Merge "init attribute-based encryption"

9 files changed, 861 insertions, 0 deletions

diff --git a/moon-abe/pbc-0.5.14/misc/darray.c b/moon-abe/pbc-0.5.14/misc/darray.c
new file mode 100644
index 00000000..50b127f3
--- /dev/null
+++ b/moon-abe/pbc-0.5.14/misc/darray.c
@@ -0,0 +1,176 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "pbc_memory.h"
+#include "darray.h"
+
+#define NDEBUG
+#include <assert.h>
+
+enum {
+    max_init = 8
+};
+
+void darray_init(darray_ptr a)
+{
+    a->max = max_init;
+    a->count = 0;
+    a->item = pbc_malloc(sizeof(void *) * a->max);
+}
+
+darray_ptr darray_new(void)
+{
+    darray_ptr res = pbc_malloc(sizeof(darray_t));
+    darray_init(res);
+    return res;
+}
+
+void darray_remove_all(darray_ptr a)
+{
+    a->max = max_init;
+    a->count = 0;
+    pbc_free(a->item);
+    a->item = pbc_malloc(sizeof(void *) * a->max);
+}
+
+void darray_remove_last(darray_ptr a)
+{
+    assert(a->count > 0);
+    a->count--;
+}
+
+static void darray_realloc(darray_ptr a, int size)
+{
+    a->max = size;
+    a->item = pbc_realloc(a->item, sizeof(void *) * a->max);
+}
+
+void darray_append(darray_ptr a, void *p)
+{
+    if (a->count == a->max) {
+        if (!a->max) a->max = max_init;
+        else a->max *= 2;
+        a->item = pbc_realloc(a->item, sizeof(void *) * a->max);
+    }
+    a->item[a->count] = p;
+    a->count++;
+}
+
+int darray_index_of(darray_ptr a, void *p)
+{
+    int i;
+    for (i=0; i<a->count; i++) {
+        if (a->item[i] == p) return i;
+    }
+    return -1;
+}
+
+void darray_clear(darray_t a)
+{
+    pbc_free(a->item);
+    a->max = 0;
+    a->count = 0;
+}
+
+void darray_free(darray_ptr a) {
+  darray_clear(a);
+  pbc_free(a);
+}
+
+void darray_remove_index(darray_ptr a, int n)
+{
+    assert(a->count >= n-1);
+    a->count--;
+    memmove(&a->item[n], &a->item[n+1], sizeof(void *) * (a->count - n));
+}
+
+void darray_remove(darray_ptr a, void *p)
+{
+    int i;
+    for (i=0; i<a->count; i++) {
+        if (a->item[i] == p) {
+            a->count--;
+            memmove(&a->item[i], &a->item[i+1], sizeof(void *) * (a->count - i));
+            return;
+        }
+    }
+    assert(0);
+}
+
+void darray_remove_with_test(darray_ptr a, int (*test)(void *))
+{
+    int i;
+    for (i=0; i<a->count; i++) {
+        if (test(a->item[i])) {
+            for (;i<a->count; i++) {
+                a->item[i] = a->item[i+1];
+            }
+            a->count--;
+        }
+    }
+}
+
+void darray_copy(darray_ptr dst, darray_ptr src)
+{
+    darray_realloc(dst, src->count);
+    memcpy(dst->item, src->item, src->count * sizeof(void *));
+    dst->count = src->count;
+}
+
+void darray_forall(darray_t a, void (*func)(void *))
+{
+    int i, n = a->count;
+    for (i=0; i<n; i++) {
+        func(a->item[i]);
+    }
+}
+
+void darray_forall2(darray_t a,
+                    void (*func)(void *darray_item, void *scope_ptr),
+                    void *scope_ptr)
+{
+    int i, n = a->count;
+    for (i=0; i<n; i++) {
+        func(a->item[i], scope_ptr);
+    }
+}
+
+void darray_forall3(darray_t a,
+                    void (*func)(void *darray_item,
+                                 void *scope_ptr1,
+                                 void *scope_ptr2),
+                    void *scope_ptr1,
+                    void *scope_ptr2)
+{
+    int i, n = a->count;
