/*
Copyright (c) 1991 Bell Communications Research, Inc. (Bellcore)

Permission to use, copy, modify, and distribute this material 
for any purpose and without fee is hereby granted, provided 
that the above copyright notice and this permission notice 
appear in all copies, and that the name of Bellcore not be 
used in advertising or publicity pertaining to this 
material without the specific, prior written permission 
of an authorized representative of Bellcore.  BELLCORE 
MAKES NO REPRESENTATIONS ABOUT THE ACCURACY OR SUITABILITY 
OF THIS MATERIAL FOR ANY PURPOSE.  IT IS PROVIDED "AS IS", 
WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES.
*/

#define NEWLINE_CHAR '\n'
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <errno.h>

static void
output64chunk(int c1, int c2, int c3, int pads, FILE *outfile);

static signed char basis_64[] =
   "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

static signed char index_64[128] = {
    -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,
    -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,62, -1,-1,-1,63,
    52,53,54,55, 56,57,58,59, 60,61,-1,-1, -1,-1,-1,-1,
    -1, 0, 1, 2,  3, 4, 5, 6,  7, 8, 9,10, 11,12,13,14,
    15,16,17,18, 19,20,21,22, 23,24,25,-1, -1,-1,-1,-1,
    -1,26,27,28, 29,30,31,32, 33,34,35,36, 37,38,39,40,
    41,42,43,44, 45,46,47,48, 49,50,51,-1, -1,-1,-1,-1
};

#define char64(c)  (((c) < 0 || (c) > 127) ? -1 : index_64[(c)])

/*
char64(c)
char c;
{
    char *s = (char *) strchr(basis_64, c);
    if (s) return(s-basis_64);
    return(-1);
}
*/

/* the following gets a character, but fakes it properly into two chars if there's a newline character */
static int InNewline=0;

static int
nextcharin (FILE *infile, int PortableNewlines)
{
    int c;

#ifndef NEWLINE_CHAR
    return(getc(infile));
#else
    if (!PortableNewlines) return(getc(infile));
    if (InNewline) {
        InNewline = 0;
        return(10); /* LF */
    }
    c = getc(infile);
    if (c == NEWLINE_CHAR) {
        InNewline = 1;
        return(13); /* CR */
    }
    return(c);
#endif
}

static void
to64(FILE *infile, FILE *outfile, int PortableNewlines) 
{
    int c1, c2, c3, ct=0;
    InNewline = 0; /* always reset it */
    while ((c1 = nextcharin(infile, PortableNewlines)) != EOF) {
        c2 = nextcharin(infile, PortableNewlines);
        if (c2 == EOF) {
            output64chunk(c1, 0, 0, 2, outfile);
        } else {
            c3 = nextcharin(infile, PortableNewlines);
            if (c3 == EOF) {
                output64chunk(c1, c2, 0, 1, outfile);
            } else {
                output64chunk(c1, c2, c3, 0, outfile);
            }
        }
        ct += 4;
        if (ct > 71) {
            putc('\n', outfile);
            ct = 0;
        }
    }
    if (ct) putc('\n', outfile);
    fflush(outfile);
}

static void
output64chunk(int c1, int c2, int c3, int pads, FILE *outfile)
{
    putc(basis_64[c1>>2], outfile);
    putc(basis_64[((c1 & 0x3)<< 4) | ((c2 & 0xF0) >> 4)], outfile);
    if (pads == 2) {
        putc('=', outfile);
        putc('=', outfile);
    } else if (pads) {
        putc(basis_64[((c2 & 0xF) << 2) | ((c3 & 0xC0) >>6)], outfile);
        putc('=', outfile);
    } else {
        putc(basis_64[((c2 & 0xF) << 2) | ((c3 & 0xC0) >>6)], outfile);
        putc(basis_64[c3 & 0x3F], outfile);
    }
}

static int
PendingBoundary(char *s, char **Boundaries, int *BoundaryCt)
{
    int i, len;

    if (s[0] != '-' || s[1] != '-') return(0);


    for (i=0; i < *BoundaryCt; ++i) {
	len = strlen(Boundaries[i]);
        if (!strncmp(s, Boundaries[i], len)) {
            if (s[len] == '-' && s[len+1] == '-') *BoundaryCt = i;
            return(1);
        }
    }
    return(0);
}

/* If we're in portable newline mode, we have to convert CRLF to the 
    local newline convention on output */

static int CRpending = 0;

#ifdef NEWLINE_CHAR
static void
almostputc(int c, FILE *outfile, int PortableNewlines)
{
    if (CRpending) {
        if (c == 10) {
            putc(NEWLINE_CHAR, outfile);
            CRpending = 0;
        } else {
            putc(13, outfile);
	    if (c != 13) {
            	putc(c, outfile);
		CRpending = 0;
	    }
        }
    } else {
        if (PortableNewlines && c == 13) {
            CRpending = 1;
        } else {
            putc(c, outfile);
        }
    }
}
#else
static void
almostputc(int c, FILE *outfile, int PortableNewlines)
{
    putc(c, outfile);
}
#endif

static void
from64(FILE *infile, FILE *outfile,
       char **boundaries, int *boundaryct, int PortableNewlines) 
{
    int c1, c2, c3, c4;
    int newline = 1, DataDone = 0;

