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Diffstat (limited to 'src/pkg/encoding/pem/pem.go')
-rw-r--r-- | src/pkg/encoding/pem/pem.go | 277 |
1 files changed, 0 insertions, 277 deletions
diff --git a/src/pkg/encoding/pem/pem.go b/src/pkg/encoding/pem/pem.go deleted file mode 100644 index 8ff7ee8c3..000000000 --- a/src/pkg/encoding/pem/pem.go +++ /dev/null @@ -1,277 +0,0 @@ -// Copyright 2009 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -// Package pem implements the PEM data encoding, which originated in Privacy -// Enhanced Mail. The most common use of PEM encoding today is in TLS keys and -// certificates. See RFC 1421. -package pem - -import ( - "bytes" - "encoding/base64" - "io" - "sort" -) - -// A Block represents a PEM encoded structure. -// -// The encoded form is: -// -----BEGIN Type----- -// Headers -// base64-encoded Bytes -// -----END Type----- -// where Headers is a possibly empty sequence of Key: Value lines. -type Block struct { - Type string // The type, taken from the preamble (i.e. "RSA PRIVATE KEY"). - Headers map[string]string // Optional headers. - Bytes []byte // The decoded bytes of the contents. Typically a DER encoded ASN.1 structure. -} - -// getLine results the first \r\n or \n delineated line from the given byte -// array. The line does not include trailing whitespace or the trailing new -// line bytes. The remainder of the byte array (also not including the new line -// bytes) is also returned and this will always be smaller than the original -// argument. -func getLine(data []byte) (line, rest []byte) { - i := bytes.Index(data, []byte{'\n'}) - var j int - if i < 0 { - i = len(data) - j = i - } else { - j = i + 1 - if i > 0 && data[i-1] == '\r' { - i-- - } - } - return bytes.TrimRight(data[0:i], " \t"), data[j:] -} - -// removeWhitespace returns a copy of its input with all spaces, tab and -// newline characters removed. -func removeWhitespace(data []byte) []byte { - result := make([]byte, len(data)) - n := 0 - - for _, b := range data { - if b == ' ' || b == '\t' || b == '\r' || b == '\n' { - continue - } - result[n] = b - n++ - } - - return result[0:n] -} - -var pemStart = []byte("\n-----BEGIN ") -var pemEnd = []byte("\n-----END ") -var pemEndOfLine = []byte("-----") - -// Decode will find the next PEM formatted block (certificate, private key -// etc) in the input. It returns that block and the remainder of the input. If -// no PEM data is found, p is nil and the whole of the input is returned in -// rest. -func Decode(data []byte) (p *Block, rest []byte) { - // pemStart begins with a newline. However, at the very beginning of - // the byte array, we'll accept the start string without it. - rest = data - if bytes.HasPrefix(data, pemStart[1:]) { - rest = rest[len(pemStart)-1 : len(data)] - } else if i := bytes.Index(data, pemStart); i >= 0 { - rest = rest[i+len(pemStart) : len(data)] - } else { - return nil, data - } - - typeLine, rest := getLine(rest) - if !bytes.HasSuffix(typeLine, pemEndOfLine) { - return decodeError(data, rest) - } - typeLine = typeLine[0 : len(typeLine)-len(pemEndOfLine)] - - p = &Block{ - Headers: make(map[string]string), - Type: string(typeLine), - } - - for { - // This loop terminates because getLine's second result is - // always smaller than its argument. - if len(rest) == 0 { - return nil, data - } - line, next := getLine(rest) - - i := bytes.Index(line, []byte{':'}) - if i == -1 { - break - } - - // TODO(agl): need to cope with values that spread across lines. - key, val := line[0:i], line[i+1:] - key = bytes.TrimSpace(key) - val = bytes.TrimSpace(val) - p.Headers[string(key)] = string(val) - rest = next - } - - i := bytes.Index(rest, pemEnd) - if i < 0 { - return decodeError(data, rest) - } - base64Data := removeWhitespace(rest[0:i]) - - p.Bytes = make([]byte, base64.StdEncoding.DecodedLen(len(base64Data))) - n, err := base64.StdEncoding.Decode(p.Bytes, base64Data) - if err != nil { - return decodeError(data, rest) - } - p.Bytes = p.Bytes[0:n] - - _, rest = getLine(rest[i+len(pemEnd):]) - - return -} - -func decodeError(data, rest []byte) (*Block, []byte) { - // If we get here then we have rejected a likely looking, but - // ultimately invalid PEM block. We need to start over from a new - // position. We have consumed the preamble line and will have consumed - // any lines which could be header lines. However, a valid preamble - // line is not a valid header line, therefore we cannot have consumed - // the preamble line for the any subsequent block. Thus, we will always - // find any valid block, no matter what bytes precede it. - // - // For example, if the input is - // - // -----BEGIN MALFORMED BLOCK----- - // junk that may look like header lines - // or data lines, but no END line - // - // -----BEGIN ACTUAL BLOCK----- - // realdata - // -----END ACTUAL BLOCK----- - // - // we've failed to parse using the first BEGIN line - // and now will try again, using the second BEGIN line. - p, rest := Decode(rest) - if p == nil { - rest = data - } - return p, rest -} - -const pemLineLength = 64 - -type lineBreaker struct { - line [pemLineLength]byte - used int - out io.Writer -} - -func (l *lineBreaker) Write(b []byte) (n int, err error) { - if l.used+len(b) < pemLineLength { - copy(l.line[l.used:], b) - l.used += len(b) - return len(b), nil - } - - n, err = l.out.Write(l.line[0:l.used]) - if err != nil { - return - } - excess := pemLineLength - l.used - l.used = 0 - - n, err = l.out.Write(b[0:excess]) - if err != nil { - return - } - - n, err = l.out.Write([]byte{'\n'}) - if err != nil { - return - } - - return l.Write(b[excess:]) -} - -func (l *lineBreaker) Close() (err error) { - if l.used > 0 { - _, err = l.out.Write(l.line[0:l.used]) - if err != nil { - return - } - _, err = l.out.Write([]byte{'\n'}) - } - - return -} - -func writeHeader(out io.Writer, k, v string) error { - _, err := out.Write([]byte(k + ": " + v + "\n")) - return err -} - -func Encode(out io.Writer, b *Block) error { - if _, err := out.Write(pemStart[1:]); err != nil { - return err - } - if _, err := out.Write([]byte(b.Type + "-----\n")); err != nil { - return err - } - - if len(b.Headers) > 0 { - const procType = "Proc-Type" - h := make([]string, 0, len(b.Headers)) - hasProcType := false - for k := range b.Headers { - if k == procType { - hasProcType = true - continue - } - h = append(h, k) - } - // The Proc-Type header must be written first. - // See RFC 1421, section 4.6.1.1 - if hasProcType { - if err := writeHeader(out, procType, b.Headers[procType]); err != nil { - return err - } - } - // For consistency of output, write other headers sorted by key. - sort.Strings(h) - for _, k := range h { - if err := writeHeader(out, k, b.Headers[k]); err != nil { - return err - } - } - if _, err := out.Write([]byte{'\n'}); err != nil { - return err - } - } - - var breaker lineBreaker - breaker.out = out - - b64 := base64.NewEncoder(base64.StdEncoding, &breaker) - if _, err := b64.Write(b.Bytes); err != nil { - return err - } - b64.Close() - breaker.Close() - - if _, err := out.Write(pemEnd[1:]); err != nil { - return err - } - _, err := out.Write([]byte(b.Type + "-----\n")) - return err -} - -func EncodeToMemory(b *Block) []byte { - var buf bytes.Buffer - Encode(&buf, b) - return buf.Bytes() -} |