From cab96d88c00355dfd217a7992ea6353a15fde87a Mon Sep 17 00:00:00 2001 From: Dorian Zedler Date: Mon, 4 Jul 2022 18:02:34 +0200 Subject: [PATCH] Feat: Boilerplate for multiple impls --- .vscode/settings.json | 3 +- .vscode/tasks.json | 1 + Implementierung/Makefile | 4 +- Implementierung/lib/md2.h | 19 +++++- Implementierung/src/main.c | 14 ++++- Implementierung/src/md2.c | 118 ++++++------------------------------- 6 files changed, 51 insertions(+), 108 deletions(-) diff --git a/.vscode/settings.json b/.vscode/settings.json index 57c9e18..a81d0b8 100644 --- a/.vscode/settings.json +++ b/.vscode/settings.json @@ -12,7 +12,8 @@ "variant": "c", "array": "c", "md2.h": "c", - "io.h": "c" + "io.h": "c", + "md2_0.h": "c" }, "editor.formatOnSave": true, "C_Cpp.default.includePath": [ diff --git a/.vscode/tasks.json b/.vscode/tasks.json index dde10c3..5ce3840 100644 --- a/.vscode/tasks.json +++ b/.vscode/tasks.json @@ -8,6 +8,7 @@ "-fdiagnostics-color=always", "-g", "${fileDirname}/*.c", + "${fileDirname}/md2_impls/*.c", "-o", "${fileDirname}/../md2" ], diff --git a/Implementierung/Makefile b/Implementierung/Makefile index 3e24247..6771640 100644 --- a/Implementierung/Makefile +++ b/Implementierung/Makefile @@ -1,6 +1,6 @@ -SRC = src/main.c src/helper.c src/io.c src/md2.c +SRC = src/main.c src/helper.c src/io.c src/md2.c src/md2_impls/md2_common.c src/md2_impls/md2_0.c OBJ = ${subst src,build,${SRC:.c=.o}} CC = gcc CFLAGS = -Ilib -ggdb @@ -23,7 +23,7 @@ build: mkdir build build/%.o: src/%.c - @mkdir -p build + @mkdir -p build/md2_impls ${CC} -c ${CFLAGS} -o $@ $< md2: ${OBJ} diff --git a/Implementierung/lib/md2.h b/Implementierung/lib/md2.h index a692a12..f0dc597 100644 --- a/Implementierung/lib/md2.h +++ b/Implementierung/lib/md2.h @@ -1,12 +1,16 @@ #ifndef MD2_H #define MD2_H +#include #include #include #include #include #include +typedef void (*md2_hash_func)(size_t len, const uint8_t buf[], uint8_t out[16]); +typedef void (*md2_checksum_func)(size_t len, uint8_t* buf); + /** * @brief Calculates checksum of buf and stores it in out * @@ -14,7 +18,7 @@ * @param buf Location of the data * @param out Destination array of for the checksum */ -void md2_hash(size_t len, const uint8_t buf[], uint8_t out[16]); +extern md2_hash_func md2_hash; /** * @brief Calculates checksum of buf and appends it to buf @@ -23,7 +27,16 @@ void md2_hash(size_t len, const uint8_t buf[], uint8_t out[16]); * @param buf Location of the data. Make sure to reserve 16 bytes more so the * chechsum fits! */ -void md2_checksum(size_t len, uint8_t* buf); +extern md2_checksum_func md2_checksum; + +/** + * @brief Choose the implementation to use + * + * @param i the implementation + * @return true when the implemenatation was changed + * @return false when the implementation does not exist + */ +bool md2_choose_implementation(int i); /** * @brief Takes a uint8_t array and converts it into a string @@ -31,6 +44,6 @@ void md2_checksum(size_t len, uint8_t* buf); * @param hash the array containing the hash * @param stringHash pointer to store the string, has to have 32 bytes space */ -void encodeHash(uint8_t hash[16], char* stringHash); +void md2_encode_hash(uint8_t hash[16], char* string_hash); #endif // MD2_H \ No newline at end of file diff --git a/Implementierung/src/main.c b/Implementierung/src/main.c index 811289d..c1afb63 100644 --- a/Implementierung/src/main.c +++ b/Implementierung/src/main.c @@ -10,7 +10,7 @@ static bool runTest(const char* message, const char* expectedHash) { md2_hash(strlen(message), message, out); char hash[32]; - encodeHash(out, hash); + md2_encode_hash(out, hash); bool ok = !strcmp(hash, expectedHash); printf("%s: md2(%s) %s == %s\n", "not ok" + (4 * ok), message, hash, @@ -20,7 +20,7 @@ static bool runTest(const char* message, const char* expectedHash) { unsigned runTests(void) { unsigned failed = 0; - // Note: cases with n<2 are not tested here. + // src: https://datatracker.ietf.org/doc/html/rfc1319#appendix-A.5 failed += !runTest("", "8350e5a3e24c153df2275c9f80692773"); failed += !runTest("a", "32ec01ec4a6dac72c0ab96fb34c0b5d1"); failed += !runTest("abc", "da853b0d3f88d99b30283a69e6ded6bb"); @@ -60,12 +60,20 @@ int main(int argc, char** argv) { break; } + if (!md2_choose_implementation(c.implementationToUse)) { + fprintf(stderr, + "%s: invalid argument, implementation '%d' does not exist!