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Diffstat (limited to 'bin/ed/cbc.c')
| -rw-r--r-- | bin/ed/cbc.c | 396 |
1 files changed, 396 insertions, 0 deletions
diff --git a/bin/ed/cbc.c b/bin/ed/cbc.c new file mode 100644 index 0000000..80ed95a --- /dev/null +++ b/bin/ed/cbc.c @@ -0,0 +1,396 @@ +/* cbc.c: This file contains the encryption routines for the ed line editor */ +/*- + * Copyright (c) 1993 The Regents of the University of California. + * All rights reserved. + * + * Copyright (c) 1993 Andrew Moore, Talke Studio. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/types.h> +#include <errno.h> +#include <pwd.h> +#ifdef DES +#include <time.h> +#include <openssl/des.h> +#define ED_DES_INCLUDES +#endif + +#include "ed.h" + + +/* + * BSD and System V systems offer special library calls that do + * block move_liness and fills, so if possible we take advantage of them + */ +#define MEMCPY(dest,src,len) memcpy((dest),(src),(len)) +#define MEMZERO(dest,len) memset((dest), 0, (len)) + +/* Hide the calls to the primitive encryption routines. */ +#define DES_XFORM(buf) \ + DES_ecb_encrypt(buf, buf, &schedule, \ + inverse ? DES_DECRYPT : DES_ENCRYPT); + +/* + * read/write - no error checking + */ +#define READ(buf, n, fp) fread(buf, sizeof(char), n, fp) +#define WRITE(buf, n, fp) fwrite(buf, sizeof(char), n, fp) + +/* + * global variables and related macros + */ + +#ifdef DES +static DES_cblock ivec; /* initialization vector */ +static DES_cblock pvec; /* padding vector */ + +static char bits[] = { /* used to extract bits from a char */ + '\200', '\100', '\040', '\020', '\010', '\004', '\002', '\001' +}; + +static int pflag; /* 1 to preserve parity bits */ + +static DES_key_schedule schedule; /* expanded DES key */ + +static unsigned char des_buf[8];/* shared buffer for get_des_char/put_des_char */ +static int des_ct = 0; /* count for get_des_char/put_des_char */ +static int des_n = 0; /* index for put_des_char/get_des_char */ +#endif + +/* init_des_cipher: initialize DES */ +void +init_des_cipher(void) +{ +#ifdef DES + int i; + + des_ct = des_n = 0; + + /* initialize the initialization vector */ + MEMZERO(ivec, 8); + + /* initialize the padding vector */ + for (i = 0; i < 8; i++) + pvec[i] = (char) (arc4random() % 256); +#endif +} + + +/* get_des_char: return next char in an encrypted file */ +int +get_des_char(FILE *fp) +{ +#ifdef DES + if (des_n >= des_ct) { + des_n = 0; + des_ct = cbc_decode(des_buf, fp); + } + return (des_ct > 0) ? des_buf[des_n++] : EOF; +#else + return (getc(fp)); +#endif +} + + +/* put_des_char: write a char to an encrypted file; return char written */ +int +put_des_char(int c, FILE *fp) +{ +#ifdef DES + if (des_n == sizeof des_buf) { + des_ct = cbc_encode(des_buf, des_n, fp); + des_n = 0; + } + return (des_ct >= 0) ? (des_buf[des_n++] = c) : EOF; +#else + return (fputc(c, fp)); +#endif +} + + +/* flush_des_file: flush an encrypted file's output; return status */ +int +flush_des_file(FILE *fp) +{ +#ifdef DES + if (des_n == sizeof des_buf) { + des_ct = cbc_encode(des_buf, des_n, fp); + des_n = 0; + } + return (des_ct >= 0 && cbc_encode(des_buf, des_n, fp) >= 0) ? 0 : EOF; +#else + return (fflush(fp)); +#endif +} + +#ifdef DES +/* + * get keyword from tty or stdin + */ +int +get_keyword(void) +{ + char *p; /* used to obtain the key */ + DES_cblock msgbuf; /* I/O buffer */ + + /* + * get the key + */ + if (*(p = getpass("Enter key: "))) { + + /* + * copy it, nul-padded, into the key area + */ + expand_des_key(msgbuf, p); + MEMZERO(p, _PASSWORD_LEN); + set_des_key(&msgbuf); + MEMZERO(msgbuf, sizeof msgbuf); + return 1; + } + return 0; +} + + +/* + * print a warning message and, possibly, terminate + */ +void +des_error(const char *s) +{ + errmsg = s ? s : strerror(errno); +} + +/* + * map a hex character to an integer + */ +int +hex_to_binary(int c, int radix) +{ + switch(c) { + case '0': return(0x0); + case '1': return(0x1); + case '2': return(radix > 2 ? 0x2 : -1); + case '3': return(radix > 3 ? 0x3 : -1); + case '4': return(radix > 4 ? 0x4 : -1); + case '5': return(radix > 5 ? 0x5 : -1); + case '6': return(radix > 6 ? 0x6 : -1); + case '7': return(radix > 7 ? 0x7 : -1); + case '8': return(radix > 8 ? 0x8 : -1); + case '9': return(radix > 9 ? 0x9 : -1); + case 'A': case 'a': return(radix > 10 ? 0xa : -1); + case 'B': case 'b': return(radix > 11 ? 0xb : -1); + case 'C': case 'c': return(radix > 12 ? 