m + add libsimple_random_bytes

Signed-off-by: Mattias Andrée <maandree@kth.se>

4 files changed, 47 insertions, 2 deletions

diff --git a/Makefile b/Makefile
index 4c2f411..95c3340 100644
--- a/Makefile
+++ b/Makefile
@@ -941,6 +941,7 @@ OBJ =\
 	qsort_ushortp.o\
 	qsort_ushortp_nul.o\
 	random_bits.o\
+	random_bytes.o\
 	random_float.o\
 	random_signed.o\
 	random_unsigned.o\
diff --git a/libsimple/random.h b/libsimple/random.h
index 29e3bbf..ecce38c 100644
--- a/libsimple/random.h
+++ b/libsimple/random.h
@@ -31,3 +31,6 @@ uintmax_t libsimple_random_bits(size_t bits, void *unused);
 uintmax_t libsimple_random_unsigned(uintmax_t (*rng)(size_t bits, void *user), void *user, uintmax_t min, uintmax_t max);
 intmax_t libsimple_random_signed(uintmax_t (*rng)(size_t bits, void *user), void *user, intmax_t min, intmax_t max);
 long double libsimple_random_float(uintmax_t (*rng)(size_t bits, void *user), void *user, long double min, long double postmax);
+
+/* TODO doc, man (since 1.7) */
+void *libsimple_random_bytes(uintmax_t (*rng)(size_t bits, void *user), void *user, void *buffer, size_t bytes);
diff --git a/random_bits.c b/random_bits.c
index 528b09e..a6d95a2 100644
--- a/random_bits.c
+++ b/random_bits.c
@@ -14,8 +14,10 @@ libsimple_random_bits(size_t bits, void *unused)
 		bits -= 8;
 	}
 
-	ret <<= bits;
-	ret |= (uintmax_t)(rand() & ((1 << bits) - 1));
+	if (bits) {
+		ret <<= bits;
+		ret |= (uintmax_t)(rand() & ((1 << bits) - 1));
+	}
 
 	(void) unused;
 	return ret;
diff --git a/random_bytes.c b/random_bytes.c
new file mode 100644
index 0000000..cd7416f
--- /dev/null
+++ b/random_bytes.c
@@ -0,0 +1,39 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#ifndef TEST
+
+
+void *
+libsimple_random_bytes(uintmax_t (*rng)(size_t bits, void *user), void *user, void *buffer, size_t bytes)
+{
+	char *buf = buffer;
+	uintmax_t rnd;
+
+	while (bytes >= sizeof(uintmax_t)) {
+		*(uintmax_t *)buf = (*rng)(sizeof(uintmax_t) * 8U, user);
+		bytes -= sizeof(uintmax_t);
+		buf = &buf[sizeof(uintmax_t)];
+	}
+
+	if (bytes) {
+		rnd = (*rng)(bytes * 8U, user);
+		while (bytes) {
+			*buf++ = (char)(rnd & 255U);
+			rnd >>= 8;
+		}
+	}
+
+	return buf;
+}
+
+
+#else
+#include "test.h"
+
+int
+main(void)
+{
+	return 0;
+}
+
+#endif