add asprintf / vasprintf from OpenSSH portable

ok deraadt@ beck@

2 files changed, 98 insertions, 0 deletions

diff --git a/crypto/Makefile.am.tpl b/crypto/Makefile.am.tpl
index 6ac6c4f..7688fb9 100644
--- a/crypto/Makefile.am.tpl
+++ b/crypto/Makefile.am.tpl
@@ -38,6 +38,10 @@ libcompat_la_SOURCES += compat/strndup.c
 libcompat_la_SOURCES += compat/strnlen.c
 endif
 
+if NO_ASPRINTF
+libcompat_la_SOURCES += compat/asprintf.c
+endif
+
 if NO_REALLOCARRAY
 libcompat_la_SOURCES += compat/reallocarray.c
 endif
diff --git a/crypto/compat/asprintf.c b/crypto/compat/asprintf.c
new file mode 100644
index 0000000..45a539d
--- /dev/null
+++ b/crypto/compat/asprintf.c
@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) 2004 Darren Tucker.
+ *
+ * Based originally on asprintf.c from OpenBSD:
+ * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <errno.h>
+#include <stdarg.h>
+#include <stdlib.h>
+
+#ifndef VA_COPY
+# ifdef HAVE_VA_COPY
+#  define VA_COPY(dest, src) va_copy(dest, src)
+# else
+#  ifdef HAVE___VA_COPY
+#   define VA_COPY(dest, src) __va_copy(dest, src)
+#  else
+#   define VA_COPY(dest, src) (dest) = (src)
+#  endif
+# endif
+#endif
+
+#define INIT_SZ 128
+
+int
+vasprintf(char **str, const char *fmt, va_list ap)
+{
+        int ret = -1;
+        va_list ap2;
+        char *string, *newstr;
+        size_t len;
+
+        VA_COPY(ap2, ap);
+        if ((string = malloc(INIT_SZ)) == NULL)
+                goto fail;
+
+        ret = vsnprintf(string, INIT_SZ, fmt, ap2);
+        if (ret >= 0 && ret < INIT_SZ) { /* succeeded with initial alloc */
+                *str = string;
+        } else if (ret == INT_MAX || ret < 0) { /* Bad length */
+                free(string);
+                goto fail;
+        } else {        /* bigger than initial, realloc allowing for nul */
+                len = (size_t)ret + 1;
+                if ((newstr = realloc(string, len)) == NULL) {
+                        free(string);
+                        goto fail;
+                } else {
+                        va_end(ap2);
+                        VA_COPY(ap2, ap);
+                        ret = vsnprintf(newstr, len, fmt, ap2);
+                        if (ret >= 0 && (size_t)ret < len) {
+                                *str = newstr;
+                        } else { /* failed with realloc'ed string, give up */
+                                free(newstr);
+                                goto fail;
+                        }
+                }
+        }
+        va_end(ap2);
+        return (ret);
+
+fail:
+        *str = NULL;
+        errno = ENOMEM;
+        va_end(ap2);
+        return (-1);
+}
+
+int asprintf(char **str, const char *fmt, ...)
+{
+        va_list ap;
+        int ret;
+        
+        *str = NULL;
+        va_start(ap, fmt);
+        ret = vasprintf(str, fmt, ap);
+        va_end(ap);
+
+        return ret;
+}