Provide fallback for keymaster implementations
Some implementations won't support ECDSA or DSA, so provide a fallback
for them by using the softkeymaster implementation. This will allow us
to universally support ECDSA and DSA on all platforms regardless of HAL
version.
Bug: 10600582
Change-Id: Ib842816cc1415ec00abb7d22c8e9b6bbe58f6a86
diff --git a/keystore/Android.mk b/keystore/Android.mk
index f495f34..47b7e84 100644
--- a/keystore/Android.mk
+++ b/keystore/Android.mk
@@ -20,7 +20,15 @@
LOCAL_CFLAGS := -Wall -Wextra -Werror
LOCAL_SRC_FILES := keystore.cpp keyblob_utils.cpp
LOCAL_C_INCLUDES := external/openssl/include
-LOCAL_SHARED_LIBRARIES := libcutils libcrypto libhardware libkeystore_binder libutils liblog libbinder
+LOCAL_SHARED_LIBRARIES := \
+ libbinder \
+ libcutils \
+ libcrypto \
+ libhardware \
+ libkeystore_binder \
+ liblog \
+ libsoftkeymaster \
+ libutils
LOCAL_MODULE := keystore
LOCAL_MODULE_TAGS := optional
LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk
diff --git a/keystore/include/keystore/keystore.h b/keystore/include/keystore/keystore.h
index 973c447..32354df 100644
--- a/keystore/include/keystore/keystore.h
+++ b/keystore/include/keystore/keystore.h
@@ -48,7 +48,8 @@
*/
enum {
KEYSTORE_FLAG_NONE = 0,
- KEYSTORE_FLAG_ENCRYPTED = 1,
+ KEYSTORE_FLAG_ENCRYPTED = 1 << 0,
+ KEYSTORE_FLAG_FALLBACK = 1 << 1,
};
/**
diff --git a/keystore/keyblob_utils.cpp b/keystore/keyblob_utils.cpp
index fd82d2a..b208073 100644
--- a/keystore/keyblob_utils.cpp
+++ b/keystore/keyblob_utils.cpp
@@ -26,9 +26,11 @@
*
* 4-byte SOFT_KEY_MAGIC
*
- * 4-byte 32-bit integer big endian for public_key_length
+ * 4-byte 32-bit integer big endian for public_key_length. This may be zero
+ * length which indicates the public key should be derived from the
+ * private key.
*
- * public_key_length bytes of public key
+ * public_key_length bytes of public key (may be empty)
*
* 4-byte 32-bit integer big endian for private_key_length
*
diff --git a/keystore/keystore.cpp b/keystore/keystore.cpp
index 12d3b44..b4cb64d 100644
--- a/keystore/keystore.cpp
+++ b/keystore/keystore.cpp
@@ -42,6 +42,8 @@
#include <hardware/keymaster.h>
+#include <keymaster/softkeymaster.h>
+
#include <utils/String8.h>
#include <utils/UniquePtr.h>
#include <utils/Vector.h>
@@ -471,6 +473,18 @@
}
}
+ bool isFallback() const {
+ return mBlob.flags & KEYSTORE_FLAG_FALLBACK;
+ }
+
+ void setFallback(bool fallback) {
+ if (fallback) {
+ mBlob.flags |= KEYSTORE_FLAG_FALLBACK;
+ } else {
+ mBlob.flags &= ~KEYSTORE_FLAG_FALLBACK;
+ }
+ }
+
void setVersion(uint8_t version) {
mBlob.version = version;
}
@@ -1004,6 +1018,23 @@
}
}
+ /*
+ * This will upgrade software-backed keys to hardware-backed keys when
+ * the HAL for the device supports the newer key types.
+ */
+ if (rc == NO_ERROR && type == TYPE_KEY_PAIR
+ && mDevice->common.module->module_api_version >= KEYMASTER_MODULE_API_VERSION_0_2
+ && keyBlob->isFallback()) {
+ ResponseCode imported = importKey(keyBlob->getValue(), keyBlob->getLength(), filename,
+ uid, keyBlob->isEncrypted() ? KEYSTORE_FLAG_ENCRYPTED : KEYSTORE_FLAG_NONE);
+
+ // The HAL allowed the import, reget the key to have the "fresh"
+ // version.
