[release-branch.go1.21] net/mail: properly handle special characters in phrase and...

Fixes a couple of misalignments with RFC 5322 which introduce
significant diffs between (mostly) conformant parsers.

This change reverts the changes made in CL50911, which allowed certain
special RFC 5322 characters to appear unquoted in the "phrase" syntax.
It is unclear why this change was made in the first place, and created
a divergence from comformant parsers. In particular this resulted in
treating comments in display names incorrectly.

Additionally properly handle trailing malformed comments in the group
syntax.

For #65083
Fixes #65848

Change-Id: I00dddc044c6ae3381154e43236632604c390f672
Reviewed-on: https://go-review.googlesource.com/c/go/+/555596
Reviewed-by: Damien Neil <dneil@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-on: https://go-review.googlesource.com/c/go/+/566195
Reviewed-by: Carlos Amedee <carlos@golang.org>

diff --git a/src/net/mail/message.go b/src/net/mail/message.go
index af516fc30f470d17d686cf4afe286e0cea099010..fc2a9e46f811ba05fbce6853949cd2251047592d 100644 (file)
--- a/src/net/mail/message.go
+++ b/src/net/mail/message.go
@@ -280,7 +280,7 @@ func (a *Address) String() string {
        // Add quotes if needed
        quoteLocal := false
        for i, r := range local {
-               if isAtext(r, false, false) {
+               if isAtext(r, false) {
                        continue
                }
                if r == '.' {
@@ -444,7 +444,7 @@ func (p *addrParser) parseAddress(handleGroup bool) ([]*Address, error) {
        if !p.consume('<') {
                atext := true
                for _, r := range displayName {
-                       if !isAtext(r, true, false) {
+                       if !isAtext(r, true) {
                                atext = false
                                break
                        }
@@ -479,7 +479,9 @@ func (p *addrParser) consumeGroupList() ([]*Address, error) {
        // handle empty group.
        p.skipSpace()
        if p.consume(';') {
-               p.skipCFWS()
+               if !p.skipCFWS() {
+                       return nil, errors.New("mail: misformatted parenthetical comment")
+               }
                return group, nil
        }
 
@@ -496,7 +498,9 @@ func (p *addrParser) consumeGroupList() ([]*Address, error) {
                        return nil, errors.New("mail: misformatted parenthetical comment")
                }
                if p.consume(';') {
-                       p.skipCFWS()
+                       if !p.skipCFWS() {
+                               return nil, errors.New("mail: misformatted parenthetical comment")
+                       }
                        break
                }
                if !p.consume(',') {
@@ -566,6 +570,12 @@ func (p *addrParser) consumePhrase() (phrase string, err error) {
        var words []string
        var isPrevEncoded bool
        for {
+               // obs-phrase allows CFWS after one word
+               if len(words) > 0 {
+                       if !p.skipCFWS() {
+                               return "", errors.New("mail: misformatted parenthetical comment")
+                       }
+               }
                // word = atom / quoted-string
                var word string
                p.skipSpace()
@@ -661,7 +671,6 @@ Loop:
 // If dot is true, consumeAtom parses an RFC 5322 dot-atom instead.
 // If permissive is true, consumeAtom will not fail on:
 // - leading/trailing/double dots in the atom (see golang.org/issue/4938)
-// - special characters (RFC 5322 3.2.3) except '<', '>', ':' and '"' (see golang.org/issue/21018)
 func (p *addrParser) consumeAtom(dot bool, permissive bool) (atom string, err error) {
        i := 0
 
@@ -672,7 +681,7 @@ Loop:
                case size == 1 && r == utf8.RuneError:
                        return "", fmt.Errorf("mail: invalid utf-8 in address: %q", p.s)
 
-               case size == 0 || !isAtext(r, dot, permissive):
+               case size == 0 || !isAtext(r, dot):
                        break Loop
 
                default:
@@ -850,18 +859,13 @@ func (e charsetError) Error() string {
 
 // isAtext reports whether r is an RFC 5322 atext character.
 // If dot is true, period is included.
-// If permissive is true, RFC 5322 3.2.3 specials is included,
-// except '<', '>', ':' and '"'.
-func isAtext(r rune, dot, permissive bool) bool {
+func isAtext(r rune, dot bool) bool {
        switch r {
        case '.':
                return dot
 
        // RFC 5322 3.2.3. specials
-       case '(', ')', '[', ']', ';', '@', '\\', ',':
-               return permissive
-
-       case '<', '>', '"', ':':
+       case '(', ')', '<', '>', '[', ']', ':', ';', '@', '\\', ',', '"': // RFC 5322 3.2.3. specials
                return false
        }
        return isVchar(r)

diff --git a/src/net/mail/message_test.go b/src/net/mail/message_test.go
index 1e1bb4092f6598874e9efa645af474ec658be5ed..1f2f62afbf406bbaec93592405461f1f05cebb7c 100644 (file)
--- a/src/net/mail/message_test.go
+++ b/src/net/mail/message_test.go
@@ -385,8 +385,11 @@ func TestAddressParsingError(t *testing.T) {
                13: {"group not closed: null@example.com", "expected comma"},
                14: {"group: first@example.com, second@example.com;", "group with multiple addresses"},
                15: {"john.doe", "missing '@' or angle-addr"},
-               16: {"john.doe@", "no angle-addr"},
+               16: {"john.doe@", "missing '@' or angle-addr"},
                17: {"John Doe@foo.bar", "no angle-addr"},
+               18: {" group: null@example.com; (asd", "misformatted parenthetical comment"},
+               19: {" group: ; (asd", "misformatted parenthetical comment"},
+               20: {`(John) Doe <jdoe@machine.example>`, "missing word in phrase:"},
        }
 
        for i, tc := range mustErrTestCases {
@@ -436,24 +439,19 @@ func TestAddressParsing(t *testing.T) {
                                Address: "john.q.public@example.com",
                        }},
                },
-               {
-                       `"John (middle) Doe" <jdoe@machine.example>`,
-                       []*Address{{
-                               Name:    "John (middle) Doe",
-                               Address: "jdoe@machine.example",
-                       }},
-               },
+               // Comment in display name
                {
                        `John (middle) Doe <jdoe@machine.example>`,
                        []*Address{{
-                               Name:    "John (middle) Doe",
+                               Name:    "John Doe",
                                Address: "jdoe@machine.example",
                        }},
                },
+               // Display name is quoted string, so comment is not a comment
                {
-                       `John !@M@! Doe <jdoe@machine.example>`,
+                       `"John (middle) Doe" <jdoe@machine.example>`,
                        []*Address{{
-                               Name:    "John !@M@! Doe",
+                               Name:    "John (middle) Doe",
                                Address: "jdoe@machine.example",
                        }},
                },
@@ -788,6 +786,26 @@ func TestAddressParsing(t *testing.T) {
                                },
                        },
                },
+               // Comment in group display name
+               {
+                       `group (comment:): a@example.com, b@example.com;`,
+                       []*Address{
+                               {
+                                       Address: "a@example.com",
+                               },
+                               {
+                                       Address: "b@example.com",
+                               },
+                       },
+               },
+               {
+                       `x(:"):"@a.example;("@b.example;`,
+                       []*Address{
+                               {
+                                       Address: `@a.example;(@b.example`,
+                               },
+                       },
+               },
        }
        for _, test := range tests {
                if len(test.exp) == 1 {