Imported Upstream version 1.0.0upstream/1.0.0

1 files changed, 153 insertions, 0 deletions

diff --git a/src/crypt.c b/src/crypt.c
new file mode 100644
index 0000000..21355d4
--- /dev/null
+++ b/src/crypt.c
@@ -0,0 +1,153 @@
+/*
+ * Copyright © 2012 Canonical Ltd.
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 3, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranties of
+ * MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <glib.h>
+
+#include <gcrypt.h>
+#include <math.h>
+
+#include "crypt.h"
+
+static gcry_cipher_hd_t
+setup_cipher (const gchar * password)
+{
+	gcry_error_t     gcryError;
+	gcry_cipher_hd_t gcryHandle;
+	
+	const size_t keyLength = gcry_cipher_get_algo_keylen(GCRY_CIPHER_AES);
+	const size_t blkLength = gcry_cipher_get_algo_blklen(GCRY_CIPHER_AES);
+	
+	// We are assuming keyLength and blkLength are the same, check it
+	if (keyLength != blkLength)
+		return NULL;
+
+	char * aesSymKey = malloc(blkLength);
+	const size_t passwordLength = strlen(password);
+	strncpy(aesSymKey, password, blkLength);
+	size_t i;
+	for (i = passwordLength; i < blkLength; ++i)
+		aesSymKey[i] = 0;
+	
+	gcryError = gcry_cipher_open(&gcryHandle, GCRY_CIPHER_AES, GCRY_CIPHER_MODE_CBC, 0);
+	if (gcryError) {
+		g_warning("gcry_cipher_open failed: %s/%s\n", gcry_strsource(gcryError), gcry_strerror(gcryError));
+		return NULL;
+	}
+
+	gcryError = gcry_cipher_setkey(gcryHandle, aesSymKey, keyLength);
+	if (gcryError) {
+		g_warning("gcry_cipher_setkey failed: %s/%s\n", gcry_strsource(gcryError), gcry_strerror(gcryError));
+		gcry_cipher_close(gcryHandle);
+		return NULL;
+	}
+
+	// Use the key as IV too
+	gcryError = gcry_cipher_setiv(gcryHandle, aesSymKey, blkLength);
+	if (gcryError) {
+		g_warning("gcry_cipher_setiv failed: %s/%s\n", gcry_strsource(gcryError), gcry_strerror(gcryError));
+		gcry_cipher_close(gcryHandle);
+		return NULL;
+	}
+
+	return gcryHandle;
+}
+
+/**
+ * do_aes_encrypt:
+ * @origBuffer: text to encrypt. Needs to be null terminated
+ * @password: password to use. Will be cut/padded with 0 if it exceeds/does not reach the needed length
+ * @outBufferLength: (out) On success contains the length of the returned buffer
+ *
+ * Returns the AES encrypted version of the text. It is responsability of the caller to free it
+ */
+gchar *
+do_aes_encrypt(const gchar *origBuffer, const gchar * password, size_t *outBufferLength)
+{
+	gcry_error_t     gcryError;
+	gcry_cipher_hd_t gcryHandle;
+	
+	gcryHandle = setup_cipher (password);
+	if (gcryHandle == NULL) {
+		return NULL;
+	}
+	
+	const size_t blkLength = gcry_cipher_get_algo_blklen(GCRY_CIPHER_AES);
+	const size_t origBufferLength = strlen(origBuffer);
+	const size_t bufferLength = ceil((double)origBufferLength / blkLength) * blkLength;
+	gchar *buffer = malloc(bufferLength);
+	memcpy(buffer, origBuffer, origBufferLength);
+	int i;
+	for (i = origBufferLength; i < bufferLength; ++i)
+		buffer[i] = 0;
+	
+	char * encBuffer = malloc(bufferLength);
+	size_t lengthDone = 0;
+	while (lengthDone < bufferLength) {
+		gcryError = gcry_cipher_encrypt(gcryHandle, &encBuffer[lengthDone], blkLength, &buffer[lengthDone], blkLength);
+		if (gcryError) {
+			g_warning("gcry_cipher_encrypt failed: %s/%s\n", gcry_strsource(gcryError), gcry_strerror(gcryError));
+			gcry_cipher_close(gcryHandle);
+			free(encBuffer);
+			return NULL;
+		}
+		lengthDone += blkLength;
+	}
+	
+	gcry_cipher_close(gcryHandle);
+	
+	*outBufferLength = bufferLength;
+	return encBuffer;
+}
+
+/**
+ * do_aes_encrypt:
+ * @encBuffer: encrypted data
+ * @password: password to use. Will be cut/padded with 0 if it exceeds/does not reach the needed length
+ * @encBufferLength: Length of encBuffer
+ *
+ * Returns the AES decrypted version of the data. It is null terminated. It is responsability of the caller to free it
+ */
+gchar *
+do_aes_decrypt(const gchar *encBuffer, const gchar * password, const size_t encBufferLength)
+{
+	gcry_error_t     gcryError;
+	gcry_cipher_hd_t gcryHandle;
+	
+	gcryHandle = setup_cipher (password);
+	if (gcryHandle == NULL) {
+		return NULL;
+	}
+	
+	const size_t blkLength = gcry_cipher_get_algo_blklen(GCRY_CIPHER_AES128);	
+	const size_t bufferLength = encBufferLength;
+	char * outBuffer = malloc(bufferLength);
+	size_t lengthDone = 0;
+	while (lengthDone < bufferLength) {
+		gcryError = gcry_cipher_decrypt(gcryHandle, &outBuffer[lengthDone], 16, &encBuffer[lengthDone], 16);
+		if (gcryError)
+		{
+			g_warning("gcry_cipher_decrypt failed: %s/%s\n", gcry_strsource(gcryError), gcry_strerror(gcryError));
+			return NULL;
+		}
+		lengthDone += blkLength;
+	}
+	
+	gcry_cipher_close(gcryHandle);
+	char *result = g_strndup(outBuffer, bufferLength);
+	free(outBuffer);
+	return result;
+}