diff options
Diffstat (limited to 'libraries/spongycastle/pg/src/main/java/org/spongycastle/bcpg/ArmoredInputStream.java')
| -rw-r--r-- | libraries/spongycastle/pg/src/main/java/org/spongycastle/bcpg/ArmoredInputStream.java | 473 |
1 files changed, 473 insertions, 0 deletions
diff --git a/libraries/spongycastle/pg/src/main/java/org/spongycastle/bcpg/ArmoredInputStream.java b/libraries/spongycastle/pg/src/main/java/org/spongycastle/bcpg/ArmoredInputStream.java new file mode 100644 index 000000000..2a0f9e3ee --- /dev/null +++ b/libraries/spongycastle/pg/src/main/java/org/spongycastle/bcpg/ArmoredInputStream.java @@ -0,0 +1,473 @@ +package org.spongycastle.bcpg; + +import java.io.EOFException; +import java.io.IOException; +import java.io.InputStream; +import java.util.Vector; + +/** + * reader for Base64 armored objects - read the headers and then start returning + * bytes when the data is reached. An IOException is thrown if the CRC check + * fails. + */ +public class ArmoredInputStream + extends InputStream +{ + /* + * set up the decoding table. + */ + private static final byte[] decodingTable; + + static + { + decodingTable = new byte[128]; + + for (int i = 'A'; i <= 'Z'; i++) + { + decodingTable[i] = (byte)(i - 'A'); + } + + for (int i = 'a'; i <= 'z'; i++) + { + decodingTable[i] = (byte)(i - 'a' + 26); + } + + for (int i = '0'; i <= '9'; i++) + { + decodingTable[i] = (byte)(i - '0' + 52); + } + + decodingTable['+'] = 62; + decodingTable['/'] = 63; + } + + /** + * decode the base 64 encoded input data. + * + * @return the offset the data starts in out. + */ + private int decode( + int in0, + int in1, + int in2, + int in3, + int[] out) + throws EOFException + { + int b1, b2, b3, b4; + + if (in3 < 0) + { + throw new EOFException("unexpected end of file in armored stream."); + } + + if (in2 == '=') + { + b1 = decodingTable[in0] &0xff; + b2 = decodingTable[in1] & 0xff; + + out[2] = ((b1 << 2) | (b2 >> 4)) & 0xff; + + return 2; + } + else if (in3 == '=') + { + b1 = decodingTable[in0]; + b2 = decodingTable[in1]; + b3 = decodingTable[in2]; + + out[1] = ((b1 << 2) | (b2 >> 4)) & 0xff; + out[2] = ((b2 << 4) | (b3 >> 2)) & 0xff; + + return 1; + } + else + { + b1 = decodingTable[in0]; + b2 = decodingTable[in1]; + b3 = decodingTable[in2]; + b4 = decodingTable[in3]; + + out[0] = ((b1 << 2) | (b2 >> 4)) & 0xff; + out[1] = ((b2 << 4) | (b3 >> 2)) & 0xff; + out[2] = ((b3 << 6) | b4) & 0xff; + + return 0; + } + } + + InputStream in; + boolean start = true; + int[] outBuf = new int[3]; + int bufPtr = 3; + CRC24 crc = new CRC24(); + boolean crcFound = false; + boolean hasHeaders = true; + String header = null; + boolean newLineFound = false; + boolean clearText = false; + boolean restart = false; + Vector headerList= new Vector(); + int lastC = 0; + boolean isEndOfStream; + + /** + * Create a stream for reading a PGP armoured message, parsing up to a header + * and then reading the data that follows. + * + * @param in + */ + public ArmoredInputStream( + InputStream in) + throws IOException + { + this(in, true); + } + + /** + * Create an armoured input stream which will assume the data starts + * straight away, or parse for headers first depending on the value of + * hasHeaders. + * + * @param in + * @param hasHeaders true if headers are to be looked for, false otherwise. + */ + public ArmoredInputStream( + InputStream in, + boolean hasHeaders) + throws IOException + { + this.in = in; + this.hasHeaders = hasHeaders; + + if (hasHeaders) + { + parseHeaders(); + } + + start = false; + } + + public int available() + throws IOException + { + return in.available(); + } + + private boolean parseHeaders() + throws IOException + { + header = null; + + int c; + int last = 0; + boolean headerFound = false; + + headerList = new Vector(); + + // + // if restart we already have a header + // + if (restart) + { + headerFound = true; + } + else + { + while ((c = in.read()) >= 0) + { + if (c == '-' && (last == 0 || last == '\n' || last == '\r')) + { + headerFound = true; + break; + } + + last = c; + } + } + + if (headerFound) + { + StringBuffer buf = new StringBuffer("-"); + boolean eolReached = false; + boolean crLf = false; + + if (restart) // we've had to look ahead two '-' + { + buf.append('-'); + } + + while ((c = in.read()) >= 0) + { + if (last == '\r' && c == '\n') + { + crLf = true; + } + if (eolReached && (last != '\r' && c == '\n')) + { + break; + } + if (eolReached && c == '\r') + { + break; + } + if (c == '\r' || (last != '\r' && c == '\n')) + { + String line = buf.toString(); + if (line.trim().length() == 0) + { + break; + } + headerList.addElement(line); + buf.setLength(0); + } + + if (c != '\n' && c != '\r') + { + buf.append((char)c); + eolReached = false; + } + else + { + if (c == '\r' || (last != '\r' && c == '\n')) + { + eolReached = true; + } + } + + last = c; + } + + if (crLf) + { + in.read(); // skip last \n + } + } + + if (headerList.size() > 0) + { + header = (String)headerList.elementAt(0); + } + + clearText = "-----BEGIN PGP SIGNED MESSAGE-----".equals(header); + newLineFound = true; + + return headerFound; + } + + /** + * @return true if we are inside the clear text section of a PGP + * signed message. + */ + public boolean isClearText() + { + return clearText; + } + + /** + * @return true if the stream is actually at end of file. + */ + public boolean isEndOfStream() + { + return isEndOfStream; + } + + /** + * Return the armor header line (if there is one) + * @return the armor header line, null if none present. + */ + public String getArmorHeaderLine() + { + return header; + } + + /** + * Return the armor headers (the lines after the armor header line), + * @return an array of armor headers, null if there aren't any. + */ + public String[] getArmorHeaders() + { + if (headerList.size() <= 1) + { + return null; + } + + String[] hdrs = new String[headerList.size() - 1]; + + for (int i = 0; i != hdrs.length; i++) + { + hdrs[i] = (String)headerList.elementAt(i + 1); + } + + return hdrs; + } + + private int readIgnoreSpace() + throws IOException + { + int c = in.read(); + + while (c == ' ' || c == '\t') + { + c = in.read(); + } + + return c; + } + + public int read() + throws IOException + { + int c; + + if (start) + { + if (hasHeaders) + { + parseHeaders(); + } + + crc.reset(); + start = false; + } + + if (clearText) + { + c = in.read(); + + if (c == '\r' || (c == '\n' && lastC != '\r')) + { + newLineFound = true; + } + else if (newLineFound && c == '-') + { + c = in.read(); + if (c == '-') // a header, not dash escaped + { + clearText = false; + start = true; + restart = true; + } + else // a space - must be a dash escape + { + c = in.read(); + } + newLineFound = false; + } + else + { + if (c != '\n' && lastC != '\r') + { + newLineFound = false; + } + } + + lastC = c; + + if (c < 0) + { + isEndOfStream = true; + } + + return c; + } + + if (bufPtr > 2 || crcFound) + { + c = readIgnoreSpace(); + + if (c == '\r' || c == '\n') + { + c = readIgnoreSpace(); + + while (c == '\n' || c == '\r') + { + c = readIgnoreSpace(); + } + + if (c < 0) // EOF + { + isEndOfStream = true; + return -1; + } + + if (c == '=') // crc reached + { + bufPtr = decode(readIgnoreSpace(), readIgnoreSpace(), readIgnoreSpace(), readIgnoreSpace(), outBuf); + if (bufPtr == 0) + { + int i = ((outBuf[0] & 0xff) << 16) + | ((outBuf[1] & 0xff) << 8) + | (outBuf[2] & 0xff); + + crcFound = true; + + if (i != crc.getValue()) + { + throw new IOException("crc check failed in armored message."); + } + return read(); + } + else + { + throw new IOException("no crc found in armored message."); + } + } + else if (c == '-') // end of record reached + { + while ((c = in.read()) >= 0) + { + if (c == '\n' || c == '\r') + { + break; + } + } + + if (!crcFound) + { + throw new IOException("crc check not found."); + } + + crcFound = false; + start = true; + bufPtr = 3; + + if (c < 0) + { + isEndOfStream = true; + } + + return -1; + } + else // data + { + bufPtr = decode(c, readIgnoreSpace(), readIgnoreSpace(), readIgnoreSpace(), outBuf); + } + } + else + { + if (c >= 0) + { + bufPtr = decode(c, readIgnoreSpace(), readIgnoreSpace(), readIgnoreSpace(), outBuf); + } + else + { + isEndOfStream = true; + return -1; + } + } + } + + c = outBuf[bufPtr++]; + + crc.update(c); + + return c; + } + + public void close() + throws IOException + { + in.close(); + } +} |