diff options
| author | nkozlovskiy <[email protected]> | 2023-09-29 12:24:06 +0300 | 
|---|---|---|
| committer | nkozlovskiy <[email protected]> | 2023-09-29 12:41:34 +0300 | 
| commit | e0e3e1717e3d33762ce61950504f9637a6e669ed (patch) | |
| tree | bca3ff6939b10ed60c3d5c12439963a1146b9711 /contrib/tools/python3/src/Python/bootstrap_hash.c | |
| parent | 38f2c5852db84c7b4d83adfcb009eb61541d1ccd (diff) | |
add ydb deps
Diffstat (limited to 'contrib/tools/python3/src/Python/bootstrap_hash.c')
| -rw-r--r-- | contrib/tools/python3/src/Python/bootstrap_hash.c | 598 | 
1 files changed, 598 insertions, 0 deletions
diff --git a/contrib/tools/python3/src/Python/bootstrap_hash.c b/contrib/tools/python3/src/Python/bootstrap_hash.c new file mode 100644 index 00000000000..1724e31bf4e --- /dev/null +++ b/contrib/tools/python3/src/Python/bootstrap_hash.c @@ -0,0 +1,598 @@ +#include "Python.h" +#include "pycore_initconfig.h" +#include "pycore_fileutils.h"     // _Py_fstat_noraise() + +#ifdef MS_WINDOWS +#  include <windows.h> +#  include <bcrypt.h> +#else +#  include <fcntl.h> +#  ifdef HAVE_SYS_STAT_H +#    include <sys/stat.h> +#  endif +#  ifdef HAVE_LINUX_RANDOM_H +#    include <linux/random.h> +#  endif +#  if defined(HAVE_SYS_RANDOM_H) && (defined(HAVE_GETRANDOM) || defined(HAVE_GETENTROPY)) +#    include <sys/random.h> +#  endif +#  if !defined(HAVE_GETRANDOM) && defined(HAVE_GETRANDOM_SYSCALL) +#    include <sys/syscall.h> +#  endif +#endif + +#ifdef _Py_MEMORY_SANITIZER +#  include <sanitizer/msan_interface.h> +#endif + +#if defined(__APPLE__) && defined(__has_builtin) +#  if __has_builtin(__builtin_available) +#    define HAVE_GETENTRYPY_GETRANDOM_RUNTIME __builtin_available(macOS 10.12, iOS 10.10, tvOS 10.0, watchOS 3.0, *) +#  endif +#endif +#ifndef HAVE_GETENTRYPY_GETRANDOM_RUNTIME +#  define HAVE_GETENTRYPY_GETRANDOM_RUNTIME 1 +#endif + + +#ifdef Py_DEBUG +int _Py_HashSecret_Initialized = 0; +#else +static int _Py_HashSecret_Initialized = 0; +#endif + +#ifdef MS_WINDOWS + +/* Fill buffer with size pseudo-random bytes generated by the Windows CryptoGen +   API. Return 0 on success, or raise an exception and return -1 on error. */ +static int +win32_urandom(unsigned char *buffer, Py_ssize_t size, int raise) +{ +    while (size > 0) +    { +        DWORD chunk = (DWORD)Py_MIN(size, PY_DWORD_MAX); +        NTSTATUS status = BCryptGenRandom(NULL, buffer, chunk, BCRYPT_USE_SYSTEM_PREFERRED_RNG); +        if (!BCRYPT_SUCCESS(status)) { +            /* BCryptGenRandom() failed */ +            if (raise) { +                PyErr_SetFromWindowsErr(0); +            } +            return -1; +        } +        buffer += chunk; +        size -= chunk; +    } +    return 0; +} + +#else /* !MS_WINDOWS */ + +#if defined(HAVE_GETRANDOM) || defined(HAVE_GETRANDOM_SYSCALL) +#define PY_GETRANDOM 1 + +/* Call getrandom() to get random bytes: + +   - Return 1 on success +   - Return 0 if getrandom() is not available (failed with ENOSYS or EPERM), +     or if getrandom(GRND_NONBLOCK) failed with EAGAIN (system urandom not +     initialized yet) and raise=0. +   - Raise an exception (if raise is non-zero) and return -1 on error: +     if getrandom() failed with EINTR, raise is non-zero and the Python signal +     handler raised an exception, or if getrandom() failed with a different +     error. + +   getrandom() is retried if it failed with EINTR: interrupted by a signal. */ +static int +py_getrandom(void *buffer, Py_ssize_t size, int blocking, int raise) +{ +    /* Is getrandom() supported by the running kernel? Set to 0 if getrandom() +       failed with ENOSYS or EPERM. Need Linux kernel 3.17 or newer, or Solaris +       11.3 or newer */ +    static int getrandom_works = 1; +    int flags; +    char *dest; +    long n; + +    if (!getrandom_works) { +        return 0; +    } + +    flags = blocking ? 