Astrée: Standardkonformität

Astrée ist ein Werkzeug zur statischen Analyse von C-Quellcode, bei der das Haupt­augenmerk darauf liegt, Laufzeitfehler aufzudecken bzw. deren Abwesenheit zu beweisen. Dazu zählt z. B. jeder Gebrauch der Sprache, der nach der C99-Norm ein undefiniertes Verhalten aufweist.

Darüberhinaus kann Astrées hochentwickelte Analyse-Engine dazu benutzt werden, den Quell­code auf verschiedenste sicherheits­relevante Eigenschaften hin zu überprüfen. Dazu zählt Konformität zu Standards wie CWE, SEI CERT und MISRA.

Diese Seite bietet einen Überblick darüber, welche Kriterien, Regeln und Empfehlungen dieser Standards Astrée überprüft.

C99

Im Anhang J von ISO/IEC 9899:1999 (E) finden sich die Verhalten, die der Standard als unspezi­fiziert, undefiniert oder implementierungs­abhängig erachtet. In drei Abschnitten werden dabei Hunderte von Szenarien behandelt.

Wie Astrée jedes einzelne dieser Szenarien abdeckt, ist in einem 34-seitigen PDF-Dokument beschrieben. Dieses finden Sie im Tool selbst unter „Help“ → „C compliance matrices“, oder erhalten es auf Anfrage kostenlos bei info@absint.com.

Vorschau des Dokuments zur C99-Konformität

Common Weakness Enumeration (CWE)

Die folgende Tabelle führt alle CWE-Regeln auf, die von Astrée 18.04 unterstützt werden. Dazu zählen Regeln mit der CWE-CCR-Abdeckung „Exact“, „CWE-more-abstract“ und „CWE-more-specific“. Regeln mit der Abdeckung „CWE-partial“ sind ausgegraut. Weitere Details können Sie im Astrée-Menü „Help“ finden, oder bei info@absint.com erfragen.

Astrée-Analysen sind sicher, d. h. jede Regel, die verletzt wird, wird auch als verletzt ge­meldet.

118Improper access of indexable resource
119Improper restriction of operations within the bounds of a memory buffer
120Buffer copy without checking size of input (‘classic buffer overflow‘)
121Stack-based buffer overflow
122Heap-based buffer overflow
123Write-what-where condition
124Buffer underwrite
125Out-of-bounds read
126Buffer over-read
127Buffer under-read
128Wrap-around error
129Improper validation of array index
130Improper handling of length parameter inconsistency
131Incorrect calculation of buffer size
170Improper null termination
188Reliance on data/memory layout
190Integer overflow or wraparound
191Integer underflow or wraparound
193Off-by-one error
194Unexpected sign extension
195Signed to unsigned conversion error
196Unsigned to signed conversion error
197Numeric truncation error
240Improper handling of inconsistent structural elements
242Use of inherently dangerous function
252Unchecked return value
253Incorrect check of function return value
362Concurrent execution using shared resource
with improper synchronization (‘race condition’)
364Signal handler race condition
365 Race condition in switch
366 Race condition within a thread
367 Time-of-check time-of-use (TOCTOU) race condition
369 Divde by zero
398 Indicator of poor code quality
404 Improper resource shutdown or release
411 Resource locking problems
415 Double free
416 Use after free
456 Missing initialization of a variable
457 Use of uninitialized variable
466 Return of pointer value outside of expected range
471 Modification of assumed-immutable data (MAID)
475 Undefined behavior for input to API
476 NULL pointer dereference
478 Missing default case in switch statement
561 Dead code
567 Unsynchronized access to shared data in a multithreaded context
573 Improper following of specification by caller
587 Assignment of a fixed address to a pointer
588 Attempt to access child of a nonstructure pointer
628 Function call with incorrectly specified arguments
662 Improper synchronization
665 Improper initialization
667 Improper locking
672 Operation on a resource after expiration or release
680 Integer overflow to buffer overflow
681 Incorrect conversion between numeric types
682 Incorrect calculation
685 Function call with incorrect number of arguments
686 Function call with incorrect argument type
690 Unchecked return value to NULL pointer dereference
754 Improper check for unusual or exceptional conditions
761 Free of pointer not at start of buffer
763 Release of invalid pointer or reference
764 Multiple locks of a critical resource
765 Multiple unlocks of a critical resource
785 Use of path manipulation function without maximum-sized buffer
786 Access of memory location before start of buffer
787 Out-of-bounds write
805 Buffer access with incorrect length value
806 Buffer access using size of source buffer
823 Use of out-of-range pointer offset
824 Access of uninitialized pointer
825 Expired pointer dereference
832 Unlock of a resource that is not locked
835 Loop with unreachable exit condition (‘infinite loop’)
908 Use of uninitialized resource

