Adding upstream version 115.8.0esr.upstream/115.8.0esr

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 879 insertions, 0 deletions

diff --git a/security/nss/lib/util/secport.c b/security/nss/lib/util/secport.c
new file mode 100644
index 0000000000..fb5223d64a
--- /dev/null
+++ b/security/nss/lib/util/secport.c
@@ -0,0 +1,879 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * secport.c - portability interfaces for security libraries
+ *
+ * This file abstracts out libc functionality that libsec depends on
+ *
+ * NOTE - These are not public interfaces
+ */
+
+#include "seccomon.h"
+#include "prmem.h"
+#include "prerror.h"
+#include "plarena.h"
+#include "secerr.h"
+#include "prmon.h"
+#include "nssilock.h"
+#include "secport.h"
+#include "prenv.h"
+#include "prinit.h"
+
+#include <stdint.h>
+
+#ifdef DEBUG
+#define THREADMARK
+#endif /* DEBUG */
+
+#ifdef THREADMARK
+#include "prthread.h"
+#endif /* THREADMARK */
+
+#if defined(XP_UNIX) || defined(XP_OS2)
+#include <stdlib.h>
+#else
+#include "wtypes.h"
+#endif
+
+#define SET_ERROR_CODE /* place holder for code to set PR error code. */
+
+#ifdef THREADMARK
+typedef struct threadmark_mark_str {
+    struct threadmark_mark_str *next;
+    void *mark;
+} threadmark_mark;
+
+#endif /* THREADMARK */
+
+/* The value of this magic must change each time PORTArenaPool changes. */
+#define ARENAPOOL_MAGIC 0xB8AC9BDF
+
+#define CHEAP_ARENAPOOL_MAGIC 0x3F16BB09
+
+typedef struct PORTArenaPool_str {
+    PLArenaPool arena;
+    PRUint32 magic;
+    PRLock *lock;
+#ifdef THREADMARK
+    PRThread *marking_thread;
+    threadmark_mark *first_mark;
+#endif
+} PORTArenaPool;
+
+/* locations for registering Unicode conversion functions.
+ * XXX is this the appropriate location?  or should they be
+ *     moved to client/server specific locations?
+ */
+PORTCharConversionFunc ucs4Utf8ConvertFunc;
+PORTCharConversionFunc ucs2Utf8ConvertFunc;
+PORTCharConversionWSwapFunc ucs2AsciiConvertFunc;
+
+/* NSPR memory allocation functions (PR_Malloc, PR_Calloc, and PR_Realloc)
+ * use the PRUint32 type for the size parameter. Before we pass a size_t or
+ * unsigned long size to these functions, we need to ensure it is <= half of
+ * the maximum PRUint32 value to avoid truncation and catch a negative size.
+ */
+#define MAX_SIZE (PR_UINT32_MAX >> 1)
+
+void *
+PORT_Alloc(size_t bytes)
+{
+    void *rv = NULL;
+
+    if (bytes <= MAX_SIZE) {
+        /* Always allocate a non-zero amount of bytes */
+        rv = PR_Malloc(bytes ? bytes : 1);
+    }
+    if (!rv) {
+        PORT_SetError(SEC_ERROR_NO_MEMORY);
+    }
+    return rv;
+}
+
+void *
+PORT_Realloc(void *oldptr, size_t bytes)
+{
+    void *rv = NULL;
+
+    if (bytes <= MAX_SIZE) {
+        rv = PR_Realloc(oldptr, bytes);
+    }
+    if (!rv) {
+        PORT_SetError(SEC_ERROR_NO_MEMORY);
+    }
+    return rv;
+}
+
+void *
+PORT_ZAlloc(size_t bytes)
+{
+    void *rv = NULL;
+
+    if (bytes <= MAX_SIZE) {
+        /* Always allocate a non-zero amount of bytes */
+        rv = PR_Calloc(1, bytes ? bytes : 1);
+    }
+    if (!rv) {
+        PORT_SetError(SEC_ERROR_NO_MEMORY);
+    }
+    return rv;
+}
+
+/* aligned_alloc is C11. This is an alternative to get aligned memory. */
+void *
+PORT_ZAllocAligned(size_t bytes, size_t alignment, void **mem)
+{
+    size_t x = alignment - 1;
+
+    /* This only works if alignment is a power of 2. */
+    if ((alignment == 0) || (alignment & (alignment - 1))) {
+        PORT_SetError(SEC_ERROR_INVALID_ARGS);
+        return NULL;
+    }
+
+    if (!mem) {
+        return NULL;
+    }
+
+    /* Always allocate a non-zero amount of bytes */
