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slowcrypt cli: chacha20-csprng

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This commit is contained in:
Alexander Nutz
2025-09-10 21:29:39 +02:00
parent f2aafd5070
commit 40520c3a9e
1 changed files with 117 additions and 8 deletions
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125
slowcrypt/slowcrypt.c
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@@ -9,6 +9,9 @@
#define SLOWCRYPT_POLY1305_IMPL
#include "../poly1305.h"
#define SLOWCRYPT_SYSTEMRAND_IMPL
#include "../systemrand.h"
struct algo
{
char const* name;
@@ -169,7 +172,8 @@ static void run_chacha20_core(char** args)
static void run_chacha20_crypt(char** args)
{
static char const help[] =
"chacha20 [--pad <padding>] [--full-chunks] <key> <nonce> <file>\n"
"chacha20 [--pad <padding>] [--init-counter <n>] [--full-chunks] <key> "
"<nonce> <file>\n"
"\n"
"Run the ChaCha20 en-/de- cryption algorithm on the given file, or "
"stdin, and output the result to stdout\n"
@@ -181,9 +185,10 @@ static void run_chacha20_crypt(char** args)
char const *key, *nonce, *fpath = "-";
unsigned int npos = 0;
unsigned int nb, i;
unsigned long ul;
uint8_t pad = 0;
int full_chunks = 0;
uint32_t counter;
uint32_t counter = 1;
slowcrypt_chacha20 state[2];
uint8_t buf[64];
uint8_t keyb[32];
@@ -202,6 +207,12 @@ static void run_chacha20_crypt(char** args)
} else if (anyeq(*args, "-pad", "--pad", "--padding") && args[1]) {
args++;
pad = (uint8_t)atoi(*args);
} else if (anyeq(*args, "-init-counter", "-initial-counter",
"--initial-counter", "--init-counter") &&
args[1]) {
args++;
sscanf(*args, "%lu", &ul);
counter = ul;
} else if (anyeq(*args, "-h", "-help", "--help")) {
printf("%s", help);
exit(0);
@@ -227,7 +238,7 @@ static void run_chacha20_crypt(char** args)
fp = file_open(fpath);
for (counter = 1; (nb = file_read_chunk(fp, buf, 64)); counter++) {
for (; (nb = file_read_chunk(fp, buf, 64)); counter++) {
for (i = nb; i < 64; i++)
buf[i] = pad;
slowcrypt_chacha20_block(state, keyb, counter, nonceb, buf);
@@ -239,6 +250,90 @@ static void run_chacha20_crypt(char** args)
file_close(fp);
}
static void run_chacha20_csprng(char** args)
{
static char const help[] =
"chacha20-csprng [--limit <num bytes>] [--init-counter <n>] [--key "
"<key>] "
"[--nonce <nonce>] \n"
"\n"
"Run the ChaCha20 function repeatedly, with incrementing counter, "
"(starting at the given initial counter, defaulting to 1),"
"writing the output to stdout.\n"
"\n"
"If no limit (in number of bytes) is given, will repeat forever.\n"
"\n"
"Both key and nonce will be generated randomly (using the highest "
"entropy random source available), unless overwritten\n";
char const* key = 0;
char const* nonce = 0;
unsigned long ul;
unsigned long limit = 0;
unsigned long nb, nwrb;
uint32_t counter = 1;
slowcrypt_chacha20 state[2];
uint8_t buf[64];
uint8_t keyb[32];
uint8_t nonceb[12];
for (; *args; args++) {
if (anyeq(*args, "-limit", "--limit") && args[1]) {
args++;
sscanf(*args, "%lu", &ul);
limit = ul;
} else if (anyeq(*args, "-init-counter", "-initial-counter",
"--initial-counter", "--init-counter") &&
args[1]) {
args++;
sscanf(*args, "%lu", &ul);
counter = ul;
} else if (anyeq(*args, "-h", "-help", "--help")) {
printf("%s", help);
exit(0);
} else if (anyeq(*args, "-key", "--key")) {
args++;
key = *args;
} else if (anyeq(*args, "-nonce", "--nonce")) {
args++;
nonce = *args;
} else {
fprintf(stderr, "Unexpected argument: %s\n", *args);
exit(1);
}
}
if (key) {
parse_hex2buf(keyb, 32, "key", key);
} else {
slowcrypt_systemrand(keyb, 32, 0);
}
if (nonce) {
parse_hex2buf(nonceb, 12, "nonce", nonce);
} else {
slowcrypt_systemrand(keyb, 12, 0);
}
if (!limit) {
for (;; counter++) {
slowcrypt_chacha20_init(state, keyb, counter, nonceb);
slowcrypt_chacha20_run(state, &state[1], 20);
slowcrypt_chacha20_serialize(buf, state);
fwrite(buf, 1, 64, stdout);
}
} else {
for (nb = 0; nb < limit; (nb += 64, counter++)) {
nwrb = limit - nb;
if (nwrb > 64)
nwrb = 64;
slowcrypt_chacha20_init(state, keyb, counter, nonceb);
slowcrypt_chacha20_run(state, &state[1], 20);
slowcrypt_chacha20_serialize(buf, state);
fwrite(buf, 1, nwrb, stdout);
}
}
}
static void run_poly1305(char** args)
{
static char const help[] =
@@ -299,11 +394,15 @@ static void run_poly1305(char** args)
file_close(fp);
}
static struct algo bytes2sum[] = {{"poly1305", run_poly1305},
{"chacha20-core", run_chacha20_core},
{0, 0}};
static struct algo bytes2scalar[] = {{"poly1305", run_poly1305},
{"chacha20-core", run_chacha20_core},
{0, 0}};
static struct algo bytes2bytes[] = {{"chacha20", run_chacha20_crypt}, {0, 0}};
static struct algo scalar2bytes[] = {{"chacha20-csprng", run_chacha20_csprng},
{0, 0}};
int main(int argc, char** argv)
{
struct algo* a;
@@ -312,15 +411,18 @@ int main(int argc, char** argv)
if (!*argv || anyeq(*argv, "-h", "-help", "--help")) {
printf("bytes -> scalar\n");
for (a = bytes2sum; a->name; a++)
for (a = bytes2scalar; a->name; a++)
printf(" %s\n", a->name);
printf("\nbytes -> bytes\n");
for (a = bytes2bytes; a->name; a++)
printf(" %s\n", a->name);
printf("\nscalar -> bytes\n");
for (a = scalar2bytes; a->name; a++)
printf(" %s\n", a->name);
return 0;
}
for (a = bytes2sum; a->name; a++) {
for (a = bytes2scalar; a->name; a++) {
if (!strcmp(a->name, *argv)) {
a->run(argv + 1);
return 0;
@@ -334,6 +436,13 @@ int main(int argc, char** argv)
}
}
for (a = scalar2bytes; a->name; a++) {
if (!strcmp(a->name, *argv)) {
a->run(argv + 1);
return 0;
}
}
fprintf(stderr, "Unknown algorithm %s\n", *argv);
return 1;
}