summaryrefslogtreecommitdiffstats
path: root/Python
diff options
context:
space:
mode:
Diffstat (limited to 'Python')
-rw-r--r--Python/pythonrun.c8
-rw-r--r--Python/random.c302
-rw-r--r--Python/sysmodule.c6
3 files changed, 314 insertions, 2 deletions
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index c4ae921..4474e79 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -73,6 +73,7 @@ extern void _PyUnicode_Init(void);
extern void _PyUnicode_Fini(void);
extern int _PyLong_Init(void);
extern void PyLong_Fini(void);
+extern void _PyRandom_Init(void);
#ifdef WITH_THREAD
extern void _PyGILState_Init(PyInterpreterState *, PyThreadState *);
@@ -91,6 +92,7 @@ int Py_FrozenFlag; /* Needed by getpath.c */
int Py_IgnoreEnvironmentFlag; /* e.g. PYTHONPATH, PYTHONHOME */
int Py_NoUserSiteDirectory = 0; /* for -s and site.py */
int Py_UnbufferedStdioFlag = 0; /* Unbuffered binary std{in,out,err} */
+int Py_HashRandomizationFlag = 0; /* for -R and PYTHONHASHSEED */
/* PyModule_GetWarningsModule is no longer necessary as of 2.6
since _warnings is builtin. This API should not be used. */
@@ -195,6 +197,12 @@ Py_InitializeEx(int install_sigs)
Py_OptimizeFlag = add_flag(Py_OptimizeFlag, p);
if ((p = Py_GETENV("PYTHONDONTWRITEBYTECODE")) && *p != '\0')
Py_DontWriteBytecodeFlag = add_flag(Py_DontWriteBytecodeFlag, p);
+ /* The variable is only tested for existence here; _PyRandom_Init will
+ check its value further. */
+ if ((p = Py_GETENV("PYTHONHASHSEED")) && *p != '\0')
+ Py_HashRandomizationFlag = add_flag(Py_HashRandomizationFlag, p);
+
+ _PyRandom_Init();
interp = PyInterpreterState_New();
if (interp == NULL)
diff --git a/Python/random.c b/Python/random.c
new file mode 100644
index 0000000..327166e
--- /dev/null
+++ b/Python/random.c
@@ -0,0 +1,302 @@
+#include "Python.h"
+#ifdef MS_WINDOWS
+#include <windows.h>
+#else
+#include <fcntl.h>
+#endif
+
+static int random_initialized = 0;
+
+#ifdef MS_WINDOWS
+typedef BOOL (WINAPI *CRYPTACQUIRECONTEXTA)(HCRYPTPROV *phProv,\
+ LPCSTR pszContainer, LPCSTR pszProvider, DWORD dwProvType,\
+ DWORD dwFlags );
+typedef BOOL (WINAPI *CRYPTGENRANDOM)(HCRYPTPROV hProv, DWORD dwLen,\
+ BYTE *pbBuffer );
+
+static CRYPTGENRANDOM pCryptGenRandom = NULL;
+/* This handle is never explicitly released. Instead, the operating
+ system will release it when the process terminates. */
+static HCRYPTPROV hCryptProv = 0;
+
+static int
+win32_urandom_init(int raise)
+{
+ HINSTANCE hAdvAPI32 = NULL;
+ CRYPTACQUIRECONTEXTA pCryptAcquireContext = NULL;
+
+ /* Obtain handle to the DLL containing CryptoAPI. This should not fail. */
+ hAdvAPI32 = GetModuleHandle("advapi32.dll");
+ if(hAdvAPI32 == NULL)
+ goto error;
+
+ /* Obtain pointers to the CryptoAPI functions. This will fail on some early
+ versions of Win95. */
+ pCryptAcquireContext = (CRYPTACQUIRECONTEXTA)GetProcAddress(
+ hAdvAPI32, "CryptAcquireContextA");
+ if (pCryptAcquireContext == NULL)
+ goto error;
+
+ pCryptGenRandom = (CRYPTGENRANDOM)GetProcAddress(hAdvAPI32,
+ "CryptGenRandom");
+ if (pCryptGenRandom == NULL)
+ goto error;
+
+ /* Acquire context */
+ if (! pCryptAcquireContext(&hCryptProv, NULL, NULL,