0xc : -1); + case 'D': case 'd': return(radix > 13 ? 0xd : -1); + case 'E': case 'e': return(radix > 14 ? 0xe : -1); + case 'F': case 'f': return(radix > 15 ? 0xf : -1); + } + /* + * invalid character + */ + return(-1); +} + +/* + * convert the key to a bit pattern + * obuf bit pattern + * kbuf the key itself + */ +void +expand_des_key(char *obuf, char *kbuf) +{ + int i, j; /* counter in a for loop */ + int nbuf[64]; /* used for hex/key translation */ + + /* + * leading '0x' or '0X' == hex key + */ + if (kbuf[0] == '0' && (kbuf[1] == 'x' || kbuf[1] == 'X')) { + kbuf = &kbuf[2]; + /* + * now translate it, bombing on any illegal hex digit + */ + for (i = 0; i < 16 && kbuf[i]; i++) + if ((nbuf[i] = hex_to_binary((int) kbuf[i], 16)) == -1) + des_error("bad hex digit in key"); + while (i < 16) + nbuf[i++] = 0; + for (i = 0; i < 8; i++) + obuf[i] = + ((nbuf[2*i]&0xf)<<4) | (nbuf[2*i+1]&0xf); + /* preserve parity bits */ + pflag = 1; + return; + } + /* + * leading '0b' or '0B' == binary key + */ + if (kbuf[0] == '0' && (kbuf[1] == 'b' || kbuf[1] == 'B')) { + kbuf = &kbuf[2]; + /* + * now translate it, bombing on any illegal binary digit + */ + for (i = 0; kbuf[i] && i < 16; i++) + if ((nbuf[i] = hex_to_binary((int) kbuf[i], 2)) == -1) + des_error("bad binary digit in key"); + while (i < 64) + nbuf[i++] = 0; + for (i = 0; i < 8; i++) + for (j = 0; j < 8; j++) + obuf[i] = (obuf[i]<<1)|nbuf[8*i+j]; + /* preserve parity bits */ + pflag = 1; + return; + } + /* + * no special leader -- ASCII + */ + (void)strncpy(obuf, kbuf, 8); +} + +/***************** + * DES FUNCTIONS * + *****************/ +/* + * This sets the DES key and (if you're using the deszip version) + * the direction of the transformation. This uses the Sun + * to map the 64-bit key onto the 56 bits that the key schedule + * generation routines use: the old way, which just uses the user- + * supplied 64 bits as is, and the new way, which resets the parity + * bit to be the same as the low-order bit in each character. The + * new way generates a greater variety of key schedules, since many + * systems set the parity (high) bit of each character to 0, and the + * DES ignores the low order bit of each character. + */ +void +set_des_key(DES_cblock *buf) /* key block */ +{ + int i, j; /* counter in a for loop */ + int par; /* parity counter */ + + /* + * if the parity is not preserved, flip it + */ + if (!pflag) { + for (i = 0; i < 8; i++) { + par = 0; + for (j = 1; j < 8; j++) + if ((bits[j] & (*buf)[i]) != 0) + par++; + if ((par & 0x01) == 0x01) + (*buf)[i] &= 0x7f; + else + (*buf)[i] = ((*buf)[i] & 0x7f) | 0x80; + } + } + + DES_set_odd_parity(buf); + DES_set_key(buf, &schedule); +} + + +/* + * This encrypts using the Cipher Block Chaining mode of DES + */ +int +cbc_encode(unsigned char *msgbuf, int n, FILE *fp) +{ + int inverse = 0; /* 0 to encrypt, 1 to decrypt */ + + /* + * do the transformation + */ + if (n == 8) { + for (n = 0; n < 8; n++) + msgbuf[n] ^= ivec[n]; + DES_XFORM((DES_cblock *)msgbuf); + MEMCPY(ivec, msgbuf, 8); + return WRITE(msgbuf, 8, fp); + } + /* + * at EOF or last block -- in either case, the last byte contains + * the character representation of the number of bytes in it + */ +/* + MEMZERO(msgbuf + n, 8 - n); +*/ + /* + * Pad the last block randomly + */ + (void)MEMCPY(msgbuf + n, pvec, 8 - n); + msgbuf[7] = n; + for (n = 0; n < 8; n++) + msgbuf[n] ^= ivec[n]; + DES_XFORM((DES_cblock *)msgbuf); + return WRITE(msgbuf, 8, fp); +} + +/* + * This decrypts using the Cipher Block Chaining mode of DES + * msgbuf I/O buffer + * fp input file descriptor + */ +int +cbc_decode(unsigned char *msgbuf, FILE *fp) +{ + DES_cblock tbuf; /* temp buffer for initialization vector */ + int n; /* number of bytes actually read */ + int c; /* used to test for EOF */ + int inverse = 1; /* 0 to encrypt, 1 to decrypt */ + + if ((n = READ(msgbuf, 8, fp)) == 8) { + /* + * do the transformation + */ + MEMCPY(tbuf, msgbuf, 8); + DES_XFORM((DES_cblock *)msgbuf); + for (c = 0; c < 8; c++) + msgbuf[c] ^= ivec[c]; + MEMCPY(ivec, tbuf, 8); + /* + * if the last one, handle it specially + */ + if ((c = fgetc(fp)) == EOF) { + n = msgbuf[7]; + if (n < 0 || n > 7) { + des_error("decryption failed (block corrupted)"); + return EOF; + } + } else + (void)ungetc(c, fp); + return n; + } + if (n > 0) + des_error("decryption failed (incomplete block)"); + else if (n < 0) + des_error("cannot read file"); + return EOF; +} +#endif /* DES */ |
