私钥解密代码使用BSAFE Library v6.0的公共接口规范?

问题描述 投票:2回答:1

最近,我承担了升级不再在Windows 10下运行的非常旧的加密代码的职责。我升级到了Visual Studio 2013,并对代码进行了一些修改以使用更好的错误报告。和代码工作正常。它使用私钥解密加密的数据。一切都很好。

Except for,当我注意到代码中的注释指示必须将某些PUBLIC指定符用作BSAFE v6.0库例程的输入时,而不是它们的PRIVATE对应符。实际上,当使用私有说明符时,我收到以下错误消息:

RSA错误:无效的密钥信息格式

注意:我的私钥未加密。

我对私有说明符为什么不起作用感到困惑,因为我正在进行私有密钥解密。

在下面的代码中,BSAFE v6.0库函数是B_SetKeyInfo,B_GetKeyInfo和B_SetAlgorithmInfo使用公共密钥说明符。

int Decrypt(unsigned char* cypherData, const string privKeyFilePathAndName, unsigned char*& plainData) {

enum { 
    IN_BUF_LEN                  = 1000, // input buffer length
    NUM_DIGITAL_SIGNATURE_BYTES = 128   // number of digital signature bytes
}; 

static unsigned char decryptedDigest[NUM_DIGITAL_SIGNATURE_BYTES]; // decrypted digest (returned)

const string delimiters = " \n"; // strtok delimeters

A_RSA_KEY       privKey;                             // private key
B_ALGORITHM_OBJ rsaAlgorithmObj;                     // rsa algorithm object
B_KEY_OBJ       privKeyObject;                       // private key object
char            inBuf[IN_BUF_LEN];                   // input buffer
char*           token;                               // strtok token
FILE*           ifp;                                 // input (private key) file pointer
int             i;                                   // index
int             stat;                                // status
unsigned char   privModulusData[NUM_MODULUS_BYTES];  // modulus data
unsigned char   privExponentData[NUM_MODULUS_BYTES]; // exponent data
unsigned int    digestLen;                           // digest length
unsigned int    partOutLen;                          // part out length

// open private key file
if ((ifp = fopen(privKeyFilePathAndName.c_str(), "r")) == NULL) {
    DisplayErrorMsg("Can't open private key file");
    return FAIL;
}

// get modulus length and exponent length
if ((fgets(inBuf, IN_BUF_LEN, ifp)) == NULL) {
    DisplayErrorMsg("Private key file error - can't read number of modulus bytes (modulus length)");
    return FAIL;
}
privKey.modulus.len = privKey.exponent.len = stoi(inBuf);

// get modulus data
if ((fgets(inBuf, IN_BUF_LEN, ifp)) == NULL) {
    DisplayErrorMsg("Private key file error - can't read modulus data");
    return FAIL;
}
token = strtok(inBuf, delimiters.c_str());
for (i = 0; token; i++) {
    privModulusData[i] = (unsigned char) stoi(token);
    token = strtok(NULL, delimiters.c_str());
}
if (i != sizeof(privModulusData)) {
    DisplayErrorMsg("Private key file error - wrong amount of modulus data");
    return FAIL;
}

// get exponent data
if ((fgets(inBuf, IN_BUF_LEN, ifp)) == NULL) {
    DisplayErrorMsg("Private key file error - can't read exponent data");
    return FAIL;
}
token = strtok(inBuf, delimiters.c_str());
for (i = 0; token; i++) {
    privExponentData[i] = (unsigned char) stoi(token);
    token = strtok(NULL, delimiters.c_str());
}
if (i != sizeof(privExponentData)) {
    DisplayErrorMsg("Private key file error - wrong amount of exponent data");
    return FAIL;
}

// close private key file and finish creating private key variable
fclose(ifp);
privKey.modulus.data = privModulusData;
privKey.exponent.data = privExponentData;

// create private key object and set to key read in from file
if ((stat = B_CreateKeyObject(&privKeyObject)) != 0) {
    DisplayRsaErrorMsg(stat);
    return FAIL;
}

// the private key is set to an Infotype of KI_RSAPublic because an error is 
// generated during decryption if we use the Infotype KI_RSAPrivate; not sure 
// why it works this way
if ((stat = B_SetKeyInfo(privKeyObject, KI_RSAPublic, (POINTER)&privKey)) != 0) {
    DisplayRsaErrorMsg(stat);
    return FAIL;
}
if ((stat = B_GetKeyInfo((POINTER *)&privKey, privKeyObject, KI_RSAPublic)) != 0) {
    DisplayRsaErrorMsg(stat);
    return FAIL;
}

// create an rsa algorithm object and set algorithm infoType to RSAPublic
if ((stat = B_CreateAlgorithmObject(&rsaAlgorithmObj)) != 0) {
    DisplayRsaErrorMsg(stat);
    return FAIL;
}
if ((stat = B_SetAlgorithmInfo(rsaAlgorithmObj, AI_RSAPublic, NULL_PTR)) != 0) {
    DisplayRsaErrorMsg(stat);
    return FAIL;
}

// perform the decryption, in stages (initial, update, and final)
if ((stat = B_DecryptInit(rsaAlgorithmObj, privKeyObject, DEMO_ALGORITHM_CHOOSER, ((A_SURRENDER_CTX*)NULL_PTR))) != 0) {
    DisplayRsaErrorMsg(stat);
    return FAIL;
}
if ((stat = B_DecryptUpdate(rsaAlgorithmObj, decryptedDigest, &digestLen, sizeof(decryptedDigest), cypherData, NUM_DIGITAL_SIGNATURE_BYTES, (B_ALGORITHM_OBJ)NULL_PTR, ((A_SURRENDER_CTX*)NULL_PTR))) != 0) {
    DisplayRsaErrorMsg(stat);
    return FAIL;
}
if ((stat = B_DecryptFinal(rsaAlgorithmObj, decryptedDigest, &partOutLen, sizeof(decryptedDigest), (B_ALGORITHM_OBJ)NULL_PTR, ((A_SURRENDER_CTX*)NULL_PTR))) != 0) {
    DisplayRsaErrorMsg(stat);
    return FAIL;
}

// set returned pointer and return pass code
plainData = decryptedDigest;
return PASS;

}

c++ cryptography rsa
1个回答
0
投票

《 RSA BSAFE Crypto-C 5.2库参考手册》指出,不建议使用KI_RSAPrivate。与RSA私钥一起使用的正确KI是KI_PKCS_RSAPrivate和KI_PKCS_RSAPrivateBER。参见here

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