1 /* Copyright (c) 2010 The Chromium OS Authors. All rights reserved. 2 * Use of this source code is governed by a BSD-style license that can be 3 * found in the LICENSE file. 4 */ 5 6 #include <openssl/pem.h> 7 8 #include <stdio.h> 9 #include <stdlib.h> 10 #include <unistd.h> 11 12 #include "cryptolib.h" 13 #include "host_common.h" 14 #include "signature_digest.h" 15 16 17 uint8_t* PrependDigestInfo(unsigned int algorithm, uint8_t* digest) { 18 const int digest_size = hash_size_map[algorithm]; 19 const int digestinfo_size = digestinfo_size_map[algorithm]; 20 const uint8_t* digestinfo = hash_digestinfo_map[algorithm]; 21 uint8_t* p = malloc(digestinfo_size + digest_size); 22 Memcpy(p, digestinfo, digestinfo_size); 23 Memcpy(p + digestinfo_size, digest, digest_size); 24 return p; 25 } 26 27 uint8_t* SignatureDigest(const uint8_t* buf, uint64_t len, 28 unsigned int algorithm) { 29 uint8_t* info_digest = NULL; 30 uint8_t* digest = NULL; 31 32 if (algorithm >= kNumAlgorithms) { 33 VBDEBUG(("SignatureDigest() called with invalid algorithm!\n")); 34 } else if ((digest = DigestBuf(buf, len, algorithm))) { 35 info_digest = PrependDigestInfo(algorithm, digest); 36 } 37 free(digest); 38 return info_digest; 39 } 40 41 uint8_t* SignatureBuf(const uint8_t* buf, uint64_t len, const char* key_file, 42 unsigned int algorithm) { 43 FILE* key_fp = NULL; 44 RSA* key = NULL; 45 uint8_t* signature = NULL; 46 uint8_t* signature_digest = SignatureDigest(buf, len, algorithm); 47 int signature_digest_len = (hash_size_map[algorithm] + 48 digestinfo_size_map[algorithm]); 49 key_fp = fopen(key_file, "r"); 50 if (!key_fp) { 51 VBDEBUG(("SignatureBuf(): Couldn't open key file: %s\n", key_file)); 52 free(signature_digest); 53 return NULL; 54 } 55 if ((key = PEM_read_RSAPrivateKey(key_fp, NULL, NULL, NULL))) 56 signature = (uint8_t*) malloc(siglen_map[algorithm]); 57 else 58 VBDEBUG(("SignatureBuf(): Couldn't read private key from file: %s\n", 59 key_file)); 60 if (signature) { 61 if (-1 == RSA_private_encrypt(signature_digest_len, /* Input length. */ 62 signature_digest, /* Input data. */ 63 signature, /* Output signature. */ 64 key, /* Key to use. */ 65 RSA_PKCS1_PADDING)) /* Padding to use. */ 66 VBDEBUG(("SignatureBuf(): RSA_private_encrypt() failed.\n")); 67 } 68 fclose(key_fp); 69 if (key) 70 RSA_free(key); 71 free(signature_digest); 72 return signature; 73 } 74
