Merge changes from topic \'boringssl_conversion\' am: 52eb93c am: 0781351

am: 9c4a0e0 * commit '9c4a0e021607f9da6130658530110e84eefc8ed9': Switch fs_mgr and adb to libcrypto_utils. Add libcrypto_utils. Change-Id: Ifc84a632bfc58b6d7034d3feb3cc435ef706c54f
2016-04-13 01:50:10 +00:00 · 2016-04-13 01:50:10 +00:00 · e21165406f
parent ea54f236f1 9c4a0e0216
commit e21165406f
14 changed files with 559 additions and 165 deletions
--- a/adb/Android.mk
+++ b/adb/Android.mk
@ -108,7 +108,7 @@ LOCAL_SANITIZE := $(adb_target_sanitize)

 # Even though we're building a static library (and thus there's no link step for
 # this to take effect), this adds the includes to our path.
-LOCAL_STATIC_LIBRARIES := libbase
+LOCAL_STATIC_LIBRARIES := libcrypto_utils_static libcrypto_static libbase

 include $(BUILD_STATIC_LIBRARY)

@ -131,7 +131,7 @@ LOCAL_SANITIZE := $(adb_host_sanitize)

 # Even though we're building a static library (and thus there's no link step for
 # this to take effect), this adds the includes to our path.
-LOCAL_STATIC_LIBRARIES := libcrypto_static libbase
+LOCAL_STATIC_LIBRARIES := libcrypto_utils_static libcrypto_static libbase

 LOCAL_C_INCLUDES_windows := development/host/windows/usb/api/
 LOCAL_MULTILIB := first
@ -151,7 +151,7 @@ LOCAL_SRC_FILES := \
    shell_service_test.cpp \

 LOCAL_SANITIZE := $(adb_target_sanitize)
-LOCAL_STATIC_LIBRARIES := libadbd
+LOCAL_STATIC_LIBRARIES := libadbd libcrypto_utils_static libcrypto_static
 LOCAL_SHARED_LIBRARIES := liblog libbase libcutils
 include $(BUILD_NATIVE_TEST)

@ -191,6 +191,7 @@ LOCAL_SANITIZE := $(adb_host_sanitize)
 LOCAL_SHARED_LIBRARIES := libbase
 LOCAL_STATIC_LIBRARIES := \
    libadb \
+    libcrypto_utils_static \
    libcrypto_static \
    libcutils \
    libdiagnose_usb \
@ -219,7 +220,7 @@ LOCAL_CFLAGS_darwin := $(LIBADB_darwin_CFLAGS)
 LOCAL_SRC_FILES := test_track_devices.cpp
 LOCAL_SANITIZE := $(adb_host_sanitize)
 LOCAL_SHARED_LIBRARIES := libbase
-LOCAL_STATIC_LIBRARIES := libadb libcrypto_static libcutils
+LOCAL_STATIC_LIBRARIES := libadb libcrypto_utils_static libcrypto_static libcutils
 LOCAL_LDLIBS += -lrt -ldl -lpthread
 include $(BUILD_HOST_EXECUTABLE)
 endif
@ -271,6 +272,7 @@ LOCAL_SANITIZE := $(adb_host_sanitize)
 LOCAL_STATIC_LIBRARIES := \
    libadb \
    libbase \
+    libcrypto_utils_static \
    libcrypto_static \
    libdiagnose_usb \
    liblog \
@ -342,11 +344,11 @@ LOCAL_STATIC_LIBRARIES := \
    libfec_rs \
    libselinux \
    liblog \
-    libmincrypt \
    libext4_utils_static \
    libsquashfs_utils \
    libcutils \
    libbase \
+    libcrypto_utils_static \
    libcrypto_static \
    libminijail

--- a/adb/adb.cpp
+++ b/adb/adb.cpp
@ -353,7 +353,8 @@ void handle_packet(apacket *p, atransport *t)
                send_auth_publickey(t);
            }
        } else if (p->msg.arg0 == ADB_AUTH_SIGNATURE) {
-            if (adb_auth_verify(t->token, p->data, p->msg.data_length)) {
+            if (adb_auth_verify(t->token, sizeof(t->token),
+                                p->data, p->msg.data_length)) {
                adb_auth_verified(t);
                t->failed_auth_attempts = 0;
            } else {
--- a/adb/adb_auth.h
+++ b/adb/adb_auth.h
@ -43,9 +43,15 @@ int adb_auth_sign(void *key, const unsigned char* token, size_t token_size,
 void *adb_auth_nextkey(void *current);
 int adb_auth_get_userkey(unsigned char *data, size_t len);

-static inline int adb_auth_generate_token(void *token, size_t token_size) { return 0; }
-static inline int adb_auth_verify(void *token, void *sig, int siglen) { return 0; }
-static inline void adb_auth_confirm_key(unsigned char *data, size_t len, atransport *t) { }
+static inline int adb_auth_generate_token(void *token, size_t token_size) {
+    return 0;
+}
+static inline int adb_auth_verify(void *token, size_t token_size,
+                                  void *sig, int siglen) {
+    return 0;
+}
+static inline void adb_auth_confirm_key(unsigned char *data, size_t len,
+                                        atransport *t) {}

 #else // !ADB_HOST

@ -54,12 +60,15 @@ static inline int adb_auth_sign(void* key, const unsigned char* token,
    return 0;
 }
 static inline void *adb_auth_nextkey(void *current) { return NULL; }
-static inline int adb_auth_get_userkey(unsigned char *data, size_t len) { return 0; }
+static inline int adb_auth_get_userkey(unsigned char *data, size_t len) {
+    return 0;
+}

 void adbd_auth_init(void);
 void adbd_cloexec_auth_socket();
 int adb_auth_generate_token(void *token, size_t token_size);
-int adb_auth_verify(uint8_t* token, uint8_t* sig, int siglen);
+int adb_auth_verify(uint8_t* token, size_t token_size,
+                    uint8_t* sig, int siglen);
 void adb_auth_confirm_key(unsigned char *data, size_t len, atransport *t);

 #endif // ADB_HOST
--- a/adb/adb_auth_client.cpp
+++ b/adb/adb_auth_client.cpp
@ -23,10 +23,14 @@
 #include <stdio.h>
 #include <string.h>

+#include <openssl/obj_mac.h>
+#include <openssl/rsa.h>
+#include <openssl/sha.h>
+
+#include <crypto_utils/android_pubkey.h>
+
 #include "cutils/list.h"
 #include "cutils/sockets.h"
-#include "mincrypt/rsa.h"
-#include "mincrypt/sha.h"

 #include "adb.h"
 #include "fdevent.h"
@ -34,7 +38,7 @@

 struct adb_public_key {
    struct listnode node;
-    RSAPublicKey key;
+    RSA* key;
 };

 static const char *key_paths[] = {
@ -66,9 +70,8 @@ static void read_keys(const char *file, struct listnode *list)
    }

    while (fgets(buf, sizeof(buf), f)) {
-        /* Allocate 4 extra bytes to decode the base64 data in-place */
        auto key = reinterpret_cast<adb_public_key*>(
-            calloc(1, sizeof(adb_public_key) + 4));
+            calloc(1, sizeof(adb_public_key)));
        if (key == nullptr) {
            D("Can't malloc key");
            break;
@ -78,15 +81,18 @@ static void read_keys(const char *file, struct listnode *list)
        if (sep)
            *sep = '\0';

-        ret = __b64_pton(buf, (u_char *)&key->key, sizeof(key->key) + 4);
-        if (ret != sizeof(key->key)) {
+        // b64_pton requires one additional byte in the target buffer for
+        // decoding to succeed. See http://b/28035006 for details.
+        uint8_t keybuf[ANDROID_PUBKEY_ENCODED_SIZE + 1];
+        ret = __b64_pton(buf, keybuf, sizeof(keybuf));
+        if (ret != ANDROID_PUBKEY_ENCODED_SIZE) {
            D("%s: Invalid base64 data ret=%d", file, ret);
            free(key);
            continue;
        }

-        if (key->key.len != RSANUMWORDS) {
-            D("%s: Invalid key len %d", file, key->key.len);
+        if (!android_pubkey_decode(keybuf, ret, &key->key)) {
+            D("%s: Failed to parse key", file);
            free(key);
            continue;
        }
@ -104,7 +110,9 @@ static void free_keys(struct listnode *list)
    while (!list_empty(list)) {
        item = list_head(list);
        list_remove(item);
-        free(node_to_item(item, struct adb_public_key, node));
+        adb_public_key* key = node_to_item(item, struct adb_public_key, node);
+        RSA_free(key->key);
+        free(key);
    }
 }

@ -139,20 +147,17 @@ int adb_auth_generate_token(void *token, size_t token_size)
    return ret * token_size;
 }

-int adb_auth_verify(uint8_t* token, uint8_t* sig, int siglen)
+int adb_auth_verify(uint8_t* token, size_t token_size, uint8_t* sig, int siglen)
 {
    struct listnode *item;
    struct listnode key_list;
    int ret = 0;

-    if (siglen != RSANUMBYTES)
-        return 0;
-
    load_keys(&key_list);

    list_for_each(item, &key_list) {
        adb_public_key* key = node_to_item(item, struct adb_public_key, node);
-        ret = RSA_verify(&key->key, sig, siglen, token, SHA_DIGEST_SIZE);
+        ret = RSA_verify(NID_sha1, token, token_size, sig, siglen, key->key);
        if (ret)
            break;
    }
--- a/adb/adb_auth_host.cpp
+++ b/adb/adb_auth_host.cpp
@ -37,14 +37,9 @@

 #include "adb.h"

-/* HACK: we need the RSAPublicKey struct
- * but RSA_verify conflits with openssl */
-#define RSA_verify RSA_verify_mincrypt
-#include "mincrypt/rsa.h"
-#undef RSA_verify
-
 #include <android-base/errors.h>
 #include <android-base/strings.h>
+#include <crypto_utils/android_pubkey.h>
 #include <cutils/list.h>

 #include <openssl/evp.h>
@ -68,54 +63,6 @@ struct adb_private_key {
 static struct listnode key_list;


-/* Convert OpenSSL RSA private key to android pre-computed RSAPublicKey format */
-static int RSA_to_RSAPublicKey(RSA *rsa, RSAPublicKey *pkey)
-{
-    int ret = 1;
-    unsigned int i;
-
-    BN_CTX* ctx = BN_CTX_new();
-    BIGNUM* r32 = BN_new();
-    BIGNUM* rr = BN_new();
-    BIGNUM* r = BN_new();
-    BIGNUM* rem = BN_new();
-    BIGNUM* n = BN_new();
-    BIGNUM* n0inv = BN_new();
-
-    if (RSA_size(rsa) != RSANUMBYTES) {
-        ret = 0;
-        goto out;
-    }
-
-    BN_set_bit(r32, 32);
-    BN_copy(n, rsa->n);
-    BN_set_bit(r, RSANUMWORDS * 32);
-    BN_mod_sqr(rr, r, n, ctx);
-    BN_div(NULL, rem, n, r32, ctx);
-    BN_mod_inverse(n0inv, rem, r32, ctx);
-
-    pkey->len = RSANUMWORDS;
-    pkey->n0inv = 0 - BN_get_word(n0inv);
-    for (i = 0; i < RSANUMWORDS; i++) {
-        BN_div(rr, rem, rr, r32, ctx);
-        pkey->rr[i] = BN_get_word(rem);
-        BN_div(n, rem, n, r32, ctx);
-        pkey->n[i] = BN_get_word(rem);
-    }
-    pkey->exponent = BN_get_word(rsa->e);
-
-out:
-    BN_free(n0inv);
-    BN_free(n);
-    BN_free(rem);
-    BN_free(r);
-    BN_free(rr);
-    BN_free(r32);
-    BN_CTX_free(ctx);
-
-    return ret;
-}
-
 static void get_user_info(char *buf, size_t len)
 {
    char hostname[1024], username[1024];
@ -156,53 +103,55 @@ static void get_user_info(char *buf, size_t len)

 static int write_public_keyfile(RSA *private_key, const char *private_key_path)
 {
-    RSAPublicKey pkey;
+    uint8_t binary_key_data[ANDROID_PUBKEY_ENCODED_SIZE];
+    uint8_t* base64_key_data = nullptr;
+    size_t base64_key_length = 0;
    FILE *outfile = NULL;
    char path[PATH_MAX], info[MAX_PAYLOAD_V1];
-    uint8_t* encoded = nullptr;
-    size_t encoded_length;
    int ret = 0;

