/* * Copyright (c) 2009 Thomas Schmitt * * This file is part of the libisofs project; you can redistribute it and/or * modify it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. See COPYING file for details. */ #include #include #include #include "writer.h" #include "messages.h" #include "ecma119.h" #include "image.h" #include "md5.h" /* This code is derived from RFC 1321 and implements computation of the "RSA Data Security, Inc. MD5 Message-Digest Algorithm" */ #define Libisofs_md5_S11 7 #define Libisofs_md5_S12 12 #define Libisofs_md5_S13 17 #define Libisofs_md5_S14 22 #define Libisofs_md5_S21 5 #define Libisofs_md5_S22 9 #define Libisofs_md5_S23 14 #define Libisofs_md5_S24 20 #define Libisofs_md5_S31 4 #define Libisofs_md5_S32 11 #define Libisofs_md5_S33 16 #define Libisofs_md5_S34 23 #define Libisofs_md5_S41 6 #define Libisofs_md5_S42 10 #define Libisofs_md5_S43 15 #define Libisofs_md5_S44 21 /* F, G, H and I are basic MD5 functions. */ #define Libisofs_md5_F(x, y, z) (((x) & (y)) | ((~x) & (z))) #define Libisofs_md5_G(x, y, z) (((x) & (z)) | ((y) & (~z))) #define Libisofs_md5_H(x, y, z) ((x) ^ (y) ^ (z)) #define Libisofs_md5_I(x, y, z) ((y) ^ ((x) | (~z))) /* ROTATE_LEFT rotates x left n bits. */ #define Libisofs_md5_ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n)))) /* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4. Rotation is separate from addition to prevent recomputation. */ #define Libisofs_md5_FF(a, b, c, d, x, s, ac) { \ (a) += Libisofs_md5_F ((b), (c), (d)) + (x) + (uint32_t)(ac); \ (a) = Libisofs_md5_ROTATE_LEFT ((a), (s)); \ (a) += (b); \ } #define Libisofs_md5_GG(a, b, c, d, x, s, ac) { \ (a) += Libisofs_md5_G ((b), (c), (d)) + (x) + (uint32_t)(ac); \ (a) = Libisofs_md5_ROTATE_LEFT ((a), (s)); \ (a) += (b); \ } #define Libisofs_md5_HH(a, b, c, d, x, s, ac) { \ (a) += Libisofs_md5_H ((b), (c), (d)) + (x) + (uint32_t)(ac); \ (a) = Libisofs_md5_ROTATE_LEFT ((a), (s)); \ (a) += (b); \ } #define Libisofs_md5_II(a, b, c, d, x, s, ac) { \ (a) += Libisofs_md5_I ((b), (c), (d)) + (x) + (uint32_t)(ac); \ (a) = Libisofs_md5_ROTATE_LEFT ((a), (s)); \ (a) += (b); \ } /* MD5 context. */ struct _libisofs_md5_ctx { uint32_t state[4]; /* state (ABCD) */ uint32_t count[2]; /* number of bits, modulo 2^64 (lsb first) */ unsigned char buffer[64]; /* input buffer */ }; typedef struct _libisofs_md5_ctx libisofs_md5_ctx; /* MD5 basic transformation. Transforms state based on block. */ static int md5__transform (uint32_t state[4], unsigned char block[64]) { uint32_t a = state[0], b = state[1], c = state[2], d = state[3], x[16]; unsigned int i, j; for (i = 0, j = 0; j < 64; i++, j += 4) x[i] = ((uint32_t)block[j]) | (((uint32_t)block[j+1]) << 8) | (((uint32_t)block[j+2]) << 16) | (((uint32_t)block[j+3]) << 24); /* Round 1 */ Libisofs_md5_FF (a, b, c, d, x[ 0], Libisofs_md5_S11, 0xd76aa478); /* 1 */ Libisofs_md5_FF (d, a, b, c, x[ 1], Libisofs_md5_S12, 0xe8c7b756); /* 2 */ Libisofs_md5_FF (c, d, a, b, x[ 2], Libisofs_md5_S13, 0x242070db); /* 3 */ Libisofs_md5_FF (b, c, d, a, x[ 3], Libisofs_md5_S14, 