    /* always reinitialize */
    CRpending = 0;
    while ((c1 = getc(infile)) != EOF) {
        if (isspace(c1)) {
            if (c1 == '\n') {
                newline = 1;
            } else {
                newline = 0;
            }
            continue;
        }
        if (newline && boundaries && c1 == '-') {
            char Buf[200];
            /* a dash is NOT base 64, so all bets are off if NOT a boundary */
            ungetc(c1, infile);
            fgets(Buf, sizeof(Buf), infile);
            if (boundaries
                 && (Buf[0] == '-')
                 && (Buf[1] == '-')
                 && PendingBoundary(Buf, boundaries, boundaryct)) {
                return;
            }
            fprintf(stderr, "Ignoring unrecognized boundary line: %s\n", Buf);
            continue;
        }
        if (DataDone) continue;
        newline = 0;
        do {
            c2 = getc(infile);
        } while (c2 != EOF && isspace(c2));
        do {
            c3 = getc(infile);
        } while (c3 != EOF && isspace(c3));
        do {
            c4 = getc(infile);
        } while (c4 != EOF && isspace(c4));
        if (c2 == EOF || c3 == EOF || c4 == EOF) {
            fprintf(stderr, "Warning: base64 decoder saw premature EOF!\n");
            return;
        }
        if (c1 == '=' || c2 == '=') {
            DataDone=1;
            continue;
        }
        c1 = char64(c1);
        c2 = char64(c2);
        almostputc(((c1<<2) | ((c2&0x30)>>4)), outfile, PortableNewlines);
        if (c3 == '=') {
            DataDone = 1;
        } else {
            c3 = char64(c3);
            almostputc((((c2&0XF) << 4) | ((c3&0x3C) >> 2)), outfile, PortableNewlines);
            if (c4 == '=') {
                DataDone = 1;
            } else {
                c4 = char64(c4);
                almostputc((((c3&0x03) <<6) | c4), outfile, PortableNewlines);
            }
        }
    }
    if (CRpending) putc(13, outfile); /* Don't drop a lone trailing char 13 */
}

static signed char basis_hex[] = "0123456789ABCDEF";
static signed char index_hex[128] = {
    -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,
    -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
     0, 1, 2, 3,  4, 5, 6, 7,  8, 9,-1,-1, -1,-1,-1,-1,
    -1,10,11,12, 13,14,15,-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,
    -1,10,11,12, 13,14,15,-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
};

/* The following version generated complaints on Solaris. */
/* #define hexchar(c)  (((c) < 0 || (c) > 127) ? -1 : index_hex[(c)])  */
/*  Since we're no longer ever calling it with anything signed, this should work: */
#define hexchar(c)  (((c) > 127) ? -1 : index_hex[(c)])

/*
hexchar(c)
char c;
{
    char *s;
    if (islower(c)) c = toupper(c);
    s = (char *) strchr(basis_hex, c);
    if (s) return(s-basis_hex);
    return(-1);
}
*/

static void
toqp(FILE *infile, FILE *outfile) 
{
    int c, ct=0, prevc=255;
    while ((c = getc(infile)) != EOF) {
        if ((c < 32 && (c != '\n' && c != '\t'))
             || (c == '=')
             || (c >= 127)
             /* Following line is to avoid single periods alone on lines,
               which messes up some dumb smtp implementations, sigh... */
             || (ct == 0 && c == '.')) {
            putc('=', outfile);
            putc(basis_hex[c>>4], outfile);
            putc(basis_hex[c&0xF], outfile);
            ct += 3;
            prevc = 'A'; /* close enough */
        } else if (c == '\n') {
            if (prevc == ' ' || prevc == '\t') {
                putc('=', outfile); /* soft & hard lines */
                putc(c, outfile);
            }
            putc(c, outfile);
            ct = 0;
            prevc = c;
        } else {
            if (c == 'F' && prevc == '\n') {
                /* HORRIBLE but clever hack suggested by MTR for sendmail-avoidance */
                c = getc(infile);
                if (c == 'r') {
                    c = getc(infile);
                    if (c == 'o') {
                        c = getc(infile);
                        if (c == 'm') {
                            c = getc(infile);
                            if (c == ' ') {
                                /* This is the case we are looking for */
                                fputs("=46rom", outfile);
                                ct += 6;
                            } else {
                                fputs("From", outfile);
                                ct += 4;
                            }
                        } else {
                            fputs("Fro", outfile);
                            ct += 3;
                        }
                    } else {
                        fputs("Fr", outfile);
                        ct += 2;
                    }
                } else {
                    putc('F', outfile);
                    ++ct;
                }
                ungetc(c, infile);
                prevc = 'x'; /* close enough -- printable */
            } else { /* END horrible hack */
                putc(c, outfile);
                ++ct;
                prevc = c;
            }
        }
        if (ct > 72) {
            putc('=', outfile);
            putc('\n', outfile);
            ct = 0;
            prevc = '\n';
        }
    }
    if (ct) {
        putc('=', outfile);
        putc('\n', outfile);
    }
}

