Incoming packet validation and header data.

.gitignore

@@ -1,2 +1,6 @@
 # Python virtual env
 /venv
+
+# VSOutput
+**/.vs/**
+**/out/**

docs/libaaa/index.md

@@ -0,0 +1,8 @@
+# LibAAA a Bare-Bone C radius packet library
+
+The following pages will explain the usage of the libaaa library. The lib is composed out of the following components:
+
+- `libaaa_pg`: C-API for packet generation 
+- `libaaa_pr`: C-API for packet reading/parsing
+- `libaaa::packet_generator`: C++ OOP wrapper for packet generation
+- `libaaa::packet_reader`: C++ OOP wrapper for packet reading/parsing 

libaaa/include/libaaa/libaaa.h

@@ -44,6 +44,9 @@
 //
 #define LIBAAA_OK 0
 #define LIBAAA_ERROR -1
+#define LIBAAA_PACKET_INVALID_LENGTH -2
+#define LIBAAA_PACKET_VALIDATION_FAILED -3
+#define LIBAAA_PACKET_INVALID_BODY -4
 
 #define LIBAAA_PACKET_MAX_SIZE 4096
 #define LIBAAA_PG_CONTEXT_SIZE 64
@@ -334,6 +337,38 @@ LIBAAA_API int libaaa_pg_write_integer64(libaaa_pg_context_t context, uint64_t v
 // === API "pr" (Packet Reader) ===
 //
 
+/*!
+ * @brief Generic packet validation (before parsing it). This will NOT catch all possible issues!
+ * 
+ * - Validates input_size
+ * - Validates packet header (size)
+ * - Validates packet header values
+ * - Validates all packets attributes size (in attribute and across packet)
+ * @param input_buffer Received network packet data
+ * @param input_size Size of the packet
+ * @return status code
+ * - LIBAAA_OK: Packet validated successfully
+ * - LIBAAA_PACKET_INVALID_LENGTH: Packet does not contain a radius header / is invalid in it's length
+ * - LIBAAA_PACKET_VALIDATION_FAILED: Packet is not a valid radius packet
+ * - LIBAAA_PACKET_INVALID_BODY: Packet's body is not valid in itself or with the header
+*/
+LIBAAA_API int libaaa_pr_validate_packet(const void* input_buffer, int input_size);
+
+/*!
+ * @brief Retrieves non attribute detail from the packet. 
+ * 
+ * Only unse this function when the packet has been validated by the "libaaa_pr_validate_packet" function.
+ * This function can be called on the following return values from "libaaa_pr_validate_packet": 
+ * LIBAAA_OK, LIBAAA_PACKET_VALIDATION_FAILED, LIBAAA_PACKET_INVALID_BODY
+ * 
+ * @param input_buffer Input buffer to read header from
+ * @param code Output radius code
+ * @param identifier Output radius identifier
+ * @param authenticator Output radius authenticator (16-Bytes)
+ * @return 
+*/
+LIBAAA_API void libaaa_pr_get_packet_details(const void* input_buffer, libaaa_radius_code_t* code, uint8_t* identifier, char* authenticator);
+
 #ifdef __cplusplus
 }
 #endif // __cplusplus

libaaa/src/libaaa.c

@@ -240,7 +240,7 @@ LIBAAA_API int libaaa_pg_finalize(libaaa_pg_context_t context)
     __libaaa_ats_finish(ctx);
 
     // Write packet length and return it
-    __libaaa_hton(&ctx->buffer_head, &ctx->buffer[__LIBAAA_PO_HEADER_LENGTH], 2);
+    __libaaa_hton((char*)&ctx->buffer_head, (char*)&ctx->buffer[__LIBAAA_PO_HEADER_LENGTH], 2);
     return ctx->buffer_head;
 }
 
@@ -364,7 +364,7 @@ LIBAAA_API int libaaa_pg_attribute_begin_extended_vendor_specific(libaaa_pg_cont
 LIBAAA_API int libaaa_pg_write_integer(libaaa_pg_context_t context, uint32_t value)
 {
     uint32_t swap;
-    __libaaa_hton(&value, &swap, sizeof(uint32_t));
+    __libaaa_hton((char*)&value, (char*)&swap, sizeof(uint32_t));
     return __libaaa_ats_write(context, &swap, sizeof(uint32_t));
 }
 