0xc1bdceee); /* 4 */ Libisofs_md5_FF (a, b, c, d, x[ 4], Libisofs_md5_S11, 0xf57c0faf); /* 5 */ Libisofs_md5_FF (d, a, b, c, x[ 5], Libisofs_md5_S12, 0x4787c62a); /* 6 */ Libisofs_md5_FF (c, d, a, b, x[ 6], Libisofs_md5_S13, 0xa8304613); /* 7 */ Libisofs_md5_FF (b, c, d, a, x[ 7], Libisofs_md5_S14, 0xfd469501); /* 8 */ Libisofs_md5_FF (a, b, c, d, x[ 8], Libisofs_md5_S11, 0x698098d8); /* 9 */ Libisofs_md5_FF (d, a, b, c, x[ 9], Libisofs_md5_S12, 0x8b44f7af); /* 10 */ Libisofs_md5_FF (c, d, a, b, x[10], Libisofs_md5_S13, 0xffff5bb1); /* 11 */ Libisofs_md5_FF (b, c, d, a, x[11], Libisofs_md5_S14, 0x895cd7be); /* 12 */ Libisofs_md5_FF (a, b, c, d, x[12], Libisofs_md5_S11, 0x6b901122); /* 13 */ Libisofs_md5_FF (d, a, b, c, x[13], Libisofs_md5_S12, 0xfd987193); /* 14 */ Libisofs_md5_FF (c, d, a, b, x[14], Libisofs_md5_S13, 0xa679438e); /* 15 */ Libisofs_md5_FF (b, c, d, a, x[15], Libisofs_md5_S14, 0x49b40821); /* 16 */ /* Round 2 */ Libisofs_md5_GG (a, b, c, d, x[ 1], Libisofs_md5_S21, 0xf61e2562); /* 17 */ Libisofs_md5_GG (d, a, b, c, x[ 6], Libisofs_md5_S22, 0xc040b340); /* 18 */ Libisofs_md5_GG (c, d, a, b, x[11], Libisofs_md5_S23, 0x265e5a51); /* 19 */ Libisofs_md5_GG (b, c, d, a, x[ 0], Libisofs_md5_S24, 0xe9b6c7aa); /* 20 */ Libisofs_md5_GG (a, b, c, d, x[ 5], Libisofs_md5_S21, 0xd62f105d); /* 21 */ Libisofs_md5_GG (d, a, b, c, x[10], Libisofs_md5_S22, 0x2441453); /* 22 */ Libisofs_md5_GG (c, d, a, b, x[15], Libisofs_md5_S23, 0xd8a1e681); /* 23 */ Libisofs_md5_GG (b, c, d, a, x[ 4], Libisofs_md5_S24, 0xe7d3fbc8); /* 24 */ Libisofs_md5_GG (a, b, c, d, x[ 9], Libisofs_md5_S21, 0x21e1cde6); /* 25 */ Libisofs_md5_GG (d, a, b, c, x[14], Libisofs_md5_S22, 0xc33707d6); /* 26 */ Libisofs_md5_GG (c, d, a, b, x[ 3], Libisofs_md5_S23, 0xf4d50d87); /* 27 */ Libisofs_md5_GG (b, c, d, a, x[ 8], Libisofs_md5_S24, 0x455a14ed); /* 28 */ Libisofs_md5_GG (a, b, c, d, x[13], Libisofs_md5_S21, 0xa9e3e905); /* 29 */ Libisofs_md5_GG (d, a, b, c, x[ 2], Libisofs_md5_S22, 0xfcefa3f8); /* 30 */ Libisofs_md5_GG (c, d, a, b, x[ 7], Libisofs_md5_S23, 0x676f02d9); /* 31 */ Libisofs_md5_GG (b, c, d, a, x[12], Libisofs_md5_S24, 0x8d2a4c8a); /* 32 */ /* Round 3 */ Libisofs_md5_HH (a, b, c, d, x[ 5], Libisofs_md5_S31, 0xfffa3942); /* 33 */ Libisofs_md5_HH (d, a, b, c, x[ 8], Libisofs_md5_S32, 0x8771f681); /* 34 */ Libisofs_md5_HH (c, d, a, b, x[11], Libisofs_md5_S33, 0x6d9d6122); /* 35 */ Libisofs_md5_HH (b, c, d, a, x[14], Libisofs_md5_S34, 0xfde5380c); /* 36 */ Libisofs_md5_HH (a, b, c, d, x[ 1], Libisofs_md5_S31, 0xa4beea44); /* 37 */ Libisofs_md5_HH (d, a, b, c, x[ 4], Libisofs_md5_S32, 0x4bdecfa9); /* 38 */ Libisofs_md5_HH (c, d, a, b, x[ 7], Libisofs_md5_S33, 0xf6bb4b60); /* 39 */ Libisofs_md5_HH (b, c, d, a, x[10], Libisofs_md5_S34, 0xbebfbc70); /* 40 */ Libisofs_md5_HH (a, b, c, d, x[13], Libisofs_md5_S31, 0x289b7ec6); /* 41 */ Libisofs_md5_HH (d, a, b, c, x[ 0], Libisofs_md5_S32, 0xeaa127fa); /* 42 */ Libisofs_md5_HH (c, d, a, b, x[ 3], Libisofs_md5_S33, 0xd4ef3085); /* 43 */ Libisofs_md5_HH (b, c, d, a, x[ 6], Libisofs_md5_S34, 0x4881d05); /* 44 */ Libisofs_md5_HH (a, b, c, d, x[ 9], Libisofs_md5_S31, 0xd9d4d039); /* 45 */ Libisofs_md5_HH (d, a, b, c, x[12], Libisofs_md5_S32, 0xe6db99e5); /* 46 */ Libisofs_md5_HH (c, d, a, b, x[15], Libisofs_md5_S33, 0x1fa27cf8); /* 47 */ Libisofs_md5_HH (b, c, d, a, x[ 2], Libisofs_md5_S34, 0xc4ac5665); /* 48 */ /* Round 4 */ Libisofs_md5_II (a, b, c, d, x[ 0], Libisofs_md5_S41, 0xf4292244); /* 49 */ Libisofs_md5_II (d, a, b, c, x[ 7], Libisofs_md5_S42, 0x432aff97); /* 50 */ Libisofs_md5_II (c, d, a, b, x[14], Libisofs_md5_S43, 0xab9423a7); /* 51 */ Libisofs_md5_II (b, c, d, a, x[ 5], Libisofs_md5_S44, 0xfc93a039); /* 52 */ Libisofs_md5_II (a, b, c, d, x[12], Libisofs_md5_S41, 0x655b59c3); /* 53 */ Libisofs_md5_II (d, a, b, c, x[ 3], Libisofs_md5_S42, 0x8f0ccc92); /* 54 */ Libisofs_md5_II (c, d, a, b, x[10], Libisofs_md5_S43, 0xffeff47d); /* 55 */ Libisofs_md5_II (b, c, d, a, x[ 1], Libisofs_md5_S44, 0x85845dd1); /* 56 */ Libisofs_md5_II (a, b, c, d, x[ 8], Libisofs_md5_S41, 0x6fa87e4f); /* 57 */ Libisofs_md5_II (d, a, b, c, x[15], Libisofs_md5_S42, 0xfe2ce6e0); /* 58 */ Libisofs_md5_II (c, d, a, b, x[ 6], Libisofs_md5_S43, 0xa3014314); /* 59 */ Libisofs_md5_II (b, c, d, a, x[13], Libisofs_md5_S44, 0x4e0811a1); /* 60 */ Libisofs_md5_II (a, b, c, d, x[ 4], Libisofs_md5_S41, 0xf7537e82); /* 61 */ Libisofs_md5_II (d, a, b, c, x[11], Libisofs_md5_S42, 0xbd3af235); /* 62 */ Libisofs_md5_II (c, d, a, b, x[ 2], Libisofs_md5_S43, 0x2ad7d2bb); /* 63 */ Libisofs_md5_II (b, c, d, a, x[ 9], Libisofs_md5_S44, 0xeb86d391); /* 64 */ state[0] += a; state[1] += b; state[2] += c; state[3] += d; /* Zeroize sensitive information. */ memset ((char *) x, 0, sizeof (x)); return(1); } static int md5__encode(unsigned char *output, uint32_t *input, unsigned int len) { unsigned int i, j; for (i = 0, j = 0; j < len; i++, j += 4) { output[j] = (unsigned char)(input[i] & 0xff); output[j+1] = (unsigned char)((input[i] >> 8) & 0xff); output[j+2] = (unsigned char)((input[i] >> 16) & 0xff); output[j+3] = (unsigned char)((input[i] >> 24) & 0xff); } return(1); } static int md5_init(libisofs_md5_ctx *ctx, int flag) { ctx->count[0] = ctx->count[1] = 0; /* Load magic initialization constants. */ ctx->state[0] = 0x67452301; ctx->state[1] = 0xefcdab89; ctx->state[2] = 0x98badcfe; ctx->state[3] = 0x10325476; return(1); } /* MD5 block update operation. Continues an MD5 message-digest operation, processing another message block, and updating the context. */ static int md5_update(libisofs_md5_ctx *ctx, unsigned char *data, int datalen, int flag) { unsigned int i, index, partlen; /* Compute number of bytes mod 64 */ index = (unsigned int)((ctx->count[0] >> 3) & 0x3F); /* Update number of bits */ if ((ctx->count[0] += ((uint32_t) datalen << 3)) < ((uint32_t) datalen << 3)) ctx->count[1]++; ctx->count[1] += ((uint32_t) datalen >> 29); partlen = 64 - index; /* Transform as many times as possible. */ if (datalen >= partlen) { memcpy((char *) &ctx->buffer[index], (char *) data, partlen); md5__transform(ctx->state, ctx->buffer); for (i = partlen; i + 63 < datalen; i += 