/* * Copyright (c) Edward Thomson. All rights reserved. * * This file is part of ntlmclient, distributed under the MIT license. * For full terms and copyright information, and for third-party * copyright information, see the included LICENSE.txt file. */ #include #include #include "ntlm.h" #include "unicode.h" #include "compat.h" typedef unsigned int UTF32; /* at least 32 bits */ typedef unsigned short UTF16; /* at least 16 bits */ typedef unsigned char UTF8; /* typically 8 bits */ /* Some fundamental constants */ #define UNI_REPLACEMENT_CHAR (UTF32)0x0000FFFD #define UNI_MAX_BMP (UTF32)0x0000FFFF #define UNI_MAX_UTF16 (UTF32)0x0010FFFF #define UNI_MAX_UTF32 (UTF32)0x7FFFFFFF #define UNI_MAX_LEGAL_UTF32 (UTF32)0x0010FFFF #define UNI_MAX_UTF8_BYTES_PER_CODE_POINT 4 typedef enum { conversionOK, /* conversion successful */ sourceExhausted, /* partial character in source, but hit end */ targetExhausted, /* insuff. room in target for conversion */ sourceIllegal /* source sequence is illegal/malformed */ } ConversionResult; typedef enum { strictConversion = 0, lenientConversion } ConversionFlags; static const int halfShift = 10; /* used for shifting by 10 bits */ static const UTF32 halfBase = 0x0010000UL; static const UTF32 halfMask = 0x3FFUL; #define UNI_SUR_HIGH_START (UTF32)0xD800 #define UNI_SUR_HIGH_END (UTF32)0xDBFF #define UNI_SUR_LOW_START (UTF32)0xDC00 #define UNI_SUR_LOW_END (UTF32)0xDFFF #define false 0 #define true 1 /* --------------------------------------------------------------------- */ /* * Index into the table below with the first byte of a UTF-8 sequence to * get the number of trailing bytes that are supposed to follow it. * Note that *legal* UTF-8 values can't have 4 or 5-bytes. The table is * left as-is for anyone who may want to do such conversion, which was * allowed in earlier algorithms. */ static const char trailingBytesForUTF8[256] = { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 }; /* * Magic values subtracted from a buffer value during UTF8 conversion. * This table contains as many values as there might be trailing bytes * in a UTF-8 sequence. */ static const UTF32 offsetsFromUTF8[6] = { 0x00000000UL, 0x00003080UL, 0x000E2080UL, 0x03C82080UL, 0xFA082080UL, 0x82082080UL }; /* * Once the bits are split out into bytes of UTF-8, this is a mask OR-ed * into the first byte, depending on how many bytes follow. There are * as many entries in this table as there are UTF-8 sequence types. * (I.e., one byte sequence, two byte... etc.). Remember that sequencs * for *legal* UTF-8 will be 4 or fewer bytes total. */ static const UTF8 firstByteMark[7] = { 0x00, 0x00, 0xC0, 0xE0, 0xF0, 0xF8, 0xFC }; /* --------------------------------------------------------------------- */ /* The interface converts a whole buffer to avoid function-call overhead. * Constants have been gathered. Loops & conditionals have been removed as * much as possible for efficiency, in favor of drop-through switches. * (See "Note A" at the bottom of the file for equivalent code.) * If your compiler supports it, the "isLegalUTF8" call can be turned * into an inline function. */ static ConversionResult ConvertUTF16toUTF8 ( const UTF16** sourceStart, const UTF16* sourceEnd, UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags) { ConversionResult result = conversionOK; const UTF16* source = *sourceStart; UTF8* target = *targetStart; while (source < sourceEnd) { UTF32 ch; unsigned short bytesToWrite = 0; const UTF32 byteMask = 0xBF; const UTF32 byteMark = 0x80; const UTF16* oldSource = source; /* In case we have to back up because of target overflow. */ ch = *source++; /* If we have a surrogate pair, convert to UTF32 first. */ if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_HIGH_END) { /* If the 16 bits following the high surrogate are in the source buffer... */ if (source < sourceEnd) { UTF32 ch2 = *source; /* If it's a low surrogate, convert to UTF32. */ if (ch2 >= UNI_SUR_LOW_START && ch2 <= UNI_SUR_LOW_END) { ch = ((ch - UNI_SUR_HIGH_START) << halfShift) + (ch2 - UNI_SUR_LOW_START) + halfBase; ++source; } else if (flags == strictConversion) { /* it's