+ if (imported == NO_ERROR) {
+ rc = get(filename, keyBlob, TYPE_KEY_PAIR, uid);
+ }
+ }
+
if (type != TYPE_ANY && keyBlob->getType() != type) {
ALOGW("key found but type doesn't match: %d vs %d", keyBlob->getType(), type);
return KEY_NOT_FOUND;
@@ -1056,16 +1087,26 @@
return SYSTEM_ERROR;
}
+ bool isFallback = false;
rc = mDevice->import_keypair(mDevice, key, keyLen, &data, &dataLength);
if (rc) {
- ALOGE("Error while importing keypair: %d", rc);
- return SYSTEM_ERROR;
+ // If this is an old device HAL, try to fall back to an old version
+ if (mDevice->common.module->module_api_version < KEYMASTER_MODULE_API_VERSION_0_2) {
+ rc = openssl_import_keypair(mDevice, key, keyLen, &data, &dataLength);
+ isFallback = true;
+ }
+
+ if (rc) {
+ ALOGE("Error while importing keypair: %d", rc);
+ return SYSTEM_ERROR;
+ }
}
Blob keyBlob(data, dataLength, NULL, 0, TYPE_KEY_PAIR);
free(data);
keyBlob.setEncrypted(flags & KEYSTORE_FLAG_ENCRYPTED);
+ keyBlob.setFallback(isFallback);
return put(filename, &keyBlob, uid);
}
@@ -1688,6 +1729,7 @@
uint8_t* data;
size_t dataLength;
int rc;
+ bool isFallback = false;
const keymaster_device_t* device = mKeyStore->getDevice();
if (device == NULL) {
@@ -1698,7 +1740,7 @@
return ::SYSTEM_ERROR;
}
- if (keyType == EVP_PKEY_DSA && device->client_version >= 2) {
+ if (keyType == EVP_PKEY_DSA) {
keymaster_dsa_keygen_params_t dsa_params;
memset(&dsa_params, '\0', sizeof(dsa_params));
@@ -1734,8 +1776,13 @@
return ::SYSTEM_ERROR;
}
- rc = device->generate_keypair(device, TYPE_DSA, &dsa_params, &data, &dataLength);
- } else if (keyType == EVP_PKEY_EC && device->client_version >= 2) {
+ if (device->common.module->module_api_version >= KEYMASTER_MODULE_API_VERSION_0_2) {
+ rc = device->generate_keypair(device, TYPE_DSA, &dsa_params, &data, &dataLength);
+ } else {
+ isFallback = true;
+ rc = openssl_generate_keypair(device, TYPE_DSA, &dsa_params, &data, &dataLength);
+ }
+ } else if (keyType == EVP_PKEY_EC) {
keymaster_ec_keygen_params_t ec_params;
memset(&ec_params, '\0', sizeof(ec_params));
@@ -1747,7 +1794,12 @@
}
ec_params.field_size = keySize;
- rc = device->generate_keypair(device, TYPE_EC, &ec_params, &data, &dataLength);
+ if (device->common.module->module_api_version >= KEYMASTER_MODULE_API_VERSION_0_2) {
+ rc = device->generate_keypair(device, TYPE_EC, &ec_params, &data, &dataLength);
+ } else {
+ isFallback = true;
+ rc = openssl_generate_keypair(device, TYPE_EC, &ec_params, &data, &dataLength);
+ }
} else if (keyType == EVP_PKEY_RSA) {
keymaster_rsa_keygen_params_t rsa_params;
memset(&rsa_params, '\0', sizeof(rsa_params));
@@ -1799,6 +1851,8 @@
Blob keyBlob(data, dataLength, NULL, 0, TYPE_KEY_PAIR);
free(data);
+ keyBlob.setFallback(isFallback);
+
return mKeyStore->put(filename.string(), &keyBlob, callingUid);
}
@@ -1863,8 +1917,13 @@
params.digest_type = DIGEST_NONE;
params.padding_type = PADDING_NONE;
- rc = device->sign_data(device, ¶ms, keyBlob.getValue(), keyBlob.getLength(),
- data, length, out, outLength);
+ if (keyBlob.isFallback()) {
+ rc = openssl_sign_data(device, ¶ms, keyBlob.getValue(), keyBlob.getLength(), data,
+ length, out, outLength);
+ } else {
+ rc = device->sign_data(device, ¶ms, keyBlob.getValue(), keyBlob.getLength(), data,
+ length, out, outLength);
+ }
if (rc) {
ALOGW("device couldn't sign data");
return ::SYSTEM_ERROR;
@@ -1910,8 +1969,13 @@
params.digest_type = DIGEST_NONE;
params.padding_type = PADDING_NONE;
- rc = device->verify_data(device, ¶ms, keyBlob.getValue(), keyBlob.getLength(),
- data, dataLength, signature, signatureLength);
+ if (keyBlob.isFallback()) {
+ rc = openssl_verify_data(device, ¶ms, keyBlob.getValue(), keyBlob.getLength(), data,
+ dataLength, signature, signatureLength);
+ } else {
+ rc = device->verify_data(device, ¶ms, keyBlob.getValue(), keyBlob.getLength(), data,
+ dataLength, signature, signatureLength);
+ }
if (rc) {
return ::SYSTEM_ERROR;
} else {
@@ -1958,8 +2022,14 @@
return ::SYSTEM_ERROR;
}
- int rc = device->get_keypair_public(device, keyBlob.getValue(), keyBlob.getLength(), pubkey,
- pubkeyLength);
+ int rc;
+ if (keyBlob.isFallback()) {
+ rc = openssl_get_keypair_public(device, keyBlob.getValue(), keyBlob.getLength(), pubkey,
+ pubkeyLength);
+ } else {
+ rc = device->get_keypair_public(device, keyBlob.getValue(), keyBlob.getLength(), pubkey,
+ pubkeyLength);
+ }
if (rc) {
return ::SYSTEM_ERROR;
}
@@ -1997,7 +2067,7 @@
rc = ::SYSTEM_ERROR;
} else {
// A device doesn't have to implement delete_keypair.
- if (device->delete_keypair != NULL) {
+ if (device->delete_keypair != NULL && !keyBlob.isFallback()) {
if (device->delete_keypair(device, keyBlob.getValue(), keyBlob.getLength())) {
rc = ::SYSTEM_ERROR;
}
@@ -2210,7 +2280,7 @@
if (keyBlob.getType() == ::TYPE_KEY_PAIR) {
// A device doesn't have to implement delete_keypair.
- if (device->delete_keypair != NULL) {
+ if (device->delete_keypair != NULL && !keyBlob.isFallback()) {
if (device->delete_keypair(device, keyBlob.getValue(), keyBlob.getLength())) {
rc = ::SYSTEM_ERROR;
ALOGW("device couldn't remove %s", filename.string());