--- pgp/src/armor.c 2018/04/24 16:40:28 1.1.1.4 +++ pgp/src/armor.c 2018/04/24 16:41:21 1.1.1.5 @@ -1,1089 +1,1076 @@ -/* armor.c - ASCII/binary encoding/decoding based partly on PEM RFC1113. - PGP: Pretty Good(tm) Privacy - public key cryptography for the masses. - - (c) Copyright 1990-1992 by Philip Zimmermann. All rights reserved. - The author assumes no liability for damages resulting from the use - of this software, even if the damage results from defects in this - software. No warranty is expressed or implied. - - All the source code Philip Zimmermann wrote for PGP is available for - free under the "Copyleft" General Public License from the Free - Software Foundation. A copy of that license agreement is included in - the source release package of PGP. Code developed by others for PGP - is also freely available. Other code that has been incorporated into - PGP from other sources was either originally published in the public - domain or was used with permission from the various authors. See the - PGP User's Guide for more complete information about licensing, - patent restrictions on certain algorithms, trademarks, copyrights, - and export controls. -*/ - -#include -#include -#include -#include "mpilib.h" -#include "fileio.h" -#include "mpiio.h" -#include "language.h" -#include "pgp.h" -#include "crypto.h" -#include "armor.h" - -static int dpem_file(char *infile, char *outfile); -static crcword crchware(byte ch, crcword poly, crcword accum); -static int pem_file(char *infilename, char *outfilename, char *clearfilename); -static int pemdecode(FILE *in, FILE *out); -static void mk_crctbl(crcword poly); -static boolean is_pemfile(char *infile); - -/* Begin PEM routines. - This converts a binary file into printable ASCII characters, in a - radix-64 form mostly compatible with the PEM RFC1113 format. - This makes it easier to send encrypted files over a 7-bit channel. -*/ - -/* Index this array by a 6 bit value to get the character corresponding - * to that value. - */ -static -unsigned char bintoasc[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ\ -abcdefghijklmnopqrstuvwxyz0123456789+/"; - -/* Index this array by a 7 bit value to get the 6-bit binary field - * corresponding to that value. Any illegal characters return high bit set. - */ -static -unsigned char asctobin[] = { - 0200,0200,0200,0200,0200,0200,0200,0200, - 0200,0200,0200,0200,0200,0200,0200,0200, - 0200,0200,0200,0200,0200,0200,0200,0200, - 0200,0200,0200,0200,0200,0200,0200,0200, - 0200,0200,0200,0200,0200,0200,0200,0200, - 0200,0200,0200,0076,0200,0200,0200,0077, - 0064,0065,0066,0067,0070,0071,0072,0073, - 0074,0075,0200,0200,0200,0200,0200,0200, - 0200,0000,0001,0002,0003,0004,0005,0006, - 0007,0010,0011,0012,0013,0014,0015,0016, - 0017,0020,0021,0022,0023,0024,0025,0026, - 0027,0030,0031,0200,0200,0200,0200,0200, - 0200,0032,0033,0034,0035,0036,0037,0040, - 0041,0042,0043,0044,0045,0046,0047,0050, - 0051,0052,0053,0054,0055,0056,0057,0060, - 0061,0062,0063,0200,0200,0200,0200,0200 -}; -static long infile_line; /* Current line number for mult decodes */ - -/************************************************************************/ - -/* CRC Routines. */ -/* These CRC functions are derived from code in chapter 19 of the book - "C Programmer's Guide to Serial Communications", by Joe Campbell. - Generalized to any CRC width by Philip Zimmermann. -*/ - -#define byte unsigned char - -#define CRCBITS 24 /* may be 16, 24, or 32 */ -/* #define maskcrc(crc) ((crcword)(crc)) */ /* if CRCBITS is 16 or 32 */ -#define maskcrc(crc) ((crc) & 0xffffffL) /* if CRCBITS is 24 */ -#define CRCHIBIT ((crcword) (1L<<(CRCBITS-1))) /* 0x8000 if CRCBITS is 16 */ -#define CRCSHIFTS (CRCBITS-8) - -/* Notes on making a good 24-bit CRC-- - The primitive irreducible polynomial of degree 23 over GF(2), - 040435651 (octal), comes from Appendix C of "Error Correcting Codes, - 2nd edition" by Peterson and Weldon, page 490. This polynomial was - chosen for its uniform density of ones and zeros, which has better - error detection properties than polynomials with a minimal number of - nonzero terms. Multiplying this primitive degree-23 polynomial by - the polynomial x+1 yields the additional property of detecting any - odd number of bits in error, which means it adds parity. This - approach was recommended by Neal Glover. - - To multiply the polynomial 040435651 by x+1, shift it left 1 bit and - bitwise add (xor) the unshifted version back in. Dropping the unused - upper bit (bit 24) produces a CRC-24 generator bitmask of 041446373 - octal, or 0x864cfb hex. - - You can detect spurious leading zeros or framing errors in the - message by initializing the CRC accumulator to some agreed-upon - nonzero "random-like" value, but this is a bit nonstandard. -*/ - -#define CCITTCRC 0x1021 /* CCITT's 16-bit CRC generator polynomial */ -#define PRZCRC 0x864cfbL /* PRZ's 24-bit CRC generator polynomial */ -#define CRCINIT 0xB704CEL /* Init value for CRC accumulator */ - -static -crcword crctable[256]; /* Table for speeding up CRC's */ - -/* mk_crctbl derives a CRC lookup table from the CRC polynomial. - The table is used later by the crcbytes function given below. - mk_crctbl only needs to be called once at the dawn of time. - - The theory behind mk_crctbl is that table[i] is initialized - with the CRC of i, and this is related to the CRC of i>>1, - so the CRC of i>>1 (pointed to by p) can be used to derive - the CRC of i (pointed to by q). -*/ -static -void mk_crctbl(crcword poly) -{ int i; - crcword t, *p, *q; - p = q = crctable; - *q++ = 0; - *q++ = poly; - for (i = 1; i < 128; i++) - { t = *++p; - if (t & CRCHIBIT) - { t <<= 1; - *q++ = t ^ poly; - *q++ = t; - } - else - { t <<= 1; - *q++ = t; - *q++ = t ^ poly; - } - } -} - -/* - * Accumulate a buffer's worth of bytes into a CRC accumulator, - * returning the new CRC value. - */ -crcword -crcbytes(byte *buf, unsigned len, register crcword accum) -{ - do { - accum = accum<<8 ^ crctable[(byte)(accum>>CRCSHIFTS) ^ *buf++]; - } while (--len); - return maskcrc(accum); -} /* crcbytes */ - -/* Initialize the CRC table using our codes */ -void init_crc(void) -{ mk_crctbl(PRZCRC); -} - - -/************************************************************************/ - - -/* ENC is the basic 1 character encoding function to make a char printing */ -#define ENC(c) ((int)bintoasc[((c) & 077)]) -#define PAD '=' - -/* - * output one group of up to 3 bytes, pointed at by p, on file f. - * if fewer than 3 are present, the 1 or two extras must be zeros. - */ -static void outdec(char *p, FILE *f, int count) -{ - int c1, c2, c3, c4; - - c1 = *p >> 2; - c2 = ((*p << 4) & 060) | ((p[1] >> 4) & 017); - c3 = ((p[1] << 2) & 074) | ((p[2] >> 6) & 03); - c4 = p[2] & 077; - putc(ENC(c1), f); - putc(ENC(c2), f); - if (count == 1) - { putc(PAD, f); - putc(PAD, f); - } - else - { putc(ENC(c3), f); - if (count == 2) - putc(PAD, f); - else - putc(ENC(c4), f); - } -} /* outdec */ - - -/* Output the CRC value, MSB first per normal CRC conventions */ -static void outcrc (word32 crc, FILE *outFile) -{ /* Output crc */ - char crcbuf[4]; - crcbuf[0] = (crc>>16) & 0xff; - crcbuf[1] = (crc>>8) & 0xff; - crcbuf[2] = (crc>>0) & 0xff; - putc(PAD,outFile); - outdec (crcbuf,outFile,3); - putc('\n',outFile); -} /* outcrc */ - -/* Return filename for output (text mode), but replace last letter(s) of - * filename with the ascii for num. It will use the appropriate number - * of digits for ofnum when converting num, so if ofnum < 10, use 1 digit, - * >= 10 and < 100 use 2 digits, >= 100 and < 1000 use 3 digits. If its - * >= 1000, then we have other problems to worry about, and this might do - * weird things. - */ -static char *numFilename( char *fname, int num, int ofnum) -{ static char fnamenum[MAX_PATH]; - int len; - int offset = 1; - - strcpy (fnamenum, fname); - len = strlen (fnamenum); - do { - fnamenum[len-offset] = '0' + (num%10); - num /= 10; - ofnum /= 10; - offset++; - } while (ofnum >= 1 && offset < 4); - return(fnamenum); -} - -/* - * Reads and discards a line from the given file. Returns -1 on error or - * EOF, 0 if the line is blank, and 1 if the line is not blank. - */ -static int -skipline(FILE *f) -{ - int state, flag, c; - - state = 0; - flag = 0; - for (;;) { - c = getc(f); - if (c == '\n') - return flag; - if (state) - { ungetc(c, f); - return flag; - } - if (c == EOF) - return -1; - if (c == '\r') - state = 1; - else if (c != ' ') - flag = 1; - } -} /* skipline */ - -/* - * Copies a line from the input file to the output. Does NOT copy the - * trailing newline. Returns -1 on EOF or error, 0 if the line was terminated - * by EOF, and 1 if the line was terminated with a newline sequence. - */ -static int -copyline(FILE *in, FILE *out) -{ - int state, flag, c; - - state = 0; - for (;;) { - c = getc(in); - if (c == '\n') - return 1; - if (state) - { ungetc(c, in); - return 1; - } - if (c == EOF) - return 0; - if (c == '\r') - state = 1; - else - putc(c, out); - } -} /* copyline */ - -/* - * Reads a line from file f, up to the size of the buffer. The line in the - * buffer will NOT include line termination, although any of (CR, LF, CRLF) - * is accepted on input. The return value is -1 on error, 0 if the line - * was terminated abnormally (EOF, error, or out of buffer space), and - * 1 if the line was terminated normally. - * - * Passing in a buffer less than 2 characters long is not a terribly bright - * idea. - */ -static int -getline(char *buf, int n, FILE *f) -{ - int state; - char *p; - int c; - - state = 0; - p = buf; - for (;;) - { c = getc(f); - if (c == '\n') - { *p = 0; - return 1; /* Line terminated with \n or \r\n */ - } - if (state) - { ungetc(c, f); - *p = 