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mime64.c
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1994-09-30
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16KB
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692 lines
/* mime64 */
/* MIME base64 encoder/decoder by Karl Hahn hahn@lds.loral.com 3-Aug-94 */
/* modified 30-Sep-94 by Karl Hahn hahn@lds.loral.com: handle multiple
content */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
char alphabet[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
"0123456789+/";
enum TOKENTYPE { NONE, BLANKS, PUNCT, TAG, NAME, CONTENT };
struct TOKEN {
char *text;
int length;
int index;
enum TOKENTYPE type;
};
int compare_token( struct TOKEN *token, char *text )
{
int index=0;
int count;
int result;
char blivit1, blivit2;
count = token->length;
if ( count > 0 )
{
result = 1;
}
else
{
result = 0;
}
while ( (count > 0) && ( result != 0 ) )
{
blivit1 = token->text[index++];
if ( (blivit1 >= 'a' ) && (blivit1 <= 'z') )
{
blivit1 -= ' ';
}
blivit2 = *text++;
if ( (blivit2 >= 'a' ) && (blivit2 <= 'z') )
{
blivit2 -= ' ';
}
if ( blivit1 != blivit2 )
{
result = 0;
}
count--;
}
return result;
}
int ispunct( char blivit )
{
if ( ( ( blivit < '0' ) ||
( ( blivit > '9' ) && (blivit < 'A') ) ||
( blivit > 'Z' ) ) &&
( blivit != '-') && (blivit != '/') && (blivit != '.') )
{
return 1;
}
else
{
return 0;
}
}
void acquire_token( char *line, enum TOKENTYPE type, struct TOKEN *token )
{
int doneflag=0, startflag=1;
int index;
enum TOKENTYPE nextstate=NONE;
char blivit;
if (token->type == NONE)
{
token->index = 0;
token->length = 0;
}
index = token->index + token->length;
token->text = 0;
while ( doneflag == 0 )
{
blivit = line[index];
if ( (blivit >= 'a') && (blivit <= 'z') )
{
blivit -= ' ';
}
switch (token->type)
{
case NONE:
if ( blivit == ' ')
{
index++;
token->index++;
}
else
{
token->type = TAG;
nextstate = TAG;
}
break;
case BLANKS:
if ( blivit == ' ')
{
index++;
}
else if ( ispunct( blivit ) )
{
token->type = PUNCT;
token->index = index;
}
else
{
token->type = nextstate;
token->index = index;
}
break;
case PUNCT:
if ( blivit < ' ')
{
doneflag = 1;
token->type = NONE;
token->index = index;
token->text = line + index;
token->length = 0;
}
else if ( blivit == ' ' )
{
token->type = BLANKS;
token->index = index;
if ( line[ token->index ] == ';' )
{
nextstate = NAME;
}
else if ( line[ token->index ] == '=' )
{
nextstate = CONTENT;
}
}
else if ( ispunct( blivit ) )
{
index++;
}
else
{
if ( line[ token->index ] == ';' )
{
nextstate = NAME;
}
else if ( line[ token->index ] == '=' )
{
nextstate = CONTENT;
}
token->type = nextstate;
token->index = index;
}
break;
case TAG:
if ( ispunct( blivit ) )
{
token->length = index - token->index;
token->text = line + token->index;
nextstate = NAME;
if ( ( ( type == TAG ) || ( type == NONE ) ) && !startflag)
{
doneflag = 1;
}
else if (blivit == ' ')
{
token->type = BLANKS;
token->index = index;
}
else
{
token->type = PUNCT;
token->index = index;
}
}
else
{
index++;
}
break;
case NAME:
if ( ispunct( blivit ) )
{
token->length = index - token->index;
token->text = line + token->index;
nextstate = CONTENT;
if ( ( ( type == NAME ) || ( type == NONE ) ) && !startflag )
{
doneflag = 1;
}
else if (blivit == ' ')
{
token->type = BLANKS;
token->index = index;
}
else
{
token->type = PUNCT;
token->index = index;
}
}
else
{
index++;
}
break;