static void
fromqp(FILE *infile, FILE *outfile, char **boundaries, int *boundaryct) 
{
    unsigned int c1, c2;
    int sawnewline = 1, neednewline = 0;
    /* The neednewline hack is necessary because the newline leading into 
      a multipart boundary is part of the boundary, not the data */

    while ((c1 = getc(infile)) != EOF) {
        if (sawnewline && boundaries && (c1 == '-')) {
            char Buf[200];
            unsigned char *s;

            ungetc(c1, infile);
            fgets(Buf, sizeof(Buf), infile);
            if (boundaries
                 && (Buf[0] == '-')
                 && (Buf[1] == '-')
                 && PendingBoundary(Buf, boundaries, boundaryct)) {
                return;
            }
            /* Not a boundary, now we must treat THIS line as q-p, sigh */
            if (neednewline) {
                putc('\n', outfile);
                neednewline = 0;
            }
            for (s=(unsigned char *) Buf; *s; ++s) {
                if (*s == '=') {
                    if (!*++s) break;
                    if (*s == '\n') {
                        /* ignore it */
                        sawnewline = 1;
                    } else {
                        c1 = hexchar(*s);
                        if (!*++s) break;
                        c2 = hexchar(*s);
                        putc(c1<<4 | c2, outfile);
                    }
                } else {
#ifdef MSDOS
                    if (*s == '\n')
                        putc('\r', outfile);	/* insert CR for binary-mode write */
#endif
                    putc(*s, outfile);
                }
            }
        } else {
            if (neednewline) {
                putc('\n', outfile);
                neednewline = 0;
            }
            if (c1 == '=') {
                sawnewline = 0;
                c1 = getc(infile);
                if (c1 == '\n') {
                    /* ignore it */
                    sawnewline = 1;
                } else {
                    c2 = getc(infile);
                    c1 = hexchar(c1);
                    c2 = hexchar(c2);
                    putc(c1<<4 | c2, outfile);
                    if (c2 == '\n') sawnewline = 1;
                }
            } else {
                if (c1 == '\n') {
                    sawnewline = 1;
                    neednewline = 1;
                } else {
                    sawnewline = 0;
                    putc(c1, outfile);
                }
            }
        }
    }
    if (neednewline) {
        putc('\n', outfile);
        neednewline = 0;
    }    
}


/*
Copyright (c) 1991 Bell Communications Research, Inc. (Bellcore)

Permission to use, copy, modify, and distribute this material 
for any purpose and without fee is hereby granted, provided 
that the above copyright notice and this permission notice 
appear in all copies, and that the name of Bellcore not be 
used in advertising or publicity pertaining to this 
material without the specific, prior written permission 
of an authorized representative of Bellcore.  BELLCORE 
MAKES NO REPRESENTATIONS ABOUT THE ACCURACY OR SUITABILITY 
OF THIS MATERIAL FOR ANY PURPOSE.  IT IS PROVIDED "AS IS", 
WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES.
*/
#ifdef MSDOS
#include <fcntl.h>
#endif

#define BASE64 1
#define QP 2 /* quoted-printable */

int main(int argc, char *argv[])
{
    int encode = 1, which = BASE64, i, portablenewlines = 0;
    FILE *fp = stdin;
    FILE *fpo = stdout;

    for (i=1; i<argc; ++i) {
        if (argv[i][0] == '-') {
	    switch (argv[i][1]) {
		case 'o':
		    if (++i >= argc) {
			fprintf(stderr, "mimencode: -o requires a file name.\n");
			exit(-1);
		    }
		    fpo = fopen(argv[i], "w");
		    if (!fpo) {
			perror(argv[i]);
			exit(-1);
		    }
		    break;
                case 'u':
                    encode = 0;
                    break;
                case 'q':
                    which = QP;
                    break;
                case 'p':
                    portablenewlines = 1;
                    break;
                case 'b':
                    which = BASE64;
                    break;
		default:
                    fprintf(stderr,
                       "Usage: mmencode [-u] [-q] [-b] [-p] [-o outputfile] [file name]\n");
                    exit(-1);
            }
        } else {
#ifdef MSDOS
            if (encode)
                fp = fopen(argv[i], "rb");
            else
            {
                fp = fopen(argv[i], "rt");
                setmode(fileno(fpo), O_BINARY);
            } /* else */
#else
            fp = fopen(argv[i], "r");
#endif /* MSDOS */
            if (!fp) {
                perror(argv[i]);
                exit(-1);
            }
        }
    }
#ifdef MSDOS
    if (fp == stdin) setmode(fileno(fp), O_BINARY);
#endif /* MSDOS */
    if (which == BASE64) {
        if (encode) {
            to64(fp, fpo, portablenewlines);
        } else {
            from64(fp,fpo, (char **) NULL, (int *) 0, portablenewlines);
        }
    } else {
        if (encode) toqp(fp, fpo); else fromqp(fp, fpo, NULL, 0);
    }
    return(0);
}