+    *mem = PORT_ZAlloc((bytes ? bytes : 1) + x);
+    if (!*mem) {
+        PORT_SetError(SEC_ERROR_NO_MEMORY);
+        return NULL;
+    }
+
+    return (void *)(((uintptr_t)*mem + x) & ~(uintptr_t)x);
+}
+
+void *
+PORT_ZAllocAlignedOffset(size_t size, size_t alignment, size_t offset)
+{
+    PORT_Assert(offset < size);
+    if (offset > size) {
+        return NULL;
+    }
+
+    void *mem = NULL;
+    void *v = PORT_ZAllocAligned(size, alignment, &mem);
+    if (!v) {
+        return NULL;
+    }
+
+    PORT_Assert(mem);
+    *((void **)((uintptr_t)v + offset)) = mem;
+    return v;
+}
+
+void
+PORT_Free(void *ptr)
+{
+    if (ptr) {
+        PR_Free(ptr);
+    }
+}
+
+void
+PORT_ZFree(void *ptr, size_t len)
+{
+    if (ptr) {
+        memset(ptr, 0, len);
+        PR_Free(ptr);
+    }
+}
+
+char *
+PORT_Strdup(const char *str)
+{
+    size_t len = PORT_Strlen(str) + 1;
+    char *newstr;
+
+    newstr = (char *)PORT_Alloc(len);
+    if (newstr) {
+        PORT_Memcpy(newstr, str, len);
+    }
+    return newstr;
+}
+
+void
+PORT_SetError(int value)
+{
+    PR_SetError(value, 0);
+    return;
+}
+
+int
+PORT_GetError(void)
+{
+    return (PR_GetError());
+}
+
+/********************* Arena code follows *****************************
+ * ArenaPools are like heaps.  The memory in them consists of large blocks,
+ * called arenas, which are allocated from the/a system heap.  Inside an
+ * ArenaPool, the arenas are organized as if they were in a stack.  Newly
+ * allocated arenas are "pushed" on that stack.  When you attempt to
+ * allocate memory from an ArenaPool, the code first looks to see if there
+ * is enough unused space in the top arena on the stack to satisfy your
+ * request, and if so, your request is satisfied from that arena.
+ * Otherwise, a new arena is allocated (or taken from NSPR's list of freed
+ * arenas) and pushed on to the stack.  The new arena is always big enough
+ * to satisfy the request, and is also at least a minimum size that is
+ * established at the time that the ArenaPool is created.
+ *
+ * The ArenaMark function returns the address of a marker in the arena at
+ * the top of the arena stack.  It is the address of the place in the arena
+ * on the top of the arena stack from which the next block of memory will
+ * be allocated.  Each ArenaPool has its own separate stack, and hence
+ * marks are only relevant to the ArenaPool from which they are gotten.
+ * Marks may be nested.  That is, a thread can get a mark, and then get
+ * another mark.
+ *
+ * It is intended that all the marks in an ArenaPool may only be owned by a
+ * single thread.  In DEBUG builds, this is enforced.  In non-DEBUG builds,
+ * it is not.  In DEBUG builds, when a thread gets a mark from an
+ * ArenaPool, no other thread may acquire a mark in that ArenaPool while
+ * that mark exists, that is, until that mark is unmarked or released.
+ * Therefore, it is important that every mark be unmarked or released when
+ * the creating thread has no further need for exclusive ownership of the
+ * right to manage the ArenaPool.
+ *
+ * The ArenaUnmark function discards the ArenaMark at the address given,
+ * and all marks nested inside that mark (that is, acquired from that same
+ * ArenaPool while that mark existed).   It is an error for a thread other
+ * than the mark's creator to try to unmark it.  When a thread has unmarked
+ * all its marks from an ArenaPool, then another thread is able to set
+ * marks in that ArenaPool.  ArenaUnmark does not deallocate (or "pop") any
+ * memory allocated from the ArenaPool since the mark was created.
