diff --git a/TPs/TP03/compile_commands.json b/TPs/TP03/compile_commands.json
new file mode 100644
index 0000000..469619e
--- /dev/null
+++ b/TPs/TP03/compile_commands.json
@@ -0,0 +1,17 @@
+[
+  {
+    "arguments": [
+      "/usr/bin/gcc",
+      "-c",
+      "-Wall",
+      "-O2",
+      "-I/opt/homebrew/opt/openssl@3.2/include",
+      "-o",
+      "pbenc_aes_ctr_hmac",
+      "pbenc_aes_ctr_hmac.c"
+    ],
+    "directory": "/Users/afonso/projects/University/4ano/2sem/ES/2324-G05/TPs/TP03",
+    "file": "/Users/afonso/projects/University/4ano/2sem/ES/2324-G05/TPs/TP03/pbenc_aes_ctr_hmac.c",
+    "output": "/Users/afonso/projects/University/4ano/2sem/ES/2324-G05/TPs/TP03/pbenc_aes_ctr_hmac"
+  }
+]
diff --git a/TPs/TP03/pbenc_aes_ctr_hmac b/TPs/TP03/pbenc_aes_ctr_hmac
new file mode 100755
index 0000000..cb20297
Binary files /dev/null and b/TPs/TP03/pbenc_aes_ctr_hmac differ
diff --git a/TPs/TP03/pbenc_aes_ctr_hmac.c b/TPs/TP03/pbenc_aes_ctr_hmac.c
index dc03ee6..79e823e 100644
--- a/TPs/TP03/pbenc_aes_ctr_hmac.c
+++ b/TPs/TP03/pbenc_aes_ctr_hmac.c
@@ -19,7 +19,7 @@ int aes_ctr(const char *input_file, const char *output_file, const unsigned char
 
 	int input_size = BUF_SIZE;
 	int output_size = input_size + (cipher_block_size - 1);
-	int u_len = 0, f_len = 0;
+	int f_len = 0;
 
 	unsigned char input_buf[input_size], output_buf[output_size];
 
@@ -45,30 +45,44 @@ int aes_ctr(const char *input_file, const char *output_file, const unsigned char
 		return 1;
 	}
 
-	// EVP_MAC *mac = EVP_MAC_fetch(NULL, "HMAC", NULL);
-	// if (!mac) {
-	// 	fprintf(stderr, "Error creating HMAC\n");
-	// 	fclose(finput);
-	// 	fclose(foutput);
-	// 	return 1;
-	// }
-	//
-	// EVP_MAC_CTX *hctx = NULL;
-	// if (!(hctx = EVP_MAC_CTX_new(mac))) {
-	// 	fprintf(stderr, "Error creating HMAC context\n");
-	// 	fclose(finput);
-	// 	fclose(foutput);
-	// 	return 1;
-	// }
-	// const OSSL_PARAM params[] = {OSSL_PARAM_UTF8_STRING(OSSL_MAC, "SHA256", 0), OSSL_PARAM_END};
+	EVP_MAC *mac = EVP_MAC_fetch(NULL, "HMAC", NULL);
+	if (!mac) {
+		fprintf(stderr, "Error creating HMAC\n");
+		fclose(finput);
+		fclose(foutput);
+		return 1;
+	}
 
-	// Set the digest type to SHA256
-	// if (EVP_MAC_CTX_set_params(hctx, EVP_sha256()) != 1) {
-	// 	fprintf(stderr, "Error setting HMAC digest type\n");
-	// 	fclose(finput);
-	// 	fclose(foutput);
-	// 	return 1;
-	// }
+	EVP_MAC_CTX *hctx = NULL;
+	if (!(hctx = EVP_MAC_CTX_new(mac))) {
+		fprintf(stderr, "Error creating HMAC context\n");
+		fclose(finput);
+		fclose(foutput);
+		return 1;
+	}
+
+	// Set parameters for HMAC algorithm
+	OSSL_PARAM params[2], *p = params;
+	const EVP_MD *md = EVP_sha256();
+	*p++ = OSSL_PARAM_construct_utf8_string("digest", (char *)EVP_MD_name(md), 0);
+	*p = OSSL_PARAM_construct_end();
+
+	unsigned char *hmac = malloc(32);
+	unsigned char *mac_input;
+	if (enc) {
+		mac_input = output_buf;
+	} else {
+		mac_input = input_buf;
+	}
+
+	fseek(finput, 0, SEEK_END);
+	long file_size = ftell(finput);
+	rewind(finput);
+	if (!enc) {
+		// Remove the size of the SALT, IV and HMAC from the file size
+		fseek(finput, 32, SEEK_SET);
+		file_size -= 64;
+	}
 
