+
+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));
+// cli_putc('c'); uart_flush(0);
+ rsa_dec(&x, key);
+// cli_putc('d'); uart_flush(0);
+ 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;
+}
+
+