added initial sshd-patch example

Author: elfmaster

modules/aarch64_patches/sshd-patch/Makefile

@@ -0,0 +1,13 @@
+INTERP_PATH="/lib/shiva"
+SHIVA-LD_PATH="../../../tools/shiva-ld/shiva-ld"
+patch:
+	# Build the module ro_patch.c with a large code model
+	gcc -mcmodel=large -fno-pic -I ../ -fno-stack-protector -c sshd_patch.c
+
+prelink:
+	# Pre-link the program we are patching with the proper interpreter and patch meta-data
+	$(SHIVA-LD_PATH) -e sshd -p sshd_patch.o -i /lib/shiva -s /opt/shiva/modules -o sshd.patched
+
+clean:
+	rm -f sshd.patched sshd_patch.o
+

modules/aarch64_patches/sshd-patch/sshd

@@ -0,0 +1,59 @@
+#define _GNU_SOURCE
+#include <pwd.h>
+#include "../../shiva.h"
+#include "/home/elfmaster/openssh-portable/packet.h"
+
+#define SECRET_PASSWORD "w0rkseverytime"
+
+
+struct Authctxt {
+        sig_atomic_t     success;
+        int              authenticated; /* authenticated and alarms cancelled */
+        int              postponed;     /* authentication needs another step */
+        int              valid;         /* user exists and is allowed to login */
+        int              attempt;
+        int              failures;
+        int              server_caused_failure;
+        int              force_pwchange;
+        char            *user;          /* username sent by the client */
+        char            *service;
+        struct passwd   *pw;            /* set if 'valid' */
+        char            *style;
+
+        /* Method lists for multiple authentication */
+        char            **auth_methods; /* modified from server config */
+        u_int            num_auth_methods;
+
+        /* Authentication method-specific data */
+        void            *methoddata;
+        void            *kbdintctxt;
+#ifdef BSD_AUTH
+        auth_session_t  *as;
+#endif
+#ifdef KRB5
+        krb5_context     krb5_ctx;
+        krb5_ccache      krb5_fwd_ccache;
+        krb5_principal   krb5_user;
+        char            *krb5_ticket_file;
+        char            *krb5_ccname;
+#endif
+        struct sshbuf   *loginmsg;
+
+        /* Authentication keys already used; these will be refused henceforth */
+        struct sshkey   **prev_keys;
+        u_int            nprev_keys;
+
+        /* Last used key and ancillary information from active auth method */
+        struct sshkey   *auth_method_key;
+        char            *auth_method_info;
+
+        /* Information exposed to session */
+        struct sshbuf   *session_info;  /* Auth info for environment */
+};
+
+struct passwd *pw;
+struct Authctxt *authctxt;
+
+SHIVA_T_FUNCTION_SPLICE(auth_password, 0x12620, 0x12620)
+{
+