Flesh out more of the SE driver

exosphere/se.c

@@ -1,9 +1,12 @@
+#include <stdint.h>
+#include <stddef.h>
+
 #include "utils.h"
 #include "cache.h"
 #include "se.h"
 
 void trigger_se_rsa_op(void *buf, size_t size);
-void trigger_se_aes_op(unsigned int op, void *dst, size_t dst_size, const void *src, size_t src_size);
+void trigger_se_blocking_op(unsigned int op, void *dst, size_t dst_size, const void *src, size_t src_size);
 
 /* Globals for driver. */
 volatile security_engine_t *g_security_engine;
@@ -13,6 +16,21 @@ unsigned int (*g_se_callback)(void);
 unsigned int g_se_modulus_sizes[KEYSLOT_RSA_MAX];
 unsigned int g_se_exp_sizes[KEYSLOT_RSA_MAX];
 
+/* Initialize a SE linked list. */
+void ll_init(se_ll_t *ll, void *buffer, size_t size) {
+    ll->num_entries = 0; /* 1 Entry. */
+    
+    if (buffer != NULL) {
+        ll->addr_info.address = get_physical_address(buffer);
+        ll->addr_info.size = (uint32_t) size;
+    } else {
+        ll->addr_info.address = 0;
+        ll->addr_info.size = 0;
+    }
+
+    flush_dcache_range((uint8_t *)ll, (uint8_t *)ll + sizeof(*ll));
+}
+
 /* Set the global security engine pointer. */
 void set_security_engine_address(security_engine_t *security_engine) {
     g_security_engine = security_engine;
@@ -31,6 +49,18 @@ void set_security_engine_callback(unsigned int (*callback)(void)) {
     g_se_callback = callback;
 }
 
+/* Fires on Security Engine operation completion. */
+void se_operation_completed(void) {
+    if (g_security_engine == NULL) {
+        panic();
+    }
+    g_security_engine->INT_ENABLE_REG = 0;
+    if (g_se_callback != NULL) {
+        g_se_callback();
+        g_se_callback = NULL;
+    }
+}
+
 /* Set the flags for an AES keyslot. */
 void set_aes_keyslot_flags(unsigned int keyslot, unsigned int flags) {
     if (g_security_engine == NULL || keyslot >= KEYSLOT_AES_MAX) {
@@ -190,3 +220,67 @@ void se_exp_mod(unsigned int keyslot, void *buf, size_t size, unsigned int (*cal
 
     while (!(g_security_engine->INT_STATUS_REG & 2)) { /* Wait a while */ }
 }
+
+void se_get_exp_mod_output(void *buf, size_t size) {
+    size_t num_dwords = (size >> 2);
+    if (num_dwords < 1) {
+        return;
+    }
+    
+    uint32_t *p_out = ((uint32_t *)buf) + num_dwords - 1;
+    uint32_t out_ofs = 0;
+    
+    /* Copy endian swapped output. */
+    while (num_dwords) {
+        *p_out = read32be(g_security_engine->RSA_OUTPUT, offset);
+        offset += 4;
+        p_out--;
+        num_dwords--;
+    }
+}
+
+void trigger_se_rsa_op(void *buf, size_t size) {
+    se_ll_t in_ll;
+    ll_init(&in_ll, buf, size);
+    
+    /* Set the input LL. */
+    g_security_engine->IN_LL_ADDR_REG = get_physical_address(&in_ll);
+    
+    /* Set registers for operation. */
+    g_security_engine->ERR_STATUS_REG = g_security_engine->ERR_STATUS_REG;
+    g_security_engine->INT_STATUS_REG = g_security_engine->INT_STATUS_REG;
+    g_security_engine->OPERATION_REG = 1;
+    
+    /* Ensure writes go through. */
+    __asm__ __volatile__ ("dsb ish" : : : "memory");
+}
+
+void trigger_se_blocking_op(unsigned int op, void *dst, size_t dst_size, const void *src, size_t src_size) {
+    se_ll_t in_ll;
+    se_ll_t out_ll;
+    
+    ll_init(&in_ll, src, src_size);
+    ll_init(&out_ll, dst, dst_size);
+    
+    /* Set the LLs. */
+    g_security_engine->IN_LL_ADDR_REG = get_physical_address(&in_ll);
+    g_security_enging->OUT_LL_ADDR_REG = get_physical_address(&out_ll);
+    
+    /* Set registers for operation. */
+    g_security_engine->ERR_STATUS_REG = g_security_engine->ERR_STATUS_REG;
+    g_security_engine->INT_STATUS_REG = g_security_engine->INT_STATUS_REG;
+    g_security_engine->OPERATION_REG = op;
+    
+    while (!(g_security_engine->INT_STATUS_REG & 0x10)) { /* Wait a while */ }
+    se_check_for_error();
+}
+
+void se_check_for_error(void) {
+    if (g_security_engine == NULL) {
+        panic();
+    }
+    
+    if (g_security_engine->INT_STATUS_REG & 0x10000 || g_security_engine->FLAGS_REG & 3 || g_security_engine->ERR_STATUS_REG) {
+        panic();
+    }
+}

