go.mod: golang.org/x/crypto v0.1.0

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>

vendor/golang.org/x/net/http2/hpack/encode.go

@@ -191,7 +191,7 @@ func appendTableSize(dst []byte, v uint32) []byte {
 // bit prefix, to dst and returns the extended buffer.
 //
 // See
-// http://http2.github.io/http2-spec/compression.html#integer.representation
+// https://httpwg.org/specs/rfc7541.html#integer.representation
 func appendVarInt(dst []byte, n byte, i uint64) []byte {
 	k := uint64((1 << n) - 1)
 	if i < k {

vendor/golang.org/x/net/http2/hpack/hpack.go

@@ -59,7 +59,7 @@ func (hf HeaderField) String() string {
 
 // Size returns the size of an entry per RFC 7541 section 4.1.
 func (hf HeaderField) Size() uint32 {
-	// http://http2.github.io/http2-spec/compression.html#rfc.section.4.1
+	// https://httpwg.org/specs/rfc7541.html#rfc.section.4.1
 	// "The size of the dynamic table is the sum of the size of
 	// its entries. The size of an entry is the sum of its name's
 	// length in octets (as defined in Section 5.2), its value's
@@ -158,7 +158,7 @@ func (d *Decoder) SetAllowedMaxDynamicTableSize(v uint32) {
 }
 
 type dynamicTable struct {
-	// http://http2.github.io/http2-spec/compression.html#rfc.section.2.3.2
+	// https://httpwg.org/specs/rfc7541.html#rfc.section.2.3.2
 	table          headerFieldTable
 	size           uint32 // in bytes
 	maxSize        uint32 // current maxSize
@@ -307,27 +307,27 @@ func (d *Decoder) parseHeaderFieldRepr() error {
 	case b&128 != 0:
 		// Indexed representation.
 		// High bit set?
-		// http://http2.github.io/http2-spec/compression.html#rfc.section.6.1
+		// https://httpwg.org/specs/rfc7541.html#rfc.section.6.1
 		return d.parseFieldIndexed()
 	case b&192 == 64:
 		// 6.2.1 Literal Header Field with Incremental Indexing
 		// 0b10xxxxxx: top two bits are 10
-		// http://http2.github.io/http2-spec/compression.html#rfc.section.6.2.1
+		// https://httpwg.org/specs/rfc7541.html#rfc.section.6.2.1
 		return d.parseFieldLiteral(6, indexedTrue)
 	case b&240 == 0:
 		// 6.2.2 Literal Header Field without Indexing
 		// 0b0000xxxx: top four bits are 0000
-		// http://http2.github.io/http2-spec/compression.html#rfc.section.6.2.2
+		// https://httpwg.org/specs/rfc7541.html#rfc.section.6.2.2
 		return d.parseFieldLiteral(4, indexedFalse)
 	case b&240 == 16:
 		// 6.2.3 Literal Header Field never Indexed
 		// 0b0001xxxx: top four bits are 0001
-		// http://http2.github.io/http2-spec/compression.html#rfc.section.6.2.3
+		// https://httpwg.org/specs/rfc7541.html#rfc.section.6.2.3
 		return d.parseFieldLiteral(4, indexedNever)
 	case b&224 == 32:
 		// 6.3 Dynamic Table Size Update
 		// Top three bits are '001'.
-		// http://http2.github.io/http2-spec/compression.html#rfc.section.6.3
+		// https://httpwg.org/specs/rfc7541.html#rfc.section.6.3
 		return d.parseDynamicTableSizeUpdate()
 	}
 
@@ -420,7 +420,7 @@ var errVarintOverflow = DecodingError{errors.New("varint integer overflow")}
 
 // readVarInt reads an unsigned variable length integer off the
 // beginning of p. n is the parameter as described in
-// http://http2.github.io/http2-spec/compression.html#rfc.section.5.1.
+// https://httpwg.org/specs/rfc7541.html#rfc.section.5.1.
 //
 // n must always be between 1 and 8.
 //

vendor/golang.org/x/net/http2/hpack/huffman.go

@@ -169,25 +169,50 @@ func buildRootHuffmanNode() {
 // AppendHuffmanString appends s, as encoded in Huffman codes, to dst
 // and returns the extended buffer.
 func AppendHuffmanString(dst []byte, s string) []byte {
-	rembits := uint8(8)
-
+	// This relies on the maximum huffman code length being 30 (See tables.go huffmanCodeLen array)
+	// So if a uint64 buffer has less than 32 valid bits can always accommodate another huffmanCode.
+	var (
+		x uint64 // buffer
+		n uint   // number valid of bits present in x
+	)
 	for i := 0; i < len(s); i++ {
-		if rembits == 8 {
-			dst = append(dst, 0)
+		c := s[i]
+		n += uint(huffmanCodeLen[c])
+		x <<= huffmanCodeLen[c] % 64
+		x |= uint64(huffmanCodes[c])
+		if n >= 32 {
+			n %= 32             // Normally would be -= 32 but %= 32 informs compiler 0 <= n <= 31 for upcoming shift
+			y := uint32(x >> n) // Compiler doesn't combine memory writes if y isn't uint32
+			dst = append(dst, byte(y>>24), byte(y>>16), byte(y>>8), byte(y))
 		}
-		dst, rembits = appendByteToHuffmanCode(dst, rembits, s[i])
 	}
-
-	if rembits < 8 {
-		// special EOS symbol
-		code := uint32(0x3fffffff)
-		nbits := uint8(30)
-
-		t := uint8(code >> (nbits - rembits))
-		dst[len(dst)-1] |= t
+	// Add padding bits if necessary
+	if over := n % 8; over > 0 {
+		const (
+			eosCode    = 0x3fffffff
+			eosNBits   = 30
+			eosPadByte = eosCode >> (eosNBits - 8)
+		)
+		pad := 8 - over
+		x = (x << pad) | (eosPadByte >> over)
+		n += pad // 8 now divides into n exactly
 	}
-
-	return dst
+	// n in (0, 8, 16, 24, 32)
+	switch n / 8 {
+	case 0:
+		return dst
+	case 1:
+		return append(dst, byte(x))
+	case 2:
+		y := uint16(x)
+		return append(dst, byte(y>>8), byte(y))
+	case 3:
+		y := uint16(x >> 8)
+		return append(dst, byte(y>>8), byte(y), byte(x))
+	}
+	//	case 4:
+	y := uint32(x)
+	return append(dst, byte(y>>24), byte(y>>16), byte(y>>8), byte(y))
 }
 
 // HuffmanEncodeLength returns the number of bytes required to encode
@@ -199,35 +224,3 @@ func HuffmanEncodeLength(s string) uint64 {
 	}
 	return (n + 7) / 8
 }
-
-// appendByteToHuffmanCode appends Huffman code for c to dst and
-// returns the extended buffer and the remaining bits in the last
-// element. The appending is not byte aligned and the remaining bits
-// in the last element of dst is given in rembits.
-func appendByteToHuffmanCode(dst []byte, rembits uint8, c byte) ([]byte, uint8) {
-	code := huffmanCodes[c]
-	nbits := huffmanCodeLen[c]
-
-	for {
-		if rembits > nbits {
-			t := uint8(code << (rembits - nbits))
-			dst[len(dst)-1] |= t
-			rembits -= nbits
-			break
-		}
-
-		t := uint8(code >> (nbits - rembits))
-		dst[len(dst)-1] |= t
-
-		nbits -= rembits
-		rembits = 8
-
-		if nbits == 0 {
-			break
-		}
-
-		dst = append(dst, 0)
-	}
-
-	return dst, rembits
-}