0; - return 1; /* Line terminated with \r */ - } - if (c == EOF) - { *p = 0; - return (p == buf) ? -1 : 0; /* Error */ - } - if (c == '\r') - state = 1; - else if (--n > 0) - *p++ = c; - else - { - ungetc(c, f); - *p = 0; - return 0; /* Out of buffer space */ - } - } /* for (;;) */ -} /* getline */ - -/* - * Read a line from file f, buf must be able to hold at least 80 characters. - * Strips trailing spaces and line terminator, can read LF, CRLF and CR - * textfiles. Anything after 80 characters is ignored. It can't be ASCII - * armor anyway. - */ -static char * -get_armor_line(char *buf, FILE *f) -{ - int c, n = 79; - char *p = buf; - - do { - c = getc(f); - if (c == '\n' || c == '\r' || c == EOF) - break; - *p++ = c; - } while (--n > 0); - if (p == buf && c == EOF) - { *buf = '\0'; - return NULL; - } - /* skip to end of line */ - while (c != '\n' && c != '\r' && c != EOF) - c = getc(f); - if (c == '\r' && (c = getc(f)) != '\n') - ungetc(c, f); - while (--p >= buf && *p == ' ') - ; - *++p = '\0'; - return buf; -} - - -/* - * Encode a file in sections. 64 ASCII bytes * 720 lines = 46K, - * recommended max. Usenet message size is 50K so this leaves a nice - * margin for .signature. In the interests of orthogonality and - * programmer laziness no check is made for a message containing only - * a few lines (or even just an 'end') after a section break. - */ -#define LINE_LEN 48L -int pem_lines = 720; -#define BYTES_PER_SECTION (LINE_LEN * pem_lines) - -#if 1 -/* This limit is advisory only; longer lines are handled properly. - * The only requirement is that this be at least as long as the longest - * delimiter string used by PGP - * (e.g. "-----BEGIN PGP MESSAGE, PART %02d/%02d-----\n") - */ -#define MAX_LINE_SIZE 80 -#else -#ifdef MSDOS /* limited stack space */ -#define MAX_LINE_SIZE 256 -#else -#define MAX_LINE_SIZE 1024 -#endif -#endif - -#ifndef VMS -/* armored files are opened in binary mode so that CRLF/LF/CR files - can be handled by all systems */ -#define FOPRPEM FOPRBIN -#else -#define FOPRPEM FOPRTXT -#endif - -extern boolean verbose; /* Undocumented command mode in PGP.C */ -extern boolean filter_mode; - -/* - * Copy from infilename to outfilename, PEM encoding as you go along, - * and with breaks every - * pem_lines lines. - * If clearfilename is non-NULL, first output that file preceded by a - * special header line. - */ -static -int pem_file(char *infilename, char *outfilename, char *clearfilename) -{ - char buffer[MAX_LINE_SIZE]; - int i, rc, bytesRead, lines = 0; - int noSections, currentSection = 1; - long fileLen; - crcword crc; - FILE *inFile, *outFile, *clearFile; - char *blocktype = "MESSAGE"; - - /* open input file as binary */ - if ((inFile = fopen(infilename,FOPRBIN)) == NULL) - { - return(1); - } - - if (!outfilename || pem_lines == 0) - noSections = 1; - else - { /* Evaluate how many parts this file will comprise */ - fseek(inFile,0L,SEEK_END); - fileLen = ftell(inFile); - rewind(inFile); - noSections = (fileLen + BYTES_PER_SECTION - 1) / BYTES_PER_SECTION; - if (noSections > 99) - { - pem_lines = ((fileLen+LINE_LEN-1)/LINE_LEN + 98) / 99; - noSections = (fileLen + BYTES_PER_SECTION - 1) / BYTES_PER_SECTION; - fprintf(pgpout, "value for \"armorlines\" is too low, using %d\n", pem_lines); - } - } - - if (outfilename == NULL) - outFile = stdout; - else - { if (noSections > 1) - { force_extension(outfilename, ASC_EXTENSION); - outFile = fopen (numFilename (outfilename, 1, noSections), FOPWTXT); - } - else - outFile = fopen(outfilename,FOPWTXT); - } - - if (outFile == NULL) - { fclose(inFile); - return(1); - } - - if (clearfilename) - { if ((clearFile = fopen(clearfilename,FOPRTXT)) == NULL) - { fclose (inFile); - if (outFile != stdout) - fclose (outFile); - return(1); - } - fprintf (outFile, "-----BEGIN PGP SIGNED MESSAGE-----\n\n"); - while ((i = getline(buffer, sizeof buffer, clearFile)) >= 0) - { - /* Quote lines beginning with '-' as per RFC1113; - * Also quote lines beginning with "From "; this is - * for Unix mailers which add ">" to such lines. - */ - if (buffer[0] == '-' || strncmp(buffer, "From ", 5)==0) - fputs("- ", outFile); - fputs(buffer, outFile); - /* If there is more on this line, copy it */ - if (i == 0) - if (copyline(clearFile, outFile) <= 0) - break; - fputc('\n', outFile); - } - fclose (clearFile); - putc('\n', outFile); - blocktype = "SIGNATURE"; - } - - - if (noSections == 1) - { - byte ctb = 0; - ctb = getc(inFile); - if (is_ctb_type(ctb, CTB_CERT_PUBKEY_TYPE)) - blocktype = "PUBLIC KEY BLOCK"; - fprintf (outFile, "-----BEGIN PGP %s-----\n",blocktype); - rewind(inFile); - } - else - fprintf (outFile, "-----BEGIN PGP MESSAGE, PART %02d/%02d-----\n", - 1, noSections); - fprintf (outFile, "Version: %s\n",rel_version); - fprintf (outFile, "\n"); - - init_crc(); - crc = CRCINIT; - - while((bytesRead = fread(buffer,1,LINE_LEN,inFile)) > 