SEI CERT C Coding Standard

Die folgenden Tabellen listen die von Astrée 18.04 unterstützten SEI-CERT-Regeln und -Empfehlungen. Die aus­gegrauten Einträge werden nur teilweise unterstützt. Gefahrenstellen-Zeichen markieren Empfehlungen, die per Definition von keinem Tool automatisch überprüft werden können. Weitere Details erhalten Sie auf Anfrage bei info@absint.com.

Regel 01: Präprozessor
PRE32-C Do not use preprocessor directives in invocations of function-like macros
Regel 02: Deklarationen und Initialisierung
DCL30-C Declare objects with appropriate storage durations
DCL31-C Declare identifiers before using them
DCL36-C Do not declare an identifier with conflicting linkage classifications
DCL37-C Do not declare or define a reserved identifier
DCL38-C Use the correct syntax when declaring a flexible array member
DCL40-C Do not create incompatible declarations of the same function or object
DCL41-C Do not declare variables inside a switch statement before the first case label
Regel 03: Ausdrücke
EXP30-C Do not depend on the order of evaluation for side effects
EXP32-C Do not access a volatile object through a nonvolatile reference
EXP33-C Do not read uninitialized memory
EXP34-C Do not dereference null pointers
EXP36-C Do not cast pointers into more strictly aligned pointer types
EXP37-C Call functions with the correct number and type of arguments
EXP43-C Avoid undefined behavior when using restrict-qualified pointers
EXP44-C Do not rely on side effects in operands to sizeof, _Alignof, or _Generic
EXP45-C Do not perform assignments in selection statements
EXP46-C Do not use a bitwise operator with a Boolean-like operand
Regel 04: Integer
INT30-C Ensure that unsigned integer operations do not wrap
INT31-C Ensure that integer conversions do not result in lost or misinterpreted data
INT32-C Ensure that operations on signed integers do not result in overflow
INT33-C Ensure that division and remainder operations do not result in divide-by-zero errors
INT34-C Do not shift an expression by a negative number of bits
or by greater than or equal to the number of bits that exist in the operand
INT36-C Converting a pointer to integer or integer to pointer
Regel 05: Gleitkommazahlen
FLP30-C Do not use floating-point variables as loop counters
FLP32-C
FLP34-C Ensure that floating-point conversions are within range of the new type
Regel 06: Felder
ARR30-C Do not form or use out-of-bounds pointers or array subscripts
ARR36-C Do not subtract or compare two pointers that do not refer to the same array
ARR37-C Do not add or subtract an integer to a pointer to a non-array object
Regel 07: Zeichen und Strings
STR30-C Do not attempt to modify string literals
STR31-C Guarantee that storage for strings has sufficient space
for character data and the null terminator
STR32-C Do not pass a non-null-terminated character sequence
to a library function that expects a string
STR37-C Arguments to character-handling functions must be
representable as an unsigned char
Regel 08: Speicherverwaltung
MEM30-C Do not access freed memory
MEM31-C Free dynamically allocated memory when no longer needed
MEM34-C Only free memory allocated dynamically
MEM35-C Allocate sufficient memory for an object
Regel 09: Input/Output
FIO37-C Do not assume that fgets() or fgetws()
returns a nonempty string when successful
FIO38-C Do not copy a FILE object
Regel 10: Umgebung
ENV33-C Do not call system()
Regel 11: Signale
SIG30-C Call only asynchronous-safe functions within signal handlers
SIG31-C Do not access shared objects in signal handlers
SIG34-C Do not call signal() from within interruptible signal handlers
Regel 12: Fehlerbehandlung
ERR33-C Detect and handle standard library errors
Regel 14: Nebenläufigkeit
CON32-C Prevent data races when accessing bit-fields from multiple threads
CON33-C Avoid race conditions when using library functions
CON37-C Do not call signal() in a multithreaded program
Regel 48: Verschiedenes
MSC30-C Do not use the rand() function for generating pseudorandom numbers
MSC37-C Ensure that control never reaches the end of a non-void function
Empfehlung 01: Präprozessor
PRE00-C Prefer inline or static functions to function-like macros
PRE01-C Use parentheses within macros around parameter names
PRE05-C Understand macro replacement when concatenating tokens
or performing stringification
PRE06-C Enclose header files in an inclusion guard
PRE07-C Avoid using repeated question marks
Empfehlung 02: Deklarationen und Initialisierung
DCL00-C Const-qualify immutable objects
DCL01-C Do not reuse variable names in subscopes
