Catch read error at end of compressed data.

Also, catch garbage after compressed data if checking for consistency.

Adresses issue #478

lib/zip_algorithm_bzip2.c

@@ -208,11 +208,11 @@ input(void *ud, zip_uint8_t *data, zip_uint64_t length) {
 }
 
 
-static void
-end_of_input(void *ud) {
+static bool end_of_input(void *ud) {
     struct ctx *ctx = (struct ctx *)ud;
 
     ctx->end_of_input = true;
+    return ctx->zstr.avail_in != 0;
 }
 
 

lib/zip_algorithm_deflate.c

@@ -196,11 +196,11 @@ input(void *ud, zip_uint8_t *data, zip_uint64_t length) {
 }
 
 
-static void
-end_of_input(void *ud) {
+static bool end_of_input(void *ud) {
     struct ctx *ctx = (struct ctx *)ud;
 
     ctx->end_of_input = true;
+    return ctx->zstr.avail_in != 0;
 }
 
 

lib/zip_algorithm_xz.c

@@ -302,11 +302,11 @@ input(void *ud, zip_uint8_t *data, zip_uint64_t length) {
 }
 
 
-static void
-end_of_input(void *ud) {
+static bool end_of_input(void *ud) {
     struct ctx *ctx = (struct ctx *)ud;
 
     ctx->end_of_input = true;
+    return ctx->zstr.avail_in != 0;
 }
 
 

lib/zip_algorithm_zstd.c

@@ -211,11 +211,11 @@ input(void *ud, zip_uint8_t *data, zip_uint64_t length) {
 }
 
 
-static void
-end_of_input(void *ud) {
+static bool end_of_input(void *ud) {
     struct ctx *ctx = (struct ctx *)ud;
 
     ctx->end_of_input = true;
+    return ctx->in.pos != ctx->in.size;
 }
 
 

lib/zip_source_compress.c

@@ -44,6 +44,7 @@ struct context {
     bool can_store;
     bool is_stored; /* only valid if end_of_stream is true */
     bool compress;
+    bool check_consistency;
     zip_int32_t method;
 
     zip_uint64_t size;
@@ -86,11 +87,10 @@ static size_t implementations_size = sizeof(implementations) / sizeof(implementa
 static zip_source_t *compression_source_new(zip_t *za, zip_source_t *src, zip_int32_t method, bool compress, zip_uint32_t compression_flags);
 static zip_int64_t compress_callback(zip_source_t *, void *, void *, zip_uint64_t, zip_source_cmd_t);
 static void context_free(struct context *ctx);
-static struct context *context_new(zip_int32_t method, bool compress, zip_uint32_t compression_flags, zip_compression_algorithm_t *algorithm);
+static struct context *context_new(zip_int32_t method, bool compress, zip_uint32_t compression_flags, zip_compression_algorithm_t *algorithm, bool check_consistency);
 static zip_int64_t compress_read(zip_source_t *, struct context *, void *, zip_uint64_t);
 
-zip_compression_algorithm_t *
-_zip_get_compression_algorithm(zip_int32_t method, bool compress) {
+zip_compression_algorithm_t *_zip_get_compression_algorithm(zip_int32_t method, bool compress) {
     size_t i;
     zip_uint16_t real_method = ZIP_CM_ACTUAL(method);
 
@@ -108,16 +108,14 @@ _zip_get_compression_algorithm(zip_int32_t method, bool compress) {
     return NULL;
 }
 
-ZIP_EXTERN int
-zip_compression_method_supported(zip_int32_t method, int compress) {
+ZIP_EXTERN int zip_compression_method_supported(zip_int32_t method, int compress) {
     if (method == ZIP_CM_STORE) {
         return 1;
     }
     return _zip_get_compression_algorithm(method, compress) != NULL;
 }
 
-zip_source_t *
-zip_source_compress(zip_t *za, zip_source_t *src, zip_int32_t method, zip_uint32_t compression_flags) {
+zip_source_t *zip_source_compress(zip_t *za, zip_source_t *src, zip_int32_t method, zip_uint32_t compression_flags) {
     return compression_source_new(za, src, method, true, compression_flags);
 }
 
@@ -127,8 +125,7 @@ zip_source_decompress(zip_t *za, zip_source_t *src, zip_int32_t method) {
 }
 
