On Wed, 21 Mar 2012, Mikulas Patocka wrote: > > > On Tue, 20 Mar 2012, Mandeep Singh Baines wrote: > > > > I can introduce a switch to make it accept the old format. Do you want to? > > > > > > > We can carry that as an out-of-tree patch until we migrate. > > > > On the other hand, it might be nice to support prepend or append. > > > > I don't too strong feelings but it might be nice to have > > prepend/append flag. Would definitely make our life easier. > > This is improved patch that supports both the old format and the new > format. I checked that it is interoperable with with the old Google > userspace tool and with the original Google kernel driver. > > Mikulas This is the new userspace tool that supports both formats. Mikulas --- /* link with -lpopt -lcrypto */ #define _FILE_OFFSET_BITS 64 #include <stdio.h> #include <stdlib.h> #include <stdint.h> #include <stdarg.h> #include <unistd.h> #include <errno.h> #include <string.h> #include <sys/types.h> #include <sys/stat.h> #include <sys/ioctl.h> #include <sys/mount.h> #include <arpa/inet.h> #include <popt.h> #include <openssl/evp.h> #include <openssl/rand.h> #define DEFAULT_BLOCK_SIZE 4096 #define DM_VERITY_MAX_LEVELS 63 #define DEFAULT_SALT_SIZE 32 #define MAX_SALT_SIZE 384 #define MODE_VERIFY 0 #define MODE_CREATE 1 #define MODE_ACTIVATE 2 #define MAX_FORMAT_VERSION 1 static int mode = -1; static int use_superblock = 1; static const char *dm_device; static const char *data_device; static const char *hash_device; static const char *hash_algorithm = NULL; static const char *root_hash; static int version = -1; static int data_block_size = 0; static int hash_block_size = 0; static long long hash_start = 0; static long long data_blocks = 0; static const char *salt_string = NULL; static FILE *data_file; static FILE *hash_file; static off_t data_file_blocks; static off_t hash_file_blocks; static off_t used_hash_blocks; static const EVP_MD *evp; static unsigned char *root_hash_bytes; static unsigned char *calculated_digest; static unsigned char *salt_bytes; static unsigned salt_size; static unsigned digest_size; static unsigned char digest_size_bits; static unsigned char levels; static unsigned char hash_per_block_bits; static off_t hash_level_block[DM_VERITY_MAX_LEVELS]; static off_t hash_level_size[DM_VERITY_MAX_LEVELS]; static off_t superblock_position; static int retval = 0; struct superblock { uint8_t signature[8]; uint8_t version; uint8_t data_block_bits; uint8_t hash_block_bits; uint8_t pad1[1]; uint16_t salt_size; uint8_t pad2[2]; uint32_t data_blocks_hi; uint32_t data_blocks_lo; uint8_t algorithm[16]; uint8_t salt[MAX_SALT_SIZE]; uint8_t pad3[88]; }; #define DM_VERITY_SIGNATURE "verity\0\0" #define DM_VERITY_VERSION 0 static void help(poptContext popt_context, enum poptCallbackReason reason, struct poptOption *key, const char *arg, void *data) { poptPrintHelp(popt_context, stdout, 0); exit(0); } static struct poptOption popt_help_options[] = { { NULL, 0, POPT_ARG_CALLBACK, help, 0, NULL, NULL }, { "help", 'h', POPT_ARG_NONE, NULL, 0, "Show help", NULL }, POPT_TABLEEND }; static struct poptOption popt_options[] = { { NULL, '\0', POPT_ARG_INCLUDE_TABLE, popt_help_options, 0, NULL, NULL }, { "create", 'c', POPT_ARG_VAL, &mode, MODE_CREATE, "Create hash", NULL }, { "verify", 'v', POPT_ARG_VAL, &mode, MODE_VERIFY, "Verify integrity", NULL }, { "activate", 'a', POPT_ARG_VAL, &mode, MODE_ACTIVATE, "Activate the device", NULL }, { "data-block-size", 0, POPT_ARG_INT, &data_block_size, 0, "Block size on the data device", "bytes" }, { "hash-block-size", 0, POPT_ARG_INT, &hash_block_size, 0, "Block size on the hash device", "bytes" }, { "data-blocks", 