uint8_t dsa_verify_message(const dsa_signature_t* s, const void* m, uint16_t m_len_b,
const hfdesc_t* hash_desc, const dsa_ctx_t* ctx) {
bigint_t z;
uint8_t n_B = ctx->domain.q.length_B;
uint8_t hash_value[(hfal_hash_getHashsize(hash_desc)+7)/8];
hfal_hash_mem(hash_desc, hash_value, m, m_len_b);
z.wordv=hash_value;
z.length_B=n_B;
bigint_changeendianess(&z);
bigint_adjust(&z);
return dsa_verify_bigint(s, &z, ctx);
}
void hfal_test(const hfdesc_t* hd, const void* msg, uint32_t length_b){
if(hd->type!=HFDESC_TYPE_HASHFUNCTION)
return;
uint16_t dlen = (hd->hashsize_b+7)/8;
uint8_t digest[dlen];
cli_putstr("\r\n=== ");
cli_putstr(hd->name);
cli_putstr(" ===\r\n message:");
cli_hexdump_block(msg, (length_b+7)/8, 4, 16);
hfal_hash_mem(hd, digest, msg, length_b);
cli_putstr(" \r\n digest:");
cli_hexdump_block(digest, dlen, 4, 16);
cli_putstr("\r\n");
}
void hfal_test(const hfdesc_t *hd, void *msg, uint32_t length_b){
if(pgm_read_byte(&(hd->type))!=HFDESC_TYPE_HASHFUNCTION)
return;
uint16_t dlen = (pgm_read_word(&(hd->hashsize_b))+7)/8;
uint8_t digest[dlen];
cli_putstr_P(PSTR("\r\n=== "));
cli_putstr_P((void*)pgm_read_word(&(hd->name)));
cli_putstr_P(PSTR(" ===\r\n message:"));
cli_hexdump_block(msg, (length_b+7)/8, 4, 16);
hfal_hash_mem(hd, digest, msg, length_b);
cli_putstr_P(PSTR(" \r\n digest:"));
cli_hexdump_block(digest, dlen, 4, 16);
cli_putstr_P(PSTR("\r\n"));
}
void shavs_test3(void){ /* Monte Carlo tests for SHA-3 */
uint16_t expected_input;
uint16_t count;
uint8_t v;
uint8_t index=0;
char c;
if(!shavs_algo){
cli_putstr("\r\nERROR: select algorithm first!");
return;
}
uint8_t ml=shavs_algo->hashsize_b/8;
uint8_t m[ml+128];
for(;;){
while((c=cli_getc_cecho())!='S' && c!='s'){
if(!isblank((uint8_t)c)){
cli_putstr("\r\nERROR: wrong input (1) [0x");
cli_hexdump(&c, 1);
cli_putstr("]!\r\n");
return;
}
}
if((c=cli_getc_cecho())!='e' && c!='E'){
cli_putstr("\r\nERROR: wrong input (2)!\r\n");
return;
}
if((c=cli_getc_cecho())!='e' && c!='E'){
cli_putstr("\r\nERROR: wrong input (3)!\r\n");
return;
}
if((c=cli_getc_cecho())!='d' && c!='D'){
cli_putstr("\r\nERROR: wrong input (4)!\r\n");
return;
}
while((c=cli_getc_cecho())!='='){
if(!isblank((uint8_t)c)){
cli_putstr("\r\nERROR: wrong input (5)!\r\n");
return;
}
}
expected_input = 1024/4;
memset(m+ml, 0, 1024/8);
do{
v=0xff;
c=cli_getc_cecho();
if(c>='0' && c<='9'){
v = c - '0';
}else{
c |= 'A'^'a';
if(c>='a' && c<='f'){
v = c - 'a' +10;
}
}
if(v<0x10){
c=m[ml+index/2];
if(index&1){
c |= v;
}else{
c |=v<<4;
}
m[ml+index/2]=c;
index++;
expected_input--;
}
}while(expected_input);
/* so we have the seed */
cli_putstr("\r\nstarting processing");
uint16_t j;
for(count=0; count<100; ++count){
for(j=0; j<1000; ++j){
