mox/imapserver/parse.go
Mechiel Lukkien aef99a72d8
imapserver: prevent unbounded memory allocations when handling a command
some commands, like search, can specify any number of literals, of arbitrary
size.  we already limited individual literals to 100kb. but you could specify
many of them, causing unbounded memory consumption. this change adds a limit of
1000 literals in a command, and a limit of 1mb of total combined memory for
literals. once the limits are exceeded, a TOOBIG error code is returned.

unbounded memory use could only be triggered on authenticated connections.

this addresses the same issue as CVE-2024-34055 for cyrus-imap, by damian
poddebniak.
2024-06-10 15:00:18 +02:00

976 lines
21 KiB
Go

package imapserver
import (
"errors"
"fmt"
"net/textproto"
"strconv"
"strings"
"time"
)
var (
listWildcards = "%*"
char = charRange('\x01', '\x7f')
ctl = charRange('\x01', '\x19')
quotedSpecials = `"\`
respSpecials = "]"
atomChar = charRemove(char, "(){ "+ctl+listWildcards+quotedSpecials+respSpecials)
astringChar = atomChar + respSpecials
)
func charRange(first, last rune) string {
r := ""
c := first
r += string(c)
for c < last {
c++
r += string(c)
}
return r
}
func charRemove(s, remove string) string {
r := ""
next:
for _, c := range s {
for _, x := range remove {
if c == x {
continue next
}
}
r += string(c)
}
return r
}
type parser struct {
// Orig is the line in original casing, and upper in upper casing. We often match
// against upper for easy case insensitive handling as IMAP requires, but sometimes
// return from orig to keep the original case.
orig string
upper string
o int // Current offset in parsing.
contexts []string // What we're parsing, for error messages.
literals int // Literals in command, for limit.
literalSize int64 // Total size of literals in command, for limit.
conn *conn
}
// toUpper upper cases bytes that are a-z. strings.ToUpper does too much. and
// would replace invalid bytes with unicode replacement characters, which would
// break our requirement that offsets into the original and upper case strings
// point to the same character.
func toUpper(s string) string {
r := []byte(s)
for i, c := range r {
if c >= 'a' && c <= 'z' {
r[i] = c - 0x20
}
}
return string(r)
}
func newParser(s string, conn *conn) *parser {
return &parser{s, toUpper(s), 0, nil, 0, 0, conn}
}
func (p *parser) xerrorf(format string, args ...any) {
var err error
errmsg := fmt.Sprintf(format, args...)
remaining := fmt.Sprintf("remaining %q", p.orig[p.o:])
if len(p.contexts) > 0 {
remaining += ", context " + strings.Join(p.contexts, ",")
}
remaining = " (" + remaining + ")"
if p.conn.account != nil {
errmsg += remaining
err = errors.New(errmsg)
} else {
err = errors.New(errmsg + remaining)
}
panic(syntaxError{"", "", errmsg, err})
}
func (p *parser) context(s string) func() {
p.contexts = append(p.contexts, s)
return func() {
p.contexts = p.contexts[:len(p.contexts)-1]
}
}
func (p *parser) empty() bool {
return p.o == len(p.upper)
}
func (p *parser) xempty() {
if !p.empty() {
p.xerrorf("leftover data")
}
}
func (p *parser) hasPrefix(s string) bool {
return strings.HasPrefix(p.upper[p.o:], s)
}
func (p *parser) take(s string) bool {
if !p.hasPrefix(s) {
return false
}
p.o += len(s)
return true
}