0, POPT_ARG_LONGLONG, &data_blocks, 0, "The number of blocks in the data file", "blocks" }, { "hash-start", 0, POPT_ARG_LONGLONG, &hash_start, 0, "Starting block on the hash device", "512-byte sectors" }, { "salt", 0, POPT_ARG_STRING, &salt_string, 0, "Salt", "hex string" }, { "algorithm", 0, POPT_ARG_STRING, &hash_algorithm, 0, "Hash algorithm (default sha256)", "string" }, { "no-superblock", 0, POPT_ARG_VAL, &use_superblock, 0, "Do not create/use superblock" }, { "format", 0, POPT_ARG_INT, &version, 0, "Format version (0 - original Google code, 1 - new format)", "number" }, POPT_TABLEEND }; #if defined(__GNUC__) && __GNUC__ >= 2 __attribute__((__format__(__printf__, 1, 2))) #endif static void exit_err(const char *msg, ...) { va_list args; va_start(args, msg); vfprintf(stderr, msg, args); va_end(args); fputc('\n', stderr); exit(2); } static void stream_err(FILE *f, const char *msg) { if (ferror(f)) { perror(msg); exit(2); } else if (feof(f)) { exit_err("eof on %s", msg); } else { exit_err("unknown error on %s", msg); } } static void *xmalloc(size_t s) { void *ptr = malloc(!s ? 1 : s); if (!ptr) exit_err("out of memory"); return ptr; } static char *xstrdup(const char *str) { return strcpy(xmalloc(strlen(str) + 1), str); } static char *xprint(unsigned long long num) { size_t s = snprintf(NULL, 0, "%llu", num); char *p = xmalloc(s + 1); snprintf(p, s + 1, "%llu", num); return p; } static char *xhexprint(unsigned char *bytes, size_t len) { size_t i; char *p = xmalloc(len * 2 + 1); p[0] = 0; for (i = 0; i < len; i++) snprintf(p + i * 2, 3, "%02x", bytes[i]); return p; } static off_t get_size(FILE *f, const char *name) { struct stat st; int h = fileno(f); if (h < 0) { perror("fileno"); exit(2); } if (fstat(h, &st)) { perror("fstat"); exit(2); } if (S_ISREG(st.st_mode)) { return st.st_size; } else if (S_ISBLK(st.st_mode)) { unsigned long long size64; unsigned long sizeul; if (!ioctl(h, BLKGETSIZE64, &size64)) { return_size64: if ((off_t)size64 < 0 || (off_t)size64 != size64) { size_overflow: exit_err("%s: device size overflow", name); } return size64; } if (!ioctl(h, BLKGETSIZE, &sizeul)) { size64 = (unsigned long long)sizeul * 512; if (size64 / 512 != sizeul) goto size_overflow; goto return_size64; } perror("BLKGETSIZE"); exit(2); } else { exit_err("%s is not a file or a block device", name); } return -1; /* never reached, shut up warning */ } static void block_fseek(FILE *f, off_t block, int block_size) { unsigned long long pos = (unsigned long long)block * block_size; if (pos / block_size != block || (off_t)pos < 0 || (off_t)pos != pos) exit_err("seek position overflow"); if (fseeko(f, pos, SEEK_SET)) { perror("fseek"); exit(2); } } static off_t verity_position_at_level(off_t block, int level) { return block >> (level * hash_per_block_bits); } static void calculate_positions(void) { unsigned long long hash_position; int i; digest_size_bits = 0; while (1 << digest_size_bits < digest_size) digest_size_bits++; hash_per_block_bits = 0; while (((hash_block_size / digest_size) >> hash_per_block_bits) > 1) hash_per_block_bits++; if (!hash_per_block_bits) exit_err("at least two hashes must fit in a hash file block"); levels = 0; if (data_file_blocks) { while (hash_per_block_bits * levels < 64 && (unsigned long long)(data_file_blocks - 1) >> (hash_per_block_bits * levels)) levels++; } if (levels > DM_VERITY_MAX_LEVELS) exit_err("too many tree levels"); hash_position = hash_start * 512 / hash_block_size; for (i = levels - 1; i >= 0; i--) { off_t s; hash_level_block[i] = hash_position; s = verity_position_at_level(data_file_blocks, i); s = (s >> hash_per_block_bits) + !!