memcmp: Introduce and use consttime_memeq

[secnet.git] / util.c

diff --git a/util.c b/util.c
index a795223600bbdd731e1ea36c525da8140ad49328..3d119874eb1c11c7d7b9e367a6bf1a2bef6c4b4b 100644 (file)
--- a/util.c
+++ b/util.c
@@ -74,6 +74,12 @@ void *safe_malloc(size_t size, const char *message)
     }
     return r;
 }
+void *safe_malloc_ary(size_t size, size_t count, const char *message) {
+    if (count >= INT_MAX/size) {
+       fatal("array allocation overflow: %s", message);
+    }
+    return safe_malloc(size*count, message);
+}
 
 /* Convert a buffer into its MP_INT representation */
 void read_mpbin(MP_INT *a, uint8_t *bin, int binsize)
@@ -133,7 +139,7 @@ static uint8_t hexval(uint8_t c)
 }
 
 /* Convert a MP_INT into a buffer; return length; truncate if necessary */
-uint32_t write_mpbin(MP_INT *a, uint8_t *buffer, uint32_t buflen)
+int32_t write_mpbin(MP_INT *a, uint8_t *buffer, int32_t buflen)
 {
     char *hb;
     int i,j,l;
@@ -160,6 +166,7 @@ static const char *phases[NR_PHASES]={
     "PHASE_GETOPTS",
     "PHASE_READCONFIG",
     "PHASE_SETUP",
+    "PHASE_DAEMONIZE",
     "PHASE_GETRESOURCES",
     "PHASE_DROPPRIV",
     "PHASE_RUN",
@@ -198,12 +205,17 @@ bool_t remove_hook(uint32_t phase, hook_fn *fn, void *state)
     return False;
 }
 
-void log(struct log_if *lf, int priority, const char *message, ...)
+void vslilog(struct log_if *lf, int priority, const char *message, va_list ap)
+{
+    lf->vlog(lf->st,priority,message,ap);
+}
+
+void slilog(struct log_if *lf, int priority, const char *message, ...)
 {
     va_list ap;
     
     va_start(ap,message);
-    lf->vlog(lf->st,priority,message,ap);
+    vslilog(lf,priority,message,ap);
     va_end(ap);
 }
 
@@ -213,48 +225,53 @@ struct buffer {
 };
 
 void buffer_assert_free(struct buffer_if *buffer, cstring_t file,
-                       uint32_t line)
+                       int line)
 {
     if (!buffer->free) {
-       fatal("BUF_ASSERT_FREE, %s line %d, owned by %s",
-             file,line,buffer->owner);
+       fprintf(stderr,"secnet: BUF_ASSERT_FREE, %s line %d, owned by %s",
+               file,line,buffer->owner);
+       assert(!"buffer_assert_free failure");
     }
 }
 
 void buffer_assert_used(struct buffer_if *buffer, cstring_t file,
-                       uint32_t line)
+                       int line)
 {
     if (buffer->free) {
-       fatal("BUF_ASSERT_USED, %s line %d, last owned by %s",
-             file,line,buffer->owner);
+       fprintf(stderr,"secnet: BUF_ASSERT_USED, %s line %d, last owned by %s",
+               file,line,buffer->owner);
+       assert(!"buffer_assert_used failure");
     }
 }
 
-void buffer_init(struct buffer_if *buffer, uint32_t max_start_pad)
+void buffer_init(struct buffer_if *buffer, int32_t max_start_pad)
 {
     buffer->start=buffer->base+max_start_pad;
     buffer->size=0;
 }
 
-void *buf_append(struct buffer_if *buf, uint32_t amount) {
+void *buf_append(struct buffer_if *buf, int32_t amount) {
     void *p;
+    assert(buf->size <= buf->len - amount);
     p=buf->start + buf->size;
     buf->size+=amount;
     return p;
 }
 
-void *buf_prepend(struct buffer_if *buf, uint32_t amount) {
+void *buf_prepend(struct buffer_if *buf, int32_t amount) {
+    assert(amount <= buf->start - buf->base);
     buf->size+=amount;
     return buf->start-=amount;
 }
 
-void *buf_unappend(struct buffer_if *buf, uint32_t amount) {
+void *buf_unappend(struct buffer_if *buf, int32_t amount) {
     if (buf->size < amount) return 0;
     return buf->start+(buf->size-=amount);
 }
 
-void *buf_unprepend(struct buffer_if *buf, uint32_t amount) {
+void *buf_unprepend(struct buffer_if *buf, int32_t amount) {
     void *p;
+    if (buf->size < amount) return 0;
     p=buf->start;
     buf->start+=amount;
     buf->size-=amount;
@@ -265,14 +282,15 @@ void *buf_unprepend(struct buffer_if *buf, uint32_t amount) {
    network byte order. */
 void buf_append_string(struct buffer_if *buf, cstring_t s)
 {
-    uint16_t len;
+    size_t len;
 
     len=strlen(s);
+    /* fixme: if string is longer than 65535, result is a corrupted packet */
     buf_append_uint16(buf,len);
     memcpy(buf_append(buf,len),s,len);
 }
 
-void buffer_new(struct buffer_if *buf, uint32_t len)
+void buffer_new(struct buffer_if *buf, int32_t len)
 {
     buf->free=True;
     buf->owner=NULL;
@@ -285,6 +303,34 @@ void buffer_new(struct buffer_if *buf, uint32_t len)
     buf->base=safe_malloc(len,"buffer_new");
 }
 
+void buffer_readonly_view(struct buffer_if *buf, const void *data, int32_t len)
+{
+    buf->free=False;
+    buf->owner="READONLY";
+    buf->flags=0;
+    buf->loc.file=NULL;
+    buf->loc.line=0;
+    buf->size=buf->len=len;
+    buf->base=buf->start=(uint8_t*)data;
+}
+
+void buffer_readonly_clone(struct buffer_if *out, const struct buffer_if *in)
+{
+    buffer_readonly_view(out,in->start,in->size);
+}
+
+void buffer_copy(struct buffer_if *dst, const struct buffer_if *src)
+{
+    if (dst->len < src->len) {
+       dst->base=realloc(dst->base,src->len);
+       if (!dst->base) fatal_perror("buffer_copy");
+       dst->len = src->len;
+    }
+    dst->start = dst->base + (src->start - src->base);
+    dst->size = src->size;
+    memcpy(dst->start, src->start, dst->size);
+}
+
 static list_t *buffer_apply(closure_t *self, struct cloc loc, dict_t *context,
                            list_t *args)
 {
@@ -335,7 +381,22 @@ static list_t *buffer_apply(closure_t *self, struct cloc loc, dict_t *context,
     return new_closure(&st->cl);
 }
 
-init_module util_module;
+int consttime_memeq(const void *s1in, const void *s2in, size_t n)
+{
+    const uint8_t *s1=s1in, *s2=s2in;
+    register volatile uint8_t accumulator=0;
+
+    while (n-- > 0) {
+       accumulator |= (*s1++ ^ *s2++);
+    }
+    accumulator |= accumulator >> 4; /* constant-time             */
+    accumulator |= accumulator >> 2; /*  boolean canonicalisation */
+    accumulator |= accumulator >> 1;
+    accumulator &= 1;
+    accumulator ^= 1;
+    return accumulator;
+}
+
 void util_module(dict_t *dict)
 {
     add_closure(dict,"sysbuffer",buffer_apply);