+ *
+ * ArenaRelease "pops" the stack back to the mark, deallocating all the
+ * memory allocated from the arenas in the ArenaPool since that mark was
+ * created, and removing any arenas from the ArenaPool that have no
+ * remaining active allocations when that is done.  It implicitly releases
+ * any marks nested inside the mark being explicitly released.  It is the
+ * only operation, other than destroying the arenapool, that potentially
+ * reduces the number of arenas on the stack.  Otherwise, the stack grows
+ * until the arenapool is destroyed, at which point all the arenas are
+ * freed or returned to a "free arena list", depending on their sizes.
+ */
+PLArenaPool *
+PORT_NewArena(unsigned long chunksize)
+{
+    PORTArenaPool *pool;
+
+    if (chunksize > MAX_SIZE) {
+        PORT_SetError(SEC_ERROR_NO_MEMORY);
+        return NULL;
+    }
+    pool = PORT_ZNew(PORTArenaPool);
+    if (!pool) {
+        return NULL;
+    }
+    pool->magic = ARENAPOOL_MAGIC;
+    pool->lock = PZ_NewLock(nssILockArena);
+    if (!pool->lock) {
+        PORT_Free(pool);
+        return NULL;
+    }
+    PL_InitArenaPool(&pool->arena, "security", chunksize, sizeof(double));
+    return (&pool->arena);
+}
+
+void
+PORT_InitCheapArena(PORTCheapArenaPool *pool, unsigned long chunksize)
+{
+    pool->magic = CHEAP_ARENAPOOL_MAGIC;
+    PL_InitArenaPool(&pool->arena, "security", chunksize, sizeof(double));
+}
+
+void *
+PORT_ArenaAlloc(PLArenaPool *arena, size_t size)
+{
+    void *p = NULL;
+
+    PORTArenaPool *pool = (PORTArenaPool *)arena;
+
+    if (size <= 0) {
+        size = 1;
+    }
+
+    if (size > MAX_SIZE) {
+        /* you lose. */
+    } else
+        /* Is it one of ours?  Assume so and check the magic */
+        if (ARENAPOOL_MAGIC == pool->magic) {
+        PZ_Lock(pool->lock);
+#ifdef THREADMARK
+        /* Most likely one of ours.  Is there a thread id? */
+        if (pool->marking_thread &&
+            pool->marking_thread != PR_GetCurrentThread()) {
+            /* Another thread holds a mark in this arena */
+            PZ_Unlock(pool->lock);
+            PORT_SetError(SEC_ERROR_NO_MEMORY);
+            PORT_Assert(0);
+            return NULL;
+        } /* tid != null */
+#endif    /* THREADMARK */
+        PL_ARENA_ALLOCATE(p, arena, size);
+        PZ_Unlock(pool->lock);
+    } else {
+        PL_ARENA_ALLOCATE(p, arena, size);
+    }
+
+    if (!p) {
+        PORT_SetError(SEC_ERROR_NO_MEMORY);
+    }
+
+    return (p);
+}
+
+void *
+PORT_ArenaZAlloc(PLArenaPool *arena, size_t size)
+{
+    void *p;
+
+    if (size <= 0)
+        size = 1;
+
+    p = PORT_ArenaAlloc(arena, size);
+
+    if (p) {
+        PORT_Memset(p, 0, size);
+    }
+
+    return (p);
+}
+
+static PRCallOnceType setupUseFreeListOnce;
+static PRBool useFreeList;
+
+static PRStatus
+SetupUseFreeList(void)
+{
+    useFreeList = (PR_GetEnvSecure("NSS_DISABLE_ARENA_FREE_LIST") == NULL);
+    return PR_SUCCESS;
+}
+
+/*
+ * If zero is true, zeroize the arena memory before freeing it.