+    for (i=0; i<n; i++) {
+        func(a->item[i], scope_ptr1, scope_ptr2);
+    }
+}
+
+void darray_forall4(darray_t a,
+                    void (*func)(void *darray_item,
+                                 void *scope_ptr1,
+                                 void *scope_ptr2,
+                                 void *scope_ptr3),
+                    void *scope_ptr1,
+                    void *scope_ptr2,
+                    void *scope_ptr3)
+{
+    int i, n = a->count;
+    for (i=0; i<n; i++) {
+        func(a->item[i], scope_ptr1, scope_ptr2, scope_ptr3);
+    }
+}
+
+void *darray_at_test(darray_ptr a,
+                     int (*test)(void *data, void *scope_ptr),
+                     void *scope_ptr)
+{
+    int i;
+    for (i = 0; i < a->count; i++) {
+        void *p = a->item[i];
+        if (test(p, scope_ptr)) return p;
+    }
+    return NULL;
+}
diff --git a/moon-abe/pbc-0.5.14/misc/darray.h b/moon-abe/pbc-0.5.14/misc/darray.h
new file mode 100644
index 00000000..ecbd04ad
--- /dev/null
+++ b/moon-abe/pbc-0.5.14/misc/darray.h
@@ -0,0 +1,92 @@
+// darray = "dynamic array"
+// A linked-list implementation using C arrays.
+
+#ifndef __PBC_DARRAY_H__
+#define __PBC_DARRAY_H__
+
+#pragma GCC visibility push(hidden)
+
+struct darray_s {
+  void **item;
+  int count;
+  int max;
+};
+
+typedef struct darray_s darray_t[1];
+typedef struct darray_s *darray_ptr;
+
+/*@manual darray
+Initialize a dynamic array 'a'. Must be called before 'a' is used.
+*/
+void darray_init(darray_t a);
+darray_ptr darray_new(void);
+
+void darray_free(darray_ptr a);
+
+/*@manual darray
+Clears a dynamic array 'a'. Should be called after 'a' is no longer needed.
+*/
+void darray_clear(darray_t a);
+
+/*@manual darray
+Appends 'p' to the dynamic array 'a'.
+*/
+void darray_append(darray_t a, void *p);
+
+/*@manual darray
+Returns the pointer at index 'i' in the dynamic array 'a'.
+*/
+static inline void *darray_at(darray_t a, int i) {
+  return a->item[i];
+}
+
+int darray_index_of(darray_ptr a, void *p);
+void darray_remove(darray_ptr a, void *p);
+void darray_remove_last(darray_ptr a);
+void darray_remove_with_test(darray_ptr a, int (*test)(void *));
+
+/*@manual darray
+Removes the pointer at index 'i' in the dynamic array 'a'.
+*/
+void darray_remove_index(darray_ptr a, int n);
+void darray_copy(darray_ptr dst, darray_ptr src);
+void darray_remove_all(darray_ptr d);
+void darray_forall(darray_t a, void (*func)(void *));
+void darray_forall2(darray_t a,
+                    void (*func)(void *darray_item, void *scope_ptr),
+                    void *scope_ptr);
+void darray_forall3(darray_t a,
+                    void (*func)(void *darray_item,
+                                 void *scope_ptr1,
+                                 void *scope_ptr2),
+                    void *scope_ptr1,
+                    void *scope_ptr2);
+void darray_forall4(darray_t a,
+                    void (*func)(void *darray_item,
+                                 void *scope_ptr1,
+                                 void *scope_ptr2,
+                                 void *scope_ptr3),
+                    void *scope_ptr1,
+                    void *scope_ptr2,
+                    void *scope_ptr3);
+
+void *darray_at_test(darray_ptr a, int (*test)(void *,void *), void *scope_ptr);
+
+/*@manual darray
+Returns the number of pointers held in 'a'.