-    if (snprintf(path, sizeof(path), "%s.pub", private_key_path) >=
-        (int)sizeof(path)) {
-        D("Path too long while writing public key");
-        return 0;
-    }
-
-    if (!RSA_to_RSAPublicKey(private_key, &pkey)) {
+    if (!android_pubkey_encode(private_key, binary_key_data,
+                               sizeof(binary_key_data))) {
        D("Failed to convert to publickey");
-        return 0;
-    }
-
-    outfile = fopen(path, "w");
-    if (!outfile) {
-        D("Failed to open '%s'", path);
-        return 0;
+        goto out;
    }

    D("Writing public key to '%s'", path);

 #if defined(OPENSSL_IS_BORINGSSL)
-    if (!EVP_EncodedLength(&encoded_length, sizeof(pkey))) {
+    if (!EVP_EncodedLength(&base64_key_length, sizeof(binary_key_data))) {
        D("Public key too large to base64 encode");
        goto out;
    }
 #else
    /* While we switch from OpenSSL to BoringSSL we have to implement
     * |EVP_EncodedLength| here. */
-    encoded_length = 1 + ((sizeof(pkey) + 2) / 3 * 4);
+    base64_key_length = 1 + ((sizeof(binary_key_data) + 2) / 3 * 4);
 #endif

-    encoded = new uint8_t[encoded_length];
-    if (encoded == nullptr) {
+    base64_key_data = new uint8_t[base64_key_length];
+    if (base64_key_data == nullptr) {
        D("Allocation failure");
        goto out;
    }

-    encoded_length = EVP_EncodeBlock(encoded, (uint8_t*) &pkey, sizeof(pkey));
+    base64_key_length = EVP_EncodeBlock(base64_key_data, binary_key_data,
+                                        sizeof(binary_key_data));
    get_user_info(info, sizeof(info));

-    if (fwrite(encoded, encoded_length, 1, outfile) != 1 ||
+    if (snprintf(path, sizeof(path), "%s.pub", private_key_path) >=
+        (int)sizeof(path)) {
+        D("Path too long while writing public key");
+        goto out;
+    }
+
+    outfile = fopen(path, "w");
+    if (!outfile) {
+        D("Failed to open '%s'", path);
+        goto out;
+    }
+
+    if (fwrite(base64_key_data, base64_key_length, 1, outfile) != 1 ||
        fwrite(info, strlen(info), 1, outfile) != 1) {
        D("Write error while writing public key");
        goto out;
@ -214,7 +163,7 @@ static int write_public_keyfile(RSA *private_key, const char *private_key_path)
    if (outfile != NULL) {
        fclose(outfile);
    }
-    delete[] encoded;
+    delete[] base64_key_data;
    return ret;
 }

--- a/fs_mgr/Android.mk
+++ b/fs_mgr/Android.mk
@ -7,7 +7,7 @@ common_static_libraries := \
    libfec \
    libfec_rs \
    libbase \
-    libmincrypt \
+    libcrypto_utils_static \
    libcrypto_static \
    libext4_utils_static \
    libsquashfs_utils
--- a/fs_mgr/fs_mgr.c
+++ b/fs_mgr/fs_mgr.c
@ -14,35 +14,32 @@
 * limitations under the License.
 */

+#include <ctype.h>
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <libgen.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <unistd.h>
-#include <fcntl.h>
-#include <ctype.h>
 #include <sys/mount.h>
 #include <sys/stat.h>
-#include <errno.h>
+#include <sys/swap.h>
 #include <sys/types.h>
 #include <sys/wait.h>
-#include <libgen.h>
 #include <time.h>
-#include <sys/swap.h>
-#include <dirent.h>
-#include <ext4.h>
-#include <ext4_sb.h>
-#include <ext4_crypt_init_extensions.h>
+#include <unistd.h>
+
+#include <ext4.h>
+#include <ext4_crypt_init_extensions.h>
+#include <ext4_sb.h>

-#include <linux/loop.h>
-#include <private/android_filesystem_config.h>
 #include <cutils/android_reboot.h>
 #include <cutils/partition_utils.h>
 #include <cutils/properties.h>
+#include <linux/loop.h>
 #include <logwrap/logwrap.h>
-
-#include "mincrypt/rsa.h"
-#include "mincrypt/sha.h"
-#include "mincrypt/sha256.h"
+#include <private/android_filesystem_config.h>

 #include "ext4_utils.h"
 #include "wipe.h"
--- a/fs_mgr/fs_mgr_verity.cpp
+++ b/fs_mgr/fs_mgr_verity.cpp
@ -14,29 +14,29 @@
 * limitations under the License.
 */

+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
 #include <inttypes.h>
+#include <libgen.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <unistd.h>
-#include <fcntl.h>
-#include <ctype.h>
 #include <sys/mount.h>
 #include <sys/stat.h>
-#include <errno.h>
 #include <sys/types.h>
 #include <sys/wait.h>
-#include <libgen.h>
 #include <time.h>
+#include <unistd.h>

 #include <android-base/file.h>
-#include <private/android_filesystem_config.h>
+#include <crypto_utils/android_pubkey.h>
 #include <cutils/properties.h>
 #include <logwrap/logwrap.h>
-
-#include "mincrypt/rsa.h"
-#include "mincrypt/sha.h"
-#include "mincrypt/sha256.h"
+#include <openssl/obj_mac.h>
+#include <openssl/rsa.h>
+#include <openssl/sha.h>
+#include <private/android_filesystem_config.h>

