build

either change to PIN to an empty one or "4321"

README.md

@@ -61,9 +61,11 @@ git checkout ${VERSION_TO_BUILD}
 git submodule update --init --recursive
 ```
 
-## Installing the toolchain
+## Installing the toolchain and applying updates
 
-In order to compile ARM code, you need the ARM compiler and other things like bundling bootloader and firmware require the `solo-python` python package. Check our [documentation](https://docs.solokeys.io/solo/) for details
+In order to compile ARM code, you need the ARM compiler and other things like bundling bootloader and firmware require the [solo-python](https://github.com/solokeys/solo-python) python package. Check our [documentation](https://docs.solokeys.io/solo/) for details.
+
+You can update your solokey after running `pip3 install solo-python` with `solo key update` for the latest version. To apply a custom image use `solo program bootloader <file>(.json|.hex)`.
 
 ## Installing the toolkit and compiling in Docker 
 Alternatively, you can use Docker to create a container with the toolchain.

STABLE_VERSION

@@ -1 +1 @@
-3.1.1
+4.0.0

default.nix

@@ -0,0 +1,24 @@
+let
+  pkgs = import (fetchTarball { url = "https://github.com/NixOS/nixpkgs/archive/20.03.tar.gz"; sha256 = "0182ys095dfx02vl2a20j1hz92dx3mfgz2a6fhn31bqlp1wa8hlq"; }) {};
+  pyPackages = (python-packages: with python-packages; ([
+    solo-python pytest
+  ] ++ (with builtins; map (d: getAttr d python-packages) (filter (d: stringLength d > 0) (pkgs.lib.splitString "\n" (builtins.readFile ./tools/requirements.txt))))));
+  python-with-my-packages = pkgs.python3.withPackages pyPackages;
+  src = ./.;
+in
+with pkgs; stdenv.mkDerivation {
+	name = "solo";
+	outputs = [ "out" ];
+	src = with lib; builtins.filterSource (path: type: !(hasSuffix path "hex" || hasSuffix path "sha256")) src;
+	buildInputs = [ gnumake gcc gcc-arm-embedded-8 git python-with-my-packages ];
+	phases = [ "unpackPhase" "configurePhase" "buildPhase" "installPhase" ];
+	installPhase = ''
+        	mkdir -p $out/firmware $out
+        	cd targets/stm32l432
+        	make cbor
+		make build-hacker
+        	cp *.hex *.sha256 *.elf cubeconfig_stm32l442.ioc $out/firmware/ 
+        '';
+	keepDebugInfo = true;
+}
+

fido2/ctap.h

@@ -16,7 +16,9 @@
 #define CTAP_CLIENT_PIN             0x06
 #define CTAP_RESET                  0x07
 #define GET_NEXT_ASSERTION          0x08
+#define CTAP_CBOR_CRED_MGMT         0x0A
 #define CTAP_VENDOR_FIRST           0x40
+#define CTAP_CBOR_CRED_MGMT_PRE     0x41
 #define CTAP_VENDOR_LAST            0xBF
 
 #define MC_clientDataHash         0x01
@@ -37,6 +39,19 @@
 #define GA_pinAuth                0x06
 #define GA_pinProtocol            0x07
 
+#define CM_cmd                    0x01
+    #define CM_cmdMetadata        0x01
+    #define CM_cmdRPBegin         0x02
+    #define CM_cmdRPNext          0x03
+    #define CM_cmdRKBegin         0x04
+    #define CM_cmdRKNext          0x05
+    #define CM_cmdRKDelete        0x06