func (p *parser) xtake(s string) {
if !p.take(s) {
p.xerrorf("expected %s", s)
}
}
func (p *parser) xnonempty() {
if p.empty() {
p.xerrorf("unexpected end")
}
}
func (p *parser) xtakeall() string {
r := p.orig[p.o:]
p.o = len(p.orig)
return r
}
func (p *parser) xtake1n(n int, what string) string {
if n == 0 {
p.xerrorf("expected chars from %s", what)
}
return p.xtaken(n)
}
func (p *parser) xtakechars(s string, what string) string {
p.xnonempty()
for i, c := range p.orig[p.o:] {
if !contains(s, c) {
return p.xtake1n(i, what)
}
}
return p.xtakeall()
}
func (p *parser) xtaken(n int) string {
if p.o+n > len(p.orig) {
p.xerrorf("not enough data")
}
r := p.orig[p.o : p.o+n]
p.o += n
return r
}
func (p *parser) space() bool {
return p.take(" ")
}
func (p *parser) xspace() {
if !p.space() {
p.xerrorf("expected space")
}
}
func (p *parser) digits() string {
var n int
for _, c := range p.upper[p.o:] {
if c < '0' || c > '9' {
break
}
n++
}
if n == 0 {
return ""
}
s := p.upper[p.o : p.o+n]
p.o += n
return s
}
func (p *parser) nznumber() (uint32, bool) {
o := p.o
for o < len(p.upper) && p.upper[o] >= '0' && p.upper[o] <= '9' {
o++
}
if o == p.o {
return 0, false
}
if n, err := strconv.ParseUint(p.upper[p.o:o], 10, 32); err != nil {
return 0, false
} else if n == 0 {
return 0, false
} else {
p.o = o
return uint32(n), true
}
}
func (p *parser) xnznumber() uint32 {
n, ok := p.nznumber()
if !ok {
p.xerrorf("expected non-zero number")
}
return n
}
func (p *parser) number() (uint32, bool) {
o := p.o
for o < len(p.upper) && p.upper[o] >= '0' && p.upper[o] <= '9' {
o++
}
if o == p.o {
return 0, false
}
n, err := strconv.ParseUint(p.upper[p.o:o], 10, 32)
if err != nil {
return 0, false
}
p.o = o
return uint32(n), true
}
func (p *parser) xnumber() uint32 {
n, ok := p.number()
if !ok {
p.xerrorf("expected number")
}
return n
}
func (p *parser) xnumber64() int64 {
s := p.digits()
if s == "" {
p.xerrorf("expected number64")
}
v, err := strconv.ParseInt(s, 10, 63) // ../rfc/9051:6794 ../rfc/7162:297
if err != nil {
p.xerrorf("parsing number64 %q: %v", s, err)
}
return v
}
func (p *parser) xnznumber64() int64 {
v := p.xnumber64()
if v == 0 {
p.xerrorf("expected non-zero number64")
}
return v
}
// l should be a list of uppercase words, the first match is returned
func (p *parser) takelist(l ...string) (string, bool) {
for _, w := range l {
if p.take(w) {
return w, true
}
}
return "", false
}
func (p *parser) xtakelist(l ...string) string {
w, ok := p.takelist(l...)
if !ok {
p.xerrorf("expected one of %s", strings.Join(l, ","))
}
return w
}
func (p *parser) xstring() (r string) {
if p.take(`"`) {
esc := false
r := ""
for i, c := range p.orig[p.o:] {
if c == '\\' {
esc = true
} else if c == '\x00' || c == '\r' || c == '\n' {
p.xerrorf("invalid nul, cr or lf in string")
} else if esc {
if c == '\\' || c == '"' {
r += string(c)
esc = false
} else {
p.xerrorf("invalid escape char %c", c)
}
} else if c == '"' {
p.o += i + 1
return r
} else {
r += string(c)
}
}
p.xerrorf("missing closing dquote in string")
}
size, sync := p.xliteralSize(false, true)
s := p.conn.xreadliteral(size, sync)
line := p.conn.readline(false)
p.orig, p.upper, p.o = line, toUpper(line), 0
return s
}
func (p *parser) xnil() {
p.xtake("NIL")
}
// Returns NIL as empty string.