 #include "fec/io.h"

@ -83,48 +83,45 @@ struct verity_state {

 extern struct fs_info info;

-static RSAPublicKey *load_key(const char *path)
+static RSA *load_key(const char *path)
 {
-    RSAPublicKey* key = static_cast<RSAPublicKey*>(malloc(sizeof(RSAPublicKey)));
-    if (!key) {
-        ERROR("Can't malloc key\n");
-        return NULL;
-    }
+    uint8_t key_data[ANDROID_PUBKEY_ENCODED_SIZE];

    FILE* f = fopen(path, "r");
    if (!f) {
        ERROR("Can't open '%s'\n", path);
-        free(key);
+        free(key_data);
        return NULL;
    }

-    if (!fread(key, sizeof(*key), 1, f)) {
+    if (!fread(key_data, sizeof(key_data), 1, f)) {
        ERROR("Could not read key!\n");
        fclose(f);
-        free(key);
-        return NULL;
-    }
-
-    if (key->len != RSANUMWORDS) {
-        ERROR("Invalid key length %d\n", key->len);
-        fclose(f);
-        free(key);
+        free(key_data);
        return NULL;
    }

    fclose(f);
+
+    RSA* key = NULL;
+    if (!android_pubkey_decode(key_data, sizeof(key_data), &key)) {
+        ERROR("Could not parse key!\n");
+        free(key_data);
+        return NULL;
+    }
+
    return key;
 }

-static int verify_table(const uint8_t *signature, const char *table,
-        uint32_t table_length)
+static int verify_table(const uint8_t *signature, size_t signature_size,
+        const char *table, uint32_t table_length)
 {
-    RSAPublicKey *key;
-    uint8_t hash_buf[SHA256_DIGEST_SIZE];
+    RSA *key;
+    uint8_t hash_buf[SHA256_DIGEST_LENGTH];
    int retval = -1;

    // Hash the table
-    SHA256_hash((uint8_t*)table, table_length, hash_buf);
+    SHA256((uint8_t*)table, table_length, hash_buf);

    // Now get the public key from the keyfile
    key = load_key(VERITY_TABLE_RSA_KEY);
@ -134,11 +131,8 @@ static int verify_table(const uint8_t *signature, const char *table,
    }

    // verify the result
-    if (!RSA_verify(key,
-                    signature,
-                    RSANUMBYTES,
-                    (uint8_t*) hash_buf,
-                    SHA256_DIGEST_SIZE)) {
+    if (!RSA_verify(NID_sha256, hash_buf, sizeof(hash_buf), signature,
+                    signature_size, key)) {
        ERROR("Couldn't verify table\n");
        goto out;
    }
@ -146,7 +140,7 @@ static int verify_table(const uint8_t *signature, const char *table,
    retval = 0;

 out:
-    free(key);
+    RSA_free(key);
    return retval;
 }

@ -610,8 +604,8 @@ static int compare_last_signature(struct fstab_rec *fstab, int *match)
    off64_t offset = 0;
    struct fec_handle *f = NULL;
    struct fec_verity_metadata verity;
-    uint8_t curr[SHA256_DIGEST_SIZE];
-    uint8_t prev[SHA256_DIGEST_SIZE];
+    uint8_t curr[SHA256_DIGEST_LENGTH];
+    uint8_t prev[SHA256_DIGEST_LENGTH];

    *match = 1;

@ -629,7 +623,7 @@ static int compare_last_signature(struct fstab_rec *fstab, int *match)
        goto out;
    }

-    SHA256_hash(verity.signature, RSANUMBYTES, curr);
+    SHA256(verity.signature, sizeof(verity.signature), curr);

    if (snprintf(tag, sizeof(tag), VERITY_LASTSIG_TAG "_%s",
            basename(fstab->mount_point)) >= (int)sizeof(tag)) {
@ -637,7 +631,7 @@ static int compare_last_signature(struct fstab_rec *fstab, int *match)
        goto out;
    }

-    if (metadata_find(fstab->verity_loc, tag, SHA256_DIGEST_SIZE,
+    if (metadata_find(fstab->verity_loc, tag, SHA256_DIGEST_LENGTH,
            &offset) < 0) {
        goto out;
    }
@ -656,7 +650,7 @@ static int compare_last_signature(struct fstab_rec *fstab, int *match)
        goto out;
    }

-    *match = !memcmp(curr, prev, SHA256_DIGEST_SIZE);
+    *match = !memcmp(curr, prev, SHA256_DIGEST_LENGTH);

    if (!*match) {
        /* update current signature hash */
@ -919,7 +913,7 @@ int fs_mgr_setup_verity(struct fstab_rec *fstab)
    }