+#define CM_subCommandParams       0x02
+    #define CM_subCommandRpId     0x01
+    #define CM_subCommandCred     0x02
+#define CM_pinProtocol            0x03
+#define CM_pinAuth                0x04
+
 #define CP_pinProtocol            0x01
 #define CP_subCommand             0x02
     #define CP_cmdGetRetries      0x01
@@ -58,6 +73,11 @@
 #define EXT_HMAC_SECRET_REQUESTED   0x01
 #define EXT_HMAC_SECRET_PARSED      0x02
 
+#define EXT_CRED_PROTECT_INVALID                0x00
+#define EXT_CRED_PROTECT_OPTIONAL               0x01
+#define EXT_CRED_PROTECT_OPTIONAL_WITH_CREDID   0x02
+#define EXT_CRED_PROTECT_REQUIRED               0x03
+
 #define RESP_versions               0x1
 #define RESP_extensions             0x2
 #define RESP_aaguid                 0x3
@@ -141,16 +161,29 @@ typedef struct
 
 typedef struct {
     uint8_t tag[CREDENTIAL_TAG_SIZE];
-    uint8_t nonce[CREDENTIAL_NONCE_SIZE];
+    union {
+        uint8_t nonce[CREDENTIAL_NONCE_SIZE];
+        struct {
+            uint8_t _pad[CREDENTIAL_NONCE_SIZE - 4];
+            uint32_t value;
+        }__attribute__((packed)) metadata;
+    }__attribute__((packed)) entropy;
     uint8_t rpIdHash[32];
     uint32_t count;
 }__attribute__((packed)) CredentialId;
 
-struct Credential {
+struct  __attribute__((packed)) Credential {
     CredentialId id;
     CTAP_userEntity user;
 };
-typedef struct Credential CTAP_residentKey;
+typedef struct {
+    CredentialId id;
+    CTAP_userEntity user;
+
+    // Maximum amount of "extra" space in resident key.
+    uint8_t rpId[48];
+    uint8_t rpIdSize;
+} __attribute__((packed)) CTAP_residentKey;
 
 typedef struct
 {
@@ -217,6 +250,7 @@ typedef struct
 {
     uint8_t hmac_secret_present;
     CTAP_hmac_secret hmac_secret;
+    uint32_t cred_protect;
 } CTAP_extensions;
 
 typedef struct
@@ -285,6 +319,26 @@ typedef struct
 
 } CTAP_getAssertion;
 
+typedef struct
+{
+    int cmd;
+    struct {
+        uint8_t rpIdHash[32];
+        CTAP_credentialDescriptor credentialDescriptor;
+    } subCommandParams;
+
+    struct {
+        uint8_t cmd;
+        uint8_t subCommandParamsCborCopy[sizeof(CTAP_credentialDescriptor) + 16];
+    } hashed;
+    uint32_t subCommandParamsCborSize;
+
+    uint8_t pinAuth[16];
+    uint8_t pinAuthPresent;
+    int pinProtocol;
+} CTAP_credMgmt;
+
+
 typedef struct
 {
     int pinProtocol;
@@ -303,7 +357,12 @@ typedef struct
 
 
 struct _getAssertionState {
-    CTAP_authDataHeader authData;
+    // Room for both authData struct and extensions
+    struct {
+        CTAP_authDataHeader authData;
+        uint8_t extensions[80];
+    } __attribute__((packed)) buf;
+    CTAP_extensions extensions;
     uint8_t clientDataHash[CLIENT_DATA_HASH_SIZE];
     CTAP_credentialDescriptor creds[ALLOW_LIST_MAX_SIZE];
     uint8_t lastcmd;

fido2/ctap_parse.c

@@ -698,6 +698,14 @@ uint8_t ctap_parse_extensions(CborValue * val, CTAP_extensions * ext)
