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pmslavin/gist:91a9240e15badff383e399491563fb89

Created April 18, 2017 22:28
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gistfile1.txt
#include <stdio.h>
#include <stdlib.h>
#include "b64.h"
const char *const base64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
const char pad = '=';
char *b64_encode(const unsigned char *src, size_t src_len)
{
size_t pad_len = src_len % 3;
pad_len = pad_len ? 3-pad_len : pad_len;
size_t dest_len = (src_len + pad_len) / 3 * 4;
printf("[b64] dest_len: %d\n", dest_len);
printf("[b64] pad_len: %d\n", pad_len);
size_t src_idx = 0, dest_idx = 0;
char *dest = malloc((dest_len+1)*sizeof(*dest)); // Null terminate
while(src_len > 2){
dest[dest_idx++] = base64[src[src_idx] >> 2];
dest[dest_idx++] = base64[((src[src_idx] & 0x03) << 4) + (src[src_idx+1] >> 4)];
src_idx++;
dest[dest_idx++] = base64[((src[src_idx] & 0x0F) << 2) + (src[src_idx+1] >> 6)];
src_idx++;
dest[dest_idx++] = base64[src[src_idx++] & 0x3F];
src_len -= 3;
}
if(src_len){
dest[dest_idx++] = base64[src[src_idx] >> 2];
dest[dest_idx++] = base64[((src[src_idx] & 0x03) << 4)];
if(pad_len == 2){
dest[dest_idx++] = pad;
}else{
dest[dest_idx++] = base64[((src[src_idx] & 0x0F) << 2)];
}
dest[dest_idx++] = pad;
}
dest[dest_idx] = '\0';
printf("[b64] dest_idx: %d\n", dest_idx);
return dest;
}
#include <openssl/evp.h>
#include <openssl/pem.h>
#include <openssl/conf.h>
#include <openssl/err.h>
#include <string.h>
#include "b64.h"
static EVP_PKEY *localKeypair;
int main(int argc, char *argv[])
{
(void)argc;
(void)argv;
/* Load the human readable error strings for libcrypto */
ERR_load_crypto_strings();
/* Load all digest and cipher algorithms */
OpenSSL_add_all_algorithms();
/* Load config file, and other important initialisation */
OPENSSL_config(NULL);
// RAND_poll();
/* ... Do some crypto stuff here ... */
EVP_PKEY_CTX *ctx = EVP_PKEY_CTX_new_id(EVP_PKEY_DSA, NULL);
EVP_PKEY_paramgen_init(ctx);
if(!EVP_PKEY_CTX_set_dsa_paramgen_bits(ctx, 1024))
return 1;
EVP_PKEY *params = NULL;
EVP_PKEY_paramgen(ctx, &params);
EVP_PKEY_CTX *kctx = EVP_PKEY_CTX_new(params, NULL);
if(EVP_PKEY_keygen_init(kctx) <= 0)
return 2;
if(EVP_PKEY_keygen(kctx, &localKeypair) <= 0)
return 3;
// BIO *pub_raw = BIO_new(BIO_s_mem());
BIO *outbio = BIO_new_fp(stdout, BIO_NOCLOSE);
// EVP_PKEY_print_public(outbio, localKeypair, 0, NULL);
// BIO_printf(outbio, "%d bit RSA Key\n\n", EVP_PKEY_bits(localKeypair));
PEM_write_bio_PUBKEY(outbio, localKeypair);
// PEM_write_bio_DSA_PUBKEY(outbio, EVP_PKEY_get1_DSA(localKeypair));
DSA *dsa = EVP_PKEY_get1_DSA(localKeypair);
printf("dsa->p->top: %d\n", dsa->p->top);
for(int idx=dsa->p->top-1; idx>=0; idx--)
printf("%02x ", dsa->p->d[idx]);
putchar('\n');
printf("dsa->q->top: %d\n", dsa->q->top);
for(int idx=dsa->q->top-1; idx>=0; idx--)
printf("%0x ", dsa->q->d[idx]);
putchar('\n');
printf("dsa->g->top: %d\n", dsa->g->top);
for(int idx=dsa->g->top-1; idx>=0; idx--)
printf("dsa->pub_key->top: %d\n", dsa->pub_key->top);