+*/
+static inline int darray_count(darray_ptr a) {
+  return a->count;
+}
+
+static inline int darray_is_empty(darray_ptr a) {
+  return !a->count;
+}
+
+static inline void *darray_last(darray_t a) {
+  return a->item[a->count - 1];
+}
+
+#pragma GCC visibility pop
+
+#endif //__PBC_DARRAY_H__
diff --git a/moon-abe/pbc-0.5.14/misc/extend_printf.c b/moon-abe/pbc-0.5.14/misc/extend_printf.c
new file mode 100644
index 00000000..5e6537e2
--- /dev/null
+++ b/moon-abe/pbc-0.5.14/misc/extend_printf.c
@@ -0,0 +1,188 @@
+/*
+ * Behaves as gmp_printf with new conversion specifier %B for element_t types
+ */
+
+#include <stdio.h>
+#include <stdint.h> // for intptr_t
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <gmp.h>
+#include "pbc_utils.h"
+#include "pbc_field.h"
+#include "pbc_memory.h"
+
+struct sninfo_s {
+  char *s;
+  size_t size;
+  size_t left;
+  size_t result;
+};
+
+// TODO: remove repeated code for error handling
+static int do_print(int (*strcb)(void *, char *s),
+    int (*fstrcb)(void *, char *s, void *),
+    int (*elcb)(void *, element_ptr e),
+    void *data,
+    const char *format, va_list ap) {
+  // A primitive front-end for printf()-family functions. Only handles types
+  // in specifiers, and assumes they all take void * arguments.
+  // 
+  // I wish register_printf_specifier() were more widespread.
+  int count = 0, status;
+  char *copy, *c, *start, *next;
+  element_ptr e;
+  int found;
+
+  copy = pbc_strdup(format);
+  start = next = copy;
+
+  for(;;) {
+    for(;;) {
+      c = strchr(next, '%');
+      if (!c) {
+        status = strcb(data, start);
+        if (status < 0) {
+          count = -1;
+        } else count += status;
+        goto done;
+      }
+      if (!*(c + 1)) goto done;
+      if (*(c + 1) != '%') break;
+      next = c + 2;
+    }
+    *c = 0;
+    status = strcb(data, start);
+    if (status < 0) {
+      count = -1;
+      goto done;
+    } else count += status;
+    *c = '%';
+    start = c;
+    found = 0;
+    while(!found) {
+      c++;
+      switch (*c) {
+        case '\0':
+          goto done;
+        case 'B':
+          e = va_arg(ap, element_ptr);
+          status = elcb(data, e);
+          if (status < 0) {
+            count = -1;
+            goto done;
+          } else count += status;
+          found = 1;
+          break;
+        default:
+          if (strchr("diouxXeEfFgGaAcspnmZ", *c)) {
+            if (*c == 'Z') c++;
+            char ch = *(c+1);
+            *(c+1) = '\0';
+            status = fstrcb(data, start, va_arg(ap, void *));
+            if (status < 0) {
+              count = -1;
+              goto done;
+            } else count += status;
+            *(c+1) = ch;
+            found = 1;
+          }
+          break;
+      }
+    }
+    next = start = c + 1;
+  }
+
+done:
+  pbc_free(copy);
+
+  return count;
+}
+
+static int string_cb(void *file, char *s) {
+  if (fputs(s, file) == EOF) return -1;
+  return strlen(s);
+}
+
+static int format_cb(void *file, char *fstring, void *ptr) {
+  return gmp_fprintf(file, fstring, ptr);
+}
+
+static int element_cb(void *file, element_ptr e) {
+  return element_out_str(file, 0, e);
+}
+
+int element_vfprintf(FILE *stream, const char *format, va_list ap) {