0 : GRND_NONBLOCK; +    dest = buffer; +    while (0 < size) { +#if defined(__sun) && defined(__SVR4) +        /* Issue #26735: On Solaris, getrandom() is limited to returning up +           to 1024 bytes. Call it multiple times if more bytes are +           requested. */ +        n = Py_MIN(size, 1024); +#else +        n = Py_MIN(size, LONG_MAX); +#endif + +        errno = 0; +#ifdef HAVE_GETRANDOM +        if (raise) { +            Py_BEGIN_ALLOW_THREADS +            n = getrandom(dest, n, flags); +            Py_END_ALLOW_THREADS +        } +        else { +            n = getrandom(dest, n, flags); +        } +#  ifdef _Py_MEMORY_SANITIZER +        if (n > 0) { +             __msan_unpoison(dest, n); +        } +#  endif +#else +        /* On Linux, use the syscall() function because the GNU libc doesn't +           expose the Linux getrandom() syscall yet. See: +           https://sourceware.org/bugzilla/show_bug.cgi?id=17252 */ +        if (raise) { +            Py_BEGIN_ALLOW_THREADS +            n = syscall(SYS_getrandom, dest, n, flags); +            Py_END_ALLOW_THREADS +        } +        else { +            n = syscall(SYS_getrandom, dest, n, flags); +        } +#  ifdef _Py_MEMORY_SANITIZER +        if (n > 0) { +             __msan_unpoison(dest, n); +        } +#  endif +#endif + +        if (n < 0) { +            /* ENOSYS: the syscall is not supported by the kernel. +               EPERM: the syscall is blocked by a security policy (ex: SECCOMP) +               or something else. */ +            if (errno == ENOSYS || errno == EPERM) { +                getrandom_works = 0; +                return 0; +            } + +            /* getrandom(GRND_NONBLOCK) fails with EAGAIN if the system urandom +               is not initialized yet. For _PyRandom_Init(), we ignore the +               error and fall back on reading /dev/urandom which never blocks, +               even if the system urandom is not initialized yet: +               see the PEP 524. */ +            if (errno == EAGAIN && !raise && !blocking) { +                return 0; +            } + +            if (errno == EINTR) { +                if (raise) { +                    if (PyErr_CheckSignals()) { +                        return -1; +                    } +                } + +                /* retry getrandom() if it was interrupted by a signal */ +                continue; +            } + +            if (raise) { +                PyErr_SetFromErrno(PyExc_OSError); +            } +            return -1; +        } + +        dest += n; +        size -= n; +    } +    return 1; +} + +#elif defined(HAVE_GETENTROPY) +#define PY_GETENTROPY 1 + +/* Fill buffer with size pseudo-random bytes generated by getentropy(): + +   - Return 1 on success +   - Return 0 if getentropy() syscall is not available (failed with ENOSYS or +     EPERM). +   - Raise an exception (if raise is non-zero) and return -1 on error: +     if getentropy() failed with EINTR, raise is non-zero and the Python signal +     handler raised an exception, or if getentropy() failed with a different +     error. + +   getentropy() is retried if it failed with EINTR: interrupted by a signal. */ + +#if defined(__APPLE__) && defined(__has_attribute) && __has_attribute(availability) +static int +py_getentropy(char *buffer, Py_ssize_t size, int raise) +        __attribute__((availability(macos,introduced=10.12))) +        __attribute__((availability(ios,introduced=10.0))) +        __attribute__((availability(tvos,introduced=10.0))) +        __attribute__((availability(watchos,introduced=3.0))); +#endif + +static int +py_getentropy(char *buffer, Py_ssize_t size, int raise) +{ +    /* Is getentropy() supported by the running kernel? Set to 0 if +       getentropy() failed with ENOSYS or EPERM. */ +    static int getentropy_works = 1; + +    if (!getentropy_works) { +        return 0; +    } + +    while (size > 0) { +        /* getentropy() is limited to returning up to 256 bytes. Call it +           