ios用openSSL实现AES-GCM和ECB加密解密

在iOS中使用OpenSSL实现AES-GCM和ECB加密解密需要以下步骤：

1. 下载OpenSSL库并将其添加到iOS项目中。

2. 导入OpenSSL库头文件：

#import <openssl/evp.h>
#import <openssl/aes.h>

3. 实现AES-GCM加密解密：

// AES-GCM加密
+ (NSData *)AESGCMEncryptWithKey:(NSData *)key iv:(NSData *)iv aad:(NSData *)aad plainText:(NSData *)plainText tagLength:(NSUInteger)tagLength {
    EVP_CIPHER_CTX *ctx;
    int len, outlen;
    unsigned char *outbuf;
    NSData *tag = nil;
    NSData *cipherText = nil;
    
    // 初始化EVP_CIPHER_CTX
    ctx = EVP_CIPHER_CTX_new();
    EVP_EncryptInit_ex(ctx, EVP_aes_256_gcm(), NULL, NULL, NULL);
    
    // 设置key和iv
    EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_SET_IVLEN, (int)iv.length, NULL);
    EVP_EncryptInit_ex(ctx, NULL, NULL, key.bytes, iv.bytes);
    
    // 设置aad
    EVP_EncryptUpdate(ctx, NULL, &len, aad.bytes, (int)aad.length);
    
    // 加密明文
    outbuf = malloc(plