diff options
| -rw-r--r-- | src/liblzma/api/lzma/block.h | 50 | ||||
| -rw-r--r-- | src/liblzma/common/block_buffer_encoder.c | 2 | ||||
| -rw-r--r-- | src/liblzma/common/block_decoder.c | 18 | ||||
| -rw-r--r-- | src/liblzma/common/block_encoder.c | 2 | ||||
| -rw-r--r-- | src/liblzma/common/block_header_decoder.c | 12 | ||||
| -rw-r--r-- | src/liblzma/common/block_header_encoder.c | 2 | ||||
| -rw-r--r-- | src/liblzma/common/block_util.c | 2 |
7 files changed, 68 insertions, 20 deletions
diff --git a/src/liblzma/api/lzma/block.h b/src/liblzma/api/lzma/block.h index 2e982e1c..7bdcfd7c 100644 --- a/src/liblzma/api/lzma/block.h +++ b/src/liblzma/api/lzma/block.h @@ -31,11 +31,16 @@ typedef struct { /** * \brief Block format version * - * To prevent API and ABI breakages if new features are needed in - * the Block field, a version number is used to indicate which - * fields in this structure are in use. For now, version must always - * be zero. With non-zero version, most Block related functions will - * return LZMA_OPTIONS_ERROR. + * To prevent API and ABI breakages when new features are needed, + * a version number is used to indicate which fields in this + * structure are in use: + * - liblzma >= 5.0.0: version = 0 is supported. + * - liblzma >= 5.1.4beta: Support for version = 1 was added, + * which adds the ignore_check field. + * + * If version is greater than one, most Block related functions + * will return LZMA_OPTIONS_ERROR (lzma_block_header_decode() works + * with any version value). * * Read by: * - All functions that take pointer to lzma_block as argument, @@ -233,7 +238,28 @@ typedef struct { lzma_reserved_enum reserved_enum2; lzma_reserved_enum reserved_enum3; lzma_reserved_enum reserved_enum4; - lzma_bool reserved_bool1; + + /** + * \brief A flag to Block decoder to not verify the Check field + * + * This field is supported by liblzma >= 5.1.4beta if .version >= 1. + * + * If this is set to true, the integrity check won't be calculated + * and verified. Unless you know what you are doing, you should + * leave this to false. (A reason to set this to true is when the + * file integrity is verified externally anyway and you want to + * speed up the decompression, which matters mostly when using + * SHA-256 as the integrity check.) + * + * If .version >= 1, read by: + * - lzma_block_decoder() + * - lzma_block_buffer_decode() + * + * Written by (.version is ignored): + * - lzma_block_header_decode() always sets this to false + */ + lzma_bool ignore_check; + lzma_bool reserved_bool2; lzma_bool reserved_bool3; lzma_bool reserved_bool4; @@ -310,10 +336,14 @@ extern LZMA_API(lzma_ret) lzma_block_header_encode( /** * \brief Decode Block Header * - * block->version should be set to the highest value supported by the - * application; currently the only possible version is zero. This function - * will set version to the lowest value that still supports all the features - * required by the Block Header. + * block->version should (usually) be set to the highest value supported + * by the application. If the application sets block->version to a value + * higher than supported by the current liblzma version, this function will + * downgrade block->version to the highest value supported by it. Thus one + * should check the value of block->version after calling this function if + * block->version was set to a non-zero value and the application doesn't + * otherwise know that the liblzma version being used is new enough to + * support the specified block->version. * * The size of the Block Header must have already been decoded with * lzma_block_header_size_decode() macro and stored to block->header_size. diff --git a/src/liblzma/common/block_buffer_encoder.c b/src/liblzma/common/block_buffer_encoder.c index dcd574e9..39e263aa 100644 --- a/src/liblzma/common/block_buffer_encoder.c +++ b/src/liblzma/common/block_buffer_encoder.c @@ -233,7 +233,7 @@ block_buffer_encode(lzma_block *block, const lzma_allocator *allocator, // The contents of the structure may depend on the version so // check the version before validating the contents of *block. - if (block->version != 0) + if (block->version > 1) return LZMA_OPTIONS_ERROR; if ((unsigned int)(block->check) > LZMA_CHECK_ID_MAX diff --git a/src/liblzma/common/block_decoder.c b/src/liblzma/common/block_decoder.c