                 printf1(TAG_RED, "warning: hmac_secret request ignored for being wrong type\r\n");
             }
         }
+        else if (strncmp(key, "credProtect",11) == 0) {
+            if (cbor_value_get_type(&map) == CborIntegerType) {
+                ret = cbor_value_get_int(&map, (int*)&ext->cred_protect);
+                check_ret(ret);
+            } else {
+                printf1(TAG_RED, "warning: credProtect request ignored for being wrong type\r\n");
+            }
+        }
 
         ret = cbor_value_advance(&map);
         check_ret(ret);
@@ -871,7 +879,7 @@ uint8_t ctap_parse_make_credential(CTAP_makeCredential * MC, CborEncoder * encod
         {
             return ret;
         }
-        cbor_value_advance(&map);
+        ret = cbor_value_advance(&map);
         check_ret(ret);
     }
 
@@ -999,6 +1007,163 @@ uint8_t parse_allow_list(CTAP_getAssertion * GA, CborValue * it)
     return 0;
 }
 
+static uint8_t parse_cred_mgmt_subcommandparams(CborValue * val, CTAP_credMgmt * CM)
+{
+    size_t map_length;
+    int key;
+    int ret;
+    unsigned int i;
+    CborValue map;
+    size_t sz = 32;
+
+    if (cbor_value_get_type(val) != CborMapType)
+    {
+        printf2(TAG_ERR,"error, wrong type\n");
+        return CTAP2_ERR_INVALID_CBOR_TYPE;
+    }
+
+
+    ret = cbor_value_enter_container(val,&map);
+    check_ret(ret);
+    
+    const uint8_t * start_byte = cbor_value_get_next_byte(&map) - 1;
+
+    ret = cbor_value_get_map_length(val, &map_length);
+    check_ret(ret);
+
+    for (i = 0; i < map_length; i++)
+    {
+        if (cbor_value_get_type(&map) != CborIntegerType)
+        {
+            printf2(TAG_ERR,"Error, expecting integer type for map key, got %s\n", cbor_value_get_type_string(&map));
+            return CTAP2_ERR_INVALID_CBOR_TYPE;
+        }
+        ret = cbor_value_get_int(&map, &key);
+        check_ret(ret);
+        ret = cbor_value_advance(&map);
+        check_ret(ret);
+        switch(key)
+        {
+            case CM_subCommandRpId:
+                ret = cbor_value_copy_byte_string(&map, CM->subCommandParams.rpIdHash, &sz, NULL);
+                if (ret == CborErrorOutOfMemory)
+                {
+                    printf2(TAG_ERR,"Error, map key is too large\n");
+                    return CTAP2_ERR_LIMIT_EXCEEDED;
+                }
+                check_ret(ret);
+                break;
+            case CM_subCommandCred:
+                ret = parse_credential_descriptor(&map, &CM->subCommandParams.credentialDescriptor);
+                check_ret(ret);;
+                break;
+        }
+        ret = cbor_value_advance(&map);
+        check_ret(ret);
+    }
+
+    const uint8_t * end_byte = cbor_value_get_next_byte(&map);
+
+    uint32_t length = (uint32_t)end_byte - (uint32_t)start_byte;
+    if (length > sizeof(CM->hashed.subCommandParamsCborCopy))
+    {
+        return CTAP2_ERR_LIMIT_EXCEEDED;
+    }
+    // Copy the details that were hashed so they can be verified later.
