diff --git a/pdfio-crypto.c b/pdfio-crypto.c
index 2a37670..e0a9a06 100644
--- a/pdfio-crypto.c
+++ b/pdfio-crypto.c
@@ -80,7 +80,7 @@ static const uint8_t Rcon[11] =		// Round constants
 // Local functions...
 //
 
-static void	AddRoundKey(uint8_t round, state_t *state, const uint8_t *RoundKey);
+static void	AddRoundKey(size_t round, state_t *state, const uint8_t *RoundKey);
 static void	SubBytes(state_t *state);
 static void	ShiftRows(state_t *state);
 static uint8_t	xtime(uint8_t x);
@@ -252,7 +252,7 @@ _pdfioCryptoAESEncrypt(
 // This function adds the round key to state.
 // The round key is added to the state by an XOR function.
 static void
-AddRoundKey(uint8_t round, state_t *state, const uint8_t *RoundKey)
+AddRoundKey(size_t round, state_t *state, const uint8_t *RoundKey)
 {
   unsigned	i;			// Looping var
   uint8_t	*sptr = (*state)[0];	// Pointer into state
@@ -314,7 +314,7 @@ ShiftRows(state_t *state)
 static uint8_t
 xtime(uint8_t x)
 {
-  return ((x << 1) ^ ((x >> 7) * 0x1b));
+  return ((uint8_t)((x << 1) ^ ((x >> 7) * 0x1b)));
 }
 
 
@@ -466,7 +466,7 @@ Cipher(state_t *state, const _pdfio_aes_t *ctx)
 static void
 InvCipher(state_t *state, const _pdfio_aes_t *ctx)
 {
-  uint8_t round = 0;
+  size_t round;
 
   // Add the First round key to the state before starting the rounds.
   AddRoundKey(ctx->round_size, state, ctx->round_key);
diff --git a/pdfio-md5.c b/pdfio-md5.c
index 2561b35..45e1511 100644
--- a/pdfio-md5.c
+++ b/pdfio-md5.c
@@ -281,7 +281,7 @@ _pdfioCryptoMD5Append(_pdfio_md5_t *pms, const uint8_t *data, size_t nbytes)
 {
     const uint8_t *p = data;
     size_t left = nbytes;
-    int offset = (pms->count[0] >> 3) & 63;
+    size_t offset = (pms->count[0] >> 3) & 63;
     uint32_t nbits = (uint32_t)(nbytes << 3);
 
     if (nbytes == 0)
@@ -295,7 +295,7 @@ _pdfioCryptoMD5Append(_pdfio_md5_t *pms, const uint8_t *data, size_t nbytes)
 
     /* Process an initial partial block. */
     if (offset) {
-	int copy = (offset + nbytes > 64 ? 64 - offset : nbytes);
+	size_t copy = (offset + nbytes > 64 ? 64 - offset : nbytes);
 