    // verify the signature on the table
-    if (verify_table(verity.signature, verity.table,
+    if (verify_table(verity.signature, sizeof(verity.signature), verity.table,
            verity.table_length) < 0) {
        if (params.mode == VERITY_MODE_LOGGING) {
            // the user has been warned, allow mounting without dm-verity
--- a/init/Android.mk
+++ b/init/Android.mk
@ -96,7 +96,7 @@ LOCAL_STATIC_LIBRARIES := \
    libc \
    libselinux \
    liblog \
-    libmincrypt \
+    libcrypto_utils_static \
    libcrypto_static \
    libc++_static \
    libdl \
--- a/libcrypto_utils/Android.mk
+++ b/libcrypto_utils/Android.mk
@ -0,0 +1,56 @@
+#
+# Copyright (C) 2016 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+LOCAL_PATH := $(call my-dir)
+
+include $(CLEAR_VARS)
+LOCAL_MODULE := libcrypto_utils
+LOCAL_SRC_FILES := android_pubkey.c
+LOCAL_CFLAGS := -Wall -Werror -Wextra -std=c99
+LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
+LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
+LOCAL_SHARED_LIBRARIES := libcrypto
+include $(BUILD_SHARED_LIBRARY)
+
+include $(CLEAR_VARS)
+LOCAL_MODULE := libcrypto_utils
+LOCAL_SRC_FILES := android_pubkey.c
+LOCAL_CFLAGS := -Wall -Werror -Wextra -std=c99
+LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
+LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
+LOCAL_SHARED_LIBRARIES := libcrypto-host
+include $(BUILD_HOST_SHARED_LIBRARY)
+
+include $(CLEAR_VARS)
+LOCAL_MODULE := libcrypto_utils_static
+LOCAL_SRC_FILES := android_pubkey.c
+LOCAL_CFLAGS := -Wall -Werror -Wextra -std=c99
+LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
+LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
+LOCAL_STATIC_LIBRARIES := libcrypto_static
+include $(BUILD_STATIC_LIBRARY)
+
+include $(CLEAR_VARS)
+LOCAL_MODULE := libcrypto_utils_static
+LOCAL_MODULE_HOST_OS := darwin linux windows
+LOCAL_SRC_FILES := android_pubkey.c
+LOCAL_CFLAGS := -Wall -Werror -Wextra -std=c99
+LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
+LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
+LOCAL_STATIC_LIBRARIES := libcrypto_static
+include $(BUILD_HOST_STATIC_LIBRARY)
+
+include $(call all-makefiles-under,$(LOCAL_PATH))
--- a/libcrypto_utils/android_pubkey.c
+++ b/libcrypto_utils/android_pubkey.c
@ -0,0 +1,167 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <crypto_utils/android_pubkey.h>
+
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+
+// Better safe than sorry.
+#if (ANDROID_PUBKEY_MODULUS_SIZE % 4) != 0
+#error RSA modulus size must be multiple of the word size!
+#endif
+
+// Size of the RSA modulus in words.
+#define ANDROID_PUBKEY_MODULUS_SIZE_WORDS (ANDROID_PUBKEY_MODULUS_SIZE / 4)
+
+// This file implements encoding and decoding logic for Android's custom RSA
+// public key binary format. Public keys are stored as a sequence of
+// little-endian 32 bit words. Note that Android only supports little-endian
+// processors, so we don't do any byte order conversions when parsing the binary
+// struct.
+typedef struct RSAPublicKey {
+    // Modulus length. This must be ANDROID_PUBKEY_MODULUS_SIZE.
+    uint32_t modulus_size_words;
+
+    // Precomputed montgomery parameter: -1 / n[0] mod 2^32
+    uint32_t n0inv;
+
+    // RSA modulus as a little-endian array.
+    uint8_t modulus[ANDROID_PUBKEY_MODULUS_SIZE];
+
+    // Montgomery parameter R^2 as a little-endian array of little-endian words.
+    uint8_t rr[ANDROID_PUBKEY_MODULUS_SIZE];
+
+    // RSA modulus: 3 or 65537
+    uint32_t exponent;
+} RSAPublicKey;
+
+// Reverses byte order in |buffer|.
+static void reverse_bytes(uint8_t* buffer, size_t size) {
+  for (size_t i = 0; i < (size + 1) / 2; ++i) {
+    uint8_t tmp = buffer[i];
+    buffer[i] = buffer[size - i - 1];
+    buffer[size - i - 1] = tmp;
+  }
+}
+
+bool android_pubkey_decode(const uint8_t* key_buffer, size_t size, RSA** key) {
+  const RSAPublicKey* key_struct = (RSAPublicKey*)key_buffer;
+  bool ret = false;