@@ -489,6 +489,64 @@ LIBAAA_API int libaaa_pg_write_ipv4prefix(libaaa_pg_context_t context, uint8_t p
 LIBAAA_API int libaaa_pg_write_integer64(libaaa_pg_context_t context, uint64_t value)
 {
     uint64_t swap;
-    __libaaa_hton(&value, &swap, sizeof(uint64_t));
+    __libaaa_hton((char*)&value, (char*)&swap, sizeof(uint64_t));
     return __libaaa_ats_write(context, &swap, sizeof(uint64_t));
 }
+
+LIBAAA_API int libaaa_pr_validate_packet(const void* input_buffer,  int input_size)
+{
+    // (1) Network size
+    if(input_size < 20 || input_size > LIBAAA_PACKET_MAX_SIZE)
+    {
+        return LIBAAA_PACKET_INVALID_LENGTH;
+    }
+
+    // (2) Packet size
+    uint16_t packet_size = 0;
+    __libaaa_ntoh(&((const char*)input_buffer)[__LIBAAA_PO_HEADER_LENGTH], (char*)&packet_size, sizeof(uint16_t));
+    if (packet_size > input_size)
+    {
+        return LIBAAA_PACKET_VALIDATION_FAILED;
+    }
+
+    // (3) Packet header
+    uint8_t radius_code = ((const char*)input_buffer)[__LIBAAA_PO_HEADER_CODE];
+    if (radius_code == 0 || (radius_code > 5 && radius_code < 11) || radius_code > 13)
+    {
+        return LIBAAA_PACKET_VALIDATION_FAILED;
+    }
+
+    // (4) Attributes 
+    uint64_t offset = 20;
+    while (offset < packet_size)
+    {
+        // THIS
+        const char* attribute = &((const char*)input_buffer)[offset];
+        uint8_t attribute_len = attribute[__LIBAAA_PO_ATTRIBUTE_LENGTH];
+
+        // Attribute bounds
+        if (offset + attribute_len > packet_size)
+        {
+            return LIBAAA_PACKET_INVALID_BODY;
+        }
+        // Attribute size
+        if (attribute_len < 2)
+        {
+            return LIBAAA_PACKET_INVALID_BODY;
+        }
+
+        // NEXT
+        offset += attribute_len;
+    }
+
+    // Passed
+    return LIBAAA_OK;
+}
+
+LIBAAA_API void libaaa_pr_get_packet_details(const void* input_buffer, libaaa_radius_code_t* code, uint8_t* identifier, char* authenticator)
+{
+    *code = ((const char*)input_buffer)[__LIBAAA_PO_HEADER_CODE];
+    *identifier = ((const char*)input_buffer)[__LIBAAA_PO_HEADER_IDENTIFIER];
+    memcpy(authenticator, &((const char*)input_buffer)[__LIBAAA_PO_HEADER_AUTHENTICATOR], 16);
+}
+

libaaa/test/CMakeLists.txt

@@ -14,6 +14,8 @@ add_executable(libaaa_test
     ./tests/pg_empty.cpp
     ./tests/pg_attribute.cpp
     ./tests/pg_x_attribute.cpp
+    ./tests/pr_validation.cpp
+    ./tests/pr_header_data.cpp
 )
 
 target_link_libraries(libaaa_test PUBLIC GTest::gtest GTest::gtest_main GTest::gmock)

libaaa/test/tests/pr_facade.h

@@ -0,0 +1,9 @@
+#include "libaaa_test.h"
+
+class libaaa_pr_test : public ::testing::Test
+{
+    protected:
+        virtual void SetUp() override
+        {
+        }
+};

libaaa/test/tests/pr_header_data.cpp

@@ -0,0 +1,34 @@
+#include "pr_facade.h"
+
+class pr_header_data : public libaaa_pr_test {};
+
+TEST_F(pr_header_data, extract)
+{
+    // Expected values
+    uint8_t expected_code = 22;
+    uint8_t expected_id = 111;
+    uint8_t expected_authenticator[] = {
+        0x1A, 0x2A, 0x3A, 0x4A, 0x5A, 0x6A, 0x7A, 0x8A,
+        0x1B, 0x2B, 0x3B, 0x4B, 0x5B, 0x6B, 0x7B, 0x8B,
+    };
+
+    // Target values
+    uint8_t code = 0;
+    uint8_t id = 0;
+    uint8_t authenticator[16];
+    memset(authenticator, 0x0, 16);
+
+    // Retrieve packet
+    uint8_t packet[] = {
+        22, 111,                                        // Code, ID
+        0, 20,                                          // Length 
+        0x1A, 0x2A, 0x3A, 0x4A, 0x5A, 0x6A, 0x7A, 0x8A, // Authenticator
+        0x1B, 0x2B, 0x3B, 0x4B, 0x5B, 0x6B, 0x7B, 0x8B, // ...
+    };
+
+    libaaa_pr_get_packet_details(packet, &code, &id, (char*)authenticator);
+
+    EXPECT_EQ(code, expected_code);
+    EXPECT_EQ(id, expected_id);
+    ASSERT_THAT(authenticator, PacketCheck(expected_authenticator, 16));
+}

