diff options
Diffstat (limited to 'src/mongo/gotools/vendor/src/golang.org/x/crypto/pkcs12/bmp-string.go')
-rw-r--r-- | src/mongo/gotools/vendor/src/golang.org/x/crypto/pkcs12/bmp-string.go | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/src/mongo/gotools/vendor/src/golang.org/x/crypto/pkcs12/bmp-string.go b/src/mongo/gotools/vendor/src/golang.org/x/crypto/pkcs12/bmp-string.go new file mode 100644 index 00000000000..284d2a68f1e --- /dev/null +++ b/src/mongo/gotools/vendor/src/golang.org/x/crypto/pkcs12/bmp-string.go @@ -0,0 +1,50 @@ +// Copyright 2015 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 pkcs12 + +import ( + "errors" + "unicode/utf16" +) + +// bmpString returns s encoded in UCS-2 with a zero terminator. +func bmpString(s string) ([]byte, error) { + // References: + // https://tools.ietf.org/html/rfc7292#appendix-B.1 + // http://en.wikipedia.org/wiki/Plane_(Unicode)#Basic_Multilingual_Plane + // - non-BMP characters are encoded in UTF 16 by using a surrogate pair of 16-bit codes + // EncodeRune returns 0xfffd if the rune does not need special encoding + // - the above RFC provides the info that BMPStrings are NULL terminated. + + ret := make([]byte, 0, 2*len(s)+2) + + for _, r := range s { + if t, _ := utf16.EncodeRune(r); t != 0xfffd { + return nil, errors.New("pkcs12: string contains characters that cannot be encoded in UCS-2") + } + ret = append(ret, byte(r/256), byte(r%256)) + } + + return append(ret, 0, 0), nil +} + +func decodeBMPString(bmpString []byte) (string, error) { + if len(bmpString)%2 != 0 { + return "", errors.New("pkcs12: odd-length BMP string") + } + + // strip terminator if present + if l := len(bmpString); l >= 2 && bmpString[l-1] == 0 && bmpString[l-2] == 0 { + bmpString = bmpString[:l-2] + } + + s := make([]uint16, 0, len(bmpString)/2) + for len(bmpString) > 0 { + s = append(s, uint16(bmpString[0])<<8+uint16(bmpString[1])) + bmpString = bmpString[2:] + } + + return string(utf16.Decode(s)), nil +} |