case CONTENT:
if ( ispunct( blivit ) )
{
token->length = index - token->index;
token->text = line + token->index;
nextstate = NAME;
if ( ( ( type == CONTENT ) || ( type == NONE ) ) && !startflag )
{
doneflag = 1;
}
else if (blivit == ' ')
{
token->type = BLANKS;
token->index = index;
}
else
{
token->type = PUNCT;
token->index = index;
}
}
else
{
index++;
}
break;
}
startflag = 0;
}
}
void fputch( char blivit, FILE *f )
{
/* if (blivit == '\n') fputc( '\r', f );*/
fputc( blivit, f );
}
int classify_args( int narg,
char *rawargs[], char *fileargs[], char *optargs[] )
{
int index, jndex, kndex;
char *argptr;
for ( index = 0, jndex = 0, kndex = 0; index < narg; index++ )
{
argptr = rawargs[index];
if (*argptr == '-')
{
argptr++;
optargs[kndex++] = argptr;
}
else
{
fileargs[jndex++] = argptr;
}
}
return kndex;
}
int cvt_ascii( unsigned char alpha )
{
if ( (alpha >= 'A') && (alpha <= 'Z') ) return (int)(alpha - 'A');
else if ( (alpha >= 'a') && (alpha <= 'z') )
return 26 + (int)(alpha - 'a');
else if ( (alpha >= '0') && (alpha <= '9' ) )
return 52 + (int)(alpha - '0');
else if ( alpha == '+' ) return 62;
else if ( alpha == '/' ) return 63;
else if ( alpha == '=' ) return -2;
else return -1;
}
char *fileargs[64], *optargs[64];
struct STATE64 {
unsigned long int accum;
int shift;
};
int main( int nargs, char *cargs[] )
{
int n_options, n_files, index, jndex, shift, save_shift;
enum { ENCODE, DECODE } whattodo = DECODE;
int help_flag = 0, replace_flag = 0, quit = 0;
FILE *fin, *fout, *dummy;
unsigned char blivit;
unsigned long accum, value;
char buf[80], dumname[80];
char *cptr, *altptr;
int decode_state;
struct TOKEN token;
int firsttime = 1;
int skipflag = 0;
int printmsg = 1;
n_options = classify_args( nargs, cargs, fileargs, optargs );
n_files = nargs - n_options;
if ( n_files < 2 ) help_flag = 1;
for ( index = 0; index < n_options; index++ )
{
if ( ( optargs[index][0] == 'e' ) ||
( optargs[index][0] == 'E' ) ) whattodo = ENCODE;
if ( optargs[index][0] == '?' ) help_flag = 1;
}
if ( help_flag )
{
printf( "mime64 infile [outfile] [-option] [-option] etc.\n\n"
"convert between binary and MIME BASE64 format\n\n"
" -e MIME base64 encode (default is decode)\n"
" -? display help message\n\n"
"if no outfile given, output file replaces infile\n" );
}
if ( n_files < 2 ) exit(0);
if ( whattodo == DECODE )
{
fin = fopen( fileargs[1], "r" );
}
else
{
fin = fopen( fileargs[1], "rb" );
}
if ( fin == 0 )
{
printf( "%s file not found\n", fileargs[1] );
exit(-1);
}
if ( n_files > 2 )
{
if ( whattodo == DECODE )
{
sprintf( dumname, "%s", fileargs[2] );
}
else
{
fout = fopen( fileargs[2], "w" );
}
if ( fout == 0 )
{
printf( "Couldn't open %s for output\n", fileargs[2] );
}
}
else
{
if ( whattodo == DECODE )
{
sprintf( dumname, "%s", fileargs[1] );
}
else
{
fout = fopen( "$$$$$$$$.$$$", "w" );
}
replace_flag = 1;
}
do {
quit = 0;
printmsg = 1;
if ( whattodo == DECODE )
{
shift = 0;
accum = 0;
decode_state = 0;
while ( ( !feof( fin ) ) && (quit == 0) )
{
fgets( buf, 80, fin );
if ( feof( fin ) )
{
if ( dumname[0] != '\0' )
{
printf( "Unexpected end of file encountered in %s\n",
dumname );
}
exit(0);
}
if ( decode_state == 0 )
{
for ( index = 0;
(buf[index] != '\n') && (buf[index] != '\0') &&
(decode_state >= 0);
index++ )
{
if ( ( (buf[index] >= 'A') && (buf[index] <= 'Z') ) ||
( (buf[index] >= 'a') && (buf[index] <= 'z') ) ||