+ */
+void
+PORT_FreeArena(PLArenaPool *arena, PRBool zero)
+{
+    PORTArenaPool *pool = (PORTArenaPool *)arena;
+    PRLock *lock = (PRLock *)0;
+    size_t len = sizeof *arena;
+
+    if (!pool)
+        return;
+    if (ARENAPOOL_MAGIC == pool->magic) {
+        len = sizeof *pool;
+        lock = pool->lock;
+        PZ_Lock(lock);
+    }
+    if (zero) {
+        PL_ClearArenaPool(arena, 0);
+    }
+    (void)PR_CallOnce(&setupUseFreeListOnce, &SetupUseFreeList);
+    if (useFreeList) {
+        PL_FreeArenaPool(arena);
+    } else {
+        PL_FinishArenaPool(arena);
+    }
+    PORT_ZFree(arena, len);
+    if (lock) {
+        PZ_Unlock(lock);
+        PZ_DestroyLock(lock);
+    }
+}
+
+void
+PORT_DestroyCheapArena(PORTCheapArenaPool *pool)
+{
+    (void)PR_CallOnce(&setupUseFreeListOnce, &SetupUseFreeList);
+    if (useFreeList) {
+        PL_FreeArenaPool(&pool->arena);
+    } else {
+        PL_FinishArenaPool(&pool->arena);
+    }
+}
+
+void *
+PORT_ArenaGrow(PLArenaPool *arena, void *ptr, size_t oldsize, size_t newsize)
+{
+    PORTArenaPool *pool = (PORTArenaPool *)arena;
+    PORT_Assert(newsize >= oldsize);
+
+    if (newsize > MAX_SIZE) {
+        PORT_SetError(SEC_ERROR_NO_MEMORY);
+        return NULL;
+    }
+
+    if (ARENAPOOL_MAGIC == pool->magic) {
+        PZ_Lock(pool->lock);
+        /* Do we do a THREADMARK check here? */
+        PL_ARENA_GROW(ptr, arena, oldsize, (newsize - oldsize));
+        PZ_Unlock(pool->lock);
+    } else {
+        PL_ARENA_GROW(ptr, arena, oldsize, (newsize - oldsize));
+    }
+
+    return (ptr);
+}
+
+void *
+PORT_ArenaMark(PLArenaPool *arena)
+{
+    void *result;
+
+    PORTArenaPool *pool = (PORTArenaPool *)arena;
+    if (ARENAPOOL_MAGIC == pool->magic) {
+        PZ_Lock(pool->lock);
+#ifdef THREADMARK
+        {
+            threadmark_mark *tm, **pw;
+            PRThread *currentThread = PR_GetCurrentThread();
+
+            if (!pool->marking_thread) {
+                /* First mark */
+                pool->marking_thread = currentThread;
+            } else if (currentThread != pool->marking_thread) {
+                PZ_Unlock(pool->lock);
+                PORT_SetError(SEC_ERROR_NO_MEMORY);
+                PORT_Assert(0);
+                return NULL;
+            }
+
+            result = PL_ARENA_MARK(arena);
+            PL_ARENA_ALLOCATE(tm, arena, sizeof(threadmark_mark));
+            if (!tm) {
+                PZ_Unlock(pool->lock);
+                PORT_SetError(SEC_ERROR_NO_MEMORY);
+                return NULL;
+            }
+
+            tm->mark = result;
+            tm->next = (threadmark_mark *)NULL;
+
+            pw = &pool->first_mark;
+            while (*pw) {
+                pw = &(*pw)->next;
+            }
+
+            *pw = tm;
+        }
+#else  /* THREADMARK */
+        result = PL_ARENA_MARK(arena);
+#endif /* THREADMARK */
+        PZ_Unlock(pool->lock);
+    } else {
+        /* a "pure" NSPR arena */
+        result = PL_ARENA_MARK(arena);
+    }
+    return result;
+}
+
+/*
+ * This function accesses the internals of PLArena, which is why it needs
+ * to use the NSPR internal macro PL_MAKE_MEM_UNDEFINED before the memset
+ * calls.
+ *
+ * We should move this function to NSPR as PL_ClearArenaAfterMark or add
+ * a PL_ARENA_CLEAR_AND_RELEASE macro.
+ *
+ * TODO: remove the #ifdef PL_MAKE_MEM_UNDEFINED tests when NSPR 4.10+ is
+ * widely available.