 	memcpy(pms->buf + offset, p, copy);
 	if (offset + copy < 64)
diff --git a/pdfio.xcodeproj/project.pbxproj b/pdfio.xcodeproj/project.pbxproj
index a80d998..39a0005 100644
--- a/pdfio.xcodeproj/project.pbxproj
+++ b/pdfio.xcodeproj/project.pbxproj
@@ -26,6 +26,9 @@
 		279E1036267D043B00D3A349 /* ttf.c in Sources */ = {isa = PBXBuildFile; fileRef = 279E1034267D043B00D3A349 /* ttf.c */; };
 		279E103B267D04E600D3A349 /* libz.tbd in Frameworks */ = {isa = PBXBuildFile; fileRef = 279E103A267D04E600D3A349 /* libz.tbd */; };
 		27ECBD8926419DAB0025312A /* libpdfio.a in Frameworks */ = {isa = PBXBuildFile; fileRef = 273440B0263D6FE200FBFD63 /* libpdfio.a */; };
+		27F2F0602710BE92008ECD36 /* pdfio-md5.c in Sources */ = {isa = PBXBuildFile; fileRef = 27F2F05D2710BE92008ECD36 /* pdfio-md5.c */; };
+		27F2F0612710BE92008ECD36 /* pdfio-rc4.c in Sources */ = {isa = PBXBuildFile; fileRef = 27F2F05E2710BE92008ECD36 /* pdfio-rc4.c */; };
+		27F2F0622710BE92008ECD36 /* pdfio-crypto.c in Sources */ = {isa = PBXBuildFile; fileRef = 27F2F05F2710BE92008ECD36 /* pdfio-crypto.c */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -79,6 +82,9 @@
 		279E1033267D043B00D3A349 /* ttf.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ttf.h; sourceTree = "<group>"; };
 		279E1034267D043B00D3A349 /* ttf.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = ttf.c; sourceTree = "<group>"; };
 		279E103A267D04E600D3A349 /* libz.tbd */ = {isa = PBXFileReference; lastKnownFileType = "sourcecode.text-based-dylib-definition"; name = libz.tbd; path = usr/lib/libz.tbd; sourceTree = SDKROOT; };
+		27F2F05D2710BE92008ECD36 /* pdfio-md5.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = "pdfio-md5.c"; sourceTree = "<group>"; };
+		27F2F05E2710BE92008ECD36 /* pdfio-rc4.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = "pdfio-rc4.c"; sourceTree = "<group>"; };
+		27F2F05F2710BE92008ECD36 /* pdfio-crypto.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = "pdfio-crypto.c"; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -153,16 +159,19 @@
 				273440BA263D727800FBFD63 /* pdfio-array.c */,
 				273440BB263D727800FBFD63 /* pdfio-common.c */,
 				271EA703265B2B1000ACDD39 /* pdfio-content.c */,
+				27F2F05F2710BE92008ECD36 /* pdfio-crypto.c */,
 				273440BE263D727800FBFD63 /* pdfio-dict.c */,
 				273440BD263D727800FBFD63 /* pdfio-file.c */,
+				27F2F05D2710BE92008ECD36 /* pdfio-md5.c */,
 				273440BC263D727800FBFD63 /* pdfio-object.c */,
 				273440C2263D727800FBFD63 /* pdfio-page.c */,
+				27F2F05E2710BE92008ECD36 /* pdfio-rc4.c */,
 				273440BF263D727800FBFD63 /* pdfio-stream.c */,
 				273440B9263D727800FBFD63 /* pdfio-string.c */,
 				273440E3263DD7EA00FBFD63 /* pdfio-token.c */,
 				273440C0263D727800FBFD63 /* pdfio-value.c */,
-				279E1033267D043B00D3A349 /* ttf.h */,
 				279E1034267D043B00D3A349 /* ttf.c */,
+				279E1033267D043B00D3A349 /* ttf.h */,
 			);
 			name = Library;
 			sourceTree = "<group>";
@@ -281,11 +290,14 @@
 				273440CB263D727800FBFD63 /* pdfio-value.c in Sources */,
 				273440CA263D727800FBFD63 /* pdfio-stream.c in Sources */,
 				273440CD263D727800FBFD63 /* pdfio-page.c in Sources */,
+				27F2F0622710BE92008ECD36 /* pdfio-crypto.c in Sources */,
 				273440C5263D727800FBFD63 /* pdfio-array.c in Sources */,
 				273440E4263DD7EA00FBFD63 /* pdfio-token.c in Sources */,
 				273440C7263D727800FBFD63 /* pdfio-object.c in Sources */,
+				27F2F0602710BE92008ECD36 /* pdfio-md5.c in Sources */,
 				273440C4263D727800FBFD63 /* pdfio-string.c in Sources */,
 				271EA705265B2B1000ACDD39 /* pdfio-content.c in Sources */,
+				27F2F0612710BE92008ECD36 /* pdfio-rc4.c in Sources */,
 				273440C6263D727800FBFD63 /* pdfio-common.c in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;