func (p *parser) xnilString() string {
if p.take("NIL") {
return ""
}
return p.xstring()
}
func (p *parser) xastring() string {
if p.hasPrefix(`"`) || p.hasPrefix("{") || p.hasPrefix("~{") {
return p.xstring()
}
return p.xtakechars(astringChar, "astring")
}
func contains(s string, c rune) bool {
for _, x := range s {
if x == c {
return true
}
}
return false
}
func (p *parser) xtag() string {
p.xnonempty()
for i, c := range p.orig[p.o:] {
if c == '+' || !contains(astringChar, c) {
return p.xtake1n(i, "tag")
}
}
return p.xtakeall()
}
func (p *parser) xcommand() string {
for i, c := range p.upper[p.o:] {
if !(c >= 'A' && c <= 'Z' || c == ' ' && p.upper[p.o:p.o+i] == "UID") {
return p.xtake1n(i, "command")
}
}
return p.xtakeall()
}
func (p *parser) remainder() string {
return p.orig[p.o:]
}
// ../rfc/9051:6565
func (p *parser) xflag() string {
w, _ := p.takelist(`\`, "$")
s := w + p.xatom()
if s[0] == '\\' {
switch strings.ToLower(s) {
case `\answered`, `\flagged`, `\deleted`, `\seen`, `\draft`:
default:
p.xerrorf("unknown system flag %s", s)
}
}
return s
}
func (p *parser) xflagList() (l []string) {
p.xtake("(")
if !p.hasPrefix(")") {
l = append(l, p.xflag())
}
for !p.take(")") {
p.xspace()
l = append(l, p.xflag())
}
return
}
func (p *parser) xatom() string {
return p.xtakechars(atomChar, "atom")
}
func (p *parser) xdecodeMailbox(s string) string {
// UTF-7 is deprecated for IMAP4rev2-only clients, and not used with UTF8=ACCEPT.
// The future should be without UTF-7, we don't encode/decode it with modern
// clients. Most clients are IMAP4rev1, we need to handle UTF-7.
// ../rfc/3501:964 ../rfc/9051:7885
// Thunderbird will enable UTF8=ACCEPT and send "&" unencoded. ../rfc/9051:7953
if p.conn.utf8strings() {
return s
}
ns, err := utf7decode(s)
if err != nil {
p.xerrorf("decoding utf7 mailbox name: %v", err)
}
return ns
}
func (p *parser) xmailbox() string {
s := p.xastring()
return p.xdecodeMailbox(s)
}
// ../rfc/9051:6605
func (p *parser) xlistMailbox() string {
var s string
if p.hasPrefix(`"`) || p.hasPrefix("{") {
s = p.xstring()
} else {
s = p.xtakechars(atomChar+listWildcards+respSpecials, "list-char")
}
// Presumably UTF-7 encoding applies to mailbox patterns too.
return p.xdecodeMailbox(s)
}
// ../rfc/9051:6707 ../rfc/9051:6848 ../rfc/5258:1095 ../rfc/5258:1169 ../rfc/5258:1196
func (p *parser) xmboxOrPat() ([]string, bool) {
if !p.take("(") {
return []string{p.xlistMailbox()}, false
}
l := []string{p.xlistMailbox()}
for !p.take(")") {
p.xspace()
l = append(l, p.xlistMailbox())
}
return l, true
}
// ../rfc/9051:7056, RECENT ../rfc/3501:5047, APPENDLIMIT ../rfc/7889:252, HIGHESTMODSEQ ../rfc/7162:2452, DELETED-STORAGE ../rfc/9208:696
func (p *parser) xstatusAtt() string {
w := p.xtakelist("MESSAGES", "UIDNEXT", "UIDVALIDITY", "UNSEEN", "DELETED-STORAGE", "DELETED", "SIZE", "RECENT", "APPENDLIMIT", "HIGHESTMODSEQ")
if w == "HIGHESTMODSEQ" {
// HIGHESTMODSEQ is a CONDSTORE-enabling parameter. ../rfc/7162:375
p.conn.enabled[capCondstore] = true
}
return w
}
// ../rfc/9051:7133 ../rfc/9051:7034
func (p *parser) xnumSet0(allowStar, allowSearch bool) (r numSet) {
defer p.context("numSet")()
if allowSearch && p.take("$") {
return numSet{searchResult: true}
}
r.ranges = append(r.ranges, p.xnumRange0(allowStar))
for p.take(",") {
r.ranges = append(r.ranges, p.xnumRange0(allowStar))
}
return r
}
func (p *parser) xnumSet() (r numSet) {
return p.xnumSet0(true, true)
}
// parse numRange, which can be just a setNumber.