+ */
+static void
+port_ArenaZeroAfterMark(PLArenaPool *arena, void *mark)
+{
+    PLArena *a = arena->current;
+    if (a->base <= (PRUword)mark && (PRUword)mark <= a->avail) {
+/* fast path: mark falls in the current arena */
+#ifdef PL_MAKE_MEM_UNDEFINED
+        PL_MAKE_MEM_UNDEFINED(mark, a->avail - (PRUword)mark);
+#endif
+        memset(mark, 0, a->avail - (PRUword)mark);
+    } else {
+        /* slow path: need to find the arena that mark falls in */
+        for (a = arena->first.next; a; a = a->next) {
+            PR_ASSERT(a->base <= a->avail && a->avail <= a->limit);
+            if (a->base <= (PRUword)mark && (PRUword)mark <= a->avail) {
+#ifdef PL_MAKE_MEM_UNDEFINED
+                PL_MAKE_MEM_UNDEFINED(mark, a->avail - (PRUword)mark);
+#endif
+                memset(mark, 0, a->avail - (PRUword)mark);
+                a = a->next;
+                break;
+            }
+        }
+        for (; a; a = a->next) {
+            PR_ASSERT(a->base <= a->avail && a->avail <= a->limit);
+#ifdef PL_MAKE_MEM_UNDEFINED
+            PL_MAKE_MEM_UNDEFINED((void *)a->base, a->avail - a->base);
+#endif
+            memset((void *)a->base, 0, a->avail - a->base);
+        }
+    }
+}
+
+static void
+port_ArenaRelease(PLArenaPool *arena, void *mark, PRBool zero)
+{
+    PORTArenaPool *pool = (PORTArenaPool *)arena;
+    if (ARENAPOOL_MAGIC == pool->magic) {
+        PZ_Lock(pool->lock);
+#ifdef THREADMARK
+        {
+            threadmark_mark **pw;
+
+            if (PR_GetCurrentThread() != pool->marking_thread) {
+                PZ_Unlock(pool->lock);
+                PORT_SetError(SEC_ERROR_NO_MEMORY);
+                PORT_Assert(0);
+                return /* no error indication available */;
+            }
+
+            pw = &pool->first_mark;
+            while (*pw && (mark != (*pw)->mark)) {
+                pw = &(*pw)->next;
+            }
+
+            if (!*pw) {
+                /* bad mark */
+                PZ_Unlock(pool->lock);
+                PORT_SetError(SEC_ERROR_NO_MEMORY);
+                PORT_Assert(0);
+                return /* no error indication available */;
+            }
+
+            *pw = (threadmark_mark *)NULL;
+
+            if (zero) {
+                port_ArenaZeroAfterMark(arena, mark);
+            }
+            PL_ARENA_RELEASE(arena, mark);
+
+            if (!pool->first_mark) {
+                pool->marking_thread = (PRThread *)NULL;
+            }
+        }
+#else  /* THREADMARK */
+        if (zero) {
+            port_ArenaZeroAfterMark(arena, mark);
+        }
+        PL_ARENA_RELEASE(arena, mark);
+#endif /* THREADMARK */
+        PZ_Unlock(pool->lock);
+    } else {
+        if (zero) {
+            port_ArenaZeroAfterMark(arena, mark);
+        }
+        PL_ARENA_RELEASE(arena, mark);
+    }
+}
+
+void
+PORT_ArenaRelease(PLArenaPool *arena, void *mark)
+{
+    port_ArenaRelease(arena, mark, PR_FALSE);
+}
+
+/*
+ * Zeroize the arena memory before releasing it.
+ */
+void
+PORT_ArenaZRelease(PLArenaPool *arena, void *mark)
+{
+    port_ArenaRelease(arena, mark, PR_TRUE);
+}
+
+void
+PORT_ArenaUnmark(PLArenaPool *arena, void *mark)
+{
+#ifdef THREADMARK
+    PORTArenaPool *pool = (PORTArenaPool *)arena;
+    if (ARENAPOOL_MAGIC == pool->magic) {
+        threadmark_mark **pw;
+
+        PZ_Lock(pool->lock);
+
+        if (PR_GetCurrentThread() != pool->marking_thread) {
+            PZ_Unlock(pool->lock);
+            PORT_SetError(SEC_ERROR_NO_MEMORY);
+            PORT_Assert(0);
+            return /* no error indication available */;
+        }
+
+        pw = &pool->first_mark;
+        while (((threadmark_mark *)NULL != *pw) && (mark != (*pw)->mark)) {
+            pw = &(*pw)->next;
+        }
+
+        if ((threadmark_mark *)NULL == *pw) {
+            /* bad mark */
+            PZ_Unlock(pool->lock);
+            PORT_SetError(SEC_ERROR_NO_MEMORY);
+            PORT_Assert(0);
+            return /* no error indication available */;
+        }
+
+        *pw = (threadmark_mark *)NULL;
+
+        if (!pool->first_mark) {
+            pool->marking_thread = (PRThread *)NULL;
+        }
+
+        PZ_Unlock(pool->lock);
+    }
+#endif /* THREADMARK */
+}
+
+char *
+PORT_ArenaStrdup(PLArenaPool *arena, const char *str)
+{
+    int len = PORT_Strlen(str) + 1;
+    char *newstr;
+
+    newstr = (char *)PORT_ArenaAlloc(arena, len);
+    if (newstr) {
+        PORT_Memcpy(newstr, str, len);
+    }
+    return newstr;
+}
+
+/********************** end of arena functions ***********************/
+
+/****************** unicode conversion functions ***********************/
+/*
+ * NOTE: These conversion functions all assume that the multibyte
+ * characters are going to be in NETWORK BYTE ORDER, not host byte
+ * order.  This is because the only time we deal with UCS-2 and UCS-4
+ * are when the data was received from or is going to be sent out
+ * over the wire (in, e.g. certificates).
