/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ /* This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ #include "nsUTF7ToUnicode.h" #define ENC_DIRECT 0 #define ENC_BASE64 1 //---------------------------------------------------------------------- // Class nsBasicUTF7Decoder [implementation] nsBasicUTF7Decoder::nsBasicUTF7Decoder(char aLastChar, char aEscChar) : nsBufferDecoderSupport(1) { mLastChar = aLastChar; mEscChar = aEscChar; Reset(); } nsresult nsBasicUTF7Decoder::DecodeDirect( const char * aSrc, int32_t * aSrcLength, char16_t * aDest, int32_t * aDestLength) { const char * srcEnd = aSrc + *aSrcLength; const char * src = aSrc; char16_t * destEnd = aDest + *aDestLength; char16_t * dest = aDest; nsresult res = NS_OK; char ch; while (src < srcEnd) { ch = *src; // stop when we meet other chars or end of direct encoded seq. // if (!(DirectEncodable(ch)) || (ch == mEscChar)) { // but we are decoding; so we should be lax; pass everything until escchar if (ch == mEscChar) { res = NS_ERROR_UDEC_ILLEGALINPUT; break; } if (dest >= destEnd) { res = NS_OK_UDEC_MOREOUTPUT; break; } else { *dest++ = ch; src++; } } *aSrcLength = src - aSrc; *aDestLength = dest - aDest; return res; } nsresult nsBasicUTF7Decoder::DecodeBase64( const char * aSrc, int32_t * aSrcLength, char16_t * aDest, int32_t * aDestLength) { const char * srcEnd = aSrc + *aSrcLength; const char * src = aSrc; char16_t * destEnd = aDest + *aDestLength; char16_t * dest = aDest; nsresult res = NS_OK; char ch; uint32_t value; while (src < srcEnd) { ch = *src; // stop when we meet other chars or end of direct encoded seq. value = CharToValue(ch); if (value > 0xff) { res = NS_ERROR_UDEC_ILLEGALINPUT; break; } switch (mEncStep) { case 0: mEncBits = value << 10; break; case 1: mEncBits += value << 4; break; case 2: if (dest >= destEnd) { res = NS_OK_UDEC_MOREOUTPUT; break; } mEncBits += value >> 2; *(dest++) = (char16_t) mEncBits; mEncBits = (value & 0x03) << 14; break; case 3: mEncBits += value << 8; break; case 4: mEncBits += value << 2; break; case 5: if (dest >= destEnd) { res = NS_OK_UDEC_MOREOUTPUT; break; } mEncBits += value >> 4; *(dest++) = (char16_t) mEncBits; mEncBits = (value & 0x0f) << 12; break; case 6: mEncBits += value << 6; break; case 7: if (dest >= destEnd) { res = NS_OK_UDEC_MOREOUTPUT; break; } mEncBits += value; *(dest++) = (char16_t) mEncBits; mEncBits = 0; break; } if (res != NS_OK) break; src++; (++mEncStep)%=8; } *aSrcLength = src - aSrc; *aDestLength = dest - aDest; return res; } uint32_t nsBasicUTF7Decoder::CharToValue(char aChar) { if ((aChar>='A')&&(aChar<='Z')) return (uint8_t)(aChar-'A'); else if ((aChar>='a')&&(aChar<='z')) return (uint8_t)(26+aChar-'a'); else if ((aChar>='0')&&(aChar<='9')) return (uint8_t)(26+26+aChar-'0'); else if (aChar=='+') return (uint8_t)(26+26+10); else if (aChar==mLastChar) return (uint8_t)(26+26+10+1); else return 0xffff; } //---------------------------------------------------------------------- // Subclassing of nsBufferDecoderSupport class [implementation] NS_IMETHODIMP nsBasicUTF7Decoder::ConvertNoBuff(const char * aSrc, int32_t * aSrcLength, char16_t * aDest, int32_t * aDestLength) { const char * srcEnd = aSrc + *aSrcLength; const char * src = aSrc; char16_t * destEnd = aDest + *aDestLength; char16_t * dest = aDest; int32_t bcr,bcw; nsresult res = NS_OK; while (src < srcEnd) { // fist, attept to decode in the current mode bcr = srcEnd - src; bcw = destEnd - dest; if (mEncoding == ENC_DIRECT) res = DecodeDirect(src, &bcr, dest, &bcw); else if ((mFreshBase64) && (*src == '-')) { *dest = mEscChar; bcr = 0; bcw = 1; res = NS_ERROR_UDEC_ILLEGALINPUT; } else { mFreshBase64 = false; res = DecodeBase64(src, &bcr, dest, &bcw); } src += bcr; dest += bcw; // if an illegal char was encountered, test if it is an escape seq. if (res == NS_ERROR_UDEC_ILLEGALINPUT) { if (mEncoding == ENC_DIRECT) { if (*src == mEscChar) { mEncoding = ENC_BASE64; mFreshBase64 = true; mEncBits = 0; mEncStep = 0; src++; res = NS_OK; } else break; } else { mEncoding = ENC_DIRECT; res = NS_OK; // absorbe end of escape sequence if (*src == '-') src++; } } else if (res != NS_OK) break; } *aSrcLength = src - aSrc; *aDestLength = dest - aDest; return res; } NS_IMETHODIMP nsBasicUTF7Decoder::Reset() { mEncoding = ENC_DIRECT; mEncBits = 0; mEncStep = 0; return nsBufferDecoderSupport::Reset(); } //---------------------------------------------------------------------- // Class nsUTF7ToUnicode [implementation] nsUTF7ToUnicode::nsUTF7ToUnicode() : nsBasicUTF7Decoder('/', '+') { }