0) - { /* Munge up LINE_LEN characters */ - if (bytesRead < LINE_LEN) - fill0 (buffer+bytesRead, LINE_LEN-bytesRead); - - crc = crcbytes((byte *)buffer, bytesRead, crc); - for (i=0; i> 4); - *outbuf++=j; - j = (c2 << 4) | (c3 >> 2); - *outbuf++=j; - j = (c3 << 6) | c4; - *outbuf++=j; - } - - *outlength = length; - return(0); /* normal return */ - -} /* dpem_buffer */ - -static char pemfilename[MAX_PATH]; -/* - * try to open the next file of a multi-part armored file - * the sequence number is expected at the end of the file name - */ -static FILE * -open_next(void) -{ - char *p, *s, c; - FILE *fp; - - p = pemfilename + strlen(pemfilename); - while (--p >= pemfilename && isdigit(*p)) - { - if (*p != '9') - { - ++*p; - return(fopen(pemfilename, FOPRPEM)); - } - *p = '0'; - } - - /* need an extra digit */ - if (p >= pemfilename) - { /* try replacing character ( .as0 -> .a10 ) */ - c = *p; - *p = '1'; - if ((fp = fopen(pemfilename, FOPRPEM)) != NULL) - return(fp); - *p = c; /* restore original character */ - } - ++p; - for (s = p + strlen(p); s >= p; --s) - s[1] = *s; - *p = '1'; /* insert digit ( fn0 -> fn10 ) */ - - return(fopen(pemfilename, FOPRPEM)); -} - -/* - * Copy from in to out, decoding as you go, with handling for multiple - * 500-line blocks of encoded data. - */ -static -int pemdecode(FILE *in, FILE *out) -{ -char inbuf[80]; -char outbuf[80]; - -int i, n, status; -int line; -int section, currentSection = 1; -int noSections = 0; -int gotcrc = 0; -long crc=CRCINIT, chkcrc = -1; -char crcbuf[4]; -int ret_code = 0; -int end_of_message; - - init_crc(); - - for (line = 1; ; line++) /* for each input line */ - { - if (get_armor_line(inbuf, in) == NULL) - end_of_message = 1; - else - { end_of_message = (strncmp(inbuf,"-----END PGP MESSAGE,", 21) == 0); - ++infile_line; - } - - if (currentSection!=noSections && end_of_message) - { /* End of this section */ - if (gotcrc) - { if (chkcrc != crc) - { fprintf(pgpout,PSTR("ERROR: Bad ASCII armor checksum in section %d.\n"), currentSection); - ret_code = -1; /* continue with decoding to see if there are other bad parts */ - } - } - gotcrc = 0; - crc = CRCINIT; - section = 0; - - /* Try and find start of next section */ - do - { if (get_armor_line(inbuf,in) == NULL) - { FILE *nextf; - if ((nextf = open_next()) != NULL) - { - fclose(in); - in = nextf; - continue; - } - fprintf(pgpout,PSTR("Can't find section %d.\n"),currentSection + 1); - return(-1); - } - ++infile_line; - } - while (strncmp(inbuf,"-----BEGIN PGP MESSAGE",22)); - - /* Make sure this section is the correct one */ - if (2 != sscanf(inbuf,"-----BEGIN PGP MESSAGE, PART %d/%d", - §ion,&noSections)) - { fprintf(pgpout,PSTR("Badly formed section header, part %d.\n"), - currentSection+1); - return(-1); - } - if (section != ++currentSection) - { fprintf(pgpout,PSTR("Sections out of order, expected part %d"),currentSection); - if (section) - fprintf(pgpout,PSTR(", got part %d\n"),section); - else - fputc('\n',pgpout); - return(-1); - } - - /* Skip header after BEGIN line */ - do { - ++infile_line; - if (get_armor_line(inbuf, in) == NULL) - { - fprintf(pgpout,PSTR("ERROR: Hit EOF in header of section %d.\n"), - currentSection); - return(-1); - } - } while (inbuf[0] != '\0'); - - /* Continue decoding */ - continue; - } - - /* Quit when hit the -----END PGP MESSAGE----- line or a blank, - or handle checksum */ - if (inbuf[0] == PAD) /* Checksum lines start with PAD char */ - { - /* If the already-armored file is sent through MIME - * and gets armored again, '=' will become '=3D'. - * To make life easier, we detect and work around this - * idiosyncracy. - */ - if (strlen(inbuf) == 7 && - inbuf[1] == '3' && inbuf[2] == 'D') - status = dpem_buffer(inbuf+3, crcbuf, &n); - else - status = dpem_buffer(inbuf+1, crcbuf, &n); - if ( status < 0 || n != 3 ) - { fprintf(pgpout,PSTR("ERROR: Badly formed ASCII armor checksum, line %d.\n"),line); - return -1; - } - chkcrc = (((long)crcbuf[0]<<16)&0xff0000L) + - ((crcbuf[1]<<8)&0xff00L) + (crcbuf[2]&0xffL); - gotcrc = 1; - continue; - } - if (inbuf[0] == '\0') - { fprintf(pgpout,PSTR("WARNING: No ASCII armor `END' line.\n")); - break; - } - if (strncmp(inbuf, "-----END PGP ", 13) == 0) - break; - - status = dpem_buffer(inbuf,outbuf,&n); - - if (status == -1) - { fprintf(pgpout,PSTR("ERROR: Bad ASCII armor character, line %d.\n"), line); - gotcrc = 1; /* this will print part number, continue with next part */ - ret_code = -1; - } - - if (n > sizeof outbuf) - { fprintf(pgpout,PSTR("ERROR: Bad ASCII armor line length %d on line %d.\n"), - n, line); - return -1; - } - - crc = crcbytes((byte *)outbuf, n, crc); - if (fwrite(outbuf,1,n,out) != n) - { ret_code = -1; - break; - } - - } /* line */ - - if (gotcrc) - { if (chkcrc != crc) - { fprintf(pgpout,PSTR("ERROR: Bad ASCII armor checksum")); - if (noSections > 0) - fprintf(pgpout,PSTR(" in section %d"), noSections); - fputc('\n',pgpout); - return -1; - } - } - else - fprintf(pgpout,PSTR("Warning: Transport armor lacks a checksum.