(s & ((1 << hash_per_block_bits) - 1)); hash_level_size[i] = s; if (hash_position + s < hash_position || (off_t)(hash_position + s) < 0 || (off_t)(hash_position + s) != hash_position + s) exit_err("hash device offset overflow"); hash_position += s; } used_hash_blocks = hash_position; } static void create_or_verify_zero(FILE *wr, unsigned char *left_block, unsigned left_bytes) { if (left_bytes) { if (mode != MODE_CREATE) { unsigned x; if (fread(left_block, left_bytes, 1, wr) != 1) stream_err(wr, "read"); for (x = 0; x < left_bytes; x++) if (left_block[x]) { retval = 1; fprintf(stderr, "spare area is not zeroed at position %lld\n", (long long)ftello(wr) - left_bytes); } } else { if (fwrite(left_block, left_bytes, 1, wr) != 1) stream_err(wr, "write"); } } } static void create_or_verify_stream(FILE *rd, FILE *wr, int block_size, off_t blocks) { unsigned char *left_block = xmalloc(hash_block_size); unsigned char *data_buffer = xmalloc(block_size); unsigned char *read_digest = mode != MODE_CREATE ? xmalloc(digest_size) : NULL; off_t blocks_to_write = (blocks >> hash_per_block_bits) + !!(blocks & ((1 << hash_per_block_bits) - 1)); EVP_MD_CTX ctx; EVP_MD_CTX_init(&ctx); memset(left_block, 0, hash_block_size); while (blocks_to_write--) { unsigned x; unsigned left_bytes = hash_block_size; for (x = 0; x < 1 << hash_per_block_bits; x++) { if (!blocks) break; blocks--; if (fread(data_buffer, block_size, 1, rd) != 1) stream_err(rd, "read"); if (EVP_DigestInit_ex(&ctx, evp, NULL) != 1) exit_err("EVP_DigestInit_ex failed"); if (version >= 1) { if (EVP_DigestUpdate(&ctx, salt_bytes, salt_size) != 1) exit_err("EVP_DigestUpdate failed"); } if (EVP_DigestUpdate(&ctx, data_buffer, block_size) != 1) exit_err("EVP_DigestUpdate failed"); if (!version) { if (EVP_DigestUpdate(&ctx, salt_bytes, salt_size) != 1) exit_err("EVP_DigestUpdate failed"); } if (EVP_DigestFinal_ex(&ctx, calculated_digest, NULL) != 1) exit_err("EVP_DigestFinal_ex failed"); if (!wr) break; if (mode != MODE_CREATE) { if (fread(read_digest, digest_size, 1, wr) != 1) stream_err(wr, "read"); if (memcmp(read_digest, calculated_digest, digest_size)) { retval = 1; fprintf(stderr, "verification failed at position %lld in %s file\n", (long long)ftello(rd) - block_size, rd == data_file ? "data" : "metadata"); } } else { if (fwrite(calculated_digest, digest_size, 1, wr) != 1) stream_err(wr, "write"); } if (!version) { left_bytes -= digest_size; } else { create_or_verify_zero(wr, left_block, (1 << digest_size_bits) - digest_size); left_bytes -= 1 << digest_size_bits; } } if (wr) create_or_verify_zero(wr, left_block, left_bytes); } if (mode == MODE_CREATE && wr) { if (fflush(wr)) { perror("fflush"); exit(1); } if (ferror(wr)) { stream_err(wr, "write"); } } if (EVP_MD_CTX_cleanup(&ctx) != 1) exit_err("EVP_MD_CTX_cleanup failed"); free(left_block); free(data_buffer); if (mode != MODE_CREATE) free(read_digest); } char **make_target_line(void) { const int line_elements = 14; char **line = xmalloc(line_elements * sizeof(char *)); int i = 0; char *algorithm_copy = xstrdup(hash_algorithm); /* transform ripemdXXX to rmdXXX */ if (!strncmp(algorithm_copy, "ripemd", 6)) memmove(algorithm_copy + 1, algorithm_copy + 4, strlen(algorithm_copy + 4) + 1); line[i++] = xstrdup("0"); line[i++] = xprint((unsigned long long)data_file_blocks * data_block_size / 512); line[i++] = xstrdup("verity"); line[i++] = xprint(version); line[i++] = xstrdup(data_device); line[i++] = xstrdup(hash_device); line[i++] = xprint(data_block_size); line[i++] = xprint(hash_block_size); line[i++] = xprint(data_file_blocks); line[i++] = xprint(hash_start * 512 / hash_block_size); line[i++] = algorithm_copy; line[i++] = xhexprint(calculated_digest, digest_size); line[i++] = !salt_size ? xstrdup("-") : xhexprint(salt_bytes, salt_size); line[i++] = NULL; if (i > line_elements) exit_err("INTERNAL ERROR: insufficient array size"); return line; } void free_target_line(char **line) { int i; for (i = 0; line[i]; i++) free(line[i]); free(line); } static void create_or_verify(void) { int i; if (mode != MODE_ACTIVATE) for (i = 0; i < levels; i++) { block_fseek(hash_file, hash_level_block[i], hash_block_size); if (!i) { block_fseek(data_file, 0, data_block_size); create_or_verify_stream(data_file, hash_file, data_block_size, data_file_blocks); } else { FILE *hash_file_2 = fopen(hash_device, "r"); if (!hash_file_2) { perror(hash_device); exit(2); } block_fseek(hash_file_2, hash_level_block[i - 1], hash_block_size); create_or_verify_stream(hash_file_2, hash_file, hash_block_size, hash_level_size[i - 1]); fclose(hash_file_2); } } if (levels) { block_fseek(hash_file, hash_level_block[levels - 1], hash_block_size); create_or_verify_stream(hash_file, NULL, hash_block_size, 1); } else { block_fseek(data_file, 0, data_block_size); create_or_verify_stream(data_file, NULL, data_block_size, data_file_blocks); } if (mode != MODE_CREATE) { if (memcmp(calculated_digest, root_hash_bytes, digest_size)) { fprintf(stderr, "verification failed in the root block\n"); retval = 1; } if (!retval && mode == MODE_VERIFY) fprintf(stderr, "hash successfully verified\n"); } else { char **target_line; char *p; if (fsync(fileno(hash_file))) { perror("fsync"); exit(1); } printf("hash device size: %llu\n", (unsigned long long)used_hash_blocks * hash_block_size); printf("data block size %u, hash block size %u, %u tree levels\n", data_block_size, hash_block_size, levels); if (salt_size) p = xhexprint(salt_bytes, salt_size); else p = xstrdup("-"); printf("salt: %s\n", p); free(p); p = xhexprint(calculated_digest, digest_size); printf("root hash: %s\n", p); free(p); printf("target line:"); target_line = make_target_line(); for (i = 0; target_line[i]; i++) printf(" %s", target_line[i]); free_target_line(target_line); printf("\n"); } } static void activate(void) { int i; size_t len = 1; char *table_arg; char **target_line = make_target_line(); for (i = 0; target_line[i]; i++) { if (i) len++; len += strlen(target_line[i]); } table_arg = xmalloc(len); table_arg[0] = 0; for (i = 0; target_line[i]; i++) { if (i) strcat(table_arg, " "); strcat(table_arg, target_line[i]); } free_target_line(target_line); execlp("dmsetup", "dmsetup", "-r", "create", dm_device, "--table", table_arg, NULL); perror("dmsetup"); exit(2); } static void get_hex(const char *string, unsigned char **result, size_t len, const char *description) { size_t rl = strlen(string); unsigned u; if (strspn(string, "0123456789ABCDEFabcdef") != rl) exit_err("invalid %s", description); if (rl != len * 2) exit_err("invalid length of %s", description); *result = xmalloc(len); memset(*result, 0, len); for (u = 0; u < rl; u++) { unsigned char c = (string[u] & 15) + (string[u] > '9' ? 9 : 0); (*result)[u / 2] |= c << (((u & 1) ^ 1) << 2); } } static struct superblock superblock; static void load_superblock(void) { long long sb_data_blocks; block_fseek(hash_file, superblock_position, 1); if (fread(&superblock, sizeof(struct superblock), 1, hash_file) != 1) stream_err(hash_file, "read"); if (memcmp(superblock.signature, DM_VERITY_SIGNATURE, sizeof(superblock.signature))) exit_err("superblock not found on the hash device"); if (superblock.version > MAX_FORMAT_VERSION) exit_err("unknown version"); if (superblock.data_block_bits < 9 || superblock.data_block_bits >= 