+ */
+
+void
+PORT_SetUCS4_UTF8ConversionFunction(PORTCharConversionFunc convFunc)
+{
+    ucs4Utf8ConvertFunc = convFunc;
+}
+
+void
+PORT_SetUCS2_ASCIIConversionFunction(PORTCharConversionWSwapFunc convFunc)
+{
+    ucs2AsciiConvertFunc = convFunc;
+}
+
+void
+PORT_SetUCS2_UTF8ConversionFunction(PORTCharConversionFunc convFunc)
+{
+    ucs2Utf8ConvertFunc = convFunc;
+}
+
+PRBool
+PORT_UCS4_UTF8Conversion(PRBool toUnicode, unsigned char *inBuf,
+                         unsigned int inBufLen, unsigned char *outBuf,
+                         unsigned int maxOutBufLen, unsigned int *outBufLen)
+{
+    if (!ucs4Utf8ConvertFunc) {
+        return sec_port_ucs4_utf8_conversion_function(toUnicode,
+                                                      inBuf, inBufLen, outBuf, maxOutBufLen, outBufLen);
+    }
+
+    return (*ucs4Utf8ConvertFunc)(toUnicode, inBuf, inBufLen, outBuf,
+                                  maxOutBufLen, outBufLen);
+}
+
+PRBool
+PORT_UCS2_UTF8Conversion(PRBool toUnicode, unsigned char *inBuf,
+                         unsigned int inBufLen, unsigned char *outBuf,
+                         unsigned int maxOutBufLen, unsigned int *outBufLen)
+{
+    if (!ucs2Utf8ConvertFunc) {
+        return sec_port_ucs2_utf8_conversion_function(toUnicode,
+                                                      inBuf, inBufLen, outBuf, maxOutBufLen, outBufLen);
+    }
+
+    return (*ucs2Utf8ConvertFunc)(toUnicode, inBuf, inBufLen, outBuf,
+                                  maxOutBufLen, outBufLen);
+}
+
+PRBool
+PORT_ISO88591_UTF8Conversion(const unsigned char *inBuf,
+                             unsigned int inBufLen, unsigned char *outBuf,
+                             unsigned int maxOutBufLen, unsigned int *outBufLen)
+{
+    return sec_port_iso88591_utf8_conversion_function(inBuf, inBufLen,
+                                                      outBuf, maxOutBufLen, outBufLen);
+}
+
+PRBool
+PORT_UCS2_ASCIIConversion(PRBool toUnicode, unsigned char *inBuf,
+                          unsigned int inBufLen, unsigned char *outBuf,
+                          unsigned int maxOutBufLen, unsigned int *outBufLen,
+                          PRBool swapBytes)
+{
+    if (!ucs2AsciiConvertFunc) {
+        return PR_FALSE;
+    }
+
+    return (*ucs2AsciiConvertFunc)(toUnicode, inBuf, inBufLen, outBuf,
+                                   maxOutBufLen, outBufLen, swapBytes);
+}
+
+/* Portable putenv.  Creates/replaces an environment variable of the form
+ *  envVarName=envValue
+ */
+int
+NSS_PutEnv(const char *envVarName, const char *envValue)
+{
+    SECStatus result = SECSuccess;
+#ifdef _WIN32
+    PRBool setOK;
+
+    setOK = SetEnvironmentVariable(envVarName, envValue);
+    if (!setOK) {
+        SET_ERROR_CODE
+        return SECFailure;
+    }
+#elif defined(__GNUC__) && __GNUC__ >= 7
+    int setEnvFailed;
+    setEnvFailed = setenv(envVarName, envValue, 1);
+    if (setEnvFailed) {
+        SET_ERROR_CODE
+        return SECFailure;
+    }
+#else
+    char *encoded = (char *)PORT_ZAlloc(strlen(envVarName) + 2 + strlen(envValue));
+    if (!encoded) {
+        return SECFailure;
+    }
+    strcpy(encoded, envVarName);
+    strcat(encoded, "=");
+    strcat(encoded, envValue);
+    int putEnvFailed = putenv(encoded); /* adopt. */
+
+    if (putEnvFailed) {
+        SET_ERROR_CODE
+        result = SECFailure;
+        PORT_Free(encoded);
+    }
+#endif
+    return result;
+}
+
+/*
+ * Perform a constant-time compare of two memory regions. The return value is
+ * 0 if the memory regions are equal and non-zero otherwise.