+  uint8_t modulus_buffer[ANDROID_PUBKEY_MODULUS_SIZE];
+  RSA* new_key = RSA_new();
+  if (!new_key) {
+    goto cleanup;
+  }
+
+  // Check |size| is large enough and the modulus size is correct.
+  if (size < sizeof(RSAPublicKey)) {
+    goto cleanup;
+  }
+  if (key_struct->modulus_size_words != ANDROID_PUBKEY_MODULUS_SIZE_WORDS) {
+    goto cleanup;
+  }
+
+  // Convert the modulus to big-endian byte order as expected by BN_bin2bn.
+  memcpy(modulus_buffer, key_struct->modulus, sizeof(modulus_buffer));
+  reverse_bytes(modulus_buffer, sizeof(modulus_buffer));
+  new_key->n = BN_bin2bn(modulus_buffer, sizeof(modulus_buffer), NULL);
+  if (!new_key->n) {
+    goto cleanup;
+  }
+
+  // Read the exponent.
+  new_key->e = BN_new();
+  if (!new_key->e || !BN_set_word(new_key->e, key_struct->exponent)) {
+    goto cleanup;
+  }
+
+  // Note that we don't extract the montgomery parameters n0inv and rr from
+  // the RSAPublicKey structure. They assume a word size of 32 bits, but
+  // BoringSSL may use a word size of 64 bits internally, so we're lacking the
+  // top 32 bits of n0inv in general. For now, we just ignore the parameters
+  // and have BoringSSL recompute them internally. More sophisticated logic can
+  // be added here if/when we want the additional speedup from using the
+  // pre-computed montgomery parameters.
+
+  *key = new_key;
+  ret = true;
+
+cleanup:
+  if (!ret && new_key) {
+    RSA_free(new_key);
+  }
+  return ret;
+}
+
+static bool android_pubkey_encode_bignum(const BIGNUM* num, uint8_t* buffer) {
+  if (!BN_bn2bin_padded(buffer, ANDROID_PUBKEY_MODULUS_SIZE, num)) {
+    return false;
+  }
+
+  reverse_bytes(buffer, ANDROID_PUBKEY_MODULUS_SIZE);
+  return true;
+}
+
+bool android_pubkey_encode(const RSA* key, uint8_t* key_buffer, size_t size) {
+  RSAPublicKey* key_struct = (RSAPublicKey*)key_buffer;
+  bool ret = false;
+  BN_CTX* ctx = BN_CTX_new();
+  BIGNUM* r32 = BN_new();
+  BIGNUM* n0inv = BN_new();
+  BIGNUM* rr = BN_new();
+
+  if (sizeof(RSAPublicKey) > size ||
+      RSA_size(key) != ANDROID_PUBKEY_MODULUS_SIZE) {
+    goto cleanup;
+  }
+
+  // Store the modulus size.
+  key_struct->modulus_size_words = ANDROID_PUBKEY_MODULUS_SIZE_WORDS;
+
+  // Compute and store n0inv = -1 / N[0] mod 2^32.
+  if (!ctx || !r32 || !n0inv || !BN_set_bit(r32, 32) ||
+      !BN_mod(n0inv, key->n, r32, ctx) ||
+      !BN_mod_inverse(n0inv, n0inv, r32, ctx) || !BN_sub(n0inv, r32, n0inv)) {
+    goto cleanup;
+  }
+  key_struct->n0inv = (uint32_t)BN_get_word(n0inv);
+
+  // Store the modulus.
+  if (!android_pubkey_encode_bignum(key->n, key_struct->modulus)) {
+    goto cleanup;
+  }
+
+  // Compute and store rr = (2^(rsa_size)) ^ 2 mod N.
+  if (!ctx || !rr || !BN_set_bit(rr, ANDROID_PUBKEY_MODULUS_SIZE * 8) ||
+      !BN_mod_sqr(rr, rr, key->n, ctx) ||
+      !android_pubkey_encode_bignum(rr, key_struct->rr)) {
+    goto cleanup;
+  }
+
+  // Store the exponent.
+  key_struct->exponent = (uint32_t)BN_get_word(key->e);
+
+  ret = true;
+
+cleanup:
+  BN_free(rr);
+  BN_free(n0inv);
+  BN_free(r32);
+  BN_CTX_free(ctx);
+  return ret;
+}
--- a/libcrypto_utils/include/crypto_utils/android_pubkey.h
+++ b/libcrypto_utils/include/crypto_utils/android_pubkey.h
@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef CRYPTO_UTILS_ANDROID_PUBKEY_H
+#define CRYPTO_UTILS_ANDROID_PUBKEY_H
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#include <openssl/rsa.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Size of an RSA modulus such as an encrypted block or a signature.
+#define ANDROID_PUBKEY_MODULUS_SIZE (2048 / 8)
+
+// Size of an encoded RSA key.
+#define ANDROID_PUBKEY_ENCODED_SIZE \
+  (3 * sizeof(uint32_t) + 2 * ANDROID_PUBKEY_MODULUS_SIZE)
+
+/* Allocates a new RSA |key| object, decodes a public RSA key stored in
+ * Android's custom binary format from |key_buffer| and sets the key parameters
+ * in |key|. |size| specifies the size of the key buffer and must be at least