libaaa/test/tests/pr_validation.cpp

@@ -0,0 +1,96 @@
+#include "pr_facade.h"
+
+class pr_validation : public libaaa_pr_test {};
+
+TEST_F(pr_validation, size_invalid)
+{
+    // Retrieve packet
+    uint8_t packet[] = {
+        0, 0, 0, 0,
+    };
+
+    EXPECT_EQ(libaaa_pr_validate_packet(packet, 4), LIBAAA_PACKET_INVALID_LENGTH);
+}
+
+TEST_F(pr_validation, header_valid)
+{
+    // Retrieve packet
+    uint8_t packet[] = {
+        1, 2,                   // Code, ID
+        0, 20,                  // Length 
+        0, 0, 0, 0, 0, 0, 0, 0, // Authenticator
+        0, 0, 0, 0, 0, 0, 0, 0, // ...
+    };
+
+    EXPECT_EQ(libaaa_pr_validate_packet(packet, 20), LIBAAA_OK);
+}
+
+TEST_F(pr_validation, header_valid_padding)
+{
+    // Retrieve packet
+    uint8_t packet[] = {
+        1, 2,                   // Code, ID
+        0, 20,                  // Length 
+        0, 0, 0, 0, 0, 0, 0, 0, // Authenticator
+        0, 0, 0, 0, 0, 0, 0, 0, // ...
+        0, 0, 0, 0, 0, 0, 0, 0, 
+        0, 0, 0, 0,
+    };
+
+    EXPECT_EQ(libaaa_pr_validate_packet(packet, 32), LIBAAA_OK);
+}
+
+TEST_F(pr_validation, header_invalid)
+{
+    // Retrieve packet
+    uint8_t packet[] = {
+        160, 2,                 // Code, ID
+        0, 20,                  // Length 
+        0, 0, 0, 0, 0, 0, 0, 0, // Authenticator
+        0, 0, 0, 0, 0, 0, 0, 0, // ...
+    };
+
+    EXPECT_EQ(libaaa_pr_validate_packet(packet, 20), LIBAAA_PACKET_VALIDATION_FAILED);
+}
+
+TEST_F(pr_validation, attribute_valid)
+{
+    // Retrieve packet
+    uint8_t packet[] = {
+        1, 2,                   // Code, ID
+        0, 22,                  // Length 
+        0, 0, 0, 0, 0, 0, 0, 0, // Authenticator
+        0, 0, 0, 0, 0, 0, 0, 0, // ...
+        5, 2,
+    };
+
+    EXPECT_EQ(libaaa_pr_validate_packet(packet, 22), LIBAAA_OK);
+}
+
+TEST_F(pr_validation, attribute_invalid)
+{
+    // Retrieve packet
+    uint8_t packet[] = {
+        1, 2,                   // Code, ID
+        0, 22,                  // Length 
+        0, 0, 0, 0, 0, 0, 0, 0, // Authenticator
+        0, 0, 0, 0, 0, 0, 0, 0, // ...
+        5, 0,
+    };
+
+    EXPECT_EQ(libaaa_pr_validate_packet(packet, 22), LIBAAA_PACKET_INVALID_BODY);
+}
+
+TEST_F(pr_validation, attribute_header_missmatch)
+{
+    // Retrieve packet
+    uint8_t packet[] = {
+        1, 2,                   // Code, ID
+        0, 22,                  // Length 
+        0, 0, 0, 0, 0, 0, 0, 0, // Authenticator
+        0, 0, 0, 0, 0, 0, 0, 0, // ...
+        5, 5, 0, 0, 0,          // <-- Valid attributes but invalid header size
+    };
+
+    EXPECT_EQ(libaaa_pr_validate_packet(packet, 25), LIBAAA_PACKET_INVALID_BODY);
+}

mkdocs.yml

@@ -22,7 +22,22 @@ nav:
   - About: "index.md"
   - LibAAA: 
     - About: "libaaa/index.md"
-    - Reference: "libaaa/reference.md"
+    - libaaa_pg:
+      - Reference: "libaaa/libaaa_pg/reference.md"
+      - User Guide: "libaaa/libaaa_pg/guide.md"
+      - Example: "libaaa/libaaa_pg/example.md"
+    - libaaa_pr:
+      - Reference: "libaaa/libaaa_pr/reference.md"
+      - User Guide: "libaaa/libaaa_pr/guide.md"
+      - Example: "libaaa/libaaa_pr/example.md"
+    - "libaaa::packet_generator":
+      - Reference: "libaaa/packet_generator/reference.md"
+      - User Guide: "libaaa/packet_generator/guide.md"
+      - Example: "libaaa/packet_generator/example.md"
+    - "libaaa::packet_reader":
+      - Reference: "libaaa/packet_reader/reference.md"
+      - User Guide: "libaaa/packet_reader/guide.md"
+      - Example: "libaaa/packet_reader/example.md"
   - LibAAA-Server: "libaaa-server/index.md"
   - LibAAA-Client: "libaaa-client/index.md"