>From f065065fce4cc6179880d5255f994e026d431717 Mon Sep 17 00:00:00 2001
From: Ben Sartor <address@hidden>
Date: Thu, 22 Jan 2015 18:59:55 +0100
Subject: [PATCH 12/12] selectCommonAlgo now prevents adding the same element
 twice

---
 src/cryptoUtils.c      | 24 ++++++++++++++++--------
 test/bzrtpCryptoTest.c |  8 ++++----
 2 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/src/cryptoUtils.c b/src/cryptoUtils.c
index b4f3988..a2dafc2 100644
--- a/src/cryptoUtils.c
+++ b/src/cryptoUtils.c
@@ -438,17 +438,25 @@ int updateCryptoFunctionPointers(bzrtpChannelContext_t *zrtpChannelContext) {
  * @return		the number of common algorithms found
  */
 uint8_t selectCommonAlgo(uint8_t masterArray[7], uint8_t masterArrayLength, uint8_t slaveArray[7], uint8_t slaveArrayLength, uint8_t commonArray[7]) {
-	int i,j;
+	int i;
 	uint8_t commonLength = 0;
+	const int bitsProInt = 8*sizeof(int);
+	const int algosBitmapSize = 256/bitsProInt;
+	int algosBitmap[algosBitmapSize];
+
+	memset(algosBitmap, 0, sizeof(int)*algosBitmapSize);
+	for (i=0; i<slaveArrayLength; i++) {
+		algosBitmap[slaveArray[i]/bitsProInt] = algosBitmap[slaveArray[i]/bitsProInt] | 1 << (slaveArray[i] % bitsProInt);
+	}
+
 	for (i=0; i<masterArrayLength; i++) {
-		for(j=0; j<slaveArrayLength; j++) {
-			if (masterArray[i] == slaveArray[j]) { /* found one, insert it in the common array */
-				commonArray[commonLength] = masterArray[i];
-				commonLength++;
+		if (algosBitmap[masterArray[i]/bitsProInt] & (1 << (masterArray[i] % bitsProInt))) {
+			algosBitmap[masterArray[i]/bitsProInt] ^= 1 << (masterArray[i] % bitsProInt);
+			commonArray[commonLength] = masterArray[i];
+			commonLength++;
 
-				if (commonLength == 7) {
-					return commonLength;
-				}
+			if (commonLength == 7) {
+				return commonLength;
 			}
 		}
 	}
diff --git a/test/bzrtpCryptoTest.c b/test/bzrtpCryptoTest.c
index 1f8c6d2..605c036 100644
--- a/test/bzrtpCryptoTest.c
+++ b/test/bzrtpCryptoTest.c
@@ -645,15 +645,15 @@ void test_algoSetterGetter(void) {
 
 	CU_TEST(testAlgoSetterGetter(ZRTP_KEYAGREEMENT_TYPE, (uint8_t []){ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH2k}, 2, (uint8_t []){ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH2k}, 2));
 	CU_TEST(testAlgoSetterGetter(ZRTP_KEYAGREEMENT_TYPE, (uint8_t []){ZRTP_KEYAGREEMENT_DH2k, ZRTP_KEYAGREEMENT_DH3k}, 2, (uint8_t []){ZRTP_KEYAGREEMENT_DH2k, ZRTP_KEYAGREEMENT_DH3k}, 2));
-	CU_TEST(testAlgoSetterGetter(ZRTP_KEYAGREEMENT_TYPE, (uint8_t []){ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH3k}, 2, (uint8_t []){ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH3k}, 2));
+	CU_TEST(testAlgoSetterGetter(ZRTP_KEYAGREEMENT_TYPE, (uint8_t []){ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH3k}, 2, (uint8_t []){ZRTP_KEYAGREEMENT_DH3k}, 1));
 	CU_TEST(testAlgoSetterGetter(ZRTP_KEYAGREEMENT_TYPE, (uint8_t []){ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_EC25}, 2, (uint8_t []){ZRTP_KEYAGREEMENT_DH3k}, 1));
 	CU_TEST(testAlgoSetterGetter(ZRTP_KEYAGREEMENT_TYPE, (uint8_t []){ZRTP_KEYAGREEMENT_EC25, ZRTP_KEYAGREEMENT_DH3k}, 2, (uint8_t []){ZRTP_KEYAGREEMENT_DH3k}, 1));
 	CU_TEST(testAlgoSetterGetter(ZRTP_KEYAGREEMENT_TYPE, (uint8_t []){ZRTP_KEYAGREEMENT_EC25, ZRTP_KEYAGREEMENT_EC52}, 2, NULL, 0));
 
