Geremy Condra | 649fd55 | 2013-10-21 20:34:13 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2013 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
Adam Langley | f239299 | 2015-05-11 12:17:25 -0700 | [diff] [blame] | 17 | #define _GNU_SOURCE /* needed for asprintf */ |
| 18 | |
Geremy Condra | 649fd55 | 2013-10-21 20:34:13 +0000 | [diff] [blame] | 19 | #include <stdio.h> |
Adam Langley | f239299 | 2015-05-11 12:17:25 -0700 | [diff] [blame] | 20 | #include <stdlib.h> |
Geremy Condra | 649fd55 | 2013-10-21 20:34:13 +0000 | [diff] [blame] | 21 | #include <string.h> |
Geremy Condra | 649fd55 | 2013-10-21 20:34:13 +0000 | [diff] [blame] | 22 | #include <sys/stat.h> |
Adam Langley | f239299 | 2015-05-11 12:17:25 -0700 | [diff] [blame] | 23 | #include <sys/types.h> |
Geremy Condra | 649fd55 | 2013-10-21 20:34:13 +0000 | [diff] [blame] | 24 | #include <unistd.h> |
| 25 | |
| 26 | /* HACK: we need the RSAPublicKey struct |
| 27 | * but RSA_verify conflits with openssl */ |
| 28 | #define RSA_verify RSA_verify_mincrypt |
| 29 | #include "mincrypt/rsa.h" |
| 30 | #undef RSA_verify |
| 31 | |
| 32 | #include <openssl/evp.h> |
| 33 | #include <openssl/objects.h> |
| 34 | #include <openssl/pem.h> |
| 35 | #include <openssl/rsa.h> |
| 36 | #include <openssl/sha.h> |
| 37 | |
| 38 | // Convert OpenSSL RSA private key to android pre-computed RSAPublicKey format. |
| 39 | // Lifted from secure adb's mincrypt key generation. |
| 40 | static int convert_to_mincrypt_format(RSA *rsa, RSAPublicKey *pkey) |
| 41 | { |
| 42 | int ret = -1; |
| 43 | unsigned int i; |
| 44 | |
| 45 | if (RSA_size(rsa) != RSANUMBYTES) |
| 46 | goto out; |
| 47 | |
| 48 | BN_CTX* ctx = BN_CTX_new(); |
| 49 | BIGNUM* r32 = BN_new(); |
| 50 | BIGNUM* rr = BN_new(); |
| 51 | BIGNUM* r = BN_new(); |
| 52 | BIGNUM* rem = BN_new(); |
| 53 | BIGNUM* n = BN_new(); |
| 54 | BIGNUM* n0inv = BN_new(); |
| 55 | |
| 56 | BN_set_bit(r32, 32); |
| 57 | BN_copy(n, rsa->n); |
| 58 | BN_set_bit(r, RSANUMWORDS * 32); |
| 59 | BN_mod_sqr(rr, r, n, ctx); |
| 60 | BN_div(NULL, rem, n, r32, ctx); |
| 61 | BN_mod_inverse(n0inv, rem, r32, ctx); |
| 62 | |
| 63 | pkey->len = RSANUMWORDS; |
| 64 | pkey->n0inv = 0 - BN_get_word(n0inv); |
| 65 | for (i = 0; i < RSANUMWORDS; i++) { |
| 66 | BN_div(rr, rem, rr, r32, ctx); |
| 67 | pkey->rr[i] = BN_get_word(rem); |
| 68 | BN_div(n, rem, n, r32, ctx); |
| 69 | pkey->n[i] = BN_get_word(rem); |
| 70 | } |
| 71 | pkey->exponent = BN_get_word(rsa->e); |
| 72 | |
| 73 | ret = 0; |
| 74 | |
| 75 | BN_free(n0inv); |
| 76 | BN_free(n); |
| 77 | BN_free(rem); |
| 78 | BN_free(r); |
| 79 | BN_free(rr); |
| 80 | BN_free(r32); |
| 81 | BN_CTX_free(ctx); |
| 82 | |
| 83 | out: |
| 84 | return ret; |
| 85 | } |
| 86 | |
| 87 | static int write_public_keyfile(RSA *private_key, const char *private_key_path) |
| 88 | { |
| 89 | RSAPublicKey pkey; |
| 90 | BIO *bfile = NULL; |
| 91 | char *path = NULL; |
| 92 | int ret = -1; |
| 93 | |
| 94 | if (asprintf(&path, "%s.pub", private_key_path) < 0) |
| 95 | goto out; |
| 96 | |
| 97 | if (convert_to_mincrypt_format(private_key, &pkey) < 0) |
| 98 | goto out; |
| 99 | |
| 100 | bfile = BIO_new_file(path, "w"); |
| 101 | if (!bfile) |
| 102 | goto out; |
| 103 | |
| 104 | BIO_write(bfile, &pkey, sizeof(pkey)); |
| 105 | BIO_flush(bfile); |
| 106 | |
| 107 | ret = 0; |
| 108 | out: |
| 109 | BIO_free_all(bfile); |
| 110 | free(path); |
| 111 | return ret; |
| 112 | } |
| 113 | |
Sami Tolvanen | 82d824a | 2014-11-06 20:22:49 -0800 | [diff] [blame] | 114 | static int convert_x509(const char *pem_file, const char *key_file) |
