]`), []byte(`{"status": "active"}`))
+	f.Add([]byte(`[["and", [["==", ".role", "admin"], [">=", ".experience", 5]]]]`), []byte(`{"role": "admin", "experience": 6}`))
+	f.Add([]byte(`[["or", [["==", ".department", "HR"], ["==", ".department", "Finance"]]]]`), []byte(`{"department": "HR"}`))
+	f.Add([]byte(`[["like", ".email", "*@company.com"]]`), []byte(`{"email": "[email protected]"}`))
+	f.Add([]byte(`[["all", ".projects", [">", ".budget", 10000]]]`), []byte(`{"projects": [{"budget": 15000}, {"budget": 8000}]}`))
+	f.Add([]byte(`[["any", ".skills", ["==", ".", "Go"]]]`), []byte(`{"skills": ["Go", "Python", "JavaScript"]}`))
+	f.Add(
+		[]byte(`[["and", [
+			["==", ".name", "Bob"],
+			["or", [[">", ".age", 25],["==", ".status", "active"]]],
+			["all", ".tasks", ["==", ".completed", true]]
+		]]]`),
+		[]byte(`{
+			"name": "Bob",
+			"age": 26,
+			"status": "active",
+			"tasks": [{"completed": true}, {"completed": true}, {"completed": false}]
+		}`),
+	)
+
+	f.Fuzz(func(t *testing.T, policyBytes []byte, dataBytes []byte) {
+		policyNode, err := ipld.Decode(policyBytes, dagjson.Decode)
+		if err != nil {
+			t.Skip()
+		}
+
+		dataNode, err := ipld.Decode(dataBytes, dagjson.Decode)
+		if err != nil {
+			t.Skip()
+		}
+
+		// policy node -> policy object
+		policy, err := FromIPLD(policyNode)
+		if err != nil {
+			t.Skip()
+		}
+
+		Match(policy, dataNode)
+	})
+}

capability/policy/policy.go

@@ -3,7 +3,6 @@ package policy
 // https://github.com/ucan-wg/delegation/blob/4094d5878b58f5d35055a3b93fccda0b8329ebae/README.md#policy
 
 import (
-	"github.com/gobwas/glob"
 	"github.com/ipld/go-ipld-prime"
 
 	"github.com/ucan-wg/go-ucan/capability/policy/selector"
@@ -90,20 +89,20 @@ func Or(stmts ...Statement) Statement {
 
 type wildcard struct {
 	selector selector.Selector
-	pattern  string
-	glob     glob.Glob // not serialized
+	pattern  glob
 }
 
 func (n wildcard) Kind() string {
 	return KindLike
 }
 
 func Like(selector selector.Selector, pattern string) (Statement, error) {
-	g, err := glob.Compile(pattern)
+	g, err := parseGlob(pattern)
 	if err != nil {
 		return nil, err
 	}
-	return wildcard{selector: selector, pattern: pattern, glob: g}, nil
+
+	return wildcard{selector: selector, pattern: g}, nil
 }
 
 type quantifier struct {

go.mod

@@ -5,7 +5,6 @@ go 1.22
 toolchain go1.22.4
 
 require (
-	github.com/gobwas/glob v0.2.3
 	github.com/ipfs/go-cid v0.4.1
 	github.com/ipld/go-ipld-prime v0.21.0
 	github.com/libp2p/go-libp2p v0.36.3

go.sum

@@ -7,8 +7,6 @@ github.com/decred/dcrd/dcrec/secp256k1/v4 v4.3.0/go.mod h1:v57UDF4pDQJcEfFUCRop3
 github.com/frankban/quicktest v1.14.6 h1:7Xjx+VpznH+oBnejlPUj8oUpdxnVs4f8XU8WnHkI4W8=
 github.com/frankban/quicktest v1.14.6/go.mod h1:4ptaffx2x8+WTWXmUCuVU6aPUX1/Mz7zb5vbUoiM6w0=
 github.com/go-yaml/yaml v2.1.0+incompatible/go.mod h1:w2MrLa16VYP0jy6N7M5kHaCkaLENm+P+Tv+MfurjSw0=
-github.com/gobwas/glob v0.2.3 h1:A4xDbljILXROh+kObIiy5kIaPYD8e96x1tgBhUI5J+Y=
-github.com/gobwas/glob v0.2.3/go.mod h1:d3Ez4x06l9bZtSvzIay5+Yzi0fmZzPgnTbPcKjJAkT8=
 github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
 github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/gopherjs/gopherjs v0.0.0-20181017120253-0766667cb4d1 h1:EGx4pi6eqNxGaHF6qqu48+N2wcFQ5qg5FXgOdqsJ5d8=