 
-static zip_source_t *
-compression_source_new(zip_t *za, zip_source_t *src, zip_int32_t method, bool compress, zip_uint32_t compression_flags) {
+static zip_source_t *compression_source_new(zip_t *za, zip_source_t *src, zip_int32_t method, bool compress, zip_uint32_t compression_flags) {
     struct context *ctx;
     zip_source_t *s2;
     zip_compression_algorithm_t *algorithm = NULL;
@@ -143,7 +140,7 @@ compression_source_new(zip_t *za, zip_source_t *src, zip_int32_t method, bool co
         return NULL;
     }
 
-    if ((ctx = context_new(method, compress, compression_flags, algorithm)) == NULL) {
+    if ((ctx = context_new(method, compress, compression_flags, algorithm, za->open_flags & ZIP_CHECKCONS)) == NULL) {
         zip_error_set(&za->error, ZIP_ER_MEMORY, 0);
         return NULL;
     }
@@ -157,8 +154,7 @@ compression_source_new(zip_t *za, zip_source_t *src, zip_int32_t method, bool co
 }
 
 
-static struct context *
-context_new(zip_int32_t method, bool compress, zip_uint32_t compression_flags, zip_compression_algorithm_t *algorithm) {
+static struct context *context_new(zip_int32_t method, bool compress, zip_uint32_t compression_flags, zip_compression_algorithm_t *algorithm, bool check_consistency) {
     struct context *ctx;
 
     if ((ctx = (struct context *)malloc(sizeof(*ctx))) == NULL) {
@@ -172,6 +168,7 @@ context_new(zip_int32_t method, bool compress, zip_uint32_t compression_flags, z
     ctx->end_of_input = false;
     ctx->end_of_stream = false;
     ctx->is_stored = false;
+    ctx->check_consistency = check_consistency;
 
     if ((ctx->ud = ctx->algorithm->allocate(ZIP_CM_ACTUAL(method), compression_flags, &ctx->error)) == NULL) {
         zip_error_fini(&ctx->error);
@@ -228,7 +225,23 @@ compress_read(zip_source_t *src, struct context *ctx, void *data, zip_uint64_t l
             ctx->end_of_stream = true;
 
             if (!ctx->end_of_input) {
-                /* TODO: garbage after stream, or compression ended before all data read */
+                n = zip_source_read(src, ctx->buffer, 1);
+                if (n < 0) {
+                    zip_error_set_from_source(&ctx->error, src);
+                    end = true;
+                    break;
+                }
+                else if (n == 0) {
+                    ctx->end_of_input = true;
+                    n = ctx->algorithm->end_of_input(ctx->ud) ? 1 : 0;
+                }
+
+                if (n > 0 && ctx->check_consistency) {
+                    /* garbage after stream, or compression ended before all data read */
+                    zip_error_set(&ctx->error, ZIP_ER_INCONS, ZIP_ER_DETAIL_COMPRESSED_DATA_TRAILING_GARBAGE);
+                    end = true;
+                    break;
+                }
             }
 
             if (ctx->first_read < 0) {

lib/zipint.h

@@ -153,7 +153,7 @@ struct zip_compression_algorithm {
     bool (*input)(void *ctx, zip_uint8_t *data, zip_uint64_t length);
 
     /* all input data has been provided */
-    void (*end_of_input)(void *ctx);
+    bool (*end_of_input)(void *ctx);
 
     /* process input data, writing to data, which has room for length bytes, update length to number of bytes written */
     zip_compression_status_t (*process)(void *ctx, zip_uint8_t *data, zip_uint64_t *length);
@@ -242,6 +242,7 @@ extern const int _zip_err_details_count;
 #define ZIP_ER_DETAIL_EOCD64_LOCATOR_MISMATCH 22 /* G EOCD64 and EOCD64 locator do not match */
 #define ZIP_ER_DETAIL_UTF8_FILENAME_MISMATCH 23 /* E UTF-8 filename is ASCII and doesn't match filename */
 #define ZIP_ER_DETAIL_UTF8_COMMENT_MISMATCH 24 /* E UTF-8 comment is ASCII and doesn't match comment */
+#define ZIP_ER_DETAIL_COMPRESSED_DATA_TRAILING_GARBAGE 25 /* G garbage at end of compressed data */
 
 /* directory entry: general purpose bit flags */
 

regress/read_incons.test

@@ -0,0 +1,9 @@
+arguments -c test.zip cat 0
+return 1
+file test.zip incons-trailing-garbage.zip
+stdout
+test
+end-of-inline-data
+stderr
+can't read file at index '0': Zip archive inconsistent: garbage at end of compressed data
+end-of-inline-data