diff options
Diffstat (limited to 'tools/applypatch/imgpatch.c')
| -rw-r--r-- | tools/applypatch/imgpatch.c | 226 |
1 files changed, 181 insertions, 45 deletions
diff --git a/tools/applypatch/imgpatch.c b/tools/applypatch/imgpatch.c index 2efe874..697cc68 100644 --- a/tools/applypatch/imgpatch.c +++ b/tools/applypatch/imgpatch.c @@ -27,24 +27,7 @@ #include "mincrypt/sha.h" #include "applypatch.h" #include "imgdiff.h" - -int Read4(unsigned char* p) { - return (int)(((unsigned int)p[3] << 24) | - ((unsigned int)p[2] << 16) | - ((unsigned int)p[1] << 8) | - (unsigned int)p[0]); -} - -long long Read8(unsigned char* p) { - return (long long)(((unsigned long long)p[7] << 56) | - ((unsigned long long)p[6] << 48) | - ((unsigned long long)p[5] << 40) | - ((unsigned long long)p[4] << 32) | - ((unsigned long long)p[3] << 24) | - ((unsigned long long)p[2] << 16) | - ((unsigned long long)p[1] << 8) | - (unsigned long long)p[0]); -} +#include "utils.h" /* * Apply the patch given in 'patch_filename' to the source data given @@ -67,7 +50,10 @@ int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size, return -1; } - if (memcmp(header, "IMGDIFF1", 8) != 0) { + // IMGDIFF1 uses CHUNK_NORMAL and CHUNK_GZIP. + // IMGDIFF2 uses CHUNK_NORMAL, CHUNK_DEFLATE, and CHUNK_RAW. + if (memcmp(header, "IMGDIFF", 7) != 0 || + (header[7] != '1' && header[7] != '2')) { fprintf(stderr, "corrupt patch file header (magic number)\n"); return -1; } @@ -76,48 +62,67 @@ int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size, int i; for (i = 0; i < num_chunks; ++i) { - // each chunk's header record starts with 28 bytes (4 + 8*3). - unsigned char chunk[28]; - if (fread(chunk, 1, 28, f) != 28) { + // each chunk's header record starts with 4 bytes. + unsigned char chunk[4]; + if (fread(chunk, 1, 4, f) != 4) { fprintf(stderr, "failed to read chunk %d record\n", i); return -1; } int type = Read4(chunk); - size_t src_start = Read8(chunk+4); - size_t src_len = Read8(chunk+12); - size_t patch_offset = Read8(chunk+20); if (type == CHUNK_NORMAL) { + unsigned char normal_header[24]; + if (fread(normal_header, 1, 24, f) != 24) { + fprintf(stderr, "failed to read chunk %d normal header data\n", i); + return -1; + } + + size_t src_start = Read8(normal_header); + size_t src_len = Read8(normal_header+8); + size_t patch_offset = Read8(normal_header+16); + fprintf(stderr, "CHUNK %d: normal patch offset %d\n", i, patch_offset); ApplyBSDiffPatch(old_data + src_start, src_len, patch_filename, patch_offset, output, ctx); } else if (type == CHUNK_GZIP) { - fprintf(stderr, "CHUNK %d: gzip patch offset %d\n", i, patch_offset); + // This branch is basically a duplicate of the CHUNK_DEFLATE + // branch, with a bit of extra processing for the gzip header + // and footer. I've avoided factoring the common code out since + // this branch will just be deleted when we drop support for + // IMGDIFF1. - // gzip chunks have an additional 40 + gzip_header_len + 8 bytes + // gzip chunks have an additional 64 + gzip_header_len + 8 bytes // in their chunk header. - unsigned char* gzip = malloc(40); - if (fread(gzip, 1, 40, f) != 40) { - fprintf(stderr, "failed to read chunk %d initial gzip data\n", i); + unsigned char* gzip = malloc(64); + if (fread(gzip, 1, 64, f) != 64) { + fprintf(stderr, "failed to read chunk %d initial gzip header data\n", + i); return -1; } - size_t gzip_header_len = Read4(gzip+36); - gzip = realloc(gzip, 40 + gzip_header_len + 8); - if (fread(gzip+40, 1, gzip_header_len+8, f) != gzip_header_len+8) { - fprintf(stderr, "failed to read chunk %d remaining gzip data\n", i); + size_t gzip_header_len = Read4(gzip+60); + gzip = realloc(gzip, 64 + gzip_header_len + 8); + if (fread(gzip+64, 1, gzip_header_len+8, f) != gzip_header_len+8) { + fprintf(stderr, "failed to read chunk %d remaining gzip header data\n", + i); return -1; } - size_t expanded_len = Read8(gzip); - size_t target_len = Read8(gzip); - int gz_level = Read4(gzip+16); - int gz_method = Read4(gzip+20); - int gz_windowBits = Read4(gzip+24); - int gz_memLevel = Read4(gzip+28); - int gz_strategy = Read4(gzip+32); + size_t src_start = Read8(gzip); + size_t src_len = Read8(gzip+8); + size_t patch_offset = Read8(gzip+16); + + size_t expanded_len = Read8(gzip+24); + size_t target_len = Read8(gzip+32); + int gz_level = Read4(gzip+40); + int gz_method = Read4(gzip+44); + int gz_windowBits = Read4(gzip+48); + int gz_memLevel = Read4(gzip+52); + int gz_strategy = Read4(gzip+56); + + fprintf(stderr, "CHUNK %d: gzip patch offset %d\n", i, patch_offset); // Decompress the source data; the chunk header tells us exactly // how big we expect it to be when decompressed. @@ -173,8 +178,8 @@ int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size, // Now compress the target data and append it to the output. // start with the gzip header. - fwrite(gzip+40, 