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author | dkf <donal.k.fellows@manchester.ac.uk> | 2013-09-14 18:25:45 (GMT) |
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committer | dkf <donal.k.fellows@manchester.ac.uk> | 2013-09-14 18:25:45 (GMT) |
commit | 0f1f636a50239c2409172a34da5fa1b1f45bf9c4 (patch) | |
tree | 409912fdc7eb0211ad6a6d3ae95417a0cf357006 /generic/tclBinary.c | |
parent | 92eea63a7df5071fddef9b89b9122a5761670908 (diff) | |
download | tcl-0f1f636a50239c2409172a34da5fa1b1f45bf9c4.zip tcl-0f1f636a50239c2409172a34da5fa1b1f45bf9c4.tar.gz tcl-0f1f636a50239c2409172a34da5fa1b1f45bf9c4.tar.bz2 |
And the decoder too.
Diffstat (limited to 'generic/tclBinary.c')
-rw-r--r-- | generic/tclBinary.c | 104 |
1 files changed, 86 insertions, 18 deletions
diff --git a/generic/tclBinary.c b/generic/tclBinary.c index 71da309..c0dd926 100644 --- a/generic/tclBinary.c +++ b/generic/tclBinary.c @@ -2690,8 +2690,8 @@ BinaryDecodeUu( Tcl_Obj *resultObj = NULL; unsigned char *data, *datastart, *dataend; unsigned char *begin, *cursor; - int i, index, size, count = 0, cut = 0, strict = 0; - char c; + int i, index, size, count = 0, strict = 0, lineLen; + unsigned char c; enum {OPT_STRICT }; static const char *const optStrings[] = { "-strict", NULL }; @@ -2717,44 +2717,112 @@ BinaryDecodeUu( dataend = data + count; size = ((count + 3) & ~3) * 3 / 4; begin = cursor = Tcl_SetByteArrayLength(resultObj, size); + lineLen = -1; + + /* + * The decoding loop. First, we get the length of line (strictly, the + * number of data bytes we expect to generate from the line) we're + * processing this time round if it is not already known (i.e., when the + * lineLen variable is set to the magic value, -1). + */ + while (data < dataend) { char d[4] = {0, 0, 0, 0}; + if (lineLen < 0) { + c = *data++; + if (c < 32 || c > 96) { + if (strict || !isspace(c)) { + goto badUu; + } + i--; + continue; + } + lineLen = (c - 32) & 0x3f; + } + + /* + * Now we read a four-character grouping. + */ + for (i=0 ; i<4 ; i++) { if (data < dataend) { d[i] = c = *data++; - if (c < 33 || c > 96) { - if (strict || !isspace(UCHAR(c))) { - goto badUu; + if (c < 32 || c > 96) { + if (strict) { + if (!isspace(c)) { + goto badUu; + } else if (c == '\n') { + goto shortUu; + } } i--; continue; } - } else { - cut++; } } - if (cut > 3) { - cut = 3; + + /* + * Translate that grouping into (up to) three binary bytes output. + */ + + if (lineLen > 0) { + *cursor++ = (((d[0] - 0x20) & 0x3f) << 2) + | (((d[1] - 0x20) & 0x3f) >> 4); + if (--lineLen > 0) { + *cursor++ = (((d[1] - 0x20) & 0x3f) << 4) + | (((d[2] - 0x20) & 0x3f) >> 2); + if (--lineLen > 0) { + *cursor++ = (((d[2] - 0x20) & 0x3f) << 6) + | (((d[3] - 0x20) & 0x3f)); + lineLen--; + } + } + } + + /* + * If we've reached the end of the line, skip until we process a + * newline. + */ + + if (lineLen == 0 && data < dataend) { + lineLen = -1; + do { + c = *data++; + if (c == '\n') { + break; + } else if (c >= 32 && c <= 96) { + data--; + break; + } else if (strict || !isspace(c)) { + goto badUu; + } + } while (data < dataend); } - *cursor++ = (((d[0] - 0x20) & 0x3f) << 2) - | (((d[1] - 0x20) & 0x3f) >> 4); - *cursor++ = (((d[1] - 0x20) & 0x3f) << 4) - | (((d[2] - 0x20) & 0x3f) >> 2); - *cursor++ = (((d[2] - 0x20) & 0x3f) << 6) - | (((d[3] - 0x20) & 0x3f)); } - if (cut > size) { - cut = size; + + /* + * Sanity check, clean up and finish. + */ + + if (lineLen > 0 && strict) { + goto shortUu; } - Tcl_SetByteArrayLength(resultObj, cursor - begin - cut); + Tcl_SetByteArrayLength(resultObj, cursor - begin); Tcl_SetObjResult(interp, resultObj); return TCL_OK; + shortUu: + Tcl_SetObjResult(interp, Tcl_ObjPrintf("short uuencode data")); + Tcl_SetErrorCode(interp, "TCL", "BINARY", "DECODE", "SHORT", NULL); + TclDecrRefCount(resultObj); + return TCL_ERROR; + badUu: Tcl_SetObjResult(interp, Tcl_ObjPrintf( "invalid uuencode character \"%c\" at position %d", c, (int) (data - datastart - 1))); + Tcl_SetErrorCode(interp, "TCL", "BINARY", "DECODE", "INVALID", NULL); TclDecrRefCount(resultObj); return TCL_ERROR; } |