+    memmove(CM->hashed.subCommandParamsCborCopy, start_byte, length);
+    CM->subCommandParamsCborSize = length;
+
+    return 0;
+}
+
+uint8_t ctap_parse_cred_mgmt(CTAP_credMgmt * CM, uint8_t * request, int length)
+{
+    int ret;
+    unsigned int i;
+    int key;
+    size_t map_length;
+    CborParser parser;
+    CborValue it,map;
+
+    memset(CM, 0, sizeof(CTAP_credMgmt));
+    ret = cbor_parser_init(request, length, CborValidateCanonicalFormat, &parser, &it);
+    check_ret(ret);
+
+    CborType type = cbor_value_get_type(&it);
+    if (type != CborMapType)
+    {
+        printf2(TAG_ERR,"Error, expecting cbor map\n");
+        return CTAP2_ERR_INVALID_CBOR_TYPE;
+    }
+
+
+    ret = cbor_value_enter_container(&it,&map);
+    check_ret(ret);
+
+    ret = cbor_value_get_map_length(&it, &map_length);
+    check_ret(ret);
+
+    printf1(TAG_PARSE, "CM map has %d elements\n", map_length);
+
+    for (i = 0; i < map_length; i++)
+    {
+        type = cbor_value_get_type(&map);
+        if (type != CborIntegerType)
+        {
+            printf2(TAG_ERR,"Error, expecting int for map key\n");
+            return CTAP2_ERR_INVALID_CBOR_TYPE;
+        }
+        ret = cbor_value_get_int_checked(&map, &key);
+        check_ret(ret);
+
+        ret = cbor_value_advance(&map);
+        check_ret(ret);
+
+        switch(key)
+        {
+            case CM_cmd:
+                printf1(TAG_PARSE, "CM_cmd\n");
+                if (cbor_value_get_type(&map) == CborIntegerType)
+                {
+                    ret = cbor_value_get_int_checked(&map, &CM->cmd);
+                    check_ret(ret);
+                    CM->hashed.cmd = CM->cmd;
+                }
+                else
+                {
+                    return CTAP2_ERR_INVALID_CBOR_TYPE;
+                }
+                break;
+            case CM_subCommandParams:
+                printf1(TAG_PARSE, "CM_subCommandParams\n");
+                ret = parse_cred_mgmt_subcommandparams(&map, CM);
+                check_ret(ret);
+                break;
+            case CM_pinProtocol:
+                printf1(TAG_PARSE, "CM_pinProtocol\n");
+                if (cbor_value_get_type(&map) == CborIntegerType)
+                {
+                    ret = cbor_value_get_int_checked(&map, &CM->pinProtocol);
+                    check_ret(ret);
+                }
+                else
+                {
+                    return CTAP2_ERR_INVALID_CBOR_TYPE;
+                }
+                break;
+            case CM_pinAuth:
+                printf1(TAG_PARSE, "CM_pinAuth\n");
+                ret = parse_fixed_byte_string(&map, CM->pinAuth, 16);
+                check_retr(ret);
+                CM->pinAuthPresent = 1;
+                break;
+        }
+        ret = cbor_value_advance(&map);
+        check_ret(ret);
+    }
+
+    return 0;
+}
 
 uint8_t ctap_parse_get_assertion(CTAP_getAssertion * GA, uint8_t * request, int length)
 {
@@ -1132,7 +1297,7 @@ uint8_t ctap_parse_get_assertion(CTAP_getAssertion * GA, uint8_t * request, int
             return ret;
         }
 
-        cbor_value_advance(&map);
+        ret = cbor_value_advance(&map);
         check_ret(ret);
     }
 

fido2/ctap_parse.h

@@ -35,6 +35,7 @@ uint8_t parse_cose_key(CborValue * it, COSE_key * cose);
 
 uint8_t ctap_parse_make_credential(CTAP_makeCredential * MC, CborEncoder * encoder, uint8_t * request, int length);
 uint8_t ctap_parse_get_assertion(CTAP_getAssertion * GA, uint8_t * request, int length);