 	// If enc is 1, then we are encrypting, else we are decrypting
 	// If we are encrypting, we need to generate an IV
@@ -86,6 +100,7 @@ int aes_ctr(const char *input_file, const char *output_file, const unsigned char
 	} else {
 		// Seek forward by 16 bytes to ignore the salt
 		if (fseek(finput, 16, SEEK_SET) != 0) {
+
 			fprintf(stderr, "Error seeking to IV position in input file\n");
 			return 1;
 		}
@@ -102,7 +117,7 @@ int aes_ctr(const char *input_file, const char *output_file, const unsigned char
 		return 1;
 	}
 
-	if (EVP_MAC_init(hctx, key, 32, NULL) != 1) {
+	if (EVP_MAC_init(hctx, key, 32, params) != 1) {
 		fprintf(stderr, "ERROR: EVP_MAC_init failed. OpenSSL error: %s\n",
 				ERR_error_string(ERR_get_error(), NULL));
 		fclose(finput);
@@ -110,10 +125,15 @@ int aes_ctr(const char *input_file, const char *output_file, const unsigned char
 		return 1;
 	}
 
-	int read_size, len;
-	unsigned char *hmac = (unsigned char *)malloc(32);
-	while ((read_size = fread(input_buf, 1, BUF_SIZE, finput)) > 0) {
-		printf("Read %d bytes, passing through CipherUpdate...\n", read_size);
+	int len;
+	while (file_size > 0) {
+		if (file_size < BUF_SIZE) {
+			BUF_SIZE = file_size;
+		}
+		size_t read_size = fread(input_buf, 1, BUF_SIZE, finput);
+		if (read_size == 0) {
+			break;
+		}
 		if (EVP_CipherUpdate(ctx, output_buf, &len, input_buf, read_size) != 1) {
 			fprintf(stderr, "ERROR: EVP_CipherUpdate failed. OpenSSL error: %s\n",
 					ERR_error_string(ERR_get_error(), NULL));
@@ -121,17 +141,18 @@ int aes_ctr(const char *input_file, const char *output_file, const unsigned char
 			fclose(foutput);
 			return 1;
 		}
-		printf("\tGot back %d bytes from CipherUpdate...\n", len);
-		printf("Writing %d bytes to %s...\n", len, output_file);
+		if (EVP_MAC_update(hctx, mac_input, read_size) != 1) {
+			fprintf(stderr, "ERROR: EVP_MAC_update failed. OpenSSL error: %s\n",
+					ERR_error_string(ERR_get_error(), NULL));
+			fclose(finput);
+			fclose(foutput);
+			return 1;
+		}
 		if (fwrite(output_buf, 1, len, foutput) != len) {
 			fprintf(stderr, "Error writing to output file\n");
 			return 1;
 		}
-		printf("\tWrote %d bytes\n", len);
-		u_len += len;
-	}
-	if (read_size == -1) {
-		fprintf(stderr, "ERROR: Reading from the file %s failed.\n", input_file);
+		file_size -= read_size;
 	}
 
 	if (EVP_CipherFinal_ex(ctx, output_buf, &f_len) != 1) {
@@ -141,10 +162,22 @@ int aes_ctr(const char *input_file, const char *output_file, const unsigned char
 		fclose(foutput);
 		return 1;
 	}
-	printf("u_len: %d, f_len: %d\n", u_len, f_len);
+	size_t m_len = 0;
+	if (EVP_MAC_final(hctx, hmac, &m_len, 32) != 1) {
+		fprintf(stderr, "ERROR: EVP_MAC_final failed. OpenSSL error: %s\n",
+				ERR_error_string(ERR_get_error(), NULL));
+		fclose(finput);
+		fclose(foutput);
+		return 1;
+	}
+	if (m_len != 32) {
+		fprintf(stderr, "ERROR: HMAC length is not 32\n");
+		fclose(finput);
+		fclose(foutput);
+		return 1;
+	}
 
 	if (f_len) {
-		printf("Writing final %d bytes to %s...\n", f_len, output_file);
 		if (fwrite(output_buf, 1, f_len, foutput) != f_len) {
 			fprintf(stderr, "Error writing to output file\n");
 			fclose(finput);
@@ -152,7 +185,32 @@ int aes_ctr(const char *input_file, const char *output_file, const unsigned char
 			return 1;
 		}
 	}
-	printf("\tWrote last %d bytes\n", f_len);
+	if (enc) {
+		if (fwrite(hmac, 1, m_len, foutput) != m_len) {
+			fprintf(stderr, "Error writing HMAC to file\n");
+			fclose(finput);
+			fclose(foutput);
+			return 1;
+		}
+	} else {
+		unsigned char *hmac2 = malloc(32);
+		if (fread(hmac2, 1, 32, finput) != 32) {
+			fprintf(stderr, "Error reading HMAC from file\n");
+			fclose(finput);
+			fclose(foutput);
+			return 1;
+		}
+		int cmp = memcmp(hmac, hmac2, 32);
+		if (cmp == 0) {
+			printf("HMACs match\n");
+		} else {
+			fprintf(stderr, "HMACs do not match\n");
+			fclose(finput);
+			fclose(foutput);
+			return 1;
+		}
+	}
+
 	fclose(finput);
 	fclose(foutput);
 