func (p *parser) xnumRange0(allowStar bool) (r numRange) {
if allowStar && p.take("*") {
r.first.star = true
} else {
r.first.number = p.xnznumber()
}
if p.take(":") {
r.last = &setNumber{}
if allowStar && p.take("*") {
r.last.star = true
} else {
r.last.number = p.xnznumber()
}
}
return
}
// ../rfc/9051:6989 ../rfc/3501:4977
func (p *parser) xsectionMsgtext() (r *sectionMsgtext) {
defer p.context("sectionMsgtext")()
msgtextWords := []string{"HEADER.FIELDS.NOT", "HEADER.FIELDS", "HEADER", "TEXT"}
w := p.xtakelist(msgtextWords...)
r = &sectionMsgtext{s: w}
if strings.HasPrefix(w, "HEADER.FIELDS") {
p.xspace()
p.xtake("(")
r.headers = append(r.headers, textproto.CanonicalMIMEHeaderKey(p.xastring()))
for {
if p.take(")") {
break
}
p.xspace()
r.headers = append(r.headers, textproto.CanonicalMIMEHeaderKey(p.xastring()))
}
}
return
}
// ../rfc/9051:6999 ../rfc/3501:4991
func (p *parser) xsectionSpec() (r *sectionSpec) {
defer p.context("parseSectionSpec")()
n, ok := p.nznumber()
if !ok {
return &sectionSpec{msgtext: p.xsectionMsgtext()}
}
defer p.context("part...")()
pt := &sectionPart{}
pt.part = append(pt.part, n)
for {
if !p.take(".") {
break
}
if n, ok := p.nznumber(); ok {
pt.part = append(pt.part, n)
continue
}
if p.take("MIME") {
pt.text = &sectionText{mime: true}
break
}
pt.text = &sectionText{msgtext: p.xsectionMsgtext()}
break
}
return &sectionSpec{part: pt}
}
// ../rfc/9051:6985 ../rfc/3501:4975
func (p *parser) xsection() *sectionSpec {
defer p.context("parseSection")()
p.xtake("[")
if p.take("]") {
return &sectionSpec{}
}
r := p.xsectionSpec()
p.xtake("]")
return r
}
// ../rfc/9051:6841
func (p *parser) xpartial() *partial {
p.xtake("<")
offset := p.xnumber()
p.xtake(".")
count := p.xnznumber()
p.xtake(">")
return &partial{offset, count}
}
// ../rfc/9051:6987
func (p *parser) xsectionBinary() (r []uint32) {
p.xtake("[")
if p.take("]") {
return nil
}
r = append(r, p.xnznumber())
for {
if !p.take(".") {
break
}
r = append(r, p.xnznumber())
}
p.xtake("]")
return r
}
var fetchAttWords = []string{
"ENVELOPE", "FLAGS", "INTERNALDATE", "RFC822.SIZE", "BODYSTRUCTURE", "UID", "BODY.PEEK", "BODY", "BINARY.PEEK", "BINARY.SIZE", "BINARY",
"RFC822.HEADER", "RFC822.TEXT", "RFC822", // older IMAP
"MODSEQ", // CONDSTORE extension.
