Merge remote-tracking branch 'fozzie/master'

This commit is contained in:
Neale Pickett 2012-06-01 10:58:32 -06:00
commit 9949705fc9
2 changed files with 131 additions and 1 deletions

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@ -1,6 +1,6 @@
CFLAGS = -Wall -Werror CFLAGS = -Wall -Werror
TARGETS = claim.cgi puzzler.cgi puzzles.cgi TARGETS = claim.cgi puzzler.cgi puzzles.cgi
TARGETS += pointscli arc4 TARGETS += pointscli arc4 tea
all: build all: build

130
packages/mcp/src/tea.c Normal file
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#include <stdio.h>
#include <unistd.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
static const char magic[4] = "tea.";
#define min(a,b) (((a)<(b))?(a):(b))
void
tea_encrypt(uint32_t *v, uint32_t *k) {
uint32_t v0=v[0], v1=v[1], sum=0, i; /* set up */
uint32_t delta=0x9e3779b9; /* a key schedule constant */
uint32_t k0=k[0], k1=k[1], k2=k[2], k3=k[3]; /* cache key */
for (i=0; i < 32; i++) { /* basic cycle start */
sum += delta;
v0 += ((v1<<4) + k0) ^ (v1 + sum) ^ ((v1>>5) + k1);
v1 += ((v0<<4) + k2) ^ (v0 + sum) ^ ((v0>>5) + k3);
} /* end cycle */
v[0]=v0; v[1]=v1;
}
/*
* Use TEA in CTR mode to create a stream cipher.
*/
static void
tea_apply(FILE *out, FILE *in, uint32_t *k, uint32_t ivec)
{
uint32_t count = 0;
uint32_t v[2];
size_t idx = sizeof v;
char *p = (char *)v;
while (1) {
int c = fgetc(in);
if (EOF == c) {
break;
}
if (sizeof v == idx) {
v[0] = ivec;
v[1] = count++;
tea_encrypt(v, k);
idx = 0;
}
fputc(c ^ p[idx++], out);
}
}
int
tea_decrypt_stream(FILE *out, FILE *in, uint32_t *k)
{
uint32_t ivec;
{
char m[4] = {0};
fread(m, sizeof m, 1, in);
if (memcmp(m, magic, 4)) {
return -1;
}
}
fread(&ivec, sizeof ivec, 1, in);
tea_apply(out, in, k, ivec);
return 0;
}
int
tea_encrypt_stream(FILE *out, FILE *in, uint32_t *k)
{
uint32_t ivec;
fwrite(magic, sizeof magic, 1, out);
{
FILE *r = fopen("/dev/urandom", "r");
if (! r) {
return -1;
}
fread(&ivec, sizeof ivec, 1, r);
fclose(r);
}
fwrite(&ivec, sizeof ivec, 1, out);
tea_apply(out, in, k, ivec);
return 0;
}
int
usage(const char *prog)
{
fprintf(stderr, "Usage: %s [-e] <PLAINTEXT\n", prog);
fprintf(stderr, "\n");
fprintf(stderr, "You must pass in a key on fd 3 or in the environment variable KEY.\n");
return EX_USAGE;
}
int
main(int argc, char *argv[])
{
uint32_t key[4] = {0};
{
char *ekey = getenv("KEY");
if (ekey) {
memcpy(key, ekey, min(strlen(ekey), sizeof(key)));
} else if (-1 == read(3, key, sizeof(key))) {
return usage(argv[0]);
}
}
if (! argv[1]) {
tea_decrypt_stream(stdout, stdin, key);
} else if (0 == strcmp(argv[1], "-e")) {
tea_encrypt_stream(stdout, stdin, key);
} else {
return usage(argv[0]);
}
return 0;
}