@@ -160,7 +218,7 @@ int aes_ctr(const char *input_file, const char *output_file, const unsigned char
 }
 
 int encrypt(char *input_file, const char *passphrase) {
-	unsigned char key[KEY_SIZE];
+	unsigned char key[KEY_SIZE * 2];
 	unsigned char salt[SALT_SIZE];
 	// Derive key from passphrase using PBKDF2
 	char *output_file = malloc(strlen(input_file) + 5);
@@ -184,8 +242,9 @@ int encrypt(char *input_file, const char *passphrase) {
 	}
 	fclose(foutput);
 
+	int pass_len = strlen(passphrase);
 	// Derive key from passphrase using PBKDF2
-	if (PKCS5_PBKDF2_HMAC(passphrase, strlen(passphrase), salt, SALT_SIZE, ITERATIONS, EVP_sha256(),
+	if (PKCS5_PBKDF2_HMAC(passphrase, pass_len, salt, SALT_SIZE, ITERATIONS, EVP_sha256(),
 						  KEY_SIZE * 2, key) != 1) {
 		fprintf(stderr, "Error deriving key from passphrase\n");
 		return 1;
@@ -268,6 +327,7 @@ int main(int argc, char *argv[]) {
 		return 1;
 	}
 	enableEcho();
+	putchar('\n');
 	passphrase[strcspn(passphrase, "\n")] = '\0'; // Remove trailing newline
 	int suc = 0;
 	if (strcmp(mode, "enc") == 0) {
diff --git a/TPs/TP03/plaintext b/TPs/TP03/plaintext
new file mode 100644
index 0000000..a9c64a9
--- /dev/null
+++ b/TPs/TP03/plaintext
@@ -0,0 +1,42 @@
+This was a triumph.
+I'm making a note here: HUGE SUCCESS.
+It's hard to overstate my satisfaction.
+Aperture Science
+We do what we must because we can.
+For the good of all of us
+Except the ones who are dead.
+But there's no sense crying over every mistake
+You just keep on trying till you run out of cake
+And the science gets done and you make a neat gun
+For the people who are still alive.
+I'm not even angry.
+I'm being so sincere right now.
+Even though you broke my heart and killed me.
+And tore me to pieces.
+And threw every piece into a fire.
+As they burned it hurt because
+I was so happy for you!
+Now these points of data make a beautiful line
+And we're out of beta, we're releasing on time.
+So I'm GLaD. I got burned.
+Think of all the things we learned
+For the people who are still alive.
+Go ahead and leave me.
+I think I prefer to stay inside.
+Maybe you'll find someone else to help you.
+Maybe Black Mesa
+THAT WAS A JOKE. Haha. FAT CHANCE.
+Anyway, this cake is great.
+It's so delicious and moist.
+Look at me still talking when there's science to do.
+When I look out there, it makes me GLaD I'm not you.
+I've experiments to run, there is research to be done
+On the people who are still alive
+And believe me I am still alive.
+I'm doing science and I'm still alive.
+I feel FANTASTIC and I'm still alive.
+While you're dying I'll be still alive.
+And when you're dead I will be still alive.
+Still alive
+Still alive
+Still alive
diff --git a/TPs/TP03/tokefile.toml b/TPs/TP03/tokefile.toml
new file mode 100644
index 0000000..dfcb7ed
--- /dev/null
+++ b/TPs/TP03/tokefile.toml
@@ -0,0 +1,15 @@
+[vars]
+CC="!which gcc"
+CFLAGS="-Wall -O2 -I/opt/homebrew/opt/openssl@3.2/include -L/opt/homebrew/opt/openssl@3.2/lib"
+LDFLAGS="-lssl -lcrypto"
+
+[targets.build]
+wildcards=["!ls -1 *.c","!ls -1 *.c | sed -e 's/\\.c$//'"]
+cmd="${CC} ${CFLAGS} ${LDFLAGS} @@ -o @@"
+
+[targets.debug]
+vars.CC="clang"
+vars.CFLAGS="-Wall -O0 -g -fsanitize=address -g -I/opt/homebrew/opt/openssl@3.2/include -L/opt/homebrew/opt/openssl@3.2/lib"
+wildcards=["!ls -1 *.c","!ls -1 *.c | sed -e 's/\\.c$//'"]
+cmd="${CC} ${CFLAGS} ${LDFLAGS} @@ -o @@"
+