}
// ../rfc/9051:6557 ../rfc/3501:4751 ../rfc/7162:2483
func (p *parser) xfetchAtt(isUID bool) (r fetchAtt) {
defer p.context("fetchAtt")()
f := p.xtakelist(fetchAttWords...)
r.peek = strings.HasSuffix(f, ".PEEK")
r.field = strings.TrimSuffix(f, ".PEEK")
switch r.field {
case "BODY":
if p.hasPrefix("[") {
r.section = p.xsection()
if p.hasPrefix("<") {
r.partial = p.xpartial()
}
}
case "BINARY":
r.sectionBinary = p.xsectionBinary()
if p.hasPrefix("<") {
r.partial = p.xpartial()
}
case "BINARY.SIZE":
r.sectionBinary = p.xsectionBinary()
case "MODSEQ":
// The RFC text mentions MODSEQ is only for FETCH, not UID FETCH, but the ABNF adds
// the attribute to the shared syntax, so UID FETCH also implements it.
// ../rfc/7162:905
// The wording about when to respond with a MODSEQ attribute could be more clear. ../rfc/7162:923 ../rfc/7162:388
// MODSEQ attribute is a CONDSTORE-enabling parameter. ../rfc/7162:377
p.conn.xensureCondstore(nil)
}
return
}
// ../rfc/9051:6553 ../rfc/3501:4748
func (p *parser) xfetchAtts(isUID bool) []fetchAtt {
defer p.context("fetchAtts")()
fields := func(l ...string) []fetchAtt {
r := make([]fetchAtt, len(l))
for i, s := range l {
r[i] = fetchAtt{field: s}
}
return r
}
if w, ok := p.takelist("ALL", "FAST", "FULL"); ok {
switch w {
case "ALL":
return fields("FLAGS", "INTERNALDATE", "RFC822.SIZE", "ENVELOPE")
case "FAST":
return fields("FLAGS", "INTERNALDATE", "RFC822.SIZE")
case "FULL":
return fields("FLAGS", "INTERNALDATE", "RFC822.SIZE", "ENVELOPE", "BODY")
}
panic("missing case")
}
if !p.hasPrefix("(") {
return []fetchAtt{p.xfetchAtt(isUID)}
}
l := []fetchAtt{}
p.xtake("(")
for {
l = append(l, p.xfetchAtt(isUID))
if !p.take(" ") {
break
}
}
p.xtake(")")
return l
}
func xint(p *parser, s string) int {
v, err := strconv.ParseInt(s, 10, 32)
if err != nil {
p.xerrorf("bad int %q: %v", s, err)
}
return int(v)
}
func (p *parser) digit() (string, bool) {
if p.empty() {
return "", false
}
c := p.orig[p.o]
if c < '0' || c > '9' {
return "", false
}
s := p.orig[p.o : p.o+1]
p.o++
return s, true
}
func (p *parser) xdigit() string {
s, ok := p.digit()
if !ok {
p.xerrorf("expected digit")
}
return s
}
// ../rfc/9051:6492 ../rfc/3501:4695
func (p *parser) xdateDayFixed() int {
if p.take(" ") {
return xint(p, p.xdigit())
}
return xint(p, p.xdigit()+p.xdigit())
}
var months = []string{"jan", "feb", "mar", "apr", "may", "jun", "jul", "aug", "sep", "oct", "nov", "dec"}
// ../rfc/9051:6495 ../rfc/3501:4698
func (p *parser) xdateMonth() time.Month {
s := strings.ToLower(p.xtaken(3))
for i, m := range months {
if m == s {
return time.Month(1 + i)
}
}
p.xerrorf("unknown month %q", s)
return 0
}
// ../rfc/9051:7120 ../rfc/3501:5067
func (p *parser) xtime() (int, int, int) {
h := xint(p, p.xtaken(2))
p.xtake(":")
m := xint(p, p.xtaken(2))
p.xtake(":")
s := xint(p, p.xtaken(2))
return h, m, s
}
// ../rfc/9051:7159 ../rfc/3501:5083
func (p *parser) xzone() (string, int) {
sign := p.xtakelist("+", "-")
s := p.xtaken(4)
v := xint(p, s)
seconds := (v/100)*3600 + (v%100)*60
if sign[0] == '-' {
seconds = -seconds
}
return sign + s, seconds
}
// ../rfc/9051:6502 ../rfc/3501:4713
func (p *parser) xdateTime() time.Time {
// DQUOTE date-day-fixed "-" date-month "-" date-year SP time SP zone DQUOTE
p.xtake(`"`)
day := p.xdateDayFixed()
p.xtake("-")
month := p.xdateMonth()
p.xtake("-")
year := xint(p, p.xtaken(4))
p.xspace()
hours, minutes, seconds := p.xtime()
p.xspace()
name, zoneSeconds := p.xzone()
p.xtake(`"`)
loc := time.FixedZone(name, zoneSeconds)
return time.Date(year, month, day, hours, minutes, seconds, 0, loc)
}
// ../rfc/9051:6655 ../rfc/7888:330 ../rfc/3501:4801
func (p *parser) xliteralSize(lit8 bool, checkSize bool) (size int64, sync bool) {
// todo: enforce that we get non-binary when ~ isn't present?
if lit8 {
p.take("~")
}
p.xtake("{")
size = p.xnumber64()
sync = !p.take("+")
p.xtake("}")
p.xempty()
if checkSize {
// ../rfc/7888:249
var errmsg string
const (
litSizeMax = 100 * 1024
totalLitSizeMax = 10 * litSizeMax
litMax = 1000
)
p.literalSize += size
p.literals++
if size > litSizeMax {
errmsg = fmt.Sprintf("max literal size %d is larger than allowed %d", size, litSizeMax)
} else if p.literalSize > totalLitSizeMax {
errmsg = fmt.Sprintf("max total literal size for command %d is larger than allowed %d", p.literalSize, totalLitSizeMax)
} else if p.literals > litMax {
errmsg = fmt.Sprintf("max literals for command %d is larger than allowed %d", p.literals, litMax)
}
if errmsg != "" {
// ../rfc/9051:357 ../rfc/3501:347
err := errors.New("literal too big: " + errmsg)
if sync {
errmsg = ""
} else {
errmsg = "* BYE [ALERT] " + errmsg
}
panic(syntaxError{errmsg, "TOOBIG", err.Error(), err})
}
}
return size, sync
}
var searchKeyWords = []string{
"ALL", "ANSWERED", "BCC",
"BEFORE", "BODY",
"CC", "DELETED", "FLAGGED",
"FROM", "KEYWORD",
"NEW", "OLD", "ON", "RECENT", "SEEN",
"SINCE", "SUBJECT",
"TEXT", "TO",
"UNANSWERED", "UNDELETED", "UNFLAGGED",
"UNKEYWORD", "UNSEEN",
"DRAFT", "HEADER",
"LARGER", "NOT",
"OR",
"SENTBEFORE", "SENTON",
"SENTSINCE", "SMALLER",
"UID", "UNDRAFT",
"MODSEQ", // CONDSTORE extension.
}
// ../rfc/9051:6923 ../rfc/3501:4957, MODSEQ ../rfc/7162:2492
// differences: rfc 9051 removes NEW, OLD, RECENT and makes SMALLER and LARGER number64 instead of number.
func (p *parser) xsearchKey() *searchKey {
if p.take("(") {
sk := p.xsearchKey()
l := []searchKey{*sk}
for !p.take(")") {
p.xspace()
l = append(l, *p.xsearchKey())
}
return &searchKey{searchKeys: l}
}
w, ok := p.takelist(searchKeyWords...)