+  return do_print(string_cb, format_cb, element_cb, stream, format, ap);
+}
+
+int element_fprintf(FILE *stream, const char *format, ...) {
+  int status;
+  va_list ap;
+
+  va_start(ap, format);
+  status = element_vfprintf(stream, format, ap);
+  va_end(ap);
+  return status;
+}
+
+int element_printf(const char *format, ...) {
+  int status;
+  va_list ap;
+
+  va_start(ap, format);
+  status = element_vfprintf(stdout, format, ap);
+  va_end(ap);
+  return status;
+}
+
+static void next(struct sninfo_s *p, int status) {
+  p->result += status;
+  p->left = p->result >= p->size ? 0 : p->size - p->result;
+}
+
+static int string_cbv(void *data, char *s) {
+  struct sninfo_s *p = data;
+  int status = snprintf(p->s + p->result, p->left, "%s", s);
+  if (status < 0) return status;
+  next(data, status);
+  return status;
+}
+
+static int format_cbv(void *data, char *fstring, void *ptr) {
+  struct sninfo_s *p = data;
+  int status = gmp_snprintf(p->s + p->result, p->left, fstring, ptr);
+  if (status < 0) return status;
+  next(data, status);
+  return status;
+}
+
+static int element_cbv(void *data, element_ptr e) {
+  struct sninfo_s *p = data;
+  int status = element_snprint(p->s + p->result, p->left, e);
+  if (status < 0) return status;
+  next(data, status);
+  return status;
+}
+
+int element_vsnprintf(char *buf, size_t size, const char *fmt, va_list ap) {
+  struct sninfo_s info;
+
+  info.s = buf;
+  info.left = info.size = size;
+  info.result = 0;
+
+  do_print(string_cbv, format_cbv, element_cbv, &info, fmt, ap);
+
+  return info.result;
+}
+
+int element_snprintf(char *buf, size_t size, const char *fmt, ...) {
+  int status;
+  va_list ap;
+
+  va_start(ap, fmt);
+  status = element_vsnprintf(buf, size, fmt, ap);
+  va_end(ap);
+  return status;
+}
diff --git a/moon-abe/pbc-0.5.14/misc/get_time.c b/moon-abe/pbc-0.5.14/misc/get_time.c
new file mode 100644
index 00000000..8932364b
--- /dev/null
+++ b/moon-abe/pbc-0.5.14/misc/get_time.c
@@ -0,0 +1,21 @@
+#include <sys/time.h>
+#include <time.h>
+
+double pbc_get_time(void) {
+  static struct timeval last_tv, tv;
+  static int first = 1;
+  static double res = 0;
+
+  if (first) {
+    gettimeofday(&last_tv, NULL);
+    first = 0;
+    return 0;
+  } else {
+    gettimeofday(&tv, NULL);
+    res += tv.tv_sec - last_tv.tv_sec;
+    res += (tv.tv_usec - last_tv.tv_usec) / 1000000.0;
+    last_tv = tv;
+
+    return res;
+  }
+}
diff --git a/moon-abe/pbc-0.5.14/misc/get_time.win32.c b/moon-abe/pbc-0.5.14/misc/get_time.win32.c
new file mode 100644
index 00000000..98463198
--- /dev/null
+++ b/moon-abe/pbc-0.5.14/misc/get_time.win32.c
@@ -0,0 +1,42 @@
+#include <stdint.h> // for intptr_t
+#include <sys/time.h>
+#include "pbc_utils.h"
+
+typedef struct _FILETIME {
+  unsigned long dwLowDateTime;
+  unsigned long dwHighDateTime;
+} FILETIME;
+
+void __stdcall GetSystemTimeAsFileTime(FILETIME*);
+
+int __cdecl gettimeofday(struct timeval* p, void* tz) {
+  UNUSED_VAR(tz);
+  union {
+    long long ns100; // Time since 1 Jan 1601 in 100ns units.
+    FILETIME ft;
+  } _now;
+
+  GetSystemTimeAsFileTime( &(_now.ft) );
+  p->tv_usec=(long)((_now.ns100 / 10LL) % 1000000LL );
+  p->tv_sec= (long)((_now.ns100-(116444736000000000LL))/10000000LL);
+  return 0; // Assume success?
