2 files changed, 15 insertions, 0 deletions
diff --git a/lib/lib5.c b/lib/lib5.c
index f637469..04c7806 100644
--- a/lib/lib5.c
+++ b/lib/lib5.c
@@ -265,6 +265,20 @@ void srp_compute_uH(struct srp_context *srpc)
 	BN_bin2bn(uH, 20, srpc->u);
 }
 
+void srp_client_s_0_prepare_k(struct srp_context *srpc)
+{
+	SHA1Context sha1;
+	BIGNUM *S = BN_new();
+	BN_zero(S);
+
+	char *s_str = malloc(BN_num_bytes(S));
+	BN_bn2bin(S, s_str);
+	SHA1Reset(&sha1);
+	SHA1Input(&sha1, s_str, BN_num_bytes(S));
+	SHA1Result(&sha1);
+	memcpy(srpc->client_K, &(sha1.Message_Digest), 20);
+}
+
 void srp_client_prepare_k(struct srp_context *srpc, char *password)
 {
 	SHA1Context sha1;
diff --git a/lib/lib5.h b/lib/lib5.h
index 4aaa7d6..bf71802 100644
--- a/lib/lib5.h
+++ b/lib/lib5.h
@@ -116,4 +116,5 @@ void srp_compute_uH(struct srp_context *srpc);
 void srp_client_prepare_k(struct srp_context *srpc, char *password);
 void srp_server_prepare_k(struct srp_context *srpc);
 void srp_context_init(struct srp_context *s);
+void srp_client_s_0_prepare_k(struct srp_context *srpc);
 #endif