add? update

client.cpp

@@ -46,13 +46,19 @@ int stream_encrypt(unsigned char *plaintext, int plaintext_len, unsigned char *k
 
     /* Initialise the encryption operation. */
     // choice for aes_256 ref: https://stackoverflow.com/questions/1220751/how-to-choose-an-aes-encryption-mode-cbc-ecb-ctr-ocb-cfb
-    EVP_EncryptInit_ex(ctx, EVP_aes_256_ctr(), NULL, key, iv);
+    if (EVP_EncryptInit_ex(ctx, EVP_aes_256_ctr(), NULL, key, iv) != 1){
+        ERR_print_errors_fp(stderr);
+    }
 
     /* Provide the message to be encrypted, and obtain the encrypted output. EVP_EncryptUpdate can be called multiple times if necessary */
-    EVP_EncryptUpdate(ctx, ciphertext, &len, plaintext, plaintext_len);
+    if (EVP_EncryptUpdate(ctx, ciphertext, &len, plaintext, plaintext_len) != 1) {
+        ERR_print_errors_fp(stderr);
+    }
 
     /* Finalize the encryption. Further cipher text bytes may be written at this stage. */
-    EVP_EncryptFinal_ex(ctx, ciphertext + len, &ciphertext_len);
+    if (EVP_EncryptFinal_ex(ctx, ciphertext + len, &ciphertext_len) != 1) {
+        ERR_print_errors_fp(stderr);
+    }
 
     /* Clean up */
     EVP_CIPHER_CTX_free(ctx);

compile.sh

@@ -19,6 +19,10 @@ file bin/server bin/client || true
 
 chmod a+x bin/server bin/client
 
+# clean up existing containers and networks
+docker compose down
+
+# start the containers
 docker compose up -d server
 docker compose run --rm -it client
 

server.cpp

@@ -45,13 +45,19 @@ int stream_decrypt(unsigned char *ciphertext, int ciphertext_len, unsigned char
     ctx = EVP_CIPHER_CTX_new();
 
     /* Initialise the decryption operation. */
-    EVP_DecryptInit_ex(ctx, EVP_aes_256_ctr(), NULL, key, iv);
+    if (EVP_DecryptInit_ex(ctx, EVP_aes_256_ctr(), NULL, key, iv) != 1){
+        ERR_print_errors_fp(stderr);
+    }
 
     /* Provide the message to be decrypted, and obtain the plaintext output. EVP_DecryptUpdate can be called multiple times if necessary */
-    EVP_DecryptUpdate(ctx, plaintext, &len, ciphertext, ciphertext_len);
+    if (EVP_DecryptUpdate(ctx, plaintext, &len, ciphertext, ciphertext_len) != 1) {
+        ERR_print_errors_fp(stderr);
+    }
 
     /* Finalize the decryption. Further plaintext bytes may be written at this stage. */
-    EVP_DecryptFinal_ex(ctx, plaintext + len, &plaintext_len);
+    if (EVP_DecryptFinal_ex(ctx, plaintext + len, &plaintext_len) != 1) {
+        ERR_print_errors_fp(stderr);
+    }
 
     /* Clean up */
     EVP_CIPHER_CTX_free(ctx);