From 3b2b2034159a3f602ebdd218066745e853b637e5 Mon Sep 17 00:00:00 2001
From: Sascha Tommasone <sascha@tommasone.me>
Date: Sat, 6 Jul 2024 14:48:43 +0200
Subject: [PATCH] [Assignment-7] add first staff public key; enabled request
 verification

---
 7-SGX_Hands-on/src/enclave/enclave.c | 52 ++++++++++++++++------------
 1 file changed, 30 insertions(+), 22 deletions(-)

diff --git a/7-SGX_Hands-on/src/enclave/enclave.c b/7-SGX_Hands-on/src/enclave/enclave.c
index 4d2e1f5..c68cd5b 100644
--- a/7-SGX_Hands-on/src/enclave/enclave.c
+++ b/7-SGX_Hands-on/src/enclave/enclave.c
@@ -65,8 +65,18 @@ const sgx_ec256_public_t authorized[2] = {
         0
     },
     {
-        0,
-        0
+        .gx = {
+            0x76, 0xe5, 0x50, 0x5e, 0x61, 0xf5, 0x2b, 0xea, 
+            0x1c, 0x49, 0x29, 0xef, 0xd2, 0x5f, 0x4f, 0x29,
+            0xd0, 0xb6, 0xfb, 0x1c, 0x4f, 0x42, 0xb5, 0x72,
+            0x00, 0x10, 0x18, 0x1a, 0x4f, 0xa3, 0x96, 0x8d
+        },
+        .gy = {
+            0xa1, 0xba, 0x0a, 0x47, 0xf1, 0xa5, 0xa4, 0x9d,
+            0xf4, 0x7d, 0x71, 0x34, 0xce, 0x2f, 0x2e, 0x93,
+            0xec, 0x04, 0xb1, 0xdd, 0xad, 0xb6, 0x4b, 0xa0,
+            0xdf, 0xb5, 0xc4, 0xf3, 0xf9, 0xa6, 0x58, 0xb2
+        }
     }
 };
 
@@ -215,7 +225,9 @@ static sgx_status_t verify_signature(const uint8_t *data, uint32_t data_size, co
 
 sgx_status_t sign_firmware(const uint8_t *data, uint32_t data_size, const uint8_t *sealed, uint32_t sealed_size, uint8_t *public_key, uint8_t *signature) {
     // invalid parameter handling
-    if((data == NULL) || (data_size == 0) || (public_key == NULL) || (signature == NULL)) {
+    if((data == NULL) || (data_size == 0)) {
+        return SGX_ERROR_INVALID_PARAMETER;
+    } else if((public_key == NULL) || (signature == NULL)) {
         return SGX_ERROR_INVALID_PARAMETER;
     } else if((sealed == NULL) || (sealed_size != get_sealed_size())) {
         return SGX_ERROR_INVALID_PARAMETER;
@@ -224,9 +236,8 @@ sgx_status_t sign_firmware(const uint8_t *data, uint32_t data_size, const uint8_
     // verify public key
     for(size_t i = 0; i < sizeof(authorized)/sizeof(authorized[0]); i++) {
         if(memcmp(public_key, authorized[i].gx, PK_SIZE) == 0) {
-            continue;
+            goto sign;
         }
-        goto sign;
     }
     return SGX_ERROR_UNEXPECTED;
     
@@ -244,34 +255,25 @@ sgx_status_t sign_firmware(const uint8_t *data, uint32_t data_size, const uint8_
     }
 
     // verify request
-    /*
     if((status = verify_signature(data, data_size, (const sgx_ec256_public_t *)public_key, (const sgx_ec256_signature_t *)signature)) != SGX_EC_VALID) {
-        sgx_ecc256_close_context(ecc_handle);
-        return status;
-    }*/
+        goto exit;
+    }
 
     // try unseal keypair
-    sgx_status_t seal_status;
-    if(seal_status = unseal_key_pair(sealed, &private, (sgx_ec256_public_t *)public_key) != SGX_SUCCESS) {
-        sgx_ecc256_close_context(ecc_handle);
-        return seal_status;
+    if(status = unseal_key_pair(sealed, &private, (sgx_ec256_public_t *)public_key) != SGX_SUCCESS) {
+        goto exit;
     }
 
     // create signature
     if((status = sgx_ecdsa_sign(data, data_size, &private, &ecc_signature, ecc_handle)) != SGX_SUCCESS) {
-        sgx_ecc256_close_context(ecc_handle);
-        return status;
+        goto exit;
     }
 
     // copy signature to return buffer
-    if(signature == NULL) {
-        sgx_ecc256_close_context(ecc_handle);
-        return SGX_ERROR_INVALID_PARAMETER;
-    }
-
     memcpy(signature, ecc_signature.x, SI_SIZE);
 
     // close ecc handle and return success
+    exit: ;
     sgx_ecc256_close_context(ecc_handle);
     return status;
 }
@@ -284,6 +286,8 @@ sgx_status_t verify_firmware(const uint8_t *data, uint32_t data_size, const uint
         return SGX_ERROR_INVALID_PARAMETER;
     } else if((sealed != NULL) && (public_key != NULL)) {
         return SGX_ERROR_INVALID_PARAMETER;
+    } else if((sealed_size != get_sealed_size()) && (public_key == NULL)) {
+        return SGX_ERROR_INVALID_PARAMETER;;
     }
 
     // declare needed structures
@@ -294,9 +298,13 @@ sgx_status_t verify_firmware(const uint8_t *data, uint32_t data_size, const uint
     if(public_key != NULL) {
         // verification only with authorized public keys
         for(size_t i = 0; i < sizeof(authorized)/sizeof(authorized[0]); i++) {
+            if(memcmp(public_key, authorized[i].gx, PK_SIZE) == 0) {
+                goto verify;
+            }
+        }   
+        return SGX_ERROR_UNEXPECTED;
 
-        }
-        
+        verify: ;
         // copy public key into struct
         memcpy(public.gx, public_key, PK_SIZE);
     } else {