multiple times if more bytes are requested. */ +        Py_ssize_t len = Py_MIN(size, 256); +        int res; + +        if (raise) { +            Py_BEGIN_ALLOW_THREADS +            res = getentropy(buffer, len); +            Py_END_ALLOW_THREADS +        } +        else { +            res = getentropy(buffer, len); +        } + +        if (res < 0) { +            /* ENOSYS: the syscall is not supported by the running kernel. +               EPERM: the syscall is blocked by a security policy (ex: SECCOMP) +               or something else. */ +            if (errno == ENOSYS || errno == EPERM) { +                getentropy_works = 0; +                return 0; +            } + +            if (errno == EINTR) { +                if (raise) { +                    if (PyErr_CheckSignals()) { +                        return -1; +                    } +                } + +                /* retry getentropy() if it was interrupted by a signal */ +                continue; +            } + +            if (raise) { +                PyErr_SetFromErrno(PyExc_OSError); +            } +            return -1; +        } + +        buffer += len; +        size -= len; +    } +    return 1; +} +#endif /* defined(HAVE_GETENTROPY) && !(defined(__sun) && defined(__SVR4)) */ + + +static struct { +    int fd; +    dev_t st_dev; +    ino_t st_ino; +} urandom_cache = { -1 }; + +/* Read random bytes from the /dev/urandom device: + +   - Return 0 on success +   - Raise an exception (if raise is non-zero) and return -1 on error + +   Possible causes of errors: + +   - open() failed with ENOENT, ENXIO, ENODEV, EACCES: the /dev/urandom device +     was not found. For example, it was removed manually or not exposed in a +     chroot or container. +   - open() failed with a different error +   - fstat() failed +   - read() failed or returned 0 + +   read() is retried if it failed with EINTR: interrupted by a signal. + +   The file descriptor of the device is kept open between calls to avoid using +   many file descriptors when run in parallel from multiple threads: +   see the issue #18756. + +   st_dev and st_ino fields of the file descriptor (from fstat()) are cached to +   check if the file descriptor was replaced by a different file (which is +   likely a bug in the application): see the issue #21207. + +   If the file descriptor was closed or replaced, open a new file descriptor +   but don't close the old file descriptor: it probably points to something +   important for some third-party code. */ +static int +dev_urandom(char *buffer, Py_ssize_t size, int raise) +{ +    int fd; +    Py_ssize_t n; + +    if (raise) { +        struct _Py_stat_struct st; +        int fstat_result; + +        if (urandom_cache.fd >= 0) { +            Py_BEGIN_ALLOW_THREADS +            fstat_result = _Py_fstat_noraise(urandom_cache.fd, &st); +            Py_END_ALLOW_THREADS + +            /* Does the fd point to the same thing as before? (issue #21207) */ +            if (fstat_result +                || st.st_dev != urandom_cache.st_dev +                || st.st_ino != urandom_cache.st_ino) { +                /* Something changed: forget the cached fd (but don't close it, +                   since it probably points to something important for some +                   third-party code). */ +                urandom_cache.fd = -1; +            } +        } +        if (urandom_cache.fd >= 0) +            fd = urandom_cache.fd; +        else { +            fd = _Py_open("/dev/urandom", O_RDONLY); +            if (fd < 0) { +                if (errno == ENOENT || errno == ENXIO || +                    errno == ENODEV || errno == EACCES) { +                    PyErr_SetString(PyExc_NotImplementedError, +                                    "/dev/urandom (or equivalent) not found"); +                } +                /* otherwise, keep the OSError exception raised by _Py_open() */ +                return -1; +            } +            if (urandom_cache.fd >= 0) { +                /* urandom_fd was initialized by another thread while we were +                   not holding the GIL, keep it. */ +                close(fd); +                fd = urandom_cache.fd; +            } +            else { +                if (_Py_fstat(fd, &st)) { +                    close(fd); +                    return -1; +                } +                else { +                    urandom_cache.fd = fd; +                    urandom_cache.st_dev = st.st_dev; +                    urandom_cache.st_ino = st.st_ino; +                } +            } +        } + +        do { +            n = _Py_read(fd, buffer, (size_t)size); +            if (n == -1) +                return -1; +            if (n == 0) { +                PyErr_Format(PyExc_RuntimeError, +                        "Failed to read %zi bytes from /dev/urandom", +                        size); +                return -1; +            } + +            buffer += n; +            size -= n; +        } while (0 < size); +    } +    else { +        fd = _Py_open_noraise("/dev/urandom", O_RDONLY); +        if (fd < 0) { +            return -1; +        } + +        while (0 < size) +        { +            do { +                n = read(fd, buffer, (size_t)size); +            } while (n < 0 && errno == EINTR); + +            if (n <= 0) { +                /* stop on error or if read(size) returned 0 */ +                close(fd); +                return -1; +            } + +            buffer += n; +            size -= n; +        } +        close(fd); +    } +    return 0; +} + +static void +dev_urandom_close(void) +{ +    if (urandom_cache.fd >= 0) { +        close(urandom_cache.fd); +        urandom_cache.fd = -1; +    } +} +#endif /* !MS_WINDOWS */ + + +/* Fill buffer with pseudo-random bytes generated by a linear congruent +   generator (LCG): + +       x(n+1) = (x(n) * 214013 + 2531011) % 2^32 + +   Use bits 23..16 of x(n) to generate a byte. */ +static void +lcg_urandom(unsigned int x0, unsigned char *buffer, size_t size) +{ +    size_t index; +    unsigned int x; + +    x = x0; +    for (index=0; index < size; index++) { +        x *= 214013; +        x += 2531011; +        /* modulo 2 ^ (8 * sizeof(int)) */ +        buffer[index] = (x >> 16) & 0xff; +    } +} + +/* Read random bytes: + +   - Return 0 on success +   - Raise an exception (if raise is non-zero) and return -1 on error + +   Used sources of entropy ordered by preference, preferred source first: + +   - BCryptGenRandom() on Windows +   - getrandom() function (ex: Linux and Solaris): call py_getrandom() +   - getentropy() function (ex: OpenBSD): call py_getentropy() +   - /dev/urandom device + +   Read from the /dev/urandom device if getrandom() or getentropy() function +   is not available or does not work. + +   Prefer getrandom() over getentropy() because getrandom() supports blocking +   and non-blocking mode: see the PEP 524. Python requires non-blocking RNG at +   startup to initialize its hash secret, but os.urandom() must block until the +   system urandom is initialized (at least on Linux 3.17 and newer). + +   Prefer getrandom() and getentropy() over reading directly /dev/urandom +   because these functions don't need file descriptors and so avoid ENFILE or +   EMFILE errors (too many open files): see the issue #18756. + +   Only the getrandom() function supports non-blocking mode. + +   Only use RNG running in the kernel. They are more secure because it is +   harder to get the internal state of a RNG running in the kernel land than a +   RNG running in the user land. The kernel has a direct access to the hardware +   and has access to hardware RNG, they are used as entropy sources. + +   Note: the OpenSSL RAND_pseudo_bytes() function does not automatically reseed +   its RNG on fork(), two child processes (with the same pid) generate the same +   