hfal_hash_mem(shavs_algo, m, m+ml, 1024);
memmove(m+ml, m, 1024/8);
}
cli_putstr("\r\n\r\nj = ");
if(count>=10){
cli_putc(count/10+'0');
}
cli_putc(count%10+'0');
cli_putstr("\r\nMD = ");
cli_hexdump(m+ml, ml);
}
}
}
uint8_t rsa_encrypt_oaep(void* dest, uint16_t* out_length,
const void* src, uint16_t length_B,
rsa_publickey_t* key, const rsa_oaep_parameter_t *p,
const rsa_label_t* label, const void* seed){
if(!p){
p = &rsa_oaep_default_parameter;
}
if(!label){
label = &rsa_oaep_default_label;
}
uint16_t hv_len = (hfal_hash_getHashsize(p->hf)+7)/8;
if(length_B > bigint_length_B(&key->modulus) - 2*hv_len - 2){
/* message too long */
return 1;
}
uint16_t buffer_len = bigint_length_B(&key->modulus);
#if DEBUG
cli_putstr("\r\n buffer_len = ");
cli_hexdump_rev(&buffer_len, 2);
cli_putstr("\r\n modulus_len = ");
cli_hexdump_rev(&key->modulus.length_B, 2);
#endif
uint8_t* buffer = (uint8_t*)dest;
uint8_t off;
/* the following needs some explanation:
* off is the offset which is used for compensating the effect of
* changeendian() when it operates on multi-byte words.
* */
off = (sizeof(bigint_word_t) - (bigint_get_first_set_bit(&key->modulus)/8+1) % sizeof(bigint_word_t))
% (sizeof(bigint_word_t));
buffer += off;
buffer_len -= off;
uint8_t* seed_buffer = buffer + 1;
uint16_t db_len = buffer_len - hv_len - 1;
uint8_t* db = seed_buffer + hv_len;
uint16_t maskbuffer_len = db_len>hv_len?db_len:hv_len;
uint8_t maskbuffer[maskbuffer_len];
bigint_t x;
memset(dest, 0, seed_buffer - buffer + off);
memset(db + hv_len, 0, db_len - hv_len - length_B -1);
hfal_hash_mem(p->hf, db, label->label, label->length_b);
db[db_len - length_B - 1] = 0x01;
memcpy(db+db_len - length_B, src, length_B);
if(seed){
memcpy(seed_buffer, seed, hv_len);
}else{
/* generate random seed */
if(!prng_get_byte){
return 2; /* ERROR: no random generator specified */
}
uint16_t i;
for(i=0; i<hv_len; ++i){
seed_buffer[i] = prng_get_byte();
}
}
#if DEBUG
cli_putstr("\r\n msg (raw, pre-feistel):\r\n");
cli_hexdump_block(dest, bigint_length_B(&key->modulus), 4, 16);
#endif
p->mgf(maskbuffer, seed_buffer, hv_len, db_len, p->mgf_parameter);
memxor(db, maskbuffer, db_len);
p->mgf(maskbuffer, db, db_len, hv_len, p->mgf_parameter);
memxor(seed_buffer, maskbuffer, hv_len);
#if DEBUG
cli_putstr("\r\n msg (raw, post-feistel):\r\n");
cli_hexdump_block(dest, bigint_length_B(&key->modulus), 4, 16);
#endif
x.info = 0;
x.length_B = key->modulus.length_B;
x.wordv = dest;
bigint_adjust(&x);
rsa_os2ip(&x, NULL, bigint_length_B(&key->modulus));
#if DEBUG
cli_putstr("\r\ninput-msg (pre enc):\r\n");
cli_hexdump_rev(&src, 2);
cli_hexdump_block(src, length_B, 4, 16);
#endif
rsa_enc(&x, key);
#if DEBUG
cli_putstr("\r\ninput-msg (post enc):\r\n");