+}
+
+double pbc_get_time(void) {
+  static struct timeval last_tv, tv;
+  static int first = 1;
+  static double res = 0;
+
+  if (first) {
+    gettimeofday(&last_tv, NULL);
+    first = 0;
+    return 0;
+  } else {
+    gettimeofday(&tv, NULL);
+    res += tv.tv_sec - last_tv.tv_sec;
+    res += (tv.tv_usec - last_tv.tv_usec) / 1000000.0;
+    last_tv = tv;
+
+    return res;
+  }
+}
diff --git a/moon-abe/pbc-0.5.14/misc/memory.c b/moon-abe/pbc-0.5.14/misc/memory.c
new file mode 100644
index 00000000..cfe80ecc
--- /dev/null
+++ b/moon-abe/pbc-0.5.14/misc/memory.c
@@ -0,0 +1,131 @@
+#include <stdlib.h>
+#include <stdint.h> // for intptr_t
+#include <stdio.h>
+#include <string.h>
+#include "pbc_utils.h"
+#include "pbc_memory.h"
+
+#ifdef SAFE_CLEAN
+/* guarantee zeroing the memory */
+static void gmp_free(void *ptr, size_t size) {
+  if(ptr)
+    memset(ptr, 0, size);
+  free(ptr);
+}
+
+static void* gmp_malloc(size_t size) {
+  return malloc(size);
+}
+
+/* guarantee zeroing the memory
+ * realloc() is not suitable for use with secure memory
+ * because memory contents are not zeroed out. */
+static void* gmp_realloc(void *old_ptr, size_t old_size, size_t new_size) {
+  void *new_ptr = malloc(new_size);
+  if(new_ptr && old_ptr)
+    memcpy(new_ptr, old_ptr, old_size);
+  gmp_free(old_ptr, old_size);
+  return new_ptr;
+}
+
+static void gmp_guarantee_zero_memory(void) {
+  __gmp_set_memory_functions(gmp_malloc, gmp_realloc, gmp_free);
+}
+
+__attribute__((constructor)) void init(void) {
+  gmp_guarantee_zero_memory();
+}
+
+/* pbc_mem is a continuous memory keeping track of its size */
+static inline size_t pbc_mem_get_size(size_t *p) {
+  return *p;
+}
+
+static inline void pbc_mem_set_size(size_t *p, size_t size) {
+  *p = size;
+}
+
+static inline void *pbc_mem_to_ptr(size_t *p) {
+  return p + 1;
+}
+
+static inline void *pbc_ptr_to_mem(size_t *p) {
+  return p - 1;
+}
+
+static void *pbc_mem_malloc(size_t size) {
+  void *ptr = malloc(size + sizeof(size_t));
+  if(ptr)
+    pbc_mem_set_size(ptr, size);
+  return ptr;
+}
+
+static void pbc_mem_free(void *ptr) {
+  memset(ptr, 0, pbc_mem_get_size(ptr) + sizeof(size_t));
+  free(ptr);
+}
+
+static void *default_pbc_malloc(size_t size) {
+  void *ptr = pbc_mem_malloc(size);
+  if(!ptr) pbc_die("malloc() error");
+  return pbc_mem_to_ptr(ptr);
+}
+
+static void *default_pbc_realloc(void *old, size_t new_size) {
+  void *new = pbc_mem_malloc(new_size);
+  if(!new) pbc_die("realloc() error");
+  if(old) {
+    old = pbc_ptr_to_mem(old);
+    memcpy(pbc_mem_to_ptr(new), pbc_mem_to_ptr(old), pbc_mem_get_size(old));
+    pbc_mem_free(old);
+  }
+  return pbc_mem_to_ptr(new);
+}
+
+static void default_pbc_free(void *ptr) {
+  if(ptr)
+    pbc_mem_free(pbc_ptr_to_mem(ptr));
+}
+#else
+static void *default_pbc_malloc(size_t size) {
+  void *res = malloc(size);
+  if (!res) pbc_die("malloc() error");
+  return res;
+}
+
+static void *default_pbc_realloc(void *ptr, size_t size) {
+  void *res = realloc(ptr, size);
+  if (!res) pbc_die("realloc() error");
+  return res;
+}
+