for(int idx=dsa->pub_key->top-1; idx>=0; idx--)
printf("%0x ", dsa->pub_key->d[idx]);
putchar('\n');
// printf("%d: %x\n", dsa->p->top, dsa->p->d);
// PEM_write_bio_PrivateKey(outbio, localKeypair, NULL, NULL, 0, NULL, NULL);
char *pwd = "rfc1034";
PEM_write_bio_PrivateKey(outbio, localKeypair, EVP_des_ede3_cbc(), pwd, strlen(pwd), NULL, NULL);
unsigned char prelude[] = {0x00, 0x00, 0x00, 0x07,
/* ssh-dss */ 0x73, 0x73, 0x68, 0x2d, 0x64, 0x73, 0x73,
0x00, 0x00, 0x00};
size_t binout_sz = sizeof(prelude) + 4*(dsa->p->top + dsa->q->top
+ dsa->g->top + dsa->pub_key->top) + 20; /* inline sizes*/
unsigned char *binout = malloc(binout_sz * sizeof(*binout));
memcpy(binout, prelude, sizeof(prelude));
size_t off = sizeof(prelude);
binout[off++] = dsa->p->top*4+1;
binout[off++] = 0x00;
for(int idx=dsa->p->top-1; idx>=0; idx--)
for(int s=3; s>=0; s--)
binout[off++] = ((unsigned int)(dsa->p->d[idx] >> (8*s)) & 0xFF);
binout[off++] = 0x00;
binout[off++] = 0x00;
binout[off++] = 0x00;
binout[off++] = dsa->q->top*4+1;
binout[off++] = 0x00;
for(int idx=dsa->q->top-1; idx>=0; idx--)
for(int s=3; s>=0; s--)
binout[off++] = ((unsigned int)(dsa->q->d[idx] >> (8*s)) & 0xFF);
binout[off++] = 0x00;
binout[off++] = 0x00;
binout[off++] = 0x00;
binout[off++] = dsa->g->top*4+1;
binout[off++] = 0x00;
for(int idx=dsa->g->top-1; idx>=0; idx--)
for(int s=3; s>=0; s--)
binout[off++] = ((unsigned int)(dsa->g->d[idx] >> (8*s)) & 0xFF);
binout[off++] = 0x00;
binout[off++] = 0x00;
binout[off++] = 0x00;
binout[off++] = dsa->pub_key->top*4+1;
binout[off++] = 0x00;
for(int idx=dsa->pub_key->top-1; idx>=0; idx--)
for(int s=3; s>=0; s--)
binout[off++] = ((unsigned int)(dsa->pub_key->d[idx] >> (8*s)) & 0xFF);
char *b64t = b64_encode((unsigned char *)binout, off);
printf("binout: %s\n", b64t);
free(b64t);
printf("ui: %d ul:%d\n", sizeof(unsigned int), sizeof(unsigned long));
unsigned int t = 0x44332211;
printf("%2x %2x %2x %2x\n", (t >> 24) & 0xFF, (t >> 16) & 0xFF, (t >> 8) & 0xFF, (t >> 0) & 0xFF);
printf("%2x %2x %2x %2x\n", (t >> 0) & 0xFF, (t >> 8) & 0xFF, (t >> 16) & 0xFF, (t >> 24) & 0xFF);
b64t = b64_encode((unsigned char *)"PQR", 3);
printf("b64t: %s\n", b64t);
free(b64t);
unsigned char c01 = 0xFF;
char c02 = 0xFF;
printf("c01: %.8x\nc02: %.8x\n", c01 >> 4, c02 >> 4);
printf("c01: %.8x\nc02: %.8x\n", c01 >> 4, (c02 >> 4) & 0x0F);
printf("c01: %.8x\nc02: %.8x\n", c01 << 4, c02 << 4);
printf("prelude: %d dsa->p->top: %d dsa->q->top: %d dsa->g->top: %d dsa->pub_key->top: %d\n", sizeof(prelude), dsa->p->top, dsa->q->top, dsa->g->top, dsa->pub_key->top);
// PEM_write_bio_DSAparams(outbio, EVP_PKEY_get1_DSA(localKeypair));
/* Clean up */
EVP_PKEY_CTX_free(ctx);
/* Removes all digests and ciphers */
EVP_cleanup();
/* if you omit the next, a small leak may be left when you make use of the BIO (low level API) for e.g. base64 transformations */
CRYPTO_cleanup_all_ex_data();
/* Remove error strings */
ERR_free_strings();
return 0;
}
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