cli_hexdump_rev(&src, 2);
cli_hexdump_block(src, length_B, 4, 16);
#endif
rsa_i2osp(NULL, &x, out_length);
return 0;
}
uint8_t rsa_decrypt_oaep(void* dest, uint16_t* out_length,
const void* src, uint16_t length_B,
rsa_privatekey_t* key, const rsa_oaep_parameter_t *p,
const rsa_label_t* label, void* seed){
// cli_putstr("\r\n -->rsa_decrypt_oaep()"); uart_flush(0);
if(!label){
label = &rsa_oaep_default_label;
}
if(!p){
p = &rsa_oaep_default_parameter;
}
uint16_t x_len, data_len;
bigint_t x;
uint16_t hv_len = hfal_hash_getHashsize(p->hf)/8;
uint8_t label_hv[hv_len];
uint16_t msg_len = bigint_get_first_set_bit(&key->modulus) / 8 + 1;
uint16_t db_len = msg_len - hv_len - 1;
uint8_t maskbuffer[db_len>hv_len?db_len:hv_len];
uint8_t *seed_buffer = dest;
uint8_t *db_buffer = seed_buffer + hv_len;
x_len = bigint_get_first_set_bit(&key->modulus)/8;
memset(dest, 0, bigint_length_B(&key->modulus) - length_B);
memcpy((uint8_t*)dest + bigint_length_B(&key->modulus) - length_B, src, length_B);
// cli_putc('a'); uart_flush(0);
x.wordv = dest;
x.length_B = key->modulus.length_B;
x.info = 0;
bigint_adjust(&x);
// cli_putc('b'); uart_flush(0);
rsa_os2ip(&x, NULL, bigint_length_B(&key->modulus));
#if DEBUG
cli_putstr_P(PSTR("\r\n rsa decrypting ..."));
#endif
rsa_dec(&x, key);
#if DEBUG
cli_putstr_P(PSTR(" [done]"));
#endif
rsa_i2osp(NULL, &x, &data_len);
// cli_putstr("\r\n msg (raw, pre-move):\r\n");
// cli_hexdump_block(dest, bigint_length_B(key->modulus), 4, 16);
if(data_len > x_len){
return 7;
}
/*
cli_putstr("\r\n moving some bytes; x_len = ");
cli_hexdump_rev(&x_len, 2);
cli_putstr(" data_len = ");
cli_hexdump_rev(&data_len, 2);
uart_flush(0);
*/
if(x_len != data_len){
memmove((uint8_t*)dest + x_len - data_len, dest, data_len);
// cli_putstr(" (oh, not dead yet?!)");
// uart_flush(0);
memset(dest, 0, x_len - data_len);
}
hfal_hash_mem(p->hf, label_hv, label->label, label->length_b);
/*
cli_putstr("\r\n msg (raw, pre-feistel):\r\n");
cli_hexdump_block(seed_buffer, bigint_length_B(key->modulus), 4, 16);
uart_flush(0);
*/
p->mgf(maskbuffer, db_buffer, db_len, hv_len, p->mgf_parameter);
memxor(seed_buffer, maskbuffer, hv_len);
p->mgf(maskbuffer, seed_buffer, hv_len, db_len, p->mgf_parameter);
memxor(db_buffer, maskbuffer, db_len);
if(memcmp(label_hv, db_buffer, hv_len)){
// cli_putstr("\r\nDBG: DB:\r\n");
// cli_hexdump_block(db_buffer, db_len, 4, 16);
return 2;
}
uint16_t ps_len=0;
while(db_buffer[hv_len + ps_len++] == 0)
;
--ps_len;
if(db_buffer[hv_len + ps_len] != 1){
return 3;
}
if(seed){
memcpy(seed, seed_buffer, hv_len);
}
msg_len = db_len - hv_len - 1 - ps_len;
memmove(dest, db_buffer + hv_len + ps_len + 1, msg_len);
*out_length = msg_len;
return 0;
}