exosphere/se.h

@@ -75,8 +75,8 @@ typedef struct security_engine {
   unsigned int _0x41C;
   unsigned int RSA_KEYTABLE_ADDR;
   unsigned int RSA_KEYTABLE_DATA;
-  unsigned int RSA_OUTPUT;
-  unsigned char _0x42C[0x3D4];
+  unsigned char RSA_OUTPUT[0x100];
+  unsigned char _0x528[0x2D8];
   unsigned int FLAGS_REG;
   unsigned int ERR_STATUS_REG;
   unsigned int _0x808;
@@ -88,16 +88,30 @@ typedef struct security_engine {
   unsigned char _0x820[0x17E0];
 } security_engine_t;
 
+typedef struct {
+    uint32_t address;
+    uint32_t size;
+} se_addr_info_t;
+
+typedef struct {
+    uint32_t num_entries; /* Set to total entries - 1 */
+    se_addr_info_t addr_info; /* This should really be an array...but for our use case it works. */
+} se_ll_t;
+
 /* TODO: Define constants for the C driver. */
 
 
 /* WIP, API subject to change. */
 
 
+/* This function MUST be registered to fire on the appropriate interrupt. */
+void se_operation_completed(void);
 
 void set_security_engine_address(security_engine_t *security_engine);
 security_engine_t *get_security_engine_address(void);
 
+void se_check_for_error(void);
+
 void set_aes_keyslot_flags(unsigned int keyslot, unsigned int flags);
 void set_rsa_keyslot_flags(unsigned int keyslot, unsigned int flags);
 void clear_aes_keyslot(unsigned int keyslot);
@@ -110,8 +124,12 @@ void set_aes_keyslot_iv(unsigned int keyslot, const void *iv, size_t iv_size);
 void set_se_ctr(const void *ctr);
 
 void se_crypt_aes(unsigned int keyslot, void *dst, size_t dst_size, const void *src, size_t src_size, unsigned int config, unsigned int mode, unsigned int (*callback)(void));
+
+
 void se_exp_mod(unsigned int keyslot, void *buf, size_t size, unsigned int (*callback)(void));
 
+void se_get_exp_mod_output(void *buf, size_t size);
+
 void se_generate_random(unsigned int keyslot, void *dst, size_t size);
 
 /* TODO: SE context save API, consider extending AES API for secure world vs non-secure world operations. */

exosphere/utils.h

@@ -6,6 +6,8 @@
 
 void panic(void);
 
+uint32_t get_physical_address(void *vaddr);
+
 static inline uint32_t read32le(const void *dword, size_t offset) {
     return *(uint32_t *)((uintptr_t)dword + offset);
 }