+ PROV_RSA_FULL, CRYPT_VERIFYCONTEXT))
+ goto error;
+
+ return 0;
+
+error:
+ if (raise)
+ PyErr_SetFromWindowsErr(0);
+ else
+ Py_FatalError("Failed to initialize Windows random API (CryptoGen)");
+ return -1;
+}
+
+/* Fill buffer with size pseudo-random bytes generated by the Windows CryptoGen
+ API. Return 0 on success, or -1 on error. */
+static int
+win32_urandom(unsigned char *buffer, Py_ssize_t size, int raise)
+{
+ Py_ssize_t chunk;
+
+ if (hCryptProv == 0)
+ {
+ if (win32_urandom_init(raise) == -1)
+ return -1;
+ }
+
+ while (size > 0)
+ {
+ chunk = size > INT_MAX ? INT_MAX : size;
+ if (!pCryptGenRandom(hCryptProv, chunk, buffer))
+ {
+ /* CryptGenRandom() failed */
+ if (raise)
+ PyErr_SetFromWindowsErr(0);
+ else
+ Py_FatalError("Failed to initialized the randomized hash "
+ "secret using CryptoGen)");
+ return -1;
+ }
+ buffer += chunk;
+ size -= chunk;
+ }
+ return 0;
+}
+#endif /* MS_WINDOWS */
+
+
+#ifdef __VMS
+/* Use openssl random routine */
+#include <openssl/rand.h>
+static int
+vms_urandom(unsigned char *buffer, Py_ssize_t size, int raise)
+{
+ if (RAND_pseudo_bytes(buffer, size) < 0) {
+ if (raise) {
+ PyErr_Format(PyExc_ValueError,
+ "RAND_pseudo_bytes");
+ } else {
+ Py_FatalError("Failed to initialize the randomized hash "
+ "secret using RAND_pseudo_bytes");
+ }
+ return -1;
+ }
+ return 0;
+}
+#endif /* __VMS */
+
+
+#if !defined(MS_WINDOWS) && !defined(__VMS)
+
+/* Read size bytes from /dev/urandom into buffer.
+ Call Py_FatalError() on error. */
+static void
+dev_urandom_noraise(char *buffer, Py_ssize_t size)
+{
+ int fd;
+ Py_ssize_t n;
+
+ assert (0 < size);
+
+ fd = open("/dev/urandom", O_RDONLY);
+ if (fd < 0)
+ Py_FatalError("Failed to open /dev/urandom");
+
+ 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 */
+ Py_FatalError("Failed to read bytes from /dev/urandom");
+ break;
+ }
+ buffer += n;
+ size -= (Py_ssize_t)n;
+ }
+ close(fd);
+}
+
+/* Read size bytes from /dev/urandom into buffer.
+ Return 0 on success, raise an exception and return -1 on error. */
+static int
+dev_urandom_python(char *buffer, Py_ssize_t size)
+{
+ int fd;
+ Py_ssize_t n;
+
+ if (size <= 0)
+ return 0;
+
+ Py_BEGIN_ALLOW_THREADS
+ fd = open("/dev/urandom", O_RDONLY);
+ Py_END_ALLOW_THREADS
+ if (fd < 0)
+ {
+ PyErr_SetFromErrnoWithFilename(PyExc_OSError, "/dev/urandom");
+ return -1;
+ }
+
+ Py_BEGIN_ALLOW_THREADS
+ do {
+ do {
+ n = read(fd, buffer, (size_t)size);
+ } while (n < 0 && errno == EINTR);
+ if (n <= 0)
+ break;
+ buffer += n;
+ size -= (Py_ssize_t)n;
+ } while (0 < size);
+ Py_END_ALLOW_THREADS
+
+ if (n <= 0)
+ {
+ /* stop on error or if read(size) returned 0 */
+ if (n < 0)
+ PyErr_SetFromErrno(PyExc_OSError);
+ else
+ PyErr_Format(PyExc_RuntimeError,
+ "Failed to read %zi bytes from /dev/urandom",
+ size);
+ close(fd);
+ return -1;
+ }
+ close(fd);
+ return 0;
+}
+#endif /* !defined(MS_WINDOWS) && !defined(__VMS) */
+
+/* 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;
+ }
+}
+
+/* Fill buffer with size pseudo-random bytes, not suitable for cryptographic
+ use, from the operating random number generator (RNG).
+
+ Return 0 on success, raise an exception and return -1 on error. */
+int
+_PyOS_URandom(void *buffer, Py_ssize_t size)
+{
+ if (size < 0) {
+ 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, 1);
+#else
+# ifdef __VMS
+ return vms_urandom((unsigned char *)buffer, size, 1);
+# else
+ return dev_urandom_python((char*)buffer, size);
+# endif
+#endif
+}
+
+void
+_PyRandom_Init(void)
+{
+ char *env;
+ void *secret = &_Py_HashSecret;
+ Py_ssize_t secret_size = sizeof(_Py_HashSecret);
+
+ if (random_initialized)
+ return;
+ random_initialized = 1;
+
+ /*
+ By default, hash randomization is disabled, and only
+ enabled if PYTHONHASHSEED is set to non-empty or if
+ "-R" is provided at the command line:
+ */
+ if (!Py_HashRandomizationFlag) {
+ /* Disable the randomized hash: */
+ memset(secret, 0, secret_size);
+ return;
+ }
+
+ /*
+ Hash randomization is enabled. Generate a per-process secret,
+ using PYTHONHASHSEED if provided.
+ */
+
+ env = Py_GETENV("PYTHONHASHSEED");
+ if (env && *env != '\0' & strcmp(env, "random") != 0) {
+ char *endptr = env;
+ unsigned long seed;
+ seed = strtoul(env, &endptr, 10);
+ if (*endptr != '\0'
+ || seed > 4294967295UL
+ || (errno == ERANGE && seed == ULONG_MAX))
+ {
+ Py_FatalError("PYTHONHASHSEED must be \"random\" or an integer "
+ "in range [0; 4294967295]");
+ }
+ if (seed == 0) {
+ /* disable the randomized hash */
+ memset(secret, 0, secret_size);
+ }
+ else {
+ lcg_urandom(seed, (unsigned char*)secret, secret_size);
+ }
+ }
+ else {
+#ifdef MS_WINDOWS
+ (void)win32_urandom((unsigned char *)secret, secret_size, 0);
+#else /* #ifdef MS_WINDOWS */
+# ifdef __VMS
+ vms_urandom((unsigned char *)secret, secret_size, 0);
+# else
+ dev_urandom_noraise((char*)secret, secret_size);
+# endif
+#endif
+ }
+}
diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index c688172..6a7e914 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -1126,6 +1126,7 @@ static PyStructSequence_Field flags_fields[] = {
/* {"unbuffered", "-u"}, */
/* {"skip_first", "-x"}, */
{"bytes_warning", "-b"},
+ {"hash_randomization", "-R"},
{0}
};
@@ -1134,9 +1135,9 @@ static PyStructSequence_Desc flags_desc = {
flags__doc__, /* doc */
flags_fields, /* fields */
#ifdef RISCOS
- 12
+ 13
#else
- 11
+ 12
#endif
};
@@ -1169,6 +1170,7 @@ make_flags(void)
/* SetFlag(saw_unbuffered_flag); */
/* SetFlag(skipfirstline); */
SetFlag(Py_BytesWarningFlag);
+ SetFlag(Py_HashRandomizationFlag);
#undef SetFlag
if (PyErr_Occurred()) {
generated by cgit v0.12 at 2024-11-17 13:04:56 (GMT)