random numbers: see issue #18747. Kernel RNGs don't have this issue, +   they have access to good quality entropy sources. + +   If raise is zero: + +   - Don't raise an exception on error +   - Don't call the Python signal handler (don't call PyErr_CheckSignals()) if +     a function fails with EINTR: retry directly the interrupted function +   - Don't release the GIL to call functions. +*/ +static int +pyurandom(void *buffer, Py_ssize_t size, int blocking, int raise) +{ +#if defined(PY_GETRANDOM) || defined(PY_GETENTROPY) +    int res; +#endif + +    if (size < 0) { +        if (raise) { +            PyErr_Format(PyExc_ValueError, +                         "negative argument not allowed"); +        } +        return -1; +    } + +    if (size == 0) { +        return 0; +    } + +#ifdef MS_WINDOWS +    return win32_urandom((unsigned char *)buffer, size, raise); +#else + +#if defined(PY_GETRANDOM) || defined(PY_GETENTROPY) +    if (HAVE_GETENTRYPY_GETRANDOM_RUNTIME) { +#ifdef PY_GETRANDOM +        res = py_getrandom(buffer, size, blocking, raise); +#else +        res = py_getentropy(buffer, size, raise); +#endif +        if (res < 0) { +            return -1; +        } +        if (res == 1) { +            return 0; +        } +        /* getrandom() or getentropy() function is not available: failed with +           ENOSYS or EPERM. Fall back on reading from /dev/urandom. */ +        } /* end of availability block */ +#endif + +    return dev_urandom(buffer, size, raise); +#endif +} + +/* Fill buffer with size pseudo-random bytes from the operating system random +   number generator (RNG). It is suitable for most cryptographic purposes +   except long living private keys for asymmetric encryption. + +   On Linux 3.17 and newer, the getrandom() syscall is used in blocking mode: +   block until the system urandom entropy pool is initialized (128 bits are +   collected by the kernel). + +   Return 0 on success. Raise an exception and return -1 on error. */ +int +_PyOS_URandom(void *buffer, Py_ssize_t size) +{ +    return pyurandom(buffer, size, 1, 1); +} + +/* Fill buffer with size pseudo-random bytes from the operating system random +   number generator (RNG). It is not suitable for cryptographic purpose. + +   On Linux 3.17 and newer (when getrandom() syscall is used), if the system +   urandom is not initialized yet, the function returns "weak" entropy read +   from /dev/urandom. + +   Return 0 on success. Raise an exception and return -1 on error. */ +int +_PyOS_URandomNonblock(void *buffer, Py_ssize_t size) +{ +    return pyurandom(buffer, size, 0, 1); +} + + +PyStatus +_Py_HashRandomization_Init(const PyConfig *config) +{ +    void *secret = &_Py_HashSecret; +    Py_ssize_t secret_size = sizeof(_Py_HashSecret_t); + +    if (_Py_HashSecret_Initialized) { +        return _PyStatus_OK(); +    } +    _Py_HashSecret_Initialized = 1; + +    if (config->use_hash_seed) { +        if (config->hash_seed == 0) { +            /* disable the randomized hash */ +            memset(secret, 0, secret_size); +        } +        else { +            /* use the specified hash seed */ +            lcg_urandom(config->hash_seed, secret, secret_size); +        } +    } +    else { +        /* use a random hash seed */ +        int res; + +        /* _PyRandom_Init() is called very early in the Python initialization +           and so exceptions cannot be used (use raise=0). + +           _PyRandom_Init() must not block Python initialization: call +           pyurandom() is non-blocking mode (blocking=0): see the PEP 524. */ +        res = pyurandom(secret, secret_size, 0, 0); +        if (res < 0) { +            return _PyStatus_ERR("failed to get random numbers " +                                 "to initialize Python"); +        } +    } +    return _PyStatus_OK(); +} + + +void +_Py_HashRandomization_Fini(void) +{ +#ifndef MS_WINDOWS +    dev_urandom_close(); +#endif +}  | 