( (buf[index] >= '0') && (buf[index] <= '9') ) ||
(buf[index] == '+') ||
(buf[index] == '/') ||
(buf[index] == '=') )
{
decode_state = 1;
}
else
{
decode_state = -2;
}
}
if ( decode_state <= 0 )
{
decode_state = 0;
token.type = NONE;
acquire_token( buf, TAG, &token );
if ( compare_token( &token, "Content-Type") )
{
do
{
acquire_token( buf, NAME, &token );
if ( compare_token( &token, "name" ) )
{
acquire_token( buf, CONTENT, &token );
if ( ( replace_flag ) ||
( firsttime == 0 ) )
{
sscanf( token.text, "%s", dumname );
replace_flag = 0;
}
}
} while ( token.type != NONE );
}
else if ( compare_token( &token, "Content-transfer-encoding" ) )
{
skipflag = 1;
do
{
acquire_token( buf, NAME, &token );
if ( compare_token( &token, "base64" ) )
{
skipflag = 0;
}
} while ( token.type != NONE );
}
continue;
}
else if ( skipflag != 0 )
{
continue;
}
}
if ( printmsg )
{
if ( skipflag )
{
printf( "Section %s not MIME base64\n", dumname );
}
else
{
printf( "Creating %s\n", dumname );
if ( strcmpi( dumname, fileargs[1] ) == 0 )
{
replace_flag = 1;
}
if ( replace_flag )
{
fout = fopen( "$$$$$$$$.$$$", "wb" );
}
else
{
fout = fopen( dumname, "wb" );
}
if ( fout == 0 )
{
printf( "Couldn't open %s for output\n", dumname );
}
}
printmsg = 0;
}
if ( fout == 0 )
{
printf( "No filename given for subsequent section\n" );
exit(-1);
}
if ( feof(fin) )
{
quit = 1;
}
if ( quit != 0 )
{
buf[0] = '\0';
}
for ( index = 0; (buf[index] != '\n') && (buf[index] != '\0'); index++)
{
value = cvt_ascii( buf[index] );
if ( value < 64 )
{
accum <<= 6;
shift += 6;
accum |= value;
if ( shift >= 8 )
{
shift -= 8;
value = accum >> shift;
blivit = (unsigned char)value & 0xFFl;
fputc( blivit, fout );
}
}
else
{
quit = 1;
break;
}
}
}
}
else
{
fprintf ( fout,
"Content-Type: text/plain; charset=US-ASCII; name=%s\n"
"Content-transfer-encoding: base64\n\n", fileargs[1] );
shift = 0;
accum = 0;
index = 0;
while ( ( !feof( fin ) ) || (shift != 0) )
{
if ( ( !feof( fin ) ) && ( quit == 0 ) )
{
blivit = fgetc( fin );
if ( feof( fin ) )
{
quit = 1;
save_shift = shift;
blivit = 0;
}
}
else
{
quit = 1;
save_shift = shift;
blivit = 0;
}
if ( (quit == 0) || (shift != 0) )
{
value = (unsigned long)blivit;
accum <<= 8;
shift += 8;
accum |= value;
} /* ENDIF */
while ( shift >= 6 )
{
shift -= 6;
value = (accum >> shift) & 0x3Fl;
blivit = alphabet[value];
buf[index++] = blivit;
if ( index >= 60 )
{
buf[index] = '\0';
fprintf( fout, "%s\n", buf );
index = 0;
}
if ( quit != 0 )
{
shift = 0;
}
}
}
if ( save_shift == 2 )
{
buf[index++] = '=';
if ( index >= 60 )
{
buf[index] = '\0';
fprintf( fout, "%s\n", buf );
index = 0;
}
buf[index++] = '=';
if ( index >= 60 )
{
buf[index] = '\0';
fprintf( fout, "%s\n", buf );
index = 0;
}
}
else if ( save_shift == 4 )
{
buf[index++] = '=';
if ( index >= 60 )
{
buf[index] = '\0';
fprintf( fout, "%s\n", buf );
index = 0;
}
}
if ( index != 0 )
{
buf[index] = '\0';
fprintf( fout, "%s\n", buf );
}
}
fclose( fout );
if ( replace_flag )
{
if ( ( whattodo == DECODE ) && ( decode_state <= 0 ) )
{
remove( "$$$$$$$$.$$$" );
printf( "No MIME base64 lines found in %s\n", fileargs[1] );
}
else
{
remove( fileargs[1] );
rename( "$$$$$$$$.$$$", fileargs[1] );
}
}
else
{
if ( ( whattodo == DECODE ) && ( decode_state <= 0 ) )
{
remove( fileargs[2] );
printf( "No MIME base64 lines found in %s\n", fileargs[1] );
}
}
fout = 0;
firsttime = 0;
dumname[0] = '\0';
} while ( !feof( fin ) );
fclose( fin );
}