1
我需要签署一个字符串,将公钥作为字符串发布,然后在其他地方使用公钥来验证签名的消息。这是该消息被签署的部分:为什么我的OpenSSL/libcrypto签名不正确?
// RSA keypair generation
EVP_PKEY *keypair = NULL;
EVP_PKEY_CTX *ctx = EVP_PKEY_CTX_new_id(EVP_PKEY_RSA, NULL);
if (1 != EVP_PKEY_keygen_init(ctx)) {
initFail = true;
}
if (1 != EVP_PKEY_CTX_set_rsa_keygen_bits(ctx, 2048)) {
initFail = true;
}
if (1 != EVP_PKEY_keygen(ctx, &keypair)) {
initFail = true;
}
EVP_PKEY_CTX_free(ctx);
// Create public key string.
BIO* bo = BIO_new(BIO_s_mem());
PEM_write_bio_PUBKEY(bo, keypair);
char buff[1000];
BIO_read(bo, &buff[0], 1000);
BIO_free(bo);
pubkey = buff;
// Create signature
size_t *slen = new size_t;
unsigned char *sig = NULL;
std::string msg;
msg = stuffThatCreatesMessage();
EVP_MD_CTX *mdctx = EVP_MD_CTX_create();
if (1 != EVP_DigestSignInit(mdctx, NULL, EVP_sha256(),
NULL, keypair)) {
initFail = true;
}
if (1 != EVP_DigestSignUpdate(mdctx, msg.c_str(), msg.length())) {
initFail = true;
}
if (1 != EVP_DigestSignFinal(mdctx, NULL, slen)) {
initFail = true;
}
sig = (unsigned char *) OPENSSL_malloc(
sizeof(unsigned char) * (*slen));
if (1 != EVP_DigestSignFinal(mdctx, sig, slen)) {
initFail = true;
}
signature = *sig;
OPENSSL_free(sig);
bool isSuccess = verifySignature(signature, pubkey, msg);
如下是字符串信息和关键的代码和实际验证签名:
bool verifySignature(std::string sig, std::string key_str, std::string msg) {
BIO* bo = BIO_new(BIO_s_mem());
BIO_write(bo, key_str.c_str(), key_str.length());
EVP_PKEY *key = EVP_PKEY_new();
PEM_read_bio_PUBKEY(bo, &key, 0, 0);
BIO_free(bo);
unsigned char *unsigned_sig = new unsigned char[sig.length()+1];
strcpy((char *) unsigned_sig, sig.c_str());
EVP_MD_CTX *mdctx = EVP_MD_CTX_create();
if (1 != EVP_DigestVerifyInit(mdctx, NULL, EVP_sha256(), NULL, key)) {
return false;
}
if (1 != EVP_DigestVerifyUpdate(mdctx, msg.c_str(), msg.length())) {
return false;
}
bool retval = (1 == EVP_DigestVerifyFinal(mdctx, unsigned_sig,
sig.length()));
delete unsigned_sig;
return retval;
}
每次我做到这一点,后者的功能告诉我的签名无效,isSuccess
变量等于0.这是因为EVP_DigestSignFinal
返回0,表示签名不正确。我哪里错了?
您是否验证了生成的密钥,保存到磁盘然后再次回读的内存在内存中是否保持相同? – didiz
是!我在测试中打印了他们两个,他们是相同的。 –
请提供调用verifySignature()的代码 – Oleg