|
Assert(status == errSecSuccess, @"信任评估失败");
// 提取私钥
status = SecIdentityCopyPrivateKey(myIdentity, &_privateKeyRef);
NSAssert(status == errSecSuccess, @"私钥创建失败");
CFRelease(items);
}
- (NSString *)RSAEncryptString:(NSString *)string {
NSData *cipher = [self RSAEncryptData:[string dataUsingEncoding:NSUTF8StringEncoding]];
return [cipher base64EncodedStringWithOptions:0];
}
- (NSData *)RSAEncryptData:(NSData *)data {
OSStatus sanityCheck = noErr;
size_t cipherBufferSize = 0;
size_t keyBufferSize = 0;
NSAssert(data, @"明文数据为空");
NSAssert(_publicKeyRef, @"公钥为空");
NSData *cipher = nil;
uint8_t *cipherBuffer = NULL;
// 计算缓冲区大小
cipherBufferSize = SecKeyGetBlockSize(_publicKeyRef);
keyBufferSize = data.length;
if (kTypeOfWrapPadding == kSecPaddingNone) {
NSAssert(keyBufferSize <= cipherBufferSize, @"加密内容太大");
} else {
NSAssert(keyBufferSize <= (cipherBufferSize - 11), @"加密内容太大");
}
// 分配缓冲区
cipherBuffer = malloc(cipherBufferSize * sizeof(uint8_t));
memset((void *)cipherBuffer, 0x0, cipherBufferSize);
// 使用公钥加密
sanityCheck = SecKeyEncrypt(_publicKeyRef,
kTypeOfWrapPadding,
(const uint8_t *)data.bytes,
keyBufferSize,
cipherBuffer,
&cipherBufferSize
);
NSAssert(sanityCheck == noErr, @"加密错误，OSStatus == %d", sanityCheck);
// 生成密文数据
cipher = [NSData dataWithBytes:(const void *)cipherBuffer length:(NSUInteger)cipherBufferSize];
if (cipherBuffer) free(cipherBuffer);
return cipher;
}
- (NSString *)RSADecryptString:(NSString *)string {
NSData *keyData = [self RSADecryptData:[[NSData alloc] initWithBase64EncodedString:string options:0]];
return [[NSString alloc] initWithData:keyData encoding:NSUTF8StringEncoding];
}
- (NSData *)RSADecryptData:(NSData *)data {
OSStatus sanityCheck = noErr;
size_t cipherBufferSize = 0;
size_t keyBufferSize = 0;
NSData *key = nil;
uint8_t *keyBuffer = NULL;
SecKeyRef privateKey = _privateKeyRef;
NSAssert(privateKey != NULL, @"私钥不存在");
// 计算缓冲区大小
cipherBufferSize = SecKeyGetBlockSize(privateKey);
keyBufferSize = data.length;
NSAssert(keyBufferSize <= cipherBufferSize, @"解密内容太大");
// 分配缓冲区
keyBuffer = malloc(keyBufferSize * sizeof(uint8_t));
memset((void *)keyBuffer, 0x0, keyBufferSize);
// 使用私钥解密
sanityCheck = SecKeyDecrypt(privateKey,
kTypeOfWrapPadding,
(const uint8_t *)data.bytes,
cipherBufferSize,
keyBuffer,
&keyBufferSize
);
NSAssert1(sanityCheck == noErr, @"解密错误，OSStatus == %d", sanityCheck);
// 生成明文数据
key = [NSData dataWithBytes:(const void *)keyBuffer length:(NSUInteger)keyBufferSize];
if (keyBuffer) free(keyBuffer);
return key;
}
@end
二、OpenSSL 生成密钥示例~
生成强度是 1024 的 RSA 私钥
$ openssl genrsa -out private.pem 1024
执行以代码生成一个私钥，Pem文件，其实Pem文件就是一般的文本格式~看下图~
这是文件：
选择一个文本编辑器打开次文件可以看到其就是一个普通的文本：
-----BEGIN RSA PRIVATE KEY-----
MIICXAIBAAKBgQCfwtWJLpe9QQiBOA/kDVdYGDYko6ieGfaIHiqiHd7Ul13k4gI+
1NgL6SfO/UAhKL6rAwTk9t8/V0bIrbCTBL6hMLc4yJkBFbDK7eLoJNnxaUwl2pLL
BSiTZQQ8vsBC6myUiZDFdCfl2PWvfEMzMYNsCob2Mw4MYWJwNub+MYe7PwIDAQAB
AoGAc8jXy5FKBa5BRK1lzujgWYdKjilSRisY4jPCwDWXzklZkk0+RV0qqw8ye7BN
LvsBnJ0Wif5lc9mEAmLnKtXwdWrHKEi70s69mZZH+ssaP3SGAEug3tY2ojSYixmB
+dWyslVb3dVzxr56fMJLfCBGAhqhmX |