1, gzip_header_len, output); - SHA_update(ctx, gzip+40, gzip_header_len); + fwrite(gzip+64, 1, gzip_header_len, output); + SHA_update(ctx, gzip+64, gzip_header_len); // we're done with the expanded_source data buffer, so we'll // reuse that memory to receive the output of deflate. @@ -212,12 +217,143 @@ int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size, deflateEnd(&strm); // lastly, the gzip footer. - fwrite(gzip+40+gzip_header_len, 1, 8, output); - SHA_update(ctx, gzip+40+gzip_header_len, 8); + fwrite(gzip+64+gzip_header_len, 1, 8, output); + SHA_update(ctx, gzip+64+gzip_header_len, 8); free(temp_data); free(uncompressed_target_data); free(gzip); + } else if (type == CHUNK_RAW) { + unsigned char raw_header[4]; + if (fread(raw_header, 1, 4, f) != 4) { + fprintf(stderr, "failed to read chunk %d raw header data\n", i); + return -1; + } + + size_t data_len = Read4(raw_header); + + fprintf(stderr, "CHUNK %d: raw data %d\n", i, data_len); + + unsigned char* temp = malloc(data_len); + if (fread(temp, 1, data_len, f) != data_len) { + fprintf(stderr, "failed to read chunk %d raw data\n", i); + return -1; + } + SHA_update(ctx, temp, data_len); + if (fwrite(temp, 1, data_len, output) != data_len) { + fprintf(stderr, "failed to write chunk %d raw data\n", i); + return -1; + } + } else if (type == CHUNK_DEFLATE) { + // deflate chunks have an additional 60 bytes in their chunk header. + unsigned char deflate_header[60]; + if (fread(deflate_header, 1, 60, f) != 60) { + fprintf(stderr, "failed to read chunk %d deflate header data\n", i); + return -1; + } + + size_t src_start = Read8(deflate_header); + size_t src_len = Read8(deflate_header+8); + size_t patch_offset = Read8(deflate_header+16); + size_t expanded_len = Read8(deflate_header+24); + size_t target_len = Read8(deflate_header+32); + int level = Read4(deflate_header+40); + int method = Read4(deflate_header+44); + int windowBits = Read4(deflate_header+48); + int memLevel = Read4(deflate_header+52); + int strategy = Read4(deflate_header+56); + + fprintf(stderr, "CHUNK %d: deflate patch offset %d\n", i, patch_offset); + + // Decompress the source data; the chunk header tells us exactly + // how big we expect it to be when decompressed. + + unsigned char* expanded_source = malloc(expanded_len); + if (expanded_source == NULL) { + fprintf(stderr, "failed to allocate %d bytes for expanded_source\n", + expanded_len); + return -1; + } + + z_stream strm; + strm.zalloc = Z_NULL; + strm.zfree = Z_NULL; + strm.opaque = Z_NULL; + strm.avail_in = src_len; + strm.next_in = (unsigned char*)(old_data + src_start); + strm.avail_out = expanded_len; + strm.next_out = expanded_source; + + int ret; + ret = inflateInit2(&strm, -15); + if (ret != Z_OK) { + fprintf(stderr, "failed to init source inflation: %d\n", ret); + return -1; + } + + // Because we've provided enough room to accommodate the output + // data, we expect one call to inflate() to suffice. + ret = inflate(&strm, Z_SYNC_FLUSH); + if (ret != Z_STREAM_END) { + fprintf(stderr, "source inflation returned %d\n", ret); + return -1; + } + // We should have filled the output buffer exactly. + if (strm.avail_out != 0) { + fprintf(stderr, "source inflation short by %d bytes\n", strm.avail_out); + return -1; + } + inflateEnd(&strm); + + // Next, apply the bsdiff patch (in memory) to the uncompressed + // data. + unsigned char* uncompressed_target_data; + ssize_t uncompressed_target_size; + if (ApplyBSDiffPatchMem(expanded_source, expanded_len, + patch_filename, patch_offset, + &uncompressed_target_data, + &uncompressed_target_size) != 0) { + return -1; + } + + // Now compress the target data and append it to the output. + + // we're done with the expanded_source data buffer, so we'll + // reuse that memory to receive the output of deflate. + unsigned char* temp_data = expanded_source; + ssize_t temp_size = expanded_len; + if (temp_size < 32768) { + // ... unless the buffer is too small, in which case we'll + // allocate a fresh one. + free(temp_data); + temp_data = malloc(32768); + temp_size = 32768; + } + + // now the deflate stream + strm.zalloc = Z_NULL; + strm.zfree = Z_NULL; + strm.opaque = Z_NULL; + strm.avail_in = uncompressed_target_size; + strm.next_in = uncompressed_target_data; + ret = deflateInit2(&strm, level, method, windowBits, memLevel, strategy); + do { + strm.avail_out = temp_size; + strm.next_out = temp_data; + ret = deflate(&strm, Z_FINISH); + size_t have = temp_size - strm.avail_out; + + if (fwrite(temp_data, 1, have, output) != have) { + fprintf(stderr, "failed to write %d compressed bytes to output\n", + have); + return -1; + } + SHA_update(ctx, temp_data, have); + } while (ret != Z_STREAM_END); + deflateEnd(&strm); + + free(temp_data); + free(uncompressed_target_data); } else { fprintf(stderr, "patch chunk %d is unknown type %d\n", i, type); return -1; |