iOS RSA加密取值为NULL

Question

使用RSA加密，_rsaPublic = PEM_read_bio_RSA_PUBKEY(bpubkey, NULL, NULL, NULL)，开始_rsaPublic取值正常，但是经过多次网络请求，进行加密，_rsaPublic取值为NULL。为什么会是NULL呢？？

Answer 1

我用的这种方法来加密的，不知道对你是否有用//.h
+(NSString *)RSAEncrypotoTheData:(NSString *)plainText publicKey:(NSString *) key;//.m
+(NSString *)RSAEncrypotoTheData:(NSString *)plainText publicKey:(NSString *) key
{
    
    SecKeyRef publicKey=[self addPublicKey:key];
    size_t cipherBufferSize = SecKeyGetBlockSize(publicKey);
    uint8_t *cipherBuffer = NULL;
    
    cipherBuffer = malloc(cipherBufferSize * sizeof(uint8_t));
    memset((void *)cipherBuffer, 0*0, cipherBufferSize);
    
    NSData *plainTextBytes = [plainText dataUsingEncoding:NSUTF8StringEncoding];
    size_t blockSize = cipherBufferSize-11;  // 这个地方比较重要是加密问组长度
    int numBlock = (int)ceil([plainTextBytes length] / (double)blockSize);
    NSMutableData *encryptedData = [[NSMutableData alloc] init];
    for (int i=0; i<numBlock; i++) {
        long bufferSize = MIN(blockSize,[plainTextBytes length]-i*blockSize);
        NSData *buffer = [plainTextBytes subdataWithRange:NSMakeRange(i * blockSize, bufferSize)];
        OSStatus status = SecKeyEncrypt(publicKey,
                                        kSecPaddingPKCS1,
                                        (const uint8_t *)[buffer bytes],
                                        [buffer length],
                                        cipherBuffer,
                                        &cipherBufferSize);
        if (status == noErr)
        {
            NSData *encryptedBytes = [[NSData alloc]
                                       initWithBytes:(const void *)cipherBuffer
                                       length:cipherBufferSize];
            [encryptedData appendData:encryptedBytes];
        }
        else
        {
            return nil;
        }
    }
    if (cipherBuffer)
    {
        free(cipherBuffer);
    }
    NSString *encrypotoResult=[NSString stringWithFormat:@"%@",[encryptedData base64EncodedStringWithOptions:0]];
    return encrypotoResult;
}