+static void default_pbc_free(void *ptr) { free(ptr); }
+#endif
+
+/* release memory got from pbc_malloc only by pbc_free(), do not use free() */
+void *(*pbc_malloc)(size_t) = default_pbc_malloc;
+/* pbc_realloc guarantees zeroing out the memory before moving old memory */
+void *(*pbc_realloc)(void *, size_t) = default_pbc_realloc;
+/* pbc_free guarantees zeroing out the memory */
+void (*pbc_free)(void *) = default_pbc_free;
+
+void pbc_set_memory_functions(void *(*malloc_fn)(size_t),
+    void *(*realloc_fn)(void *, size_t), void (*free_fn)(void *)) {
+  pbc_malloc = malloc_fn;
+  pbc_realloc = realloc_fn;
+  pbc_free = free_fn;
+}
+
+void *pbc_calloc(size_t nmemb, size_t size) {
+  void *res = pbc_malloc(nmemb * size);
+  if (!res) pbc_die("calloc() error");
+  memset(res, 0, nmemb * size);
+  return res;
+}
+
+char *pbc_strdup(const char *s) {
+  int len = strlen(s);
+  char *res = pbc_malloc(len + 1);
+  strcpy(res, s);
+  return res;
+}
diff --git a/moon-abe/pbc-0.5.14/misc/symtab.c b/moon-abe/pbc-0.5.14/misc/symtab.c
new file mode 100644
index 00000000..9d62f590
--- /dev/null
+++ b/moon-abe/pbc-0.5.14/misc/symtab.c
@@ -0,0 +1,67 @@
+#include <stdlib.h>
+#include <string.h>
+#include "pbc_memory.h"
+
+#include "symtab.h"
+
+struct entry_s {
+  char *key;
+  void *data;
+};
+typedef struct entry_s *entry_ptr;
+typedef struct entry_s entry_t[1];
+
+void symtab_init(symtab_t t) {
+  darray_init(t->list);
+}
+
+static void clear(void *data) {
+  entry_ptr e = data;
+  pbc_free(e->key);
+  pbc_free(e);
+}
+
+void symtab_clear(symtab_t t) {
+  darray_forall(t->list, clear);
+  darray_clear(t->list);
+}
+
+void symtab_put(symtab_t t, void *data, const char *key) {
+  int i, n = t->list->count;
+  entry_ptr e;
+  for (i=0; i<n; i++) {
+    e = t->list->item[i];
+    if (!strcmp(e->key, key)) goto doit;
+  }
+  e = pbc_malloc(sizeof(entry_t));
+  e->key = pbc_strdup(key);
+  darray_append(t->list, e);
+doit:
+  e->data = data;
+}
+
+int symtab_has(symtab_t t, const char *key) {
+  int i, n = t->list->count;
+  for (i = 0; i < n; i++) {
+    entry_ptr e = t->list->item[i];
+    if (!strcmp(e->key, key)) return 1;
+  }
+  return 0;
+}
+
+void *symtab_at(symtab_t t, const char *key) {
+  int i, n = t->list->count;
+  for (i=0; i<n; i++) {
+    entry_ptr e = t->list->item[i];
+    if (!strcmp(e->key, key)) return e->data;
+  }
+  return NULL;
+}
+
+void symtab_forall_data(symtab_t t, void (*func)(void *)) {
+  int i, n = t->list->count;
+  for (i=0; i<n; i++) {
+    entry_ptr e = t->list->item[i];
+    func(e->data);
+  }
+}
diff --git a/moon-abe/pbc-0.5.14/misc/symtab.h b/moon-abe/pbc-0.5.14/misc/symtab.h
new file mode 100644
index 00000000..39f255c3
--- /dev/null
+++ b/moon-abe/pbc-0.5.14/misc/symtab.h
@@ -0,0 +1,43 @@
+#ifndef __PBC_SYMTAB_H__
+#define __PBC_SYMTAB_H__
+
+#include "darray.h"
+
+#pragma GCC visibility push(hidden)
+
+struct symtab_s {
+    darray_t list;
+};
+typedef struct symtab_s symtab_t[1];
+typedef struct symtab_s *symtab_ptr;
+
+/*@manual symtab
+Initialize symbol table 't'. Must be called before 't' is used.