31) exit_err("invalid data_block_bits in the superblock"); if (superblock.hash_block_bits < 9 || superblock.hash_block_bits >= 31) exit_err("invalid data_block_bits in the superblock"); sb_data_blocks = ((unsigned long long)ntohl(superblock.data_blocks_hi) << 31 << 1) | ntohl(superblock.data_blocks_lo); if (sb_data_blocks < 0 || (off_t)sb_data_blocks < 0 || (off_t)sb_data_blocks != sb_data_blocks) exit_err("invalid data blocks in the superblock"); if (!memchr(superblock.algorithm, 0, sizeof(superblock.algorithm))) exit_err("invalid hash algorithm in the superblock"); if (ntohs(superblock.salt_size) > MAX_SALT_SIZE) exit_err("invalid salt_size in the superblock"); if (version == -1) { version = superblock.version; } else { if (version != superblock.version) exit_err("version (%d) does not match superblock value (%d)", version, superblock.version); } if (!data_block_size) { data_block_size = 1 << superblock.data_block_bits; } else { if (data_block_size != 1 << superblock.data_block_bits) exit_err("data block size (%d) does not match superblock value (%d)", data_block_size, 1 << superblock.data_block_bits); } if (!hash_block_size) { hash_block_size = 1 << superblock.hash_block_bits; } else { if (hash_block_size != 1 << superblock.hash_block_bits) exit_err("hash block size (%d) does not match superblock value (%d)", hash_block_size, 1 << superblock.hash_block_bits); } if (!data_blocks) { data_blocks = sb_data_blocks; } else { if (data_blocks != sb_data_blocks) exit_err("data blocks (%lld) does not match superblock value (%lld)", data_blocks, sb_data_blocks); } if (!hash_algorithm) { hash_algorithm = (char *)superblock.algorithm; } else { if (strcmp(hash_algorithm, (char *)superblock.algorithm)) exit_err("hash algorithm (%s) does not match superblock value (%s)", hash_algorithm, superblock.algorithm); } if (!salt_bytes) { salt_size = ntohs(superblock.salt_size); salt_bytes = xmalloc(salt_size); memcpy(salt_bytes, superblock.salt, salt_size); } else { if (salt_size != ntohs(superblock.salt_size) || memcmp(salt_bytes, superblock.salt, salt_size)) exit_err("salt does not match superblock value"); } } static void save_superblock(void) { memset(&superblock, 0, sizeof(struct superblock)); memcpy(&superblock.signature, DM_VERITY_SIGNATURE, sizeof(superblock.signature)); superblock.version = version; superblock.data_block_bits = ffs(data_block_size) - 1; superblock.hash_block_bits = ffs(hash_block_size) - 1; superblock.salt_size = htons(salt_size); superblock.data_blocks_hi = htonl(data_blocks >> 31 >> 1); superblock.data_blocks_lo = htonl(data_blocks & 0xFFFFFFFF); strncpy((char *)superblock.algorithm, hash_algorithm, sizeof superblock.algorithm); memcpy(superblock.salt, salt_bytes, salt_size); block_fseek(hash_file, superblock_position, 1); if (fwrite(&superblock, sizeof(struct superblock), 1, hash_file) != 1) stream_err(hash_file, "write"); } int main(int argc, const char **argv) { poptContext popt_context; int r; const char *s; if (sizeof(struct superblock) != 512) exit_err("INTERNAL ERROR: bad superblock size %d", sizeof(struct superblock)); OpenSSL_add_all_digests(); popt_context = poptGetContext("verity", argc, argv, popt_options, 0); poptSetOtherOptionHelp(popt_context, "[-c | -v | -a] [<device name> if activating] <data device> <hash device> [<root hash> if activating or verifying] [OPTION...]"); if (argc <= 1) { poptPrintHelp(popt_context, stdout, 0); exit(1); } r = poptGetNextOpt(popt_context); if (r < -1) exit_err("bad option %s", poptBadOption(popt_context, 0)); if (mode < 0) exit_err("verify, create or activate mode not specified"); if (mode == MODE_ACTIVATE) { dm_device = poptGetArg(popt_context); if (!dm_device) exit_err("device name is missing"); if (!