DCL07-C Include the appropriate type information in function declarators
DCL08-C Properly encode relationships in constant definitions
DCL10-C Maintain the contract between the writer and caller of variadic functions
DCL11-C Understand the type issues associated with variadic functions
DCL13-C Declare function parameters that are pointers to values not changed by the function as const
DCL15-C Declare file-scope objects or functions that do not need external linkage as static
DCL16-C Use L, not l, to indicate a long value
DCL17-C Beware of miscompiled volatile-qualified variables
DCL18-C Do not begin integer constants with 0 when specifying a decimal value
DCL19-C Minimize the scope of variables and functions
DCL20-C Explicitly specify void when a function accepts no arguments
DCL21-C Understand the storage of compound literals
DCL22-C Use volatile for data that cannot be cached
DCL23-C Guarantee that mutually visible identifiers are unique
Empfehlung 03: Ausdrücke
EXP02-C Be aware of the short-circuit behavior of the logical AND and OR operators
EXP03-C Do not assume the size of a structure is the sum of the sizes of its members
EXP08-C Ensure pointer arithmetic is used correctly
EXP10-C Do not depend on the order of evaluation of subexpressions
or the order in which side effects take place
EXP12-C Do not ignore values returned by functions
EXP19-C Use braces for the body of an if, for, or while statement
EXP20-C Perform explicit tests to determine success, true and false, and equality
Empfehlung 04: Integer
INT00-C Understand the data model used by your implementation(s)
INT02-C Understand integer conversion rules
INT07-C Use only explicitly signed or unsigned char type for numeric values
INT08-C Verify that all integer values are in range
INT09-C Ensure enumeration constants map to unique values
INT12-C Do not make assumptions about the type of a plain int bit-field
when used in an expression
INT13-C Use bitwise operators only on unsigned operands
INT18-C Evaluate integer expressions in a larger size before comparing
or assigning to that size
Empfehlung 05: Gleitkommazahlen
FLP00-C Understand the limitations of floating-point numbers
FLP01-C Take care in rearranging floating-point expressions
FLP02-C Avoid using floating-point numbers when precise computation is needed
FLP03-C Detect and handle floating-point errors
FLP04-C Check floating-point inputs for exceptional values
FLP06-C Convert integers to floating point for floating-point operations
Empfehlung 06: Felder
ARR00-C Understand how arrays work
ARR02-C Explicitly specify array bounds, even if implicitly defined by an initializer
Empfehlung 07: Zeichen und Strings
STR00-C Represent characters using an appropriate type
STR04-C Use plain char for characters in the basic character set
STR09-C Don’t assume numeric values for expressions with type plain character
STR11-C Do not specify the bound of a character array initialized with a string literal
Empfehlung 08: Speicherverwaltung
MEM01-C Store a new value in pointers immediately after free()
MEM04-C Beware of zero-length allocations
MEM07-C Ensure that the arguments to calloc(), when multiplied, do not wrap
Empfehlung 09: Input/Output
FIO14-C Understand the difference between text mode and binary mode with file streams
Empfehlung 11: Signale
SIG01-C Understand implementation-specific details regarding signal handler persistence
Empfehlung 12: Fehlerbehandlung
ERR06-C Understand the termination behavior of assert() and abort()
Empfehlung 14: Nebenläufigkeit
CON00-C Avoid race conditions with multiple threads
CON01-C Acquire and release synchronization primitives in the same module,
at the same level of abstraction
CON03-C Ensure visibility when accessing shared variables
CON06-C Ensure that every mutex outlives the data it protects
Empfehlung 15: Nebenläufigkeit (POSIX)
CON00-C Avoid race conditions with multiple threads
Empfehlung 48: Verschiedenes
MSC01-C Strive for logical completeness
MSC04-C Use comments consistently and in a readable fashion
MSC07-C Detect and remove dead code
MSC12-C Detect and remove code that has no effect or is never executed
MSC13-C Detect and remove unused values
MSC15-C Do not depend on undefined behavior
MSC17-C Finish every set of statements associated with a case label
with a break statement
MSC20-C Do not use a switch statement to transfer control into a complex block
MSC23-C Beware of vendor-specific library and language differences
MSC24-C Do not use deprecated or obsolescent functions
Empfehlung 51: Microsoft Windows
WIN03-C Understand HANDLE inheritance