+uint8_t ctap_parse_cred_mgmt(CTAP_credMgmt * CM, uint8_t * request, int length);
 uint8_t ctap_parse_client_pin(CTAP_clientPin * CP, uint8_t * request, int length);
 uint8_t parse_credential_descriptor(CborValue * arr, CTAP_credentialDescriptor * cred);
 

fido2/ctaphid.c

@@ -734,6 +734,11 @@ uint8_t ctaphid_custom_command(int len, CTAP_RESPONSE * ctap_resp, CTAPHID_WRITE
             ctaphid_write(wb, NULL, 0);
             return 1;
 #endif
+#if defined(SOLO)
+        case CTAPHID_REBOOT:
+            device_reboot();
+            return 1;
+#endif
 
 #if !defined(IS_BOOTLOADER)
         case CTAPHID_GETRNG:

fido2/ctaphid.h

@@ -27,6 +27,7 @@
 #define CTAPHID_BOOT            (TYPE_INIT | 0x50)
 #define CTAPHID_ENTERBOOT       (TYPE_INIT | 0x51)
 #define CTAPHID_ENTERSTBOOT     (TYPE_INIT | 0x52)
+#define CTAPHID_REBOOT          (TYPE_INIT | 0x53)
 #define CTAPHID_GETRNG          (TYPE_INIT | 0x60)
 #define CTAPHID_GETVERSION      (TYPE_INIT | 0x61)
 #define CTAPHID_LOADKEY         (TYPE_INIT | 0x62)

fido2/device.c

@@ -185,6 +185,22 @@ __attribute__((weak)) void ctap_store_rk(int index, CTAP_residentKey * rk)
 
 }
 
+__attribute__((weak)) void ctap_delete_rk(int index)
+{
+    CTAP_residentKey rk;
+    memset(&rk, 0xff, sizeof(CTAP_residentKey));
+
+    if (index < RK_NUM)
+    {
+        memmove(RK_STORE.rks + index, &rk, sizeof(CTAP_residentKey));
+    }
+    else
+    {
+        printf1(TAG_ERR,"Out of bounds for delete_rk\r\n");
+    }
+
+}
+
 __attribute__((weak)) void ctap_load_rk(int index, CTAP_residentKey * rk)
 {
     memmove(rk, RK_STORE.rks + index, sizeof(CTAP_residentKey));

fido2/device.h

@@ -87,6 +87,24 @@ int device_is_button_pressed();
 */
 int ctap_user_presence_test(uint32_t delay);
 
+// 
+// Return 2 for disabled, 1 for user is present, 0 user not present, -1 if cancel is requested.
+/** Test for user presence.
+ *  Perform test that user is present.  Returns status on user presence.  This is used by FIDO and U2F layer
+ *  to check if an operation should continue, or if the UP flag should be set.
+ * 
+ * @param delay number of milliseconds to delay waiting for user before timeout.
+ * @param button_confirm_colour LED colour while waiting for confirmation.
+ * 
+ * @return 2 - User presence is disabled.  Operation should continue, but UP flag not set.
+ *         1 - User presence confirmed.  Operation should continue, and UP flag is set.
+ *         0 - User presence is not confirmed.  Operation should be denied.
+ *        -1 - Operation was canceled.  Do not continue, reset transaction state.
+ * 
+ * *Optional*, the default implementation will return 1, unless a FIDO2 operation calls for no UP, where this will then return 2.
+*/
+int ctap_user_presence_test_colour(uint32_t delay, uint32_t button_confirm_colour);
+
 /** Disable the next user presence test.  This is called by FIDO2 layer when a transaction
  *  requests UP to be disabled.  The next call to ctap_user_presence_test should return 2,
  *  and then UP should be enabled again.
@@ -140,6 +158,13 @@ uint32_t ctap_rk_size();
 */
 void ctap_store_rk(int index,CTAP_residentKey * rk);
 
+/** Delete a resident key from an index.
+ * @param index to delete resident key from.  Has no effect if no RK exists at index.
+ * 
+ * *Optional*, if not implemented, operates on non-persistant RK's.
+*/
+void ctap_delete_rk(int index);
+
 /** Read a resident key from an index into memory
  * @param index to read resident key from.
  * @param rk pointer to resident key structure to write into with RK.

