1 files changed, 55 insertions, 0 deletions
diff --git a/src/crypto.c b/src/crypto.c
new file mode 100644
index 0000000..281da36
--- /dev/null
+++ b/src/crypto.c
@@ -0,0 +1,55 @@
+#include <crypto.h>
+
+#include <gpgme.h>
+
+#include <err.h>
+
+#include <fcntl.h>
+
+int crypto_verify_integrity(const char *sig, const char *file)
+{
+	int ret = -ERR;
+	
+	gpgme_check_version(NULL);
+
+	gpgme_ctx_t ctx;
+
+	gpgme_new(&ctx);
+	gpgme_set_protocol(ctx, GPGME_PROTOCOL_OPENPGP);
+	
+	int fd = open(file, O_RDONLY);
+	int sigfd = open(sig, O_RDONLY);
+
+	gpgme_data_t gfile;
+	gpgme_data_t gsig;
+	
+	gpgme_data_new_from_fd(&gfile, fd);
+	gpgme_data_new_from_fd(&gsig, sigfd);
+	
+	if (gpgme_op_verify(ctx, gsig, gfile, NULL) == GPG_ERR_NO_ERROR) {
+		printf("Signature operation ran successfully.\n");
+	} else {
+		printf("Integrity verification failed!\n");
+		ret = -INTEGRITYERR;
+		goto cleanup;
+	}
+	
+	gpgme_verify_result_t integ_res = gpgme_op_verify_result(ctx);
+
+	// Checking the first signature for now should be fine.
+	//TODO: Revisit this.
+	if ((integ_res->signatures->summary & GPGME_SIGSUM_VALID) &&
+	    (integ_res->signatures->status == GPG_ERR_NO_ERROR)) {
+		printf("Integrity check successful, "
+		       "package can be installed.\n");
+		ret = SUCCESS;
+		goto cleanup;
+	} else {
+		printf("Signature invalid!\n");
+		ret = -INTEGRITYERR;
+		goto cleanup;
+	}       
+ cleanup:
+	gpgme_release(ctx);
+	return ret;
+}