X-Git-Url: https://git.cryptolib.org/?a=blobdiff_plain;f=rsa%2Frsa_oaep.c;fp=rsa%2Frsa_oaep.c;h=0a5cf76e2ab4fca2dea3ad009661fe3cad725ace;hb=ad20a79e4270ac6d3d7c0af08efb287865dca42a;hp=0000000000000000000000000000000000000000;hpb=f47523ef3943cceaa73f0a80360472bc357d60fb;p=arm-crypto-lib.git

diff --git a/rsa/rsa_oaep.c b/rsa/rsa_oaep.c
new file mode 100644
index 0000000..0a5cf76
--- /dev/null
+++ b/rsa/rsa_oaep.c
@@ -0,0 +1,124 @@
+
+/* rsa_oaep.c */
+/*
+    This file is part of the ARM-Crypto-Lib.
+    Copyright (C) 2006-2012 Daniel Otte (daniel.otte@rub.de)
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include "memxor.h"
+#include "mgf1.h"
+#include "bigint.h"
+#include "rsa_basic.h"
+#include "rsa_oaep.h"
+
+#include "random_dummy.h"
+
+#include "hfal/hfal_sha1.h"
+
+#include "cli.h"
+#include "uart_lowlevel.h"
+
+mgf1_parameter_t mgf1_default_parameter = {
+		&sha1_desc
+};
+
+rsa_oaep_parameter_t rsa_oaep_default_parameter = {
+		mgf1,
+		&sha1_desc,
+		&mgf1_default_parameter
+};
+
+rsa_label_t rsa_oaep_default_label = {
+		0, NULL
+};
+
+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);
+	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)*8))
+			% (sizeof(bigint_word_t));
+	uart_flush(0);
+	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(buffer, 0, seed_buffer - buffer);
+	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);
+	uart_flush(0);
+	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();
+		}
+	}
+
+//void mgf1(void* dest, const void* seed, uint16_t seed_len_B, uint16_t out_length_B, const mgf1_parameter_t* p);
+	cli_hexdump_block(dest, buffer_len+off, 4, 8);
+	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);
+	cli_putstr("\r\ngot to 112\r\n");
+	uart_flush(0);
+
+	x.wordv = dest;
+	x.length_B = key->modulus->length_B;
+	bigint_adjust(&x);
+	cli_putstr("\r\ngot to 118\r\n");
+	uart_flush(0);
+
+	rsa_os2ip(&x, NULL, key->modulus->length_B * sizeof(bigint_word_t));
+	rsa_enc(&x, key);
+	rsa_i2osp(NULL, &x, out_length);
+	return 0;
+}