+ * |ANDROID_PUBKEY_ENCODED_SIZE|. The resulting |*key| can be used with the
+ * standard BoringSSL API to perform public operations.
+ *
+ * Returns true if successful, in which case the caller receives ownership of
+ * the |*key| object, i.e. needs to call RSA_free() when done with it. If there
+ * is an error, |key| is left untouched and the return value will be false.
+ */
+bool android_pubkey_decode(const uint8_t* key_buffer, size_t size, RSA** key);
+
+/* Encodes |key| in the Android RSA public key binary format and stores the
+ * bytes in |key_buffer|. |key_buffer| should be of size at least
+ * |ANDROID_PUBKEY_ENCODED_SIZE|.
+ *
+ * Returns true if successful, false on error.
+ */
+bool android_pubkey_encode(const RSA* key, uint8_t* key_buffer, size_t size);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+#endif  // CRYPTO_UTILS_ANDROID_PUBKEY_H
--- a/libcrypto_utils/tests/Android.mk
+++ b/libcrypto_utils/tests/Android.mk
@ -0,0 +1,24 @@
+#
+# Copyright (C) 2016 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+LOCAL_PATH := $(call my-dir)
+
+include $(CLEAR_VARS)
+LOCAL_MODULE := libcrypto_utils_test
+LOCAL_SRC_FILES := android_pubkey_test.cpp
+LOCAL_CFLAGS := -Wall -Werror -Wextra -std=c++11
+LOCAL_SHARED_LIBRARIES := libcrypto_utils libcrypto-host
+include $(BUILD_HOST_NATIVE_TEST)
--- a/libcrypto_utils/tests/android_pubkey_test.cpp
+++ b/libcrypto_utils/tests/android_pubkey_test.cpp
@ -0,0 +1,129 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <crypto_utils/android_pubkey.h>
+
+#include <string.h>
+
+#include <memory>
+
+#include <openssl/obj_mac.h>
+#include <openssl/rsa.h>
+
+#include <gtest/gtest.h>
+
+// Test digest to verify.
+const uint8_t kDigest[] = {
+    0x31, 0x5f, 0x5b, 0xdb, 0x76, 0xd0, 0x78, 0xc4, 0x3b, 0x8a, 0xc0,
+    0x06, 0x4e, 0x4a, 0x01, 0x64, 0x61, 0x2b, 0x1f, 0xce, 0x77, 0xc8,
+    0x69, 0x34, 0x5b, 0xfc, 0x94, 0xc7, 0x58, 0x94, 0xed, 0xd3,
+};
+
+// 2048 RSA test key.
+const uint8_t kKey2048[ANDROID_PUBKEY_ENCODED_SIZE] = {
+    0x40, 0x00, 0x00, 0x00, 0x05, 0x75, 0x61, 0xd1, 0x33, 0xf0, 0x2d, 0x12,
+    0x45, 0xfb, 0xae, 0x07, 0x02, 0x15, 0x4f, 0x3a, 0x2b, 0xa3, 0xbc, 0x49,
+    0xbd, 0x14, 0x07, 0xa0, 0xc0, 0x9f, 0x0c, 0x52, 0x60, 0x77, 0x9f, 0xa2,
+    0x31, 0xd0, 0xa7, 0xfb, 0x7e, 0xde, 0xfb, 0xc9, 0x05, 0xc0, 0x97, 0xf7,
+    0x74, 0x99, 0xe6, 0xd1, 0x08, 0xa6, 0xc2, 0x59, 0x5a, 0xd8, 0x37, 0x1d,
+    0xe0, 0x48, 0x5e, 0x63, 0x44, 0x04, 0x8b, 0x05, 0x20, 0xf6, 0x25, 0x67,
+    0x38, 0xb2, 0xb6, 0xf9, 0xbe, 0xb6, 0x1d, 0x7f, 0x1b, 0x71, 0x8a, 0xeb,
+    0xb7, 0xf8, 0x01, 0xc1, 0x5e, 0xf7, 0xfe, 0x48, 0x08, 0x27, 0x0f, 0x27,
+    0x2a, 0x64, 0x1a, 0x43, 0x8d, 0xcf, 0x5a, 0x33, 0x5c, 0x18, 0xc5, 0xf4,
+    0xe7, 0xfe, 0xee, 0xd3, 0x12, 0x62, 0xad, 0x61, 0x78, 0x9a, 0x03, 0xb0,
+    0xaf, 0xab, 0x91, 0x57, 0x46, 0xbf, 0x18, 0xc6, 0xbc, 0x0c, 0x6b, 0x55,
+    0xcd, 0xda, 0xc4, 0xcc, 0x98, 0x46, 0x91, 0x99, 0xbc, 0xa3, 0xca, 0x6c,
+    0x86, 0xa6, 0x1c, 0x8f, 0xca, 0xf8, 0xf6, 0x8a, 0x00, 0x8e, 0x05, 0xd7,
+    0x13, 0x43, 0xe2, 0xf2, 0x1a, 0x13, 0xf3, 0x50, 0x13, 0xa4, 0xf2, 0x4e,
+    0x41, 0xb1, 0x36, 0x78, 0x55, 0x4c, 0x5e, 0x27, 0xc5, 0xc0, 0x4b, 0xd8,
+    0x93, 0xaa, 0x7e, 0xf0, 0x90, 0x08, 0x10, 0x26, 0x72, 0x6d, 0xb9, 0x21,
+    0xae, 0x4d, 0x01, 0x4b, 0x55, 0x1d, 0xe7, 0x1e, 0x5e, 0x31, 0x6e, 0x62,
+    0xd1, 0x33, 0x26, 0xcb, 0xdb, 0xfe, 0x72, 0x98, 0xc8, 0x06, 0x1c, 0x12,
+    0xdf, 0xfc, 0x74, 0xe5, 0x7a, 0x6f, 0xf5, 0xa3, 0x63, 0x08, 0xe3, 0x02,
+    0x68, 0x4d, 0x7c, 0x70, 0x05, 0xec, 0x95, 0x7e, 0x24, 0xa4, 0xbc, 0x4c,
+    0xcd, 0x39, 0x14, 0xb5, 0x2a, 0x8f, 0xc1, 0xe3, 0x4e, 0xfa, 0xf8, 0x70,
+    0x50, 0x8f, 0xd5, 0x8e, 0xc7, 0xb5, 0x32, 0x89, 0x4d, 0xbb, 0x6a, 0xc1,
+    0xc1, 0xa2, 0x42, 0x57, 0x57, 0xbd, 0x2a, 0xdc, 0xa6, 0xfd, 0xc8, 0x86,
+    0x44, 0x6a, 0x03, 0x5d, 0x4d, 0x28, 0xe1, 0xde, 0xb4, 0xa9, 0xa5, 0x03,
+    0x61, 0x7a, 0x5f, 0xb1, 0x09, 0x17, 0x2b, 0x9c, 0xa2, 0x54, 0x28, 0xad,