 	CU_TEST(testAlgoSetterGetter(ZRTP_KEYAGREEMENT_TYPE, (uint8_t []){ZRTP_KEYAGREEMENT_EC52, ZRTP_KEYAGREEMENT_EC25, ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH2k}, 4, (uint8_t []){ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH2k}, 2));
 	CU_TEST(testAlgoSetterGetter(ZRTP_KEYAGREEMENT_TYPE, (uint8_t []){ZRTP_KEYAGREEMENT_Prsh, ZRTP_KEYAGREEMENT_EC52, ZRTP_KEYAGREEMENT_EC38, ZRTP_KEYAGREEMENT_EC25, ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH2k}, 6, (uint8_t []){ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH2k}, 2));
-	CU_TEST(testAlgoSetterGetter(ZRTP_KEYAGREEMENT_TYPE, (uint8_t []){ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH2k, ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH2k}, 4, (uint8_t []){ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH2k, ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH2k}, 4));
-	CU_TEST(testAlgoSetterGetter(ZRTP_KEYAGREEMENT_TYPE, (uint8_t []){ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH3k}, 8, (uint8_t []){ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH3k}, 7));
+	CU_TEST(testAlgoSetterGetter(ZRTP_KEYAGREEMENT_TYPE, (uint8_t []){ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH2k, ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH2k}, 4, (uint8_t []){ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH2k}, 2));
+	CU_TEST(testAlgoSetterGetter(ZRTP_KEYAGREEMENT_TYPE, (uint8_t []){ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH3k, ZRTP_KEYAGREEMENT_DH3k}, 8, (uint8_t []){ZRTP_KEYAGREEMENT_DH3k}, 1));
 
 	/// cipher type
 	CU_TEST(testAlgoSetterGetter(ZRTP_CIPHERBLOCK_TYPE, (uint8_t []){ZRTP_CIPHER_AES1}, 1, (uint8_t []){ZRTP_CIPHER_AES1}, 1));
@@ -663,7 +663,7 @@ void test_algoSetterGetter(void) {
 	CU_TEST(testAlgoSetterGetter(ZRTP_CIPHERBLOCK_TYPE, (uint8_t []){ZRTP_CIPHER_2FS2}, 1, NULL, 0));
 	CU_TEST(testAlgoSetterGetter(ZRTP_CIPHERBLOCK_TYPE, (uint8_t []){ZRTP_CIPHER_2FS3}, 1, NULL, 0));
 
-	CU_TEST(testAlgoSetterGetter(ZRTP_CIPHERBLOCK_TYPE, (uint8_t []){ZRTP_CIPHER_AES3, ZRTP_CIPHER_AES3}, 2, (uint8_t []){ZRTP_CIPHER_AES3, ZRTP_CIPHER_AES3}, 2));
+	CU_TEST(testAlgoSetterGetter(ZRTP_CIPHERBLOCK_TYPE, (uint8_t []){ZRTP_CIPHER_AES3, ZRTP_CIPHER_AES3}, 2, (uint8_t []){ZRTP_CIPHER_AES3}, 1));
 	CU_TEST(testAlgoSetterGetter(ZRTP_CIPHERBLOCK_TYPE, (uint8_t []){ZRTP_CIPHER_AES3, ZRTP_CIPHER_AES1}, 2, (uint8_t []){ZRTP_CIPHER_AES3, ZRTP_CIPHER_AES1}, 2));
 	CU_TEST(testAlgoSetterGetter(ZRTP_CIPHERBLOCK_TYPE, (uint8_t []){ZRTP_CIPHER_AES1, ZRTP_CIPHER_AES3}, 2, (uint8_t []){ZRTP_CIPHER_AES1, ZRTP_CIPHER_AES3}, 2));
 	CU_TEST(testAlgoSetterGetter(ZRTP_CIPHERBLOCK_TYPE, (uint8_t []){ZRTP_CIPHER_AES1, ZRTP_CIPHER_AES2}, 2, (uint8_t []){ZRTP_CIPHER_AES1}, 1));
-- 
2.1.4