fido2/log.c

@@ -51,6 +51,7 @@ struct logtag tagtable[] = {
     {TAG_NFC,"NFC"},
     {TAG_NFC_APDU, "NAPDU"},
     {TAG_CCID, "CCID"},
+    {TAG_CM, "CRED_MGMT"},
 };
 
 

fido2/log.h

@@ -48,6 +48,7 @@ typedef enum
     TAG_NFC      = (1 << 19),
     TAG_NFC_APDU = (1 << 20),
     TAG_CCID     = (1 << 21),
+    TAG_CM       = (1 << 22),
 
     TAG_NO_TAG   = (1UL << 30),
     TAG_FILENO   = (1UL << 31)

fido2/u2f.c

@@ -204,7 +204,7 @@ int8_t u2f_authenticate_credential(struct u2f_key_handle * kh, uint8_t key_handl
             printf1(TAG_U2F, "APPID does not match rpIdHash.\n");
             return 0;
         }
-        make_auth_tag(appid, cred->nonce, cred->count, tag);
+        make_auth_tag(appid, (uint8_t*)&cred->entropy, cred->count, tag);
 
         if (memcmp(cred->tag, tag, CREDENTIAL_TAG_SIZE) == 0){
             return 1;

fido2/version.c

@@ -1,4 +1,5 @@
 #include "version.h"
+#include "app.h"
 
 const version_t firmware_version 
 #ifdef SOLO

pc/device.c

@@ -449,6 +449,12 @@ void ctap_store_rk(int index, CTAP_residentKey * rk)
 
 }
 
+void ctap_delete_rk(int index)
+{
+    CTAP_residentKey rk;
+    memset(&rk, 0xff, sizeof(CTAP_residentKey));
+    memmove(RK_STORE.rks + index, &rk, sizeof(CTAP_residentKey));
+}
 
 void ctap_load_rk(int index, CTAP_residentKey * rk)
 {

shell.nix

@@ -0,0 +1,13 @@
+let
+  nixpkgs_tar = fetchTarball { url = "https://github.com/NixOS/nixpkgs/archive/20.03.tar.gz"; sha256 = "0182ys095dfx02vl2a20j1hz92dx3mfgz2a6fhn31bqlp1wa8hlq"; };
+  pkgs = import "${nixpkgs_tar}" {};
+  pyPackages = (python-packages: with python-packages; ([
+    solo-python pytest
+  ] ++ (with builtins; map (d: getAttr d python-packages) (filter (d: stringLength d > 0) (pkgs.lib.splitString "\n" (builtins.readFile ./tools/requirements.txt))))));
+  python-with-my-packages = pkgs.python3.withPackages pyPackages;
+in
+with pkgs;
+stdenv.mkDerivation {
+  name = "solo";
+  buildInputs = [ gnumake gcc gcc-arm-embedded-8 python-with-my-packages ];
+}

targets/stm32l432/linker/stm32l4xx.ld

@@ -61,7 +61,7 @@ SECTIONS
         *(.data*)
         . = ALIGN(8);
         _edata = .;
-    } >ram AT> flash
+    } >sram2 AT> flash
 
     .flag :
     {

targets/stm32l432/src/device.c

@@ -703,7 +703,11 @@ static int wait_for_button_release(uint32_t wait)
     return 0;
 }
 
-int ctap_user_presence_test(uint32_t up_delay)
+int ctap_user_presence_test(uint32_t up_delay) 
+{
+	return ctap_user_presence_test_colour(up_delay, 0);	
+}
+int ctap_user_presence_test_colour(uint32_t up_delay, uint32_t button_confirm_colour)
 {
     int ret;
 
@@ -741,8 +745,7 @@ int ctap_user_presence_test(uint32_t up_delay)
     }
 
     // Set LED status and wait.
-    led_rgb(0xff3520);
+    led_rgb(button_confirm_colour==0?0xff3520:button_confirm_colour);
-
     // Block and wait for some time.
