diff --git a/core/crypto/rand_bsd.odin b/core/crypto/rand_bsd.odin
new file mode 100644
index 000000000..8e2be1d95
--- /dev/null
+++ b/core/crypto/rand_bsd.odin
@@ -0,0 +1,12 @@
+//+build freebsd, openbsd
+package crypto
+
+foreign import libc "system:c"
+
+foreign libc {
+	arc4random_buf :: proc(buf: [^]byte, nbytes: uint) ---
+}
+
+_rand_bytes :: proc(dst: []byte) {
+	arc4random_buf(raw_data(dst), len(dst))
+}
diff --git a/core/crypto/rand_darwin.odin b/core/crypto/rand_darwin.odin
new file mode 100644
index 000000000..ec44c1491
--- /dev/null
+++ b/core/crypto/rand_darwin.odin
@@ -0,0 +1,12 @@
+package crypto
+
+import "core:fmt"
+import "core:sys/darwin"
+
+_rand_bytes :: proc(dst: []byte) {
+	res := darwin.SecRandomCopyBytes(count=len(dst), bytes=raw_data(dst))
+	if res != .Success {
+		msg := darwin.CFStringCopyToOdinString(darwin.SecCopyErrorMessageString(res))
+		panic(fmt.tprintf("crypto/rand_bytes: SecRandomCopyBytes returned non-zero result: %v %s", res, msg))
+	}
+}
diff --git a/core/crypto/rand_generic.odin b/core/crypto/rand_generic.odin
index fde91f85a..bf7abbbe2 100644
--- a/core/crypto/rand_generic.odin
+++ b/core/crypto/rand_generic.odin
@@ -1,7 +1,11 @@
+//+build !linux
+//+build !windows
+//+build !openbsd
+//+build !freebsd
+//+build !darwin
+//+build !js
 package crypto
 
-when ODIN_OS != .Linux && ODIN_OS != .OpenBSD && ODIN_OS != .Windows && ODIN_OS != .JS {
-	_rand_bytes :: proc(dst: []byte) {
-		unimplemented("crypto: rand_bytes not supported on this OS")
-	}
+_rand_bytes :: proc(dst: []byte) {
+	unimplemented("crypto: rand_bytes not supported on this OS")
 }
diff --git a/core/crypto/rand_openbsd.odin b/core/crypto/rand_openbsd.odin
deleted file mode 100644
index bae97e8f0..000000000
--- a/core/crypto/rand_openbsd.odin
+++ /dev/null
@@ -1,12 +0,0 @@
-package crypto
-
-import "core:c"
-
-foreign import libc "system:c"
-foreign libc {
-	arc4random_buf :: proc "c" (buf: rawptr, nbytes: c.size_t) ---
-}
-
-_rand_bytes :: proc (dst: []byte) {
-	arc4random_buf(raw_data(dst), len(dst))
-}
diff --git a/core/math/big/internal.odin b/core/math/big/internal.odin
index 829cbf0e2..35c95f465 100644
--- a/core/math/big/internal.odin
+++ b/core/math/big/internal.odin
@@ -2046,9 +2046,9 @@ internal_int_inverse_modulo :: proc(dest, a, b: ^Int, allocator := context.alloc
 	if internal_is_positive(a) && internal_eq(b, 1) { return internal_zero(dest)	}
 
 	/*
-		`b` cannot be negative and has to be > 1
+		`b` cannot be negative and b has to be > 1
 	*/
-	if internal_is_negative(b) || internal_gt(b, 1) { return .Invalid_Argument }
+	if internal_is_negative(b) || !internal_gt(b, 1) { return .Invalid_Argument }
 
 	/*
 		If the modulus is odd we can use a faster routine instead.
@@ -2954,4 +2954,4 @@ internal_zero_unused :: proc { internal_int_zero_unused, }
 