+    0x34, 0xc9, 0x5f, 0x6c, 0x9f, 0xb8, 0xd2, 0xa9, 0x78, 0xa7, 0xaa, 0xb3,
+    0x11, 0x2f, 0x65, 0x9b, 0x4e, 0x67, 0x0c, 0xcc, 0x20, 0x36, 0xbf, 0x26,
+    0x2b, 0x4e, 0xc0, 0xd4, 0xbd, 0x22, 0x64, 0xc4, 0x1c, 0x56, 0x69, 0xdb,
+    0x5f, 0x89, 0xe1, 0x75, 0x68, 0x8d, 0x0e, 0xab, 0x1c, 0x10, 0x1a, 0xc0,
+    0x12, 0x5d, 0x6f, 0xbd, 0x09, 0xbb, 0x47, 0xcb, 0xe7, 0x34, 0xef, 0x56,
+    0xab, 0xea, 0xc3, 0xe9, 0x7f, 0x9a, 0x3d, 0xe9, 0x2d, 0x14, 0x61, 0x25,
+    0x37, 0x5c, 0x3b, 0x4b, 0xaf, 0x5a, 0x4b, 0xc8, 0x99, 0x1a, 0x32, 0x8f,
+    0x54, 0x07, 0xd3, 0x57, 0x8a, 0x3d, 0x2a, 0xf7, 0x9e, 0x7e, 0x92, 0x2a,
+    0x50, 0xe9, 0xd8, 0xdb, 0xd6, 0x03, 0xd3, 0x8e, 0x54, 0x32, 0xce, 0x87,
+    0x93, 0x92, 0xe7, 0x75, 0xe1, 0x6b, 0x78, 0x1a, 0x85, 0xc2, 0x46, 0xa1,
+    0x31, 0xbb, 0xc7, 0xb9, 0x1d, 0xd1, 0x71, 0xe0, 0xe2, 0x9b, 0x9c, 0x0d,
+    0xa3, 0xcf, 0x93, 0x4d, 0x87, 0x7b, 0x65, 0xd9, 0xda, 0x4c, 0xd9, 0x6a,
+    0xa6, 0x36, 0xc2, 0xc7, 0xe3, 0x33, 0xe2, 0xc3, 0x83, 0xd1, 0x72, 0x54,
+    0x30, 0x81, 0x5e, 0x34, 0x2c, 0x61, 0xee, 0xf4, 0x48, 0x97, 0xb6, 0xaa,
+    0x47, 0x6a, 0x05, 0x09, 0xd8, 0x4d, 0x90, 0xaf, 0xa8, 0x4e, 0x82, 0xe4,
+    0x8e, 0xb5, 0xe2, 0x65, 0x86, 0x67, 0xe9, 0x5b, 0x4b, 0x9a, 0x68, 0x08,
+    0x30, 0xf6, 0x25, 0x8b, 0x20, 0xda, 0x26, 0x6f, 0xbd, 0x0d, 0xa5, 0xd8,
+    0x6a, 0x7b, 0x01, 0x2f, 0xab, 0x7b, 0xb5, 0xfe, 0x62, 0x37, 0x2d, 0x94,
+    0x43, 0x2f, 0x4d, 0x16, 0x01, 0x00, 0x01, 0x00,
+};
+
+// 2048 bit RSA signature.
+const uint8_t kSignature2048[ANDROID_PUBKEY_MODULUS_SIZE] = {
+    0x3a, 0x11, 0x84, 0x40, 0xc1, 0x2f, 0x13, 0x8c, 0xde, 0xb0, 0xc3, 0x89,
+    0x8a, 0x63, 0xb2, 0x50, 0x93, 0x58, 0xc0, 0x0c, 0xb7, 0x08, 0xe7, 0x6c,
+    0x52, 0x87, 0x4e, 0x78, 0x89, 0xa3, 0x9a, 0x47, 0xeb, 0x11, 0x57, 0xbc,
+    0xb3, 0x97, 0xf8, 0x34, 0xf1, 0xf7, 0xbf, 0x3a, 0xfa, 0x1c, 0x6b, 0xdc,
+    0xd1, 0x02, 0xde, 0x9a, 0x0d, 0x72, 0xe7, 0x19, 0x63, 0x81, 0x46, 0x68,
+    0x1e, 0x63, 0x64, 0xc6, 0x59, 0xe7, 0x7c, 0x39, 0xed, 0x32, 0xd2, 0xd1,
+    0xd5, 0x1f, 0x13, 0x9b, 0x52, 0xdf, 0x34, 0xa3, 0xc0, 0xc4, 0x9a, 0x63,
+    0x9b, 0x9c, 0xbe, 0x22, 0xc8, 0xd8, 0x14, 0x2f, 0x4c, 0x78, 0x36, 0xdb,
+    0x16, 0x41, 0x67, 0xc1, 0x21, 0x8a, 0x73, 0xb2, 0xe5, 0xb0, 0xd3, 0x80,
+    0x91, 0x7a, 0xbf, 0xf9, 0x59, 0x4a, 0x4d, 0x78, 0x45, 0x44, 0xa1, 0x52,
+    0x86, 0x29, 0x48, 0x4d, 0xf0, 0x5d, 0xf2, 0x55, 0xa7, 0xcd, 0xc5, 0x2b,
+    0x7b, 0xe0, 0xb1, 0xf6, 0x2a, 0xd5, 0x61, 0xba, 0x1e, 0x1e, 0x3a, 0xf0,
+    0x55, 0xbc, 0x8c, 0x44, 0x41, 0xfc, 0xb8, 0x8c, 0x76, 0xbf, 0x80, 0x58,
+    0x82, 0x35, 0x4b, 0x0c, 0xfd, 0xef, 0xd5, 0x70, 0xd1, 0x64, 0xcb, 0x46,
+    0x58, 0x37, 0xbc, 0xa9, 0x7d, 0xd4, 0x70, 0xac, 0xce, 0xec, 0xca, 0x48,
+    0xcb, 0x0a, 0x40, 0x77, 0x04, 0x59, 0xca, 0x9c, 0x7d, 0x1a, 0x0b, 0xf0,
+    0xb5, 0xdd, 0xde, 0x71, 0x18, 0xb8, 0xef, 0x90, 0x2a, 0x09, 0x42, 0x39,
+    0x74, 0xff, 0x45, 0xa1, 0x39, 0x17, 0x50, 0x89, 0xa6, 0x5f, 0xbc, 0x9c,
+    0x0c, 0x9b, 0x47, 0x25, 0x79, 0x3e, 0xe3, 0xaa, 0xaf, 0xbe, 0x73, 0x6b,
+    0xcb, 0xe7, 0x35, 0xc1, 0x27, 0x09, 0xcd, 0xeb, 0xd7, 0xcf, 0x63, 0x83,
+    0x64, 0x8c, 0x45, 0x1c, 0x1d, 0x58, 0xcc, 0xd2, 0xf8, 0x2b, 0x4c, 0x4e,
+    0x14, 0x89, 0x2d, 0x70,
+};
+
+struct AndroidPubkeyTest : public ::testing::Test {
+  void SetUp() override {
+    RSA* new_key = nullptr;
+    ASSERT_TRUE(android_pubkey_decode(kKey2048, sizeof(kKey2048), &new_key));
+    key_.reset(new_key);
+  }
+
+  std::unique_ptr<RSA, void(*)(RSA*)> key_ = {nullptr, RSA_free};
+};
+
+TEST_F(AndroidPubkeyTest, Decode) {
+  // Make sure the decoded key successfully verifies a valid signature.
+  EXPECT_TRUE(RSA_verify(NID_sha256, kDigest, sizeof(kDigest), kSignature2048,
+                         sizeof(kSignature2048), key_.get()));
+}
+
+TEST_F(AndroidPubkeyTest, Encode) {
+  uint8_t key_data[ANDROID_PUBKEY_ENCODED_SIZE];
+  ASSERT_TRUE(android_pubkey_encode(key_.get(), key_data, sizeof(key_data)));
+  ASSERT_EQ(0, memcmp(kKey2048, key_data, sizeof(kKey2048)));
+}