\n")); - - return(ret_code); /* normal return */ -} /* pemdecode */ - - -static -boolean is_pemfile(char *infile) -{ - FILE *in; - char inbuf[80]; - char outbuf[80]; - int n, status; - long il; - - if ((in = fopen(infile, FOPRPEM)) == NULL) - { /* can't open file */ - return(FALSE); - } - - /* Read to infile_line before we begin looking */ - for (il=0; il +#include +#include +#include "mpilib.h" +#include "fileio.h" +#include "mpiio.h" +#include "language.h" +#include "pgp.h" +#include "crypto.h" +#include "armor.h" + +static int dpem_file(char *infile, char *outfile); +static crcword crchware(byte ch, crcword poly, crcword accum); +static int pem_file(char *infilename, char *outfilename, char *clearfilename); +static int pemdecode(FILE *in, FILE *out); +static void mk_crctbl(crcword poly); +static boolean is_pemfile(char *infile); + +/* Begin PEM routines. + This converts a binary file into printable ASCII characters, in a + radix-64 form mostly compatible with the PEM RFC1113 format. + This makes it easier to send encrypted files over a 7-bit channel. +*/ + +/* Index this array by a 6 bit value to get the character corresponding + * to that value. + */ +static +unsigned char bintoasc[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ\ +abcdefghijklmnopqrstuvwxyz0123456789+/"; + +/* Index this array by a 7 bit value to get the 6-bit binary field + * corresponding to that value. Any illegal characters return high bit set. + */ +static +unsigned char asctobin[] = { + 0200,0200,0200,0200,0200,0200,0200,0200, + 0200,0200,0200,0200,0200,0200,0200,0200, + 0200,0200,0200,0200,0200,0200,0200,0200, + 0200,0200,0200,0200,0200,0200,0200,0200, + 0200,0200,0200,0200,0200,0200,0200,0200, + 0200,0200,0200,0076,0200,0200,0200,0077, + 0064,0065,0066,0067,0070,0071,0072,0073, + 0074,0075,0200,0200,0200,0200,0200,0200, + 0200,0000,0001,0002,0003,0004,0005,0006, + 0007,0010,0011,0012,0013,0014,0015,0016, + 0017,0020,0021,0022,0023,0024,0025,0026, + 0027,0030,0031,0200,0200,0200,0200,0200, + 0200,0032,0033,0034,0035,0036,0037,0040, + 0041,0042,0043,0044,0045,0046,0047,0050, + 0051,0052,0053,0054,0055,0056,0057,0060, + 0061,0062,0063,0200,0200,0200,0200,0200 +}; +static long infile_line; /* Current line number for mult decodes */ + +/************************************************************************/ + +/* CRC Routines. */ +/* These CRC functions are derived from code in chapter 19 of the book + "C Programmer's Guide to Serial Communications", by Joe Campbell. + Generalized to any CRC width by Philip Zimmermann. +*/ + +#define byte unsigned char + +#define CRCBITS 24 /* may be 16, 24, or 32 */ +/* #define maskcrc(crc) ((crcword)(crc)) */ /* if CRCBITS is 16 or 32 */ +#define maskcrc(crc) ((crc) & 0xffffffL) /* if CRCBITS is 24 */ +#define CRCHIBIT ((crcword) (1L<<(CRCBITS-1))) /* 0x8000 if CRCBITS is 16 */ +#define CRCSHIFTS (CRCBITS-8) + +/* + * Notes on making a good 24-bit CRC-- + * The primitive irreducible polynomial of degree 23 over GF(2), + * 040435651 (octal), comes from Appendix C of "Error Correcting Codes, + * 2nd edition" by Peterson and Weldon, page 490. This polynomial was + * chosen for its uniform density of ones and zeros, which has better + * error detection properties than polynomials with a minimal number of + * nonzero terms. Multiplying this primitive degree-23 polynomial by + * the polynomial x+1 yields the additional property of detecting any + * odd number of bits in error, which means it adds parity. This + * approach was recommended by Neal Glover. + * + * To multiply the polynomial 040435651 by x+1, shift it left 1 bit and + * bitwise add (xor) the unshifted version back in. Dropping the unused + * upper bit (bit 24) produces a CRC-24 generator bitmask of 041446373 + * octal, or 0x864cfb hex. + * + * You can detect spurious leading zeros or framing errors in the + * message by initializing the CRC accumulator to some agreed-upon + * nonzero "random-like" value, but this is a bit nonstandard. + */ + +#define CCITTCRC 0x1021 /* CCITT's 16-bit CRC generator polynomial */ +#define PRZCRC 0x864cfbL /* PRZ's 24-bit CRC generator polynomial */ +#define CRCINIT 0xB704CEL /* Init value for CRC accumulator */ + +static +crcword crctable[256]; /* Table for speeding up CRC's */ + +/* + * mk_crctbl derives a CRC lookup table from the CRC polynomial. + * The table is used later by the crcbytes function given below. + * mk_crctbl only needs to be called once at the dawn of time. + * + * The theory behind mk_crctbl is that table[i] is initialized + * with the CRC of i, and this is related to the CRC of i>>1, + * so the CRC of i>>1 (pointed to by p) can be used to derive + * the CRC of i (pointed to by q). + */ +static +void mk_crctbl(crcword poly) +{ + int i; + crcword t, *p, *q; + p = q = crctable; + *q++ = 0; + *q++ = poly; + for (i = 1; i < 128; i++) { + t = *++p; + if (t & CRCHIBIT) { + t <<= 1; + *q++ = t ^ poly; + *q++ = t; + } else { + t <<= 1; + *q++ = t; + *q++ = t ^ poly; + } + } +} + +/* + * Accumulate a buffer's worth of bytes into a CRC accumulator, + * returning the new CRC value. + */ +crcword +crcbytes(byte *buf, unsigned len, register crcword accum) +{ + do { + accum = accum<<8 ^ crctable[(byte)(accum>>CRCSHIFTS) ^ *buf++]; + } while (--len); + return maskcrc(accum); +} /* crcbytes */ + +/* Initialize the CRC table using our codes */ +void init_crc(void) +{ + mk_crctbl(PRZCRC); +} + + +/************************************************************************/ + + +/* ENC is the basic 1 character encoding function to make a char printing */ +#define ENC(c) ((int)bintoasc[((c) & 077)]) +#define PAD '=' + +/* + * output one group of up to 3 bytes, pointed at by p, on file f. + * if fewer than 3 are present, the 1 or two extras must be zeros. + */ +static void outdec(char *p, FILE *f, int count) +{ + int c1, c2, c3, c4; + + c1 = *p >> 2; + c2 = ((*p << 4) & 060) | ((p[1] >> 4) & 017); + c3 = ((p[1] << 2) & 074) | ((p[2] >> 6) & 03); + c4 = p[2] & 077; + putc(ENC(c1), f); + putc(ENC(c2), f); + if (count == 1) { + putc(PAD, f); + putc(PAD, f); + } else { + putc(ENC(c3), f); + if (count == 2) + putc(PAD, f); + else + putc(ENC(c4), f); + } +} /* outdec */ + + +/* Output the CRC value, MSB first per normal CRC conventions */ +static void outcrc (word32 crc, FILE *outFile) +{ + char crcbuf[4]; + crcbuf[0] = (crc>>16) & 0xff; + crcbuf[1] = (crc>>8) & 0xff; + crcbuf[2] = (crc>>0) & 0xff; + putc(PAD,outFile); + outdec (crcbuf,outFile,3); + putc('\n',outFile); +} /* outcrc */ + +/* Return filename for output (text mode), but replace last letter(s) of + * filename with the ascii for num. It will use the appropriate number + * of digits for ofnum when converting num, so if ofnum < 10, use 1 digit, + * >= 10 and < 100 use 2 digits, >= 100 and < 1000 use 3 digits. If its + * >= 1000, then we have other problems to worry about, and this might do + * weird things. + */ +static char *numFilename( char *fname, int num, int ofnum) +{ + static char fnamenum[MAX_PATH]; + int len; + int offset = 1; + + strcpy (fnamenum, fname); + len = strlen (fnamenum); + do { + fnamenum[len-offset] = '0' + (num%10); + num /= 10; + ofnum /= 10; + offset++; + } while (ofnum >= 1 && offset < 4); + return fnamenum; +} + +/* + * Reads and discards a line from the given file. Returns -1 on error or + * EOF, 0 if the line is blank, and 1 if the line is not blank. + */ +static int +skipline(FILE *f) +{ + int state, flag, c; + + state = 0; + flag = 0; + for (;;) { + c = getc(f); + if (c == '\n') + return flag; + if (state) { + ungetc(c, f); + return flag; + } + if (c == EOF) + return -1; + if (c == '\r') + state = 1; + else if (c != ' ') + flag = 1; + } +} /* skipline */ + +/* + * Copies a line from the input file to the output. Does NOT copy the + * trailing newline. Returns -1 on EOF or error, 0 if the line was terminated + * by EOF, and 1 if the line was terminated with a newline sequence. + */ +static int +copyline(FILE *in, FILE *out) +{ + int state, flag, c; + + state = 0; + for (;;) { + c = getc(in); + if (c == '\n') + return 1; + if (state) { + ungetc(c, in); + return 1; + } + if (c == EOF) + return 0; + if (c == '\r') + state = 1; + else + putc(c, out); + } +} /* copyline */ + +/* + * Reads a line from file f, up to the size of the buffer. The line in the + * buffer will NOT include line termination, although any of (CR, LF, CRLF) + * is accepted on input. The return value is -1 on error, 0 if the line + * was terminated abnormally (EOF, error, or out of buffer space), and + * 1 if the line was terminated normally. + * + * Passing in a buffer less than 2 characters long is not a terribly bright + * idea. + */ +static int +getline(char *buf, int n, FILE *f) +{ + int state; + char *p; + int c; + + state = 0; + p = buf; + for (;;) { + c = getc(f); + if (c == '\n') { + *p = 0; + return 1; /* Line terminated with \n or \r\n */ + } + if (state) { + ungetc(c, f); + *p = 0; + return 1; /* Line terminated with \r */ + } + if (c == EOF) { + *p = 0; + return (p == buf) ? -1 : 0; /* Error */ + } + if (c == '\r') + state = 1; + else if (--n > 0) { + *p++ = c; + } else { + ungetc(c, f); + *p = 0; + return 0; /* Out of buffer space */ + } + } /* for (;;) */ +} /* getline */ + +/* + * Read a line from file f, buf must be able to hold at least 80 characters. + * Strips trailing spaces and line terminator, can read LF, CRLF and CR + * textfiles. Anything after 80 characters is ignored. It can't be ASCII + * armor anyway. + */ +static char * +get_armor_line(char *buf, FILE *f) +{ + int c, n = 79; + char *p = buf; + + do { + c = getc(f); + if (c == '\n' || c == '\r' || c == EOF) + break; + *p++ = c; + } while (--n > 0); + if (p == buf && c == EOF) { + *buf = '\0'; + return NULL; + } + /* skip to end of line */ + while (c != '\n' && c != '\r' && c != EOF) + c = getc(f); + if (c == '\r' && (c = getc(f)) != '\n') + ungetc(c, f); + while (--p >= buf && *p == ' ') + ; + *++p = '\0'; + return buf; +} + + +/* + * Encode a file in sections. 64 ASCII bytes * 720 lines = 46K, + * recommended max. Usenet message size is 50K so this leaves a nice + * margin for .signature. In the interests of orthogonality and + * programmer laziness no check is made for a message containing only + * a few lines (or even just an 'end') after a section break. + */ +#define LINE_LEN 48L +int pem_lines = 720; +#define BYTES_PER_SECTION (LINE_LEN * pem_lines) + +#if 1 +/* This limit is advisory only; longer lines are handled properly. + * The only requirement is that this be at least as long as the longest + * delimiter string used by PGP + * (e.g. "-----BEGIN PGP MESSAGE, PART %02d/%02d-----\n") + */ +#define MAX_LINE_SIZE 80 +#else +#ifdef MSDOS /* limited stack space */ +#define MAX_LINE_SIZE 256 +#else +#define MAX_LINE_SIZE 1024 +#endif +#endif + +#ifndef VMS +/* armored files are opened in binary mode so that CRLF/LF/CR files + can be handled by all systems */ +#define FOPRPEM FOPRBIN +#else +#define FOPRPEM FOPRTXT +#endif + +extern boolean verbose; /* Undocumented command mode in PGP.C */ +extern boolean filter_mode; + +/* + * Copy from infilename to outfilename, PEM encoding as you go along, + * and with breaks every + * pem_lines lines. + * If clearfilename is non-NULL, first output that file preceded by a + * special header line. + */ +static +int pem_file(char *infilename, char *outfilename, char *clearfilename) +{ + char buffer[MAX_LINE_SIZE]; + int i, rc, bytesRead, lines = 0; + int noSections, currentSection = 1; + long fileLen; + crcword crc; + FILE *inFile, *outFile, *clearFile; + char *blocktype = "MESSAGE"; + + /* open input file as binary */ + if ((inFile = fopen(infilename,FOPRBIN)) == NULL) + return 1; + + if (!outfilename || pem_lines == 0) { + noSections = 1; + } else { + /* Evaluate how many parts this file will comprise */ + fseek(inFile,0L,SEEK_END); + fileLen = ftell(inFile); + rewind(inFile); + noSections = (fileLen + BYTES_PER_SECTION - 1) / BYTES_PER_SECTION; + if (noSections > 99) { + pem_lines = ((fileLen+LINE_LEN-1)/LINE_LEN + 98) / 99; + noSections = (fileLen + BYTES_PER_SECTION - 1) / BYTES_PER_SECTION; + fprintf(pgpout, "value for \"armorlines\" is too low, using %d\n", pem_lines); + } + } + + if (outfilename == NULL) { + outFile = stdout; + } else { + if (noSections > 1) { + force_extension(outfilename, ASC_EXTENSION); + outFile = fopen (numFilename (outfilename, 1, noSections), FOPWTXT); + } else { + outFile = fopen(outfilename,FOPWTXT); + } + } + + if (outFile == NULL) { + fclose(inFile); + return 1; + } + + if (clearfilename) { + if ((clearFile = fopen(clearfilename,FOPRTXT)) == NULL) { + fclose (inFile); + if (outFile != stdout) + fclose (outFile); + return 1; + } + fprintf (outFile, "-----BEGIN PGP SIGNED MESSAGE-----\n\n"); + while ((i = getline(buffer, sizeof buffer, clearFile)) >= 0) + { + /* Quote lines beginning with '-' as per RFC1113; + * Also quote lines beginning with "From "; this is + * for Unix mailers which add ">" to such lines. + */ + if (buffer[0] == '-' || strncmp(buffer, "From ", 5)==0) + fputs("- ", outFile); + fputs(buffer, outFile); + /* If there is more on this line, copy it */ + if (i == 0) + if (copyline(clearFile, outFile) <= 0) + break; + fputc('\n', outFile); + } + fclose (clearFile); + putc('\n', outFile); + blocktype = "SIGNATURE"; + } + + + if (noSections == 1) { + byte ctb = 0; + ctb = getc(inFile); + if (is_ctb_type(ctb, CTB_CERT_PUBKEY_TYPE)) + blocktype = "PUBLIC KEY BLOCK"; + fprintf (outFile, "-----BEGIN PGP %s-----\n",blocktype); + rewind(inFile); + } else { + fprintf (outFile, "-----BEGIN PGP MESSAGE, PART %02d/%02d-----\n", + 1, noSections); + } + fprintf (outFile, "Version: %s\n",LANG (rel_version)); + if (globalCommentString[0]) + fprintf (outFile, "Comment: %s\n", globalCommentString); + fprintf (outFile, "\n"); + + init_crc(); + crc = CRCINIT; + + while((bytesRead = fread(buffer,1,LINE_LEN,inFile)) > 0) { + /* Munge up LINE_LEN characters */ + if (bytesRead < LINE_LEN) + fill0 (buffer+bytesRead, LINE_LEN-bytesRead); + + crc = crcbytes((byte *)buffer, bytesRead, crc); + for (i=0; i> 4); + *outbuf++=j; + j = (c2 << 4) | (c3 >> 2); + *outbuf++=j; + j = (c3 << 6) | c4; + *outbuf++=j; + } + + *outlength = length; + return 0; /* normal return */ + +} /* dpem_buffer */ + +static char pemfilename[MAX_PATH]; +/* + * try to open the next file of a multi-part armored file + * the sequence number is expected