/*
Reads and returns the next DER encoded SEQUENCE from r,
which may optionally be base64 encoded and may be preceded
by "garbage". The returned data will always be DER bytes
without preceding garbage and NOT base64 encoded.
The SEQUENCE will only be recognized as valid if
it does not contain APPLICATION or PRIVATE tags or
tags >= 31.
This function takes care not to read more bytes than
necessary which allows the function to be called
multiple times on a stream of concatenated SEQUENCEs.
*/
func ReadNextSEQUENCE(r io.Reader) ([]byte, error) {
b := []byte{0}
var err error
var n int
space := true
var eaters deque.Deque
for {
n, err = r.Read(b)
if err != nil {
return nil, err
}
if n == 0 {
return nil, io.EOF
}
if b[0] == 0x30 { // SEQUENCE
eaters.Push(newRawEater())
}
if b[0] > ' ' {
if space {
eaters.Push(newBase64Eater())
}
space = false
} else {
space = true
}
for i := 0; i < eaters.Count(); {
result := eaters.At(i).(eater).Eat(b[0])
switch result {
case -1: // error
eaters.RemoveAt(i)
case 0: // ok, need more data
i++
case 1: // done
return eaters.At(i).(eater).Data(), nil
}
}
}
}
func Deque(deck *deque.Deque, data ...interface{}) string {
deck.CheckInvariant()
if deck.Count() != len(data) {
return fmt.Sprintf("Count() is %v but should be %v", deck.Count(), len(data))
}
if deck.IsEmpty() != (len(data) == 0) {
return fmt.Sprintf("IsEmpty() should be %v", (len(data) == 0))
}
if deck.IsFull() != (len(data) == deck.Capacity()) {
return fmt.Sprintf("IsFull() should be %v", (len(data) == deck.Capacity()))
}
for i := range data {
if deck.At(i) != data[i] {
return fmt.Sprintf("At(%v) is %v but should be %v", i, deck.At(i), data[i])
}
if deck.Peek(i) != data[len(data)-1-i] {
return fmt.Sprintf("Peek(%v) is %v but should be %v", i, deck.Peek(i), data[len(data)-1-i])
}
p := deck.Put(i, "x")
if p != data[i] {
return fmt.Sprintf("Put(%v,x) is %v but should be %v", i, p, data[i])
}
if deck.Put(i, p).(string) != "x" {
return fmt.Sprintf("Put is broken")
}
p = deck.Poke(i, "x")
if p != data[len(data)-1-i] {
return fmt.Sprintf("Poke(%v,x) is %v but should be %v", i, p, data[len(data)-1-i])
}
if deck.Poke(i, p).(string) != "x" {
return fmt.Sprintf("Poke is broken")
}
if deck.At(i) != data[i] {
return fmt.Sprintf("After Put/Poke At(%v) is %v but should be %v", i, deck.At(i), data[i])
}
if deck.Peek(i) != data[len(data)-1-i] {
return fmt.Sprintf("After Put/Poke Peek(%v) is %v but should be %v", i, deck.Peek(i), data[len(data)-1-i])
}
}
var zero interface{}
if deck.Peek(-1) != zero {
return fmt.Sprintf("Peek(-1) returns %v", deck.Peek(-1))
}
if deck.Peek(-1) != nil {
return fmt.Sprintf("Peek(-1) returns %v", deck.Peek(-1))
}
if deck.Poke(-1, "foo") != zero {
return fmt.Sprintf("Poke(-1,foo) returns not nil")
}
if deck.Poke(-1, "foo") != nil {
return fmt.Sprintf("Poke(-1,foo) returns not nil")
}
if deck.At(-1) != zero {
return fmt.Sprintf("At(-1) returns %v", deck.At(-1))
}
if deck.At(-1) != nil {
return fmt.Sprintf("At(-1) returns %v", deck.At(-1))
}
if deck.Put(-1, "foo") != zero {
return fmt.Sprintf("Put(-1,foo) returns not nil")
}
if deck.Put(-1, "foo") != nil {
return fmt.Sprintf("Put(-1,foo) returns not nil")
}
if deck.Peek(len(data)) != zero {
return fmt.Sprintf("Peek(len(data)) returns %v", deck.Peek(len(data)))
}
if deck.Peek(len(data)) != nil {
return fmt.Sprintf("Peek(len(data)) returns %v", deck.Peek(len(data)))
}
if deck.Poke(len(data), "foo") != zero {
return fmt.Sprintf("Poke(len(data),foo) returns not nil")
}
if deck.Poke(len(data), "foo") != nil {
return fmt.Sprintf("Poke(len(data),foo) returns not nil")
}
if deck.At(len(data)) != zero {
return fmt.Sprintf("At(len(data)) returns %v", deck.At(len(data)))
}
if deck.At(len(data)) != nil {
return fmt.Sprintf("At(len(data)) returns %v", deck.At(len(data)))
}
if deck.Put(len(data), "foo") != zero {
return fmt.Sprintf("Put(len(data),foo) returns not nil")
}
if deck.Put(len(data), "foo") != nil {
return fmt.Sprintf("Put(len(data),foo) returns not nil")
}
if deck.String() != "Deque"+fmt.Sprintf("%v", data) {
return fmt.Sprintf("String() returns \"%v\" instead of \"%v\"", deck.String(), "Deque"+fmt.Sprintf("%v", data))
}
return ""
}