index cee6c782..685c3b03 100644 --- a/src/liblzma/common/block_decoder.c +++ b/src/liblzma/common/block_decoder.c @@ -45,6 +45,9 @@ struct lzma_coder_s { /// Check of the uncompressed data lzma_check_state check; + + /// True if the integrity check won't be calculated and verified. + bool ignore_check; }; @@ -97,8 +100,9 @@ block_decode(lzma_coder *coder, const lzma_allocator *allocator, coder->block->uncompressed_size)) return LZMA_DATA_ERROR; - lzma_check_update(&coder->check, coder->block->check, - out + out_start, out_used); + if (!coder->ignore_check) + lzma_check_update(&coder->check, coder->block->check, + out + out_start, out_used); if (ret != LZMA_STREAM_END) return ret; @@ -140,7 +144,9 @@ block_decode(lzma_coder *coder, const lzma_allocator *allocator, if (coder->block->check == LZMA_CHECK_NONE) return LZMA_STREAM_END; - lzma_check_finish(&coder->check, coder->block->check); + if (!coder->ignore_check) + lzma_check_finish(&coder->check, coder->block->check); + coder->sequence = SEQ_CHECK; // Fall through @@ -155,7 +161,8 @@ block_decode(lzma_coder *coder, const lzma_allocator *allocator, // Validate the Check only if we support it. // coder->check.buffer may be uninitialized // when the Check ID is not supported. - if (lzma_check_is_supported(coder->block->check) + if (!coder->ignore_check + && lzma_check_is_supported(coder->block->check) && memcmp(coder->block->raw_check, coder->check.buffer.u8, check_size) != 0) @@ -224,6 +231,9 @@ lzma_block_decoder_init(lzma_next_coder *next, const lzma_allocator *allocator, next->coder->check_pos = 0; lzma_check_init(&next->coder->check, block->check); + next->coder->ignore_check = block->version >= 1 + ? block->ignore_check : false; + // Initialize the filter chain. return lzma_raw_decoder_init(&next->coder->next, allocator, block->filters); diff --git a/src/liblzma/common/block_encoder.c b/src/liblzma/common/block_encoder.c index 15f55f7a..def58641 100644 --- a/src/liblzma/common/block_encoder.c +++ b/src/liblzma/common/block_encoder.c @@ -166,7 +166,7 @@ lzma_block_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator, // The contents of the structure may depend on the version so // check the version first. - if (block->version != 0) + if (block->version > 1) return LZMA_OPTIONS_ERROR; // If the Check ID is not supported, we cannot calculate the check and diff --git a/src/liblzma/common/block_header_decoder.c b/src/liblzma/common/block_header_decoder.c index 416642cd..1dd982f6 100644 --- a/src/liblzma/common/block_header_decoder.c +++ b/src/liblzma/common/block_header_decoder.c @@ -46,8 +46,16 @@ lzma_block_header_decode(lzma_block *block, block->filters[i].options = NULL; } - // Always zero for now. - block->version = 0; + // Versions 0 and 1 are supported. If a newer version was specified, + // we need to downgrade it. + if (block->version > 1) + block->version = 1; + + // This isn't a Block Header option, but since the decompressor will + // read it if version >= 1, it's better to initialize it here than + // to expect the caller to do it since in almost all cases this + // should be false. + block->ignore_check = false; // Validate Block Header Size and Check type. The caller must have // already set these, so it is a programming error if this test fails. diff --git a/src/liblzma/common/block_header_encoder.c b/src/liblzma/common/block_header_encoder.c index 707dd0cb..5c5f5424 100644 --- a/src/liblzma/common/block_header_encoder.c +++ b/src/liblzma/common/block_header_encoder.c @@ -17,7 +17,7 @@ extern LZMA_API(lzma_ret) lzma_block_header_size(lzma_block *block) { - if (block->version != 0) + if (block->version > 1) return LZMA_OPTIONS_ERROR; // Block Header Size + Block Flags + CRC32. diff --git a/src/liblzma/common/block_util.c b/src/liblzma/common/block_util.c index 62c93454..00c7fe8d 100644 --- a/src/liblzma/common/block_util.c +++ b/src/liblzma/common/block_util.c @@ -51,7 +51,7 @@ lzma_block_unpadded_size(const lzma_block *block) // NOTE: This function is used for validation too, so it is // essential that these checks are always done even if // Compressed Size is unknown. - if (block == NULL || block->version != 0 + if (block == NULL || block->version > 1 || block->header_size < LZMA_BLOCK_HEADER_SIZE_MIN || block->header_size > LZMA_BLOCK_HEADER_SIZE_MAX || (block->header_size & 3) |