/* * Copyright (C) 2021 - This file is part of libecc project * * Authors: * Ryad BENADJILA * Arnaud EBALARD * * This software is licensed under a dual BSD and GPL v2 license. * See LICENSE file at the root folder of the project. */ #include "md2.h" /* All the inner MD-2 operations */ static const u8 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 }; /* MD-2 core processing. Returns 0 on success, -1 on error. */ ATTRIBUTE_WARN_UNUSED_RET static inline int md2_process(md2_context *ctx, const u8 data[MD2_BLOCK_SIZE]) { int ret; unsigned int i, j, t; u8 x[3 * MD2_BLOCK_SIZE]; MUST_HAVE((data != NULL), ret, err); MD2_HASH_CHECK_INITIALIZED(ctx, ret, err); /* Form state, block, state ^ block */ ret = local_memcpy(&x[0], ctx->md2_state, MD2_BLOCK_SIZE); EG(ret, err); ret = local_memcpy(&x[MD2_BLOCK_SIZE], data, MD2_BLOCK_SIZE); EG(ret, err); for(i = 0; i < MD2_BLOCK_SIZE; i++){ x[(2 * MD2_BLOCK_SIZE) + i] = (ctx->md2_state[i] ^ data[i]); } /* Encrypt the block during 18 rounds */ t = 0; for(i = 0; i < 18; i++){ for (j = 0; j < (3 * MD2_BLOCK_SIZE); j++){ x[j] ^= PI_SUBST[t]; t = x[j]; } t = (t + i) & 0xff; } /* Save the new state */ ret = local_memcpy(ctx->md2_state, &x[0], MD2_BLOCK_SIZE); EG(ret, err); /* Update the checksum */ t = ctx->md2_checksum[MD2_BLOCK_SIZE - 1]; for(i = 0; i < MD2_BLOCK_SIZE; i++){ ctx->md2_checksum[i] ^= PI_SUBST[data[i] ^ t]; t = ctx->md2_checksum[i]; } /* Zeroize x as not needed anymore */ ret = local_memset(x, 0, sizeof(x)); EG(ret, err); ret = 0; err: return ret; } /* Init hash function. Returns 0 on success, -1 on error. */ ATTRIBUTE_WARN_UNUSED_RET int md2_init(md2_context *ctx) { int ret; MUST_HAVE((ctx != NULL), ret, err); /* Sanity check on size */ MUST_HAVE((MD2_DIGEST_SIZE <= MAX_DIGEST_SIZE), ret, err); ctx->md2_total = 0; /* Zeroize the state */ ret = local_memset(ctx->md2_state, 0, sizeof(ctx->md2_state)); EG(ret, err); /* Zeroize the checksum */ ret = local_memset(ctx->md2_checksum, 0, sizeof(ctx->md2_checksum)); EG(ret, err); /* Tell that we are initialized */ ctx->magic = MD2_HASH_MAGIC; ret = 0; err: return ret; } ATTRIBUTE_WARN_UNUSED_RET int md2_update(md2_context *ctx, const u8 *input, u32 ilen) { const u8 *data_ptr = input; u32 remain_ilen = ilen; u16 fill; u8 left; int ret; MUST_HAVE((input != NULL) || (ilen == 0), ret, err); MD2_HASH_CHECK_INITIALIZED(ctx, ret, err); /* Nothing to process, return */ if (ilen == 0) { ret = 0; goto err; } /* Get what's left in our local buffer */ left = (ctx->md2_total & 0xF); fill = (u16)(MD2_BLOCK_SIZE - left); ctx->md2_total += ilen; if ((left > 0) && (remain_ilen >= fill)) { /* Copy data at the end of the buffer */ ret = local_memcpy(ctx->md2_buffer + left, data_ptr, fill); EG(ret, err); ret = md2_process(ctx, ctx->md2_buffer); EG(ret, err); data_ptr += fill; remain_ilen -= fill; left = 0; } while (remain_ilen >= MD2_BLOCK_SIZE) { ret = md2_process(ctx, data_ptr); EG(ret, err); data_ptr += MD2_BLOCK_SIZE; remain_ilen -= MD2_BLOCK_SIZE; } if (remain_ilen > 0) { ret = local_memcpy(ctx->md2_buffer + left, data_ptr, remain_ilen); EG(ret, err); } ret = 0; err: return ret; } /* Finalize. Returns 0 on success, -1 on error.*/ ATTRIBUTE_WARN_UNUSED_RET int md2_final(md2_context *ctx, u8 output[MD2_DIGEST_SIZE]) { int ret; unsigned int i; u8 pad_byte; MUST_HAVE((output != NULL), ret, err); MD2_HASH_CHECK_INITIALIZED(ctx, ret, err); /* This is our final step, so we proceed with the padding */ pad_byte = (u8)(MD2_BLOCK_SIZE - (ctx->md2_total % MD2_BLOCK_SIZE)); for(i = (ctx->md2_total % MD2_BLOCK_SIZE); i < MD2_BLOCK_SIZE; i++){ ctx->md2_buffer[i] = pad_byte; } /* And process the block */ ret = md2_process(ctx, ctx->md2_buffer); EG(ret, err); /* Also process the checksum */ ret = md2_process(ctx, ctx->md2_checksum); EG(ret, err); /* Output the hash result */ ret = local_memcpy(output, ctx->md2_state, MD2_DIGEST_SIZE); EG(ret, err); /* Tell that we are uninitialized */ ctx->magic = WORD(0); ret = 0; err: return ret; } /* * Scattered version performing init/update/finalize on a vector of buffers * 'inputs' with the length of each buffer passed via 'ilens'. The function * loops on pointers in 'inputs' until it finds a NULL pointer. The function * returns 0 on success, -1 on error. */ ATTRIBUTE_WARN_UNUSED_RET int md2_scattered(const u8 **inputs, const u32 *ilens, u8 output[MD2_DIGEST_SIZE]) { md2_context ctx; int ret, pos = 0; MUST_HAVE((inputs != NULL) && (ilens != NULL) && (output != NULL), ret, err); ret = md2_init(&ctx); EG(ret, err); while (inputs[pos] != NULL) { ret = md2_update(&ctx, inputs[pos], ilens[pos]); EG(ret, err); pos += 1; } ret = md2_final(&ctx, output); err: return ret; } /* * Single call version performing init/update/final on given input. * Returns 0 on success, -1 on error. */ ATTRIBUTE_WARN_UNUSED_RET int md2(const u8 *input, u32 ilen, u8 output[MD2_DIGEST_SIZE]) { md2_context ctx; int ret; ret = md2_init(&ctx); EG(ret, err); ret = md2_update(&ctx, input, ilen); EG(ret, err); ret = md2_final(&ctx, output); err: return ret; }