64) md5__transform(ctx->state, &data[i]); index = 0; } else i = 0; /* Buffer remaining data */ memcpy((char *) &ctx->buffer[index], (char *) &data[i],datalen-i); return(1); } static int md5_final(libisofs_md5_ctx *ctx, char result[16], int flag) { unsigned char bits[8], *respt; unsigned int index, padlen; static unsigned char PADDING[64] = { 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; /* Save number of bits */ md5__encode(bits, ctx->count, 8); /* Pad out to 56 mod 64. */ index = (unsigned int)((ctx->count[0] >> 3) & 0x3f); padlen = (index < 56) ? (56 - index) : (120 - index); md5_update(ctx, PADDING, padlen,0); /* Append length (before padding) */ md5_update(ctx, bits, 8,0); /* Store state in result */ respt= (unsigned char *) result; md5__encode(respt, ctx->state, 16); /* Zeroize sensitive information. */ memset ((char *) ctx, 0, sizeof (*ctx)); return(1); } int libisofs_md5(void **ctx_in, char *data, int datalen, char result[16], int flag) /* *ctx has to be NULL or point to freeable memory */ /* bit0= allocate and init *ctx bit1= transfer ctx to result bit2= with bit 0 : clone new *ctx from data bit15= free *ctx */ { unsigned char *datapt; libisofs_md5_ctx **ctx; ctx= (libisofs_md5_ctx **) ctx_in; if(flag&1) { if(*ctx!=NULL) free((char *) *ctx); *ctx= calloc(1, sizeof(libisofs_md5_ctx)); if(*ctx==NULL) return(-1); md5_init(*ctx,0); if(flag&4) memcpy((char *) *ctx,data,sizeof(libisofs_md5_ctx)); } if(*ctx==NULL) return(0); if(datalen>0) { datapt= (unsigned char *) data; md5_update(*ctx, datapt, datalen, 0); } if(flag&2) md5_final(*ctx, result, 0); if(flag&(1<<15)) { free((char *) *ctx); *ctx= NULL; } return(1); } /* ----------------------------------------------------------------------- */ /* Function to identify and manage md5sum indice of the old image. * data is supposed to be a 4 byte integer, bit 31 shall be 0, * value 0 of this integer means that it is not a valid index. */ int checksum_xinfo_func(void *data, int flag) { /* data is an int disguised as pointer. It does not point to memory. */ return 1; } #ifdef Libisofs_with_checksumS /* @flag bit0= recursion bit1= session will be appended to an existing image */ static int checksum_copy_old_nodes(Ecma119Image *target, IsoNode *node, int flag) { IsoNode *pos; IsoFile *file; IsoImage *img; int ret, i; size_t value_length; unsigned int idx = 0, old_idx = 0; char *value = NULL; void *xipt; img = target->image; if (img->checksum_array == NULL || target->checksum_buffer == NULL) return 0; if (node->type == LIBISO_FILE) { file = (IsoFile *) node; if (file->from_old_session) { ret = iso_node_get_xinfo(node, checksum_xinfo_func, &xipt); if (ret <= 0) return ret; /* xipt is an int disguised as void pointer */ old_idx = 0; for (i = 0; i < 4; i++) old_idx = (old_idx << 8) | ((unsigned char *) &xipt)[i]; if (old_idx == 0 || old_idx > img->checksum_idx_count - 1) return 0; ret = iso_node_lookup_attr(node, "isofs.cx", &value_length, &value, 0); if (ret == 1 && value_length == 4) { for (i = 0; i < 4; i++) idx = (idx << 8) | ((unsigned char *) value)[i]; if (idx > 0 && idx <= target->checksum_idx_counter) { memcpy(target->checksum_buffer + 16 * idx, img->checksum_array + 16 * old_idx, 16); } } if (value != NULL) free(value); } } else if (node->type == LIBISO_DIR) { for (pos = ((IsoDir *) node)->children; pos != NULL; pos = pos->next) { ret = checksum_copy_old_nodes(target, pos, 1); if (ret < 0) return ret; } } return ISO_SUCCESS; } #endif /* Libisofs_with_checksumS */ static int checksum_writer_compute_data_blocks(IsoImageWriter *writer) { #ifdef Libisofs_with_checksumS size_t size; Ecma119Image *t; int ret; unsigned int lba; if (writer == NULL) { return ISO_ASSERT_FAILURE; } t = writer->target; lba = t->curblock; /* (t->curblock already contains t->ms_block) */ size = (t->checksum_idx_counter + 2) / 128 + 1; t->curblock += size; /* >>> ??? reserve extra block for stream detectable checksum */; /* Allocate array of MD5 sums */ t->checksum_buffer = calloc(size, 2048); if (t->checksum_buffer == NULL) return ISO_OUT_OF_MEM; /* Copy MD5 from nodes of old image into writer->data */ ret = checksum_copy_old_nodes(t, (IsoNode *) t->image->root, 0); if (ret < 0) return ret; /* Record lba,count,size,cecksum_type in "isofs.ca" of root node */ ret = iso_root_set_isofsca((IsoNode *) t->image->root, (unsigned int) t->ms_block, lba, t->checksum_idx_counter + 2, 16, "MD5", 0); if (ret < 0) return ret; #endif /* Libisofs_with_checksumS */ return ISO_SUCCESS; } static int checksum_writer_write_vol_desc(IsoImageWriter *writer) { /* nothing needed */ return ISO_SUCCESS; } static int checksum_writer_write_data(IsoImageWriter *writer) { #ifdef Libisofs_with_checksumS int wres, res; size_t i, size; Ecma119Image *t; if (writer == NULL) { return ISO_ASSERT_FAILURE; } t = writer->target; iso_msg_debug(t->image->id, "Writing Checksums..."); /* Write image checksum to index 0 */ if (t->checksum_ctx != NULL) { /* >>> rather fork a result than killing t->checksum_ctx */; res = libisofs_md5(&(t->checksum_ctx), NULL, 0, t->image_md5, 2 | (1 << 15)); if (res > 0) memcpy(t->checksum_buffer + 0, t->image_md5, 16); } size = (t->checksum_idx_counter + 2) / 128 + 1; /* >>> write overall checksum as index t->checksum_idx_counter + 1 */; for (i = 0; i < size; i++) { wres = iso_write(t, t->checksum_buffer + ((size_t) 2048) * i, BLOCK_SIZE); if (wres < 0) return wres; } /* >>> write scdbackup checksum tag to an extra block */; #endif /* Libisofs_with_checksumS */ return ISO_SUCCESS; } static int checksum_writer_free_data(IsoImageWriter *writer) { /* nothing was allocated at writer->data */ return ISO_SUCCESS; } int checksum_writer_create(Ecma119Image *target) { IsoImageWriter *writer; writer = malloc(sizeof(IsoImageWriter)); if (writer == NULL) { return ISO_OUT_OF_MEM; } writer->compute_data_blocks = checksum_writer_compute_data_blocks; writer->write_vol_desc = checksum_writer_write_vol_desc; writer->write_data = checksum_writer_write_data; writer->free_data = checksum_writer_free_data; writer->data = NULL; writer->target = target; /* add this writer to image */ target->writers[target->nwriters++] = writer; return ISO_SUCCESS; }