at the end of the file name + */ +static FILE * +open_next(void) +{ + char *p, *s, c; + FILE *fp; + + p = pemfilename + strlen(pemfilename); + while (--p >= pemfilename && isdigit(*p)) { + if (*p != '9') { + ++*p; + return fopen(pemfilename, FOPRPEM); + } + *p = '0'; + } + + /* need an extra digit */ + if (p >= pemfilename) { + /* try replacing character ( .as0 -> .a10 ) */ + c = *p; + *p = '1'; + if ((fp = fopen(pemfilename, FOPRPEM)) != NULL) + return fp; + *p = c; /* restore original character */ + } + ++p; + for (s = p + strlen(p); s >= p; --s) + s[1] = *s; + *p = '1'; /* insert digit ( fn0 -> fn10 ) */ + + return fopen(pemfilename, FOPRPEM); +} + +/* + * Copy from in to out, decoding as you go, with handling for multiple + * 500-line blocks of encoded data. + */ +static +int pemdecode(FILE *in, FILE *out) +{ + char inbuf[80]; + char outbuf[80]; + + int i, n, status; + int line; + int section, currentSection = 1; + int noSections = 0; + int gotcrc = 0; + long crc=CRCINIT, chkcrc = -1; + char crcbuf[4]; + int ret_code = 0; + int end_of_message; + + init_crc(); + + for (line = 1; ; line++) { /* for each input line */ + if (get_armor_line(inbuf, in) == NULL) { + end_of_message = 1; + } else { + end_of_message = (strncmp(inbuf,"-----END PGP MESSAGE,", 21) == 0); + ++infile_line; + } + + if (currentSection!=noSections && end_of_message) { + /* End of this section */ + if (gotcrc) { + if (chkcrc != crc) { + fprintf(pgpout,LANG("ERROR: Bad ASCII armor checksum in section %d.\n"), currentSection); + ret_code = -1; /* continue with decoding to see if there are other bad parts */ + } + } + gotcrc = 0; + crc = CRCINIT; + section = 0; + + /* Try and find start of next section */ + do { + if (get_armor_line(inbuf,in) == NULL) { + FILE *nextf; + if ((nextf = open_next()) != NULL) { + fclose(in); + in = nextf; + continue; + } + fprintf(pgpout,LANG("Can't find section %d.\n"),currentSection + 1); + return -1; + } + ++infile_line; + } + while (strncmp(inbuf,"-----BEGIN PGP MESSAGE",22)); + + /* Make sure this section is the correct one */ + if (2 != sscanf(inbuf,"-----BEGIN PGP MESSAGE, PART %d/%d", + §ion,&noSections)) + { + fprintf(pgpout,LANG("Badly formed section header, part %d.\n"), + currentSection+1); + return -1; + } + if (section != ++currentSection) { + fprintf(pgpout,LANG("Sections out of order, expected part %d"),currentSection); + if (section) + fprintf(pgpout,LANG(", got part %d\n"),section); + else + fputc('\n',pgpout); + return -1; + } + + /* Skip header after BEGIN line */ + do { + ++infile_line; + if (get_armor_line(inbuf, in) == NULL) { + fprintf(pgpout,LANG("ERROR: Hit EOF in header of section %d.\n"), + currentSection); + return -1; + } + } while (inbuf[0] != '\0'); + + /* Continue decoding */ + continue; + } + + /* Quit when hit the -----END PGP MESSAGE----- line or a blank, + or handle checksum */ + if (inbuf[0] == PAD) { /* Checksum lines start with PAD char */ + /* If the already-armored file is sent through MIME + * and gets armored again, '=' will become '=3D'. + * To make life easier, we detect and work around this + * idiosyncracy. + */ + if (strlen(inbuf) == 7 && + inbuf[1] == '3' && inbuf[2] == 'D') + status = dpem_buffer(inbuf+3, crcbuf, &n); + else + status = dpem_buffer(inbuf+1, crcbuf, &n); + if ( status < 0 || n != 3 ) { + fprintf(pgpout,LANG("ERROR: Badly formed ASCII armor checksum, line %d.\n"),line); + return -1; + } + chkcrc = (((long)crcbuf[0]<<16)&0xff0000L) + + ((crcbuf[1]<<8)&0xff00L) + (crcbuf[2]&0xffL); + gotcrc = 1; + continue; + } + if (inbuf[0] == '\0') { + fprintf(pgpout,LANG("WARNING: No ASCII armor `END' line.\n")); + break; + } + if (strncmp(inbuf, "-----END PGP ", 13) == 0) + break; + + status = dpem_buffer(inbuf,outbuf,&n); + + if (status == -1) { + fprintf(pgpout,LANG("ERROR: Bad ASCII armor character, line %d.\n"), line); + gotcrc = 1; /* this will print part number, continue with next part */ + ret_code = -1; + } + + if (n > sizeof outbuf) { + fprintf(pgpout,LANG("ERROR: Bad ASCII armor line length %d on line %d.\n"), + n, line); + return -1; + } + + crc = crcbytes((byte *)outbuf, n, crc); + if (fwrite(outbuf,1,n,out) != n) { + ret_code = -1; + break; + } + + } /* line */ + + if (gotcrc) { + if (chkcrc != crc) { + fprintf(pgpout,LANG("ERROR: Bad ASCII armor checksum")); + if (noSections > 0) + fprintf(pgpout,LANG(" in section %d"), noSections); + fputc('\n',pgpout); + return -1; + } + } else { + fprintf(pgpout,LANG("Warning: Transport armor lacks a checksum.\n")); + } + + return ret_code; /* normal return */ +} /* pemdecode */ + + +static +boolean is_pemfile(char *infile) +{ + FILE *in; + char inbuf[80]; + char outbuf[80]; + int n, status; + long il; + + if ((in = fopen(infile, FOPRPEM)) == NULL) { + /* can't open file */ + return FALSE; + } + + /* Read to infile_line before we begin looking */ + for (il=0; il