| 115 | { |
| 116 | int ret = -1; |
| 117 | FILE *f = NULL; |
| 118 | EVP_PKEY *pkey = NULL; |
| 119 | RSA *rsa = NULL; |
| 120 | X509 *cert = NULL; |
| 121 | |
| 122 | if (!pem_file || !key_file) { |
| 123 | goto out; |
| 124 | } |
| 125 | |
| 126 | f = fopen(pem_file, "r"); |
| 127 | if (!f) { |
| 128 | printf("Failed to open '%s'\n", pem_file); |
| 129 | goto out; |
| 130 | } |
| 131 | |
| 132 | cert = PEM_read_X509(f, &cert, NULL, NULL); |
| 133 | if (!cert) { |
| 134 | printf("Failed to read PEM certificate from file '%s'\n", pem_file); |
| 135 | goto out; |
| 136 | } |
| 137 | |
| 138 | pkey = X509_get_pubkey(cert); |
| 139 | if (!pkey) { |
| 140 | printf("Failed to extract public key from certificate '%s'\n", pem_file); |
| 141 | goto out; |
| 142 | } |
| 143 | |
| 144 | rsa = EVP_PKEY_get1_RSA(pkey); |
| 145 | if (!rsa) { |
| 146 | printf("Failed to get the RSA public key from '%s'\n", pem_file); |
| 147 | goto out; |
| 148 | } |
| 149 | |
| 150 | if (write_public_keyfile(rsa, key_file) < 0) { |
| 151 | printf("Failed to write public key\n"); |
| 152 | goto out; |
| 153 | } |
| 154 | |
| 155 | ret = 0; |
| 156 | |
| 157 | out: |
| 158 | if (f) { |
| 159 | fclose(f); |
| 160 | } |
| 161 | if (cert) { |
| 162 | X509_free(cert); |
| 163 | } |
| 164 | if (pkey) { |
| 165 | EVP_PKEY_free(pkey); |
| 166 | } |
| 167 | if (rsa) { |
| 168 | RSA_free(rsa); |
| 169 | } |
| 170 | |
| 171 | return ret; |
| 172 | } |
| 173 | |
Geremy Condra | 649fd55 | 2013-10-21 20:34:13 +0000 | [diff] [blame] | 174 | static int generate_key(const char *file) |
| 175 | { |
| 176 | int ret = -1; |
| 177 | FILE *f = NULL; |
| 178 | RSA* rsa = RSA_new(); |
| 179 | BIGNUM* exponent = BN_new(); |
| 180 | EVP_PKEY* pkey = EVP_PKEY_new(); |
| 181 | |
| 182 | if (!pkey || !exponent || !rsa) { |
| 183 | printf("Failed to allocate key\n"); |
| 184 | goto out; |
| 185 | } |
| 186 | |
| 187 | BN_set_word(exponent, RSA_F4); |
| 188 | RSA_generate_key_ex(rsa, 2048, exponent, NULL); |
| 189 | EVP_PKEY_set1_RSA(pkey, rsa); |
| 190 | |
| 191 | f = fopen(file, "w"); |
| 192 | if (!f) { |
| 193 | printf("Failed to open '%s'\n", file); |
| 194 | goto out; |
| 195 | } |
| 196 | |
| 197 | if (!PEM_write_PrivateKey(f, pkey, NULL, NULL, 0, NULL, NULL)) { |
| 198 | printf("Failed to write key\n"); |
| 199 | goto out; |
| 200 | } |
| 201 | |
| 202 | if (write_public_keyfile(rsa, file) < 0) { |
| 203 | printf("Failed to write public key\n"); |
| 204 | goto out; |
| 205 | } |
| 206 | |
| 207 | ret = 0; |
| 208 | |
| 209 | out: |
| 210 | if (f) |
| 211 | fclose(f); |
| 212 | EVP_PKEY_free(pkey); |
| 213 | RSA_free(rsa); |
| 214 | BN_free(exponent); |
| 215 | return ret; |
| 216 | } |
| 217 | |
| 218 | static void usage(){ |
Sami Tolvanen | 82d824a | 2014-11-06 20:22:49 -0800 | [diff] [blame] | 219 | printf("Usage: generate_verity_key <path-to-key> | -convert <path-to-x509-pem> <path-to-key>\n"); |
Geremy Condra | 649fd55 | 2013-10-21 20:34:13 +0000 | [diff] [blame] | 220 | } |
| 221 | |
| 222 | int main(int argc, char *argv[]) { |
Sami Tolvanen | 82d824a | 2014-11-06 20:22:49 -0800 | [diff] [blame] | 223 | if (argc == 2) { |
| 224 | return generate_key(argv[1]); |
| 225 | } else if (argc == 4 && !strcmp(argv[1], "-convert")) { |
| 226 | return convert_x509(argv[2], argv[3]); |
| 227 | } else { |
Geremy Condra | 649fd55 | 2013-10-21 20:34:13 +0000 | [diff] [blame] | 228 | usage(); |
| 229 | exit(-1); |
| 230 | } |
Sami Tolvanen | 82d824a | 2014-11-06 20:22:49 -0800 | [diff] [blame] | 231 | } |