// Like GosaDecrypt() but operates in-place on buf.
// Returns true if decryption successful and false if not.
// If false is returned, the buffer contents may be destroyed, but only
// if further decryption attempts with other keys would be pointless anyway,
// because of some fatal condition (such as the data not being a multiple of
// the cipher's block size).
func GosaDecryptBuffer(buf *bytes.Buffer, key string) bool {
buf.TrimSpace()
if buf.Len() < 11 {
return false
} // minimum length of unencrypted <xml></xml>
data := buf.Bytes()
if string(data[0:5]) == "<xml>" {
return true
}
// Fixes the following:
// * gosa-si bug in the following line:
// if( $client_answer =~ s/session_id=(\d+)$// ) {
// This leaves the "." before "session_id" which breaks base64
// * new gosa-si protocol has ";IP:PORT" appended to message
// which also breaks base64
for semicolon_period := 0; semicolon_period < len(data); semicolon_period++ {
if data[semicolon_period] == ';' || data[semicolon_period] == '.' {
buf.Trim(0, semicolon_period)
data = buf.Bytes()
break
}
}
aescipher, _ := aes.NewCipher([]byte(util.Md5sum(key)))
crypter := cipher.NewCBCDecrypter(aescipher, config.InitializationVector)
cryptotest := make([]byte, (((3*aes.BlockSize)+2)/3)<<2)
n := copy(cryptotest, data)
cryptotest = cryptotest[0:n]
cryptotest = util.Base64DecodeInPlace(cryptotest)
n = (len(cryptotest) / aes.BlockSize) * aes.BlockSize
cryptotest = cryptotest[0:n]
crypter.CryptBlocks(cryptotest, cryptotest)
if !strings.Contains(string(cryptotest), "<xml>") {
return false
}
data = util.Base64DecodeInPlace(data)
buf.Trim(0, len(data))
data = buf.Bytes()
if buf.Len()%aes.BlockSize != 0 {
// this condition is fatal => further decryption attempts are pointless
buf.Reset()
return false
}
crypter = cipher.NewCBCDecrypter(aescipher, config.InitializationVector)
crypter.CryptBlocks(data, data)
buf.TrimSpace() // removes 0 padding, too
return true
}
// Handles the message "CLMSG_save_fai_log".
// buf: the decrypted message
func clmsg_save_fai_log(buf *bytes.Buffer) {
macaddress := ""
action := ""
start := 0
end := 0
data := buf.Bytes()
for i := 0; i < len(data)-19; i++ {
if data[i] == '<' {
if i+12+17 <= len(data) && match(data, i, "<macaddress>") {
macaddress = string(data[i+12 : i+12+17])
} else if match(data, i, "<fai_action>") {
for k := i + 12; k < len(data); k++ {
if data[k] == '<' {
action = string(data[i+12 : k])
i = k
break
}
}
} else if match(data, i, "<CLMSG_save_fai_log>") {
start = i + 20
} else if match(data, i, "</CLMSG_save_fai_log>") {
end = i
}
}
}
if !macAddressRegexp.MatchString(macaddress) {
util.Log(0, "ERROR! CLMSG_save_fai_log with illegal <macaddress> \"%v\"", macaddress)
return
}
if !actionRegexp.MatchString(action) {
util.Log(0, "ERROR! CLMSG_save_fai_log with illegal <fai_action> \"%v\"", action)
return
}
util.Log(1, "INFO! Received log files from client %v. Assuming CLMSG_PROGRESS 100", macaddress)
progress_msg := xml.NewHash("xml", "CLMSG_PROGRESS", "100")
progress_msg.Add("macaddress", macaddress)
clmsg_progress(progress_msg)
timestamp := util.MakeTimestamp(time.Now())
logname := action + "_" + timestamp[0:8] + "_" + timestamp[8:]
logdir := path.Join(config.FAILogPath, strings.ToLower(macaddress), logname)
// NOTE: 1kB = 1000B, 1kiB = 1024B
util.Log(1, "INFO! Storing %vkB of %v log files from %v in %v", len(data)/1000, action, macaddress, logdir)
err := os.MkdirAll(logdir, 0755)
if err != nil {
util.Log(0, "ERROR! Error creating log directory \"%v\": %v", logdir, err)
return
}
// Create convenience symlink with the system's name as alias for MAC address.
go util.WithPanicHandler(func() {
if plainname := db.SystemPlainnameForMAC(macaddress); plainname != "none" {
linkpath := path.Join(config.FAILogPath, strings.ToLower(plainname))
link_target, err := os.Readlink(linkpath)
if err != nil && !os.IsNotExist(err.(*os.PathError).Err) {
util.Log(0, "ERROR! %v exists but is not a symlink: %v", linkpath, err)
return
}
if err == nil {
if link_target == strings.ToLower(macaddress) {
return // symlink is already correct => nothing to do
}
util.Log(0, "WARNING! Machine %v has a new MAC %v . Removing old symlink %v => %v", plainname, macaddress, linkpath, link_target)
err = os.Remove(linkpath)
if err != nil {
util.Log(0, "ERROR! Removing %v failed: %v", linkpath, err)
// Don't bail out. Maybe we can create the new symlink anyway.
}
}
err = os.Symlink(strings.ToLower(macaddress), linkpath)
if err != nil && !os.IsExist(err.(*os.LinkError).Err) {
util.Log(0, "ERROR! Could not create symlink %v => %v: %v", linkpath, strings.ToLower(macaddress), err)
}
}
})
files := []int{}
for i := start; i < end; i++ {
if data[i] == ':' && match(data, i-8, "log_file") {
k := i
i++
for i < end {
if data[i] == ':' {
if k+1 < i {
files = append(files, k+1, i)
}
break
}
i++
}
}
}
files = append(files, end+8)
for i := 0; i < len(files)-1; i += 2 {
fname := string(data[files[i]:files[i+1]])
logdata := data[files[i+1]+1 : files[i+2]-8]
util.Log(1, "INFO! Processing \"%v\" (%vkB)", fname, len(logdata)/1000)
logdata = util.Base64DecodeInPlace(logdata)
// As a precaution, make sure fname contains no slashes.
fname = strings.Replace(fname, "/", "_", -1)
err = ioutil.WriteFile(path.Join(logdir, fname), logdata, 0644)
if err != nil {
util.Log(0, "ERROR! Could not store \"%v\": %v", path.Join(logdir, fname), err)
continue
}
}
}
func testBase64() {
check(util.Base64DecodeString("", nil), []byte{})
check(util.Base64DecodeInPlace([]byte{}), []byte{})
check(util.Base64DecodeString("=", nil), []byte{})
check(util.Base64DecodeInPlace([]byte("=")), []byte{})
check(util.Base64DecodeString(" = ", nil), []byte{})
check(util.Base64DecodeInPlace([]byte(" = ")), []byte{})
check(util.Base64DecodeString("/+/+", nil), []byte{0xff, 0xef, 0xfe})
check(util.Base64DecodeInPlace([]byte("/+/+")), []byte{0xff, 0xef, 0xfe})
check(util.Base64DecodeString("_-_-", nil), []byte{0xff, 0xef, 0xfe})
check(util.Base64DecodeInPlace([]byte("_-_-")), []byte{0xff, 0xef, 0xfe})
var devnull int
check(string(util.Base64DecodeString("SGFsbG8=", nil)), "Hallo")
check(string(util.Base64DecodeInPlace([]byte("SGFsbG8="))), "Hallo")
check(string(util.Base64DecodeString("SGFsbA==", nil)), "Hall")
check(string(util.Base64DecodeInPlace([]byte("SGFsbA=="))), "Hall")
check(string(util.Base64DecodeString("SGFsbG8", nil)), "Hallo")
check(string(util.Base64DecodeInPlace([]byte("SGFsbG8"))), "Hallo")
check(string(util.Base64DecodeString("SGFsbA=", nil)), "Hall")
check(string(util.Base64DecodeInPlace([]byte("SGFsbA="))), "Hall")
check(string(util.Base64DecodeString("SGFsbG8===", nil)), "Hallo")
check(string(util.Base64DecodeInPlace([]byte("SGFsbG8==="))), "Hallo")
check(string(util.Base64DecodeString("SGFsbA", nil)), "Hall")
check(string(util.Base64DecodeInPlace([]byte("SGFsbA"))), "Hall")
check(string(util.Base64DecodeString("SGFsbG8=", &devnull)), "Hallo")
check(devnull, 0)
check(string(util.Base64DecodeString("SGFsbA==", &devnull)), "Hall")
check(devnull, 0)
check(string(util.Base64DecodeString("SGFsbA=", &devnull)), "Hall")
check(devnull, 0)
check(string(util.Base64DecodeString("SGFsbG8===", &devnull)), "Hallo")
check(devnull, 0)
check(string(util.Base64DecodeString("AA", nil)), "\000")
check(string(util.Base64DecodeInPlace([]byte("AA"))), "\000")
check(string(util.Base64DecodeString("AAA", nil)), "\000\000")
check(string(util.Base64DecodeInPlace([]byte("AAA"))), "\000\000")
var zerocarry int
check(string(util.Base64DecodeString("AA", &zerocarry)), "")
check(zerocarry != 0, true)
check(string(util.Base64DecodeString("=", &zerocarry)), "\000")
check(zerocarry, 0)
check(string(util.Base64DecodeString("AAA", &zerocarry)), "")
check(zerocarry != 0, true)
check(string(util.Base64DecodeString("=", &zerocarry)), "\000\000")
check(zerocarry, 0)
testbuf := make([]byte, 1024)
for i := range testbuf {
testbuf[i] = byte(i)
}
error_list := ""
for length := 0; length <= 12; length++ {
for eq := 0; eq <= 4; eq++ {
for err := 0; err <= 12; err++ {
b64_1 := base64.StdEncoding.EncodeToString(testbuf[0 : 512-length])
testslice := b64_1[0:]
errors := []int{0}
for e := 0; e < err; e++ {
errors = append(errors, errors[e]+rand.Intn(len(testslice)-errors[e]))
}
errors = append(errors, len(testslice))
teststr := ""
for i := 0; i < len(errors)-1; i++ {
if i != 0 {
teststr = teststr + "\000\n"
}
teststr = teststr + testslice[errors[i]:errors[i+1]]
}
for i := 0; i < eq; i++ {
teststr += "="
}
// because we're concatenating we need at least 1 "=" if the
// first string ends in an incomplete block
if eq == 0 && (length&3) != 0 {
teststr += "="
}
b64_2 := base64.URLEncoding.EncodeToString(testbuf[512-length:])
testslice = b64_2[0:]
errors = []int{0}
for e := 0; e < err; e++ {
errors = append(errors, errors[e]+rand.Intn(len(testslice)-errors[e]))
}
errors = append(errors, len(testslice))
for i := 0; i < len(errors)-1; i++ {
if i != 0 {
teststr = teststr + " "
}
teststr = teststr + testslice[errors[i]:errors[i+1]]
}
for i := 0; i < eq; i++ {
teststr += "="
}
for parts := 0; parts < 5; parts++ {
stops := []int{0}
for e := 0; e < parts; e++ {
stops = append(stops, stops[e]+rand.Intn(len(teststr)-stops[e]))
}
stops = append(stops, len(teststr))
decoded := ""
carry := 0
for i := 0; i < len(stops)-1; i++ {
decoded += string(util.Base64DecodeString(teststr[stops[i]:stops[i+1]], &carry))
}
if decoded != string(testbuf) {
error_list += fmt.Sprintf("(util.Base64DecodeString() failed for length=%v eq=%v err=%v parts=%v)\n", length, eq, err, parts)
}
buffy := []byte(string(teststr))
decbuffy := util.Base64DecodeInPlace(buffy)
if &(decbuffy[0]) != &(buffy[0]) || // verify the in-place property
string(decbuffy) != string(testbuf) {
error_list += fmt.Sprintf("(util.Base64DecodeInPlace() failed for length=%v eq=%v err=%v parts=%v)\n", length, eq, err, parts)
}
}
}
}
}
check(error_list, "")
buffy := make([]byte, 1024)
st := "Nehmt, esst. Dies ist mein Leib - sprach der Schokohase"
copy(buffy[32:], st)
result := util.Base64EncodeInPlace(buffy[:32+len(st)], 32)
check(&(buffy[0]) == &(result[0]), true)
check(cap(result), cap(buffy))
check(string(result), "TmVobXQsIGVzc3QuIERpZXMgaXN0IG1laW4gTGVpYiAtIHNwcmFjaCBkZXIgU2Nob2tvaGFzZQ==")
st = "Nehmt, esst. Dies ist mein Leib - sprach der Schokohase\n"
copy(buffy[256:], st)
result = util.Base64EncodeInPlace(buffy[:256+len(st)], 256)
check(&(buffy[0]) == &(result[0]), true)
check(cap(result), cap(buffy))
check(string(result), "TmVobXQsIGVzc3QuIERpZXMgaXN0IG1laW4gTGVpYiAtIHNwcmFjaCBkZXIgU2Nob2tvaGFzZQo=")
for n := 0; n <= 12; n++ {
buffy = make([]byte, n)
for i := range buffy {
buffy[i] = byte(i)
}
check(string(util.Base64EncodeString(string(buffy))), base64.StdEncoding.EncodeToString(buffy))
}
}