2 * $DragonFly: src/lib/libskey/put.c,v 1.5 2008/09/30 16:57:05 swildner Exp $
11 static unsigned long extract (char *s,int start,int length);
12 static void standard (char *word);
13 static void insert (char *s, int x, int start, int length);
14 static int wsrch (char *w,int low,int high);
16 /* Dictionary for integer-word translations */
17 static char Wp[2048][4] = {
2068 /* Encode 8 bytes in 'c' as a string of English words.
2069 * Returns a pointer to a static buffer
2072 btoe(char *engout, char *c)
2074 char cp[9]; /* add in room for the parity 2 bits*/
2079 /* compute parity */
2080 for(p = 0,i = 0; i < 64;i += 2)
2081 p += extract(cp,i,2);
2083 cp[8] = (char)p << 6;
2084 strncat(engout,&Wp[extract(cp, 0,11)][0],4);
2086 strncat(engout,&Wp[extract(cp,11,11)][0],4);
2088 strncat(engout,&Wp[extract(cp,22,11)][0],4);
2090 strncat(engout,&Wp[extract(cp,33,11)][0],4);
2092 strncat(engout,&Wp[extract(cp,44,11)][0],4);
2094 strncat(engout,&Wp[extract(cp,55,11)][0],4);
2096 printf("engout is %s\n\r",engout);
2101 /* convert English to binary
2102 * returns 1 OK - all good words and parity is OK
2103 * 0 word not in data base
2104 * -1 badly formed in put ie > 4 char word
2105 * -2 words OK but parity is wrong
2108 etob(char *out, char *e)
2111 int i, v,l, low,high;
2119 strncpy(input,e,sizeof(input));
2121 memset(b, 0, sizeof(b));
2123 for(i=0,p=0;i<6;i++,p+=11){
2124 while ((word = strsep(&cp, " ")) != NULL && *word == '\0')
2139 if( (v = wsrch(word,low,high)) < 0 )
2141 insert(b,v,(int)p,11);
2144 /* now check the parity of what we got */
2145 for(p = 0, i = 0; i < 64; i +=2)
2146 p += extract(b, i, 2);
2148 if( (p & 3) != extract(b, 64,2) )
2155 /* Display 8 bytes as a series of 16-bit hex digits */
2157 put8(char *out, char *s)
2159 sprintf(out,"%02X%02X %02X%02X %02X%02X %02X%02X",
2160 s[0] & 0xff,s[1] & 0xff,s[2] & 0xff,
2161 s[3] & 0xff,s[4] & 0xff,s[5] & 0xff,
2162 s[6] & 0xff,s[7] & 0xff);
2166 /* Encode 8 bytes in 'cp' as stream of ascii letters.
2167 * Provided as a possible alternative to btoe()
2173 static char out[31];
2175 /* code out put by characters 6 bits each added to 0x21 (!)*/
2176 for(i=0;i <= 10;i++){
2177 /* last one is only 4 bits not 6*/
2178 out[i] = '!'+ extract(cp,6*i,i >= 10 ? 4:6);
2185 /* Internal subroutines for word encoding/decoding */
2187 /* Dictionary binary search */
2189 wsrch(char *w, int low, int high)
2195 if((j = strncmp(w,Wp[i],4)) == 0)
2196 return i; /* Found it */
2198 /* Avoid effects of integer truncation in /2 */
2199 if(strncmp(w,Wp[high],4) == 0)
2205 return -1; /* I don't *think* this can happen...*/
2207 high = i; /* Search lower half */
2209 low = i; /* Search upper half */
2213 insert(char *s, int x, int start, int length)
2221 assert(length <= 11);
2223 assert(length >= 0);
2224 assert(start +length <= 66);
2226 shift = ((8 -(( start + length) % 8))%8);
2227 y = (long) x << shift;
2228 cl = (y >> 16) & 0xff;
2229 cc = (y >> 8) & 0xff;
2231 if(shift + length > 16){
2233 s[start/8 +1] |= cc;
2234 s[start/8 +2] |= cr;
2235 } else if(shift +length > 8){
2237 s[start/8 + 1] |= cr;
2244 standard(char *word)
2250 *word = toupper(*word);
2261 /* Extract 'length' bits from the char array 's' starting with bit 'start' */
2262 static unsigned long
2263 extract(char *s, int start, int length)
2270 assert(length <= 11);
2272 assert(length >= 0);
2273 assert(start +length <= 66);
2278 x = ((long)(cl<<8 | cc) <<8 | cr) ;
2279 x = x >> (24 - (length + (start %8)));
2280 x =( x & (0xffff >> (16-length) ) );
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