if !ok {
seqs := p.xnumSet()
return &searchKey{seqSet: &seqs}
}
sk := &searchKey{op: w}
switch sk.op {
case "ALL":
case "ANSWERED":
case "BCC":
p.xspace()
sk.astring = p.xastring()
case "BEFORE":
p.xspace()
sk.date = p.xdate()
case "BODY":
p.xspace()
sk.astring = p.xastring()
case "CC":
p.xspace()
sk.astring = p.xastring()
case "DELETED":
case "FLAGGED":
case "FROM":
p.xspace()
sk.astring = p.xastring()
case "KEYWORD":
p.xspace()
sk.atom = p.xatom()
case "NEW":
case "OLD":
case "ON":
p.xspace()
sk.date = p.xdate()
case "RECENT":
case "SEEN":
case "SINCE":
p.xspace()
sk.date = p.xdate()
case "SUBJECT":
p.xspace()
sk.astring = p.xastring()
case "TEXT":
p.xspace()
sk.astring = p.xastring()
case "TO":
p.xspace()
sk.astring = p.xastring()
case "UNANSWERED":
case "UNDELETED":
case "UNFLAGGED":
case "UNKEYWORD":
p.xspace()
sk.atom = p.xatom()
case "UNSEEN":
case "DRAFT":
case "HEADER":
p.xspace()
sk.headerField = p.xastring()
p.xspace()
sk.astring = p.xastring()
case "LARGER":
p.xspace()
sk.number = p.xnumber64()
case "NOT":
p.xspace()
sk.searchKey = p.xsearchKey()
case "OR":
p.xspace()
sk.searchKey = p.xsearchKey()
p.xspace()
sk.searchKey2 = p.xsearchKey()
case "SENTBEFORE":
p.xspace()
sk.date = p.xdate()
case "SENTON":
p.xspace()
sk.date = p.xdate()
case "SENTSINCE":
p.xspace()
sk.date = p.xdate()
case "SMALLER":
p.xspace()
sk.number = p.xnumber64()
case "UID":
p.xspace()
sk.uidSet = p.xnumSet()
case "UNDRAFT":
case "MODSEQ":
// ../rfc/7162:1045 ../rfc/7162:2499
p.xspace()
if p.take(`"`) {
// We don't do anything with this field, so parse and ignore.
p.xtake(`/FLAGS/`)
if p.take(`\`) {
p.xtake(`\`) // ../rfc/7162:1072
}
p.xatom()
p.xtake(`"`)
p.xspace()
p.xtakelist("PRIV", "SHARED", "ALL")
p.xspace()
}
v := p.xnumber64()
sk.clientModseq = &v
// MODSEQ is a CONDSTORE-enabling parameter. ../rfc/7162:377
p.conn.enabled[capCondstore] = true
default:
p.xerrorf("missing case for op %q", sk.op)
}
return sk
}
// hasModseq returns whether there is a modseq filter anywhere in the searchkey.
func (sk searchKey) hasModseq() bool {
if sk.clientModseq != nil {
return true
}
for _, e := range sk.searchKeys {
if e.hasModseq() {
return true
}
}
if sk.searchKey != nil && sk.searchKey.hasModseq() {
return true
}
if sk.searchKey2 != nil && sk.searchKey2.hasModseq() {
return true
}
return false
}
// ../rfc/9051:6489 ../rfc/3501:4692
func (p *parser) xdateDay() int {
d := p.xdigit()
if s, ok := p.digit(); ok {
d += s
}
return xint(p, d)
}
// ../rfc/9051:6487 ../rfc/3501:4690
func (p *parser) xdate() time.Time {
dquote := p.take(`"`)
day := p.xdateDay()
p.xtake("-")
mon := p.xdateMonth()
p.xtake("-")
year := xint(p, p.xtaken(4))
if dquote {
p.take(`"`)
}
return time.Date(year, mon, day, 0, 0, 0, 0, time.UTC)
}