+ */
+int
+NSS_SecureMemcmp(const void *ia, const void *ib, size_t n)
+{
+    const unsigned char *a = (const unsigned char *)ia;
+    const unsigned char *b = (const unsigned char *)ib;
+    int r = 0;
+
+    for (size_t i = 0; i < n; ++i) {
+        r |= a[i] ^ b[i];
+    }
+
+    /* 0 <= r < 256, so -r has bit 8 set when r != 0 */
+    return 1 & (-r >> 8);
+}
+
+/*
+ * Perform a constant-time check if a memory region is all 0. The return value
+ * is 0 if the memory region is all zero.
+ */
+unsigned int
+NSS_SecureMemcmpZero(const void *mem, size_t n)
+{
+    const unsigned char *a = (const unsigned char *)mem;
+    int r = 0;
+
+    for (size_t i = 0; i < n; ++i) {
+        r |= a[i];
+    }
+
+    /* 0 <= r < 256, so -r has bit 8 set when r != 0 */
+    return 1 & (-r >> 8);
+}
+
+/*
+ * A "value barrier" prevents the compiler from making optimizations based on
+ * the value that a variable takes.
+ *
+ * Standard C does not have value barriers, so C implementations of them are
+ * compiler-specific and are not guaranteed to be effective. Thus, the value
+ * barriers here are a best-effort, defense-in-depth, strategy. They are not a
+ * substitute for standard constant-time programming discipline.
+ *
+ * Some implementations have a performance penalty, so value barriers should
+ * be used sparingly.
+ */
+static inline int
+value_barrier_int(int x)
+{
+#if defined(__GNUC__) || defined(__clang__)
+    /* This inline assembly trick from Chandler Carruth's CppCon 2015 talk
+     * generates no instructions.
+     *
+     * "+r"(x) means that x will be mapped to a register that is both an input
+     * and an output to the assembly routine (""). The compiler will not
+     * inspect the assembly routine itself, so it cannot assume anything about
+     * the value of x after this line.
+     */
+    __asm__(""
+            : "+r"(x)
+            : /* no other inputs */);
+    return x;
+#else
+    /* If the compiler does not support the inline assembly trick above, we can
+     * put x in `volatile` storage and read it out again. This will generate
+     * explict store and load instructions, and possibly more depending on the
+     * target.
+     */
+    volatile int y = x;
+    return y;
+#endif
+}
+
+/*
+ * A branch-free implementation of
+ *      if (!b) {
+ *           memmove(dest, src0, n);
+ *      } else {
+ *           memmove(dest, src1, n);
+ *      }
+ *
+ * The memmove is performed with src0 if `b == 0` and with src1
+ * otherwise.
+ *
+ * As with memmove, the selected src can overlap dest.
+ *
+ * Each of dest, src0, and src1 must point to an allocated buffer
+ * of at least n bytes.
+ */
+void
+NSS_SecureSelect(void *dest, const void *src0, const void *src1, size_t n, unsigned char b)
+
+{
+    // This value barrier makes it safe for the compiler to inline
+    // NSS_SecureSelect into a routine where it could otherwise infer something
+    // about the value of b, e.g. that b is 0/1 valued.
+    int w = value_barrier_int(b);
+
+    // 0 <= b < 256, and int is at least 16 bits, so -w has bits 8-15
+    // set when w != 0.
+    unsigned char mask = 0xff & (-w >> 8);
+
+    for (size_t i = 0; i < n; ++i) {
+        unsigned char s0i = ((unsigned char *)src0)[i];
+        unsigned char s1i = ((unsigned char *)src1)[i];
+        // if mask == 0 this simplifies to s0 ^ 0
+        // if mask == -1 this simplifies to s0 ^ s0 ^ s1
+        ((unsigned char *)dest)[i] = s0i ^ (mask & (s0i ^ s1i));
+    }
+}