an unpaired high surrogate */ --source; /* return to the illegal value itself */ result = sourceIllegal; break; } } else { /* We don't have the 16 bits following the high surrogate. */ --source; /* return to the high surrogate */ result = sourceExhausted; break; } } else if (flags == strictConversion) { /* UTF-16 surrogate values are illegal in UTF-32 */ if (ch >= UNI_SUR_LOW_START && ch <= UNI_SUR_LOW_END) { --source; /* return to the illegal value itself */ result = sourceIllegal; break; } } /* Figure out how many bytes the result will require */ if (ch < (UTF32)0x80) { bytesToWrite = 1; } else if (ch < (UTF32)0x800) { bytesToWrite = 2; } else if (ch < (UTF32)0x10000) { bytesToWrite = 3; } else if (ch < (UTF32)0x110000) { bytesToWrite = 4; } else { bytesToWrite = 3; ch = UNI_REPLACEMENT_CHAR; } target += bytesToWrite; if (target > targetEnd) { source = oldSource; /* Back up source pointer! */ target -= bytesToWrite; result = targetExhausted; break; } switch (bytesToWrite) { /* note: everything falls through. */ case 4: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; case 3: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; case 2: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; case 1: *--target = (UTF8)(ch | firstByteMark[bytesToWrite]); } target += bytesToWrite; } *sourceStart = source; *targetStart = target; return result; } /* --------------------------------------------------------------------- */ /* * Utility routine to tell whether a sequence of bytes is legal UTF-8. * This must be called with the length pre-determined by the first byte. * If not calling this from ConvertUTF8to*, then the length can be set by: * length = trailingBytesForUTF8[*source]+1; * and the sequence is illegal right away if there aren't that many bytes * available. * If presented with a length > 4, this returns false. The Unicode * definition of UTF-8 goes up to 4-byte sequences. */ static inline bool isLegalUTF8(const UTF8 *source, int length) { UTF8 a; const UTF8 *srcptr = source+length; switch (length) { default: return false; /* Everything else falls through when "true"... */ case 4: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false; case 3: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false; case 2: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false; switch (*source) { /* no fall-through in this inner switch */ case 0xE0: if (a < 0xA0) return false; break; case 0xED: if (a > 0x9F) return false; break; case 0xF0: if (a < 0x90) return false; break; case 0xF4: if (a > 0x8F) return false; break; default: if (a < 0x80) return false; } case 1: if (*source >= 0x80 && *source < 0xC2) return false; } if (*source > 0xF4) return false; return true; } static ConversionResult ConvertUTF8toUTF16 ( const UTF8** sourceStart, const UTF8* sourceEnd, UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags) { ConversionResult result = conversionOK; const UTF8* source = *sourceStart; UTF16* target = *targetStart; while (source < sourceEnd) { UTF32 ch = 0; unsigned short extraBytesToRead = trailingBytesForUTF8[*source]; if (extraBytesToRead >= sourceEnd - source) { result = sourceExhausted; break; } /* Do this check whether lenient or strict */ if (!isLegalUTF8(source, extraBytesToRead+1)) { result = sourceIllegal; break; } /* * The cases all fall through. See "Note A" below. */ switch (extraBytesToRead) { case 5: ch += *source++; ch <<= 6; /* remember, illegal UTF-8 */ case 4: ch += *source++; ch <<= 6; /* remember, illegal UTF-8 */ case 3: ch += *source++; ch <<= 6; case 2: ch += *source++; ch <<= 6; case 1: ch += *source++; ch <<= 6; case 0: ch += *source++; } ch -= offsetsFromUTF8[extraBytesToRead]; if (target >= targetEnd) { source -= (extraBytesToRead+1); /* Back up source pointer! */ result = targetExhausted; break; } if (ch <= UNI_MAX_BMP) { /* Target is a character <= 0xFFFF */ /* UTF-16 surrogate values are illegal in UTF-32 */ if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) { if (flags == strictConversion) { source -= (extraBytesToRead+1); /* return to the illegal value itself */ result = sourceIllegal; break; } else { *target++ = UNI_REPLACEMENT_CHAR; } } else { *target++ = (UTF16)ch; /* normal case */ } } else if (ch > UNI_MAX_UTF16) { if (flags == strictConversion) { result = sourceIllegal; source -= (extraBytesToRead+1); /* return to the start */ break; /* Bail out; shouldn't continue */ } else { *target++ = UNI_REPLACEMENT_CHAR; } } else { /* target is a character in range 0xFFFF - 0x10FFFF. */ if (target + 1 >= targetEnd) { source -= (extraBytesToRead+1); /* Back up source pointer! */ result = targetExhausted; break; } ch -= halfBase; *target++ = (UTF16)((ch >> halfShift) + UNI_SUR_HIGH_START); *target++ = (UTF16)((ch & halfMask) + UNI_SUR_LOW_START); } } *sourceStart = source; *targetStart = target; return result; } bool ntlm_unicode_init(ntlm_client *ntlm) { NTLM_UNUSED(ntlm); return true; } typedef enum { unicode_builtin_utf8_to_16, unicode_builtin_utf16_to_8 } unicode_builtin_encoding_direction; static inline bool unicode_builtin_encoding_convert( char **converted, size_t *converted_len, ntlm_client *ntlm, const char *string, size_t string_len, unicode_builtin_encoding_direction direction) { const char *in_start, *in_end; char *out, *out_start, *out_end, *new_out; size_t out_size, out_len; bool success = false; ConversionResult result; *converted = NULL; *converted_len = 0; in_start = string; in_end = in_start + string_len; /* * When translating UTF8 to UTF16, these strings are only used * internally, and we obey the given length, so we can simply * use a buffer that is 2x the size. Add an extra byte to NUL * terminate the results (two bytes for UTF16). */ if (direction == unicode_builtin_utf8_to_16) out_size = (string_len * 2 + 2); else out_size = (string_len / 2 + 1); /* Round to the nearest multiple of 8 */ out_size = (out_size + 7) & ~7; if ((out = malloc(out_size)) == NULL) { ntlm_client_set_errmsg(ntlm, "out of memory"); return false; } out_start = out; out_end = out_start + out_size; /* Make room for NUL termination */ if (direction == unicode_builtin_utf16_to_8) out_end--; while (true) { if (direction == unicode_builtin_utf8_to_16) result = ConvertUTF8toUTF16( (const UTF8 **)&in_start, (UTF8 *)in_end, (UTF16 **)&out_start, (UTF16 *)out_end, strictConversion); else result = ConvertUTF16toUTF8( (const UTF16 **)&in_start, (UTF16 *)in_end, (UTF8 **)&out_start, (UTF8 *)out_end, lenientConversion); switch (result) { case conversionOK: success = true; goto done; case sourceExhausted: ntlm_client_set_errmsg(ntlm, "invalid unicode string; trailing data remains"); goto done; case targetExhausted: break; case sourceIllegal: ntlm_client_set_errmsg(ntlm, "invalid unicode string; trailing data remains"); goto done; default: ntlm_client_set_errmsg(ntlm, "unknown unicode conversion failure"); goto done; } /* Grow buffer size by 1.5 (rounded up to a multiple of 8) */ out_size = ((((out_size << 1) - (out_size >> 1)) + 7) & ~7); if (out_size > NTLM_UNICODE_MAX_LEN) { ntlm_client_set_errmsg(ntlm, "unicode conversion too large"); goto done; } out_len = out_start - out; if ((new_out = realloc(out, out_size)) == NULL) { ntlm_client_set_errmsg(ntlm, "out of memory"); goto done; } out = new_out; out_start = new_out + out_len; out_end = out + out_size; /* Make room for NUL termination */ out_end -= (direction == unicode_builtin_utf8_to_16) ? 2 : 1; } done: if (!success) { free(out); return false; } out_len = (out_start - out); /* NUL terminate */ out[out_len] = '\0'; if (direction == unicode_builtin_utf8_to_16) out[out_len+1] = '\0'; *converted = out; *converted_len = out_len; return true; } bool ntlm_unicode_utf8_to_16( char **converted, size_t *converted_len, ntlm_client *client, const char *string, size_t string_len) { return unicode_builtin_encoding_convert(converted, converted_len, client, string, string_len, unicode_builtin_utf8_to_16); } bool ntlm_unicode_utf16_to_8( char **converted, size_t *converted_len, ntlm_client *client, const char *string, size_t string_len) { return unicode_builtin_encoding_convert(converted, converted_len, client, string, string_len, unicode_builtin_utf16_to_8); } void ntlm_unicode_shutdown(ntlm_client *ntlm) { NTLM_UNUSED(ntlm); }