     ret = wait_for_button_activate(up_delay);
     if (ret) return ret;
@@ -790,33 +793,28 @@ uint32_t ctap_rk_size(void)
 
 void ctap_store_rk(int index,CTAP_residentKey * rk)
 {
-    int page_offset = (sizeof(CTAP_residentKey) * index) / PAGE_SIZE;
+    ctap_overwrite_rk(index, rk);
-    uint32_t addr = flash_addr(page_offset + RK_START_PAGE) + ((sizeof(CTAP_residentKey)*index) % PAGE_SIZE);
+}
 
-    printf1(TAG_GREEN, "storing RK %d @ %04x\r\n", index,addr);
+void ctap_delete_rk(int index)
-
+{
-    if (page_offset < RK_NUM_PAGES)
+    CTAP_residentKey rk;
-    {
+    memset(&rk, 0xff, sizeof(CTAP_residentKey));
-        flash_write(addr, (uint8_t*)rk, sizeof(CTAP_residentKey));
+    ctap_overwrite_rk(index, &rk);
-        //dump_hex1(TAG_GREEN,rk,sizeof(CTAP_residentKey));
-    }
-    else
-    {
-        printf2(TAG_ERR,"Out of bounds reading index %d for rk\n", index);
-    }
 }
 
 void ctap_load_rk(int index,CTAP_residentKey * rk)
 {
-    int page_offset = (sizeof(CTAP_residentKey) * index) / PAGE_SIZE;
+    int byte_offset_into_page = (sizeof(CTAP_residentKey) * (index % (PAGE_SIZE/sizeof(CTAP_residentKey))));
-    uint32_t addr = flash_addr(page_offset + RK_START_PAGE) + ((sizeof(CTAP_residentKey)*index) % PAGE_SIZE);
+    int page_offset = (index)/(PAGE_SIZE/sizeof(CTAP_residentKey));
+
+    uint32_t addr = flash_addr(page_offset + RK_START_PAGE) + byte_offset_into_page;
 
     printf1(TAG_GREEN, "reading RK %d @ %04x\r\n", index, addr);
     if (page_offset < RK_NUM_PAGES)
     {
         uint32_t * ptr = (uint32_t *)addr;
         memmove((uint8_t*)rk,ptr,sizeof(CTAP_residentKey));
-        //dump_hex1(TAG_GREEN,rk,sizeof(CTAP_residentKey));
     }
     else
     {
@@ -827,22 +825,28 @@ void ctap_load_rk(int index,CTAP_residentKey * rk)
 void ctap_overwrite_rk(int index,CTAP_residentKey * rk)
 {
     uint8_t tmppage[PAGE_SIZE];
-    int page_offset = (sizeof(CTAP_residentKey) * index) / PAGE_SIZE;
-    int page = page_offset + RK_START_PAGE;
 
-    printf1(TAG_GREEN, "overwriting RK %d\r\n", index);
+    int byte_offset_into_page = (sizeof(CTAP_residentKey) * (index % (PAGE_SIZE/sizeof(CTAP_residentKey))));
+    int page_offset = (index)/(PAGE_SIZE/sizeof(CTAP_residentKey));
+
+    printf1(TAG_GREEN, "overwriting RK %d @ page %d @ addr 0x%08x-0x%08x\r\n", 
+        index, RK_START_PAGE + page_offset, 
+        flash_addr(RK_START_PAGE + page_offset) + byte_offset_into_page, 
+        flash_addr(RK_START_PAGE + page_offset) + byte_offset_into_page + sizeof(CTAP_residentKey) 
+        );
     if (page_offset < RK_NUM_PAGES)
     {
-        memmove(tmppage, (uint8_t*)flash_addr(page), PAGE_SIZE);
+        memmove(tmppage, (uint8_t*)flash_addr(RK_START_PAGE + page_offset), PAGE_SIZE);
 
-        memmove(tmppage + (sizeof(CTAP_residentKey) * index) % PAGE_SIZE, rk, sizeof(CTAP_residentKey));
+        memmove(tmppage + byte_offset_into_page, rk, sizeof(CTAP_residentKey));
-        flash_erase_page(page);
+        flash_erase_page(RK_START_PAGE + page_offset);
-        flash_write(flash_addr(page), tmppage, PAGE_SIZE);
+        flash_write(flash_addr(RK_START_PAGE + page_offset), tmppage, PAGE_SIZE);
     }
     else
     {
         printf2(TAG_ERR,"Out of bounds reading index %d for rk\n", index);
     }
+    printf1(TAG_GREEN, "4\r\n");
 }
 
 void boot_st_bootloader(void)