 /*
 	==========================    End of low-level routines   ==========================
-*/
\ No newline at end of file
+*/
diff --git a/core/sys/darwin/core_foundation.odin b/core/sys/darwin/core_foundation.odin
new file mode 100644
index 000000000..eafe1a1f3
--- /dev/null
+++ b/core/sys/darwin/core_foundation.odin
@@ -0,0 +1,98 @@
+//+build darwin
+package darwin
+
+import "core:runtime"
+
+foreign import core_foundation "system:CoreFoundation.framework"
+
+CFTypeRef   :: distinct rawptr
+
+CFStringRef :: distinct CFTypeRef
+
+CFIndex :: int
+
+CFRange :: struct {
+	location: CFIndex,
+	length:   CFIndex,
+}
+
+CFStringEncoding :: enum u32 {
+	ASCII             = 1,
+	NEXTSTEP          = 2,
+	JapaneseEUC       = 3,
+	UTF8              = 4,
+	ISOLatin1         = 5,
+	Symbol            = 6,
+	NonLossyASCII     = 7,
+	ShiftJIS          = 8,
+	ISOLatin2         = 9,
+	Unicode           = 10,
+	WindowsCP1251     = 11,
+	WindowsCP1252     = 12,
+	WindowsCP1253     = 13,
+	WindowsCP1254     = 14,
+	WindowsCP1250     = 15,
+	ISO2022JP         = 21,
+	MacOSRoman        = 30,
+
+	UTF16             = Unicode,
+
+	UTF16BigEndian    = 0x90000100,
+	UTF16LittleEndian = 0x94000100,
+
+	UTF32             = 0x8c000100,
+	UTF32BigEndian    = 0x98000100,
+	UTF32LittleEndian = 0x9c000100,
+}
+
+foreign core_foundation {
+	// Copies the character contents of a string to a local C string buffer after converting the characters to a given encoding.
+	CFStringGetCString :: proc(theString: CFStringRef, buffer: [^]byte, bufferSize: CFIndex, encoding: CFStringEncoding) -> Bool ---
+	
+	// Returns the number (in terms of UTF-16 code pairs) of Unicode characters in a string.
+	CFStringGetLength :: proc(theString: CFStringRef) -> CFIndex ---
+	
+	// Returns the maximum number of bytes a string of a specified length (in Unicode characters) will take up if encoded in a specified encoding.
+	CFStringGetMaximumSizeForEncoding :: proc(length: CFIndex, encoding: CFStringEncoding) -> CFIndex ---
+	
+	// Fetches a range of the characters from a string into a byte buffer after converting the characters to a specified encoding.
+	CFStringGetBytes :: proc(
+		thestring: CFStringRef,
+		range: CFRange,
+		encoding: CFStringEncoding,
+		lossByte: u8,
+		isExternalRepresentation: Bool,
+		buffer: [^]byte,
+		maxBufLen: CFIndex,
+		usedBufLen: ^CFIndex,
+	) -> CFIndex ---
+	
+	// Releases a Core Foundation object.
+	@(link_name="CFRelease")
+	_CFRelease :: proc(cf: CFTypeRef) ---
+}
+
+// Releases a Core Foundation object.
+CFRelease :: proc {
+	CFReleaseString,
+}
+
+// Releases a Core Foundation string.
+CFReleaseString :: #force_inline proc(theString: CFStringRef) {
+	_CFRelease(CFTypeRef(theString))
+}
+
+CFStringCopyToOdinString :: proc(theString: CFStringRef, allocator := context.allocator) -> (str: string, ok: bool) #optional_ok {
+	length := CFStringGetLength(theString)
+	max    := CFStringGetMaximumSizeForEncoding(length, .UTF8)
+
+	buf, err := make([]byte, max, allocator)
+	if err != nil { return }
+	
+	raw_str := runtime.Raw_String{
+		data = raw_data(buf),
+	}
+	CFStringGetBytes(theString, {0, length}, .UTF8, 0, false, raw_data(buf), max, &raw_str.len)
+
+	return transmute(string)raw_str, true
+}
diff --git a/core/sys/darwin/darwin.odin b/core/sys/darwin/darwin.odin
new file mode 100644
index 000000000..0b3efb1f5
--- /dev/null
+++ b/core/sys/darwin/darwin.odin
@@ -0,0 +1,4 @@
+//+build darwin
+package darwin
+
+Bool :: b8
diff --git a/core/sys/darwin/security.odin b/core/sys/darwin/security.odin
new file mode 100644
index 000000000..0c58260e7
--- /dev/null
+++ b/core/sys/darwin/security.odin
@@ -0,0 +1,26 @@
+//+build darwin
+package darwin
+
+foreign import security "system:Security.framework"
+
+// A reference to a random number generator.
+SecRandomRef :: distinct rawptr
+
+OSStatus :: distinct i32
+
+errSec :: enum OSStatus {
+	Success       = 0,  // No error.
+	Unimplemented = -4, // Function or operation not implemented.
+
+	// Many more...
+}
+
+foreign security {
+	// Synonym for nil, uses a cryptographically secure random number generator.
+	kSecRandomDefault: SecRandomRef
+	
+	// Generates an array of cryptographically secure random bytes.
+	SecRandomCopyBytes :: proc(rnd: SecRandomRef = kSecRandomDefault, count: uint, bytes: [^]byte) -> errSec ---
+
+	SecCopyErrorMessageString :: proc(status: errSec, reserved: rawptr = nil) -> CFStringRef ---
+}