*dm_device || strchr(dm_device, '/')) exit_err("invalid device name"); } data_device = poptGetArg(popt_context); if (!data_device) exit_err("data device is missing"); hash_device = poptGetArg(popt_context); if (!hash_device) exit_err("metadata device is missing"); if (mode != MODE_CREATE) { root_hash = poptGetArg(popt_context); if (!root_hash) exit_err("root hash not specified"); } s = poptGetArg(popt_context); if (s) exit_err("extra argument %s", s); data_file = fopen(data_device, "r"); if (!data_file) { perror(data_device); exit(2); } hash_file = fopen(hash_device, mode != MODE_CREATE ? "r" : "r+"); if (!hash_file && errno == ENOENT && mode == MODE_CREATE) hash_file = fopen(hash_device, "w+"); if (!hash_file) { perror(hash_device); exit(2); } if (hash_start < 0 || (unsigned long long)hash_start * 512 / 512 != hash_start || (off_t)(hash_start * 512) < 0 || (off_t)(hash_start * 512) != hash_start * 512) exit_err("invalid hash start"); if (salt_string || !use_superblock) { if (!salt_string || !strcmp(salt_string, "-")) salt_string = ""; salt_size = strlen(salt_string) / 2; if (salt_size > MAX_SALT_SIZE) exit_err("too long salt (max %d bytes)", MAX_SALT_SIZE); get_hex(salt_string, &salt_bytes, salt_size, "salt"); } if (use_superblock) { superblock_position = hash_start * 512; if (mode != MODE_CREATE) load_superblock(); } if (version == -1) version = MAX_FORMAT_VERSION; if (version < 0 || version > MAX_FORMAT_VERSION) exit_err("invalid format version"); if (!data_block_size) data_block_size = DEFAULT_BLOCK_SIZE; if (!hash_block_size) hash_block_size = data_block_size; if (data_block_size < 512 || (data_block_size & (data_block_size - 1)) || data_block_size >= 1U << 31) exit_err("invalid data block size"); if (hash_block_size < 512 || (hash_block_size & (hash_block_size - 1)) || hash_block_size >= 1U << 31) exit_err("invalid hash block size"); if (data_blocks < 0 || (off_t)data_blocks < 0 || (off_t)data_blocks != data_blocks) exit_err("invalid number of data blocks"); data_file_blocks = get_size(data_file, data_device) / data_block_size; hash_file_blocks = get_size(hash_file, hash_device) / hash_block_size; if (data_file_blocks < data_blocks) exit_err("data file is too small"); if (data_blocks) { data_file_blocks = data_blocks; } if (use_superblock) { hash_start = hash_start + (sizeof(struct superblock) + 511) / 512; hash_start = (hash_start + (hash_block_size / 512 - 1)) & ~(long long)(hash_block_size / 512 - 1); } if ((unsigned long long)hash_start * 512 % hash_block_size) exit_err("hash start not aligned on block size"); if (!hash_algorithm) hash_algorithm = "sha256"; if (strlen(hash_algorithm) >= sizeof(superblock.algorithm) && use_superblock) exit_err("hash algorithm name is too long"); evp = EVP_get_digestbyname(hash_algorithm); if (!evp) exit_err("hash algorithm %s not found", hash_algorithm); digest_size = EVP_MD_size(evp); if (!salt_bytes) { salt_size = DEFAULT_SALT_SIZE; salt_bytes = xmalloc(salt_size); if (RAND_bytes(salt_bytes, salt_size) != 1) exit_err("RAND_bytes failed"); } calculated_digest = xmalloc(digest_size); if (mode != MODE_CREATE) { get_hex(root_hash, &root_hash_bytes, digest_size, "root_hash"); } calculate_positions(); create_or_verify(); if (use_superblock) { if (mode == MODE_CREATE) save_superblock(); } fclose(data_file); fclose(hash_file); if (mode == MODE_ACTIVATE && !retval) activate(); free(salt_bytes); free(calculated_digest); if (mode != MODE_CREATE) free(root_hash_bytes); poptFreeContext(popt_context); return retval; } -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel