GPRS: Add 'input' generator functions for GPRS cipher algorithm

1 files changed, 14 insertions, 0 deletions

diff --git a/src/gprs_cipher_core.c b/src/gprs_cipher_core.c
index a72dda84..6174bd72 100644
--- a/src/gprs_cipher_core.c
+++ b/src/gprs_cipher_core.c
@@ -83,3 +83,17 @@ int gprs_cipher_supported(enum gprs_ciph_algo algo)
 
 	return 0;
 }
+
+/* GSM TS 04.64 / Section A.2.1 : Generation of 'input' */
+uint32_t gprs_cipher_gen_input_ui(uint32_t iov_ui, uint8_t sapi, uint32_t lfn, uint32_t oc)
+{
+	uint32_t sx = ((1<<27) * sapi) + (1<<31);
+
+	return (iov_ui ^ sx) + lfn + oc;
+}
+
+/* GSM TS 04.64 / Section A.2.1 : Generation of 'input' */
+uint32_t gprs_cipher_gen_input_i(uint32_t iov_i, uint32_t lfn, uint32_t oc)
+{
+	return iov_i + lfn + oc;
+}