\n", + argv[0], c.implementationToUse); + return EXIT_FAILURE; + } + printf( "Hashing file: %s\nUsing implementation: %d, doing benchmark: %d, " "benchmark cycles: %d\n", c.filename, c.implementationToUse, c.doBenchmark, c.benchmarkingCycles); // runTests(); + // return 0; size_t len; uint8_t* data = read_file(c.filename, &len); if (data == NULL) { @@ -81,7 +89,7 @@ int main(int argc, char** argv) { printf("Hash: "); char hash[32]; - encodeHash(out, hash); + md2_encode_hash(out, hash); printf("%s\n", hash); free(data); diff --git a/Implementierung/src/md2.c b/Implementierung/src/md2.c index fcb11b8..9a615c9 100644 --- a/Implementierung/src/md2.c +++ b/Implementierung/src/md2.c @@ -1,107 +1,27 @@ #include "../lib/md2.h" +// include all implementations +#include "../lib/md2_impls/md2_0.h" + +md2_hash_func md2_hash; +md2_checksum_func md2_checksum; + // The file "testfile" should lead to this hash: // fc982e558db259f298b43cd4c1241c66 -// Source: https://datatracker.ietf.org/doc/html/rfc1319 -static unsigned char PI_SUBST[256] = { - 41, 46, 67, 201, 162, 216, 124, 1, 61, 54, 84, 161, 236, 240, 6, - 19, 98, 167, 5, 243, 192, 199, 115, 140, 152, 147, 43, 217, 188, 76, - 130, 202, 30, 155, 87, 60, 253, 212, 224, 22, 103, 66, 111, 24, 138, - 23, 229, 18, 190, 78, 196, 214, 218, 158, 222, 73, 160, 251, 245, 142, - 187, 47, 238, 122, 169, 104, 121, 145, 21, 178, 7, 63, 148, 194, 16, - 137, 11, 34, 95, 33, 128, 127, 93, 154, 90, 144, 50, 39, 53, 62, - 204, 231, 191, 247, 151, 3, 255, 25, 48, 179, 72, 165, 181, 209, 215, - 94, 146, 42, 172, 86, 170, 198, 79, 184, 56, 210, 150, 164, 125, 182, - 118, 252, 107, 226, 156, 116, 4, 241, 69, 157, 112, 89, 100, 113, 135, - 32, 134, 91, 207, 101, 230, 45, 168, 2, 27, 96, 37, 173, 174, 176, - 185, 246, 28, 70, 97, 105, 52, 64, 126, 15, 85, 71, 163, 35, 221, - 81, 175, 58, 195, 92, 249, 206, 186, 197, 234, 38, 44, 83, 13, 110, - 133, 40, 132, 9, 211, 223, 205, 244, 65, 129, 77, 82, 106, 220, 55, - 200, 108, 193, 171, 250, 36, 225, 123, 8, 12, 189, 177, 74, 120, 136, - 149, 139, 227, 99, 232, 109, 233, 203, 213, 254, 59, 0, 29, 57, 242, - 239, 183, 14, 102, 88, 208, 228, 166, 119, 114, 248, 235, 117, 75, 10, - 49, 68, 80, 180, 143, 237, 31, 26, 219, 153, 141, 51, 159, 17, 131, - 20}; - -void printBuf(size_t len, uint8_t buf[len]) { - for (int i = 0; i < len; i++) { - printf("'%02x',", buf[i]); - } - printf("\n"); -} - -void md2_checksum(size_t len, uint8_t* buf) { - uint8_t l = 0; - - for (int i = 0; i < len / 16; i++) { - for (int j = 0; j < 16; j++) { - u_int8_t c = buf[i * 16 + j]; - // reference is wrong. It says: Set C[j] to S[c xor L]. But it should be: - l = buf[len + j] ^= PI_SUBST[c ^ l]; - } - } -} - -void md2_hash(size_t len, const uint8_t buf[len], uint8_t out[16]) { - // === step 1 === - int paddingNeeded = 16 - (len % 16); - uint8_t originalPadding = paddingNeeded; - len += paddingNeeded; - - // printf("len: %d\n", len); - - // +16 for the checksum - uint8_t* newBuf = calloc(len + 16, sizeof(uint8_t)); - memcpy(newBuf, buf, len - paddingNeeded); - - // printBuf(len + 16, newBuf); - - while (paddingNeeded > 0) { - newBuf[len - paddingNeeded] = originalPadding; - paddingNeeded--; - } - // printf("buf with padding: "); - // printBuf(len + 16, newBuf); - - // === step 2 === - md2_checksum(len, newBuf); - - // printf("buf with cecksum: "); - // printBuf(len + 16, newBuf); - - // === step 3 === - uint8_t* messageDigestBuf = calloc(48, sizeof(uint8_t)); - - // === step 4 === - // <= because we need to hash the last block too - for (int i = 0; i <= (len + 16) / 16 - 1; i++) { - for (int j = 0; j < 16; j++) { - messageDigestBuf[16 + j] = newBuf[i * 16 + j]; - messageDigestBuf[32 + j] = - (messageDigestBuf[16 + j] ^ messageDigestBuf[j]); - } - - u_int8_t t = 0; - - for (int j = 0; j < 18; j++) { - for (int k = 0; k < 48; k++) { - t = messageDigestBuf[k] = messageDigestBuf[k] ^ PI_SUBST[t]; - } - t = (t + j) % 256; - } - } - // printf("messageDigestBuf: \n"); - // printBuf(16, messageDigestBuf); - - memcpy(out, messageDigestBuf, 16); - - free(messageDigestBuf); - free(newBuf); -} - -void encodeHash(uint8_t hash[16], char* stringHash) { +void md2_encode_hash(uint8_t hash[16], char* string_hash) { for (int i = 0; i < 16; i++) { - sprintf(stringHash + (2 * i), "%02x", hash[i]); + sprintf(string_hash + (2 * i), "%02x", hash[i]); + } +} + +bool md2_choose_implementation(int i) { + switch (i) { + case 0: + md2_hash = md2_hash_0; + return true; + + default: + return false; } } \ No newline at end of file