diff options
-rw-r--r-- | lib/b64.go | 32 |
1 files changed, 32 insertions, 0 deletions
@@ -19,6 +19,38 @@ func HexToBase64(hex string) string { return b64 } +func Base64ToBytes(enc string) []byte { + enc = stripSpaceChars(enc) + + l := len(enc) + bs := make([]byte, 3*(l/4)) + + // Base64 decode. + for i, j := 0, 0; i <= l-4; i, j = i+4, j+3 { + // Jam 24 bits together. + a := index(enc[i])<<18 | + index(enc[i+1])<<12 | + index(enc[i+2])<<6 | + index(enc[i+3]) + + // Get first byte. + bs[j] = byte(a >> 16) + + if enc[i+2] == '=' { + return bs[0 : j+1] + } + // Get second byte. + bs[j+1] = byte((a & 0xff00) >> 8) + + if enc[i+3] == '=' { + return bs[0 : j+2] + } + // Get third byte. + bs[j+2] = byte(a & 0xff) + } + return bs +} + func encode(b uint16) string { return string(b64_table[b]) } |