diff --git a/src/utils/utils.c b/src/utils/utils.c
new file mode 100644
index 0000000..d837a60
--- /dev/null
+++ b/src/utils/utils.c
@@ -0,0 +1,109 @@
+#include <rawrtcc/code.h>
+#include <rawrtcc/utils.h>
+#include <re.h>
+#include <stdarg.h>  // va_*
+
+/*
+ * Translate a rawrtc return code to a string.
+ */
+char const* rawrtc_code_to_str(enum rawrtc_code const code) {
+    switch (code) {
+        case RAWRTC_CODE_UNKNOWN_ERROR:
+            return "unknown error";
+        case RAWRTC_CODE_NOT_IMPLEMENTED:
+            return "not implemented";
+        case RAWRTC_CODE_SUCCESS:
+            return "success";
+        case RAWRTC_CODE_INITIALISE_FAIL:
+            return "failed to initialise";
+        case RAWRTC_CODE_INVALID_ARGUMENT:
+            return "invalid argument";
+        case RAWRTC_CODE_NO_MEMORY:
+            return "no memory";
+        case RAWRTC_CODE_INVALID_STATE:
+            return "invalid state";
+        case RAWRTC_CODE_UNSUPPORTED_PROTOCOL:
+            return "unsupported protocol";
+        case RAWRTC_CODE_UNSUPPORTED_ALGORITHM:
+            return "unsupported algorithm";
+        case RAWRTC_CODE_NO_VALUE:
+            return "no value";
+        case RAWRTC_CODE_NO_SOCKET:
+            return "no socket";
+        case RAWRTC_CODE_INVALID_CERTIFICATE:
+            return "invalid certificate";
+        case RAWRTC_CODE_INVALID_FINGERPRINT:
+            return "invalid fingerprint";
+        case RAWRTC_CODE_INSUFFICIENT_SPACE:
+            return "insufficient space";
+        case RAWRTC_CODE_STILL_IN_USE:
+            return "still in use";
+        case RAWRTC_CODE_INVALID_MESSAGE:
+            return "invalid message";
+        case RAWRTC_CODE_MESSAGE_TOO_LONG:
+            return "message too long";
+        case RAWRTC_CODE_TRY_AGAIN_LATER:
+            return "try again later";
+        case RAWRTC_CODE_STOP_ITERATION:
+            return "stop iteration";
+        case RAWRTC_CODE_NOT_PERMITTED:
+            return "not permitted";
+        case RAWRTC_CODE_EXTERNAL_ERROR:
+            return "external callback error-ed";
+        default:
+            return "(no error translation)";
+    }
+}
+
+/*
+ * Translate an re error to a rawrtc code.
+ * TODO: Add codes from trice_lcand_add
+ */
+enum rawrtc_code rawrtc_error_to_code(int const code) {
+    switch (code) {
+        case 0:
+            return RAWRTC_CODE_SUCCESS;
+        case EAGAIN:
+#if (EAGAIN != EWOULDBLOCK)
+        case EWOULDBLOCK:
+#endif
+            return RAWRTC_CODE_TRY_AGAIN_LATER;
+        case EAUTH:
+            return RAWRTC_CODE_INVALID_CERTIFICATE;
+        case EBADMSG:
+            return RAWRTC_CODE_INVALID_MESSAGE;
+        case EINVAL:
+            return RAWRTC_CODE_INVALID_ARGUMENT;
+        case EMSGSIZE:
+            return RAWRTC_CODE_MESSAGE_TOO_LONG;
+        case ENOMEM:
+            return RAWRTC_CODE_NO_MEMORY;
+        case EPERM:
+            return RAWRTC_CODE_NOT_PERMITTED;
+        default:
+            return RAWRTC_CODE_UNKNOWN_ERROR;
+    }
+}
+
+/*
+ * Duplicate a string.
+ * `*destinationp` will be set to a copy of `source` and must be
+ * unreferenced.
+ */
+enum rawrtc_code rawrtc_strdup(char** const destinationp, char const* const source) {
+    int err = str_dup(destinationp, source);
+    return rawrtc_error_to_code(err);
+}
+
+/*
+ * Print a formatted string to a dynamically allocated buffer.
+ * `*destinationp` must be unreferenced.
+ */
+enum rawrtc_code rawrtc_sdprintf(char** const destinationp, char* const formatter, ...) {
+    int err;
+    va_list args;
+    va_start(args, formatter);
+    err = re_vsdprintf(destinationp, formatter, args);
+    va_end(args);
+    return rawrtc_error_to_code(err);
+}