MISRA C

RuleChecker-Screenshot

Astrée unterstützt sowohl MISRA-C:2004 als auch MISRA-C:2012 (inklusive Zusatz 1). Die Checks sind vielfältig kon­figurierbar. Jede Regel und sogar einzelne Aspekte bestimmter Regeln können individuell hinzu­geschaltet werden.

Das aktuelle Release überprüft insgesamt 277 Regeln. Eine elfseitige PDF-Beschreibung, wie Astrée jede einzelne Regel behandelt, ist auf Anfrage kostenlos erhältlich. Kontaktieren Sie dazu info@absint.com.

Nachfolgend ist nur ein schneller Überblick all der unterstützten Regelkategorien.

MISRA-C:2004
1Environment
2Language extensions
3Documentation
4Character sets
5Identifiers
6Types
7Constants
8Declarations and definitions
9Initialization
10Arithmetic type conversions
11Pointer type conversions
12Expressions
13Control statement expressions
14Control flow
15Switch statements
16Functions
17Pointers and arrays
18Structures and unions
19Preprocessing directives
20Standard libraries
21Run-time failures
MISRA-C:2012
DDirectives
1A standard C environment
2Unused code
3Comments
4Character sets and lexical convention
5Identifiers
6Types
7Literals and constants
8Declarations and definitions
9Initialization
10The essential type model
11Pointer type conversions
12Expressions
13Side effects
14Control statement expressions
15Control flow
16Switch statements
17Functions
18Pointers and arrays
19Overlapping storage
20Preprocessing directives
21Standard libraries
22Resources
MISRA-C:2012 Amendment 1
12Expressions
21Standard libraries
MISRA-C++:2008
Unterstützung für C++ ist seit dem neuesten Release 18.04 erhältlich. Die meisten MISRA-C++:2008-Regeln werden bereits unterstützt.

ISO/IEC TS 17961:2013

Die folgende Tabelle listet die von Astrée 16.10 unterstützten Regeln der ISO/IEC-TS-17961:2013-Norm. Die aus­gegrauten Einträge werden nur teilweise unterstützt. Weitere Details erhalten Sie auf Anfrage bei info@absint.com.

2Accessing freed memory
6Calling functions with incorrect arguments
10Converting a pointer to integer or integer to pointer
11Converting pointer values to more strictly aligned pointer types
12Copying a FILE object
13Declaring the same function or object in incompatible ways
14Dereferencing an out-of-domain pointer
15Escaping of the address of an automatic object
17Use of an implied default in a switch statement
21Allocating insufficient memory
22Forming or using out-of-bounds pointers or array subscripts
23Freeing memory multiple times
26Integer division errors
28Modifying string literals
29Modifying the string returned by getenv, localeconv, setlocale, and strerror
30Overflowing signed integers
34Reallocating or freeing memory that was not dynamically allocated
35Referencing uninitialized memory
36Subtracting or comparing two pointers that do not refer to the same array
38Taking the size of a pointer to determine the size of the pointed-to type
39Using a tainted value as an argument to an unprototyped function pointer
44Using identifiers that are reserved for the implementation
46Tainted, potentially mutilated, or out-of-domain integer values are used in a restricted sink