+*/
+void symtab_init(symtab_t t);
+
+/*@manual symtab
+Clears symbol table 't'. Should be called after 't' is no longer needed.
+*/
+void symtab_clear(symtab_t t);
+
+/*@manual symtab
+Puts 'value' at 'key' in 't'.
+*/
+void symtab_put(symtab_t t, void *value, const char *key);
+
+/*@manual symtab
+Returns true if 't' contains key 'key'.
+*/
+int symtab_has(symtab_t t, const char *key);
+
+/*@manual symtab
+Returns pointer at key 'key' in 't'.
+*/
+void *symtab_at(symtab_t t, const char *key);
+
+void symtab_forall_data(symtab_t t, void (*func)(void *));
+
+#pragma GCC visibility pop
+
+#endif //__PBC_SYMTAB_H__
diff --git a/moon-abe/pbc-0.5.14/misc/utils.c b/moon-abe/pbc-0.5.14/misc/utils.c
new file mode 100644
index 00000000..1a808256
--- /dev/null
+++ b/moon-abe/pbc-0.5.14/misc/utils.c
@@ -0,0 +1,101 @@
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h> // for intptr_t
+#include <gmp.h>
+
+#include "pbc_utils.h"
+#include "pbc_field.h"
+
+static int pbc_msg_to_stderr = 1;
+
+int pbc_set_msg_to_stderr(int i) {
+  return pbc_msg_to_stderr = i;
+}
+
+static int out(const char *format, ...) {
+  if (!pbc_msg_to_stderr) return 0;
+  va_list params;
+
+  va_start(params, format);
+  int res = vfprintf(stderr, format, params);
+  va_end(params);
+  return res;
+}
+
+static void print_warning(void) {
+  static int first = 1;
+  if (first) {
+    out("*** PBC asserts enabled: potential performance penalties ***\n");
+    first = 0;
+  }
+}
+
+void pbc_assert(int expr, char *msg, const char *func) {
+  print_warning();
+  if (!expr) {
+    out("PBC assert failed: %s(): %s\n", func, msg);
+    abort();
+  }
+}
+
+void pbc_assert_match2(element_ptr a, element_ptr b, const char *func) {
+  print_warning();
+  if (a->field != b->field) {
+    out("PBC assert failed: %s(): field mismatch\n", func);
+    abort();
+  }
+}
+
+void pbc_assert_match3(element_ptr a, element_ptr b, element_ptr c,
+    const char *func) {
+  print_warning();
+  if (a->field != b->field) {
+    out("PBC assert failed: %s(): first two args field mismatch\n", func);
+    abort();
+  }
+  if (b->field != c->field) {
+    out("PBC assert failed: %s(): last two args field mismatch\n", func);
+    abort();
+  }
+}
+
+// Print at most the first 1024 bytes of an error message.
+static void report(const char *prefix, const char *err, va_list params) {
+  char msg[1024];
+  element_vsnprintf(msg, sizeof(msg), err, params);
+  out("%s%s\n", prefix, msg);
+}
+
+void pbc_die(const char *err, ...) {
+  va_list params;
+
+  va_start(params, err);
+  report("fatal: ", err, params);
+  va_end(params);
+  exit(128);
+}
+
+void pbc_info(const char *err, ...) {
+  va_list params;
+
+  va_start(params, err);
+  report("", err, params);
+  va_end(params);
+}
+
+void pbc_warn(const char *err, ...) {
+  va_list params;
+
+  va_start(params, err);
+  report("warning: ", err, params);
+  va_end(params);
+}
+
+void pbc_error(const char *err, ...) {
+  va_list params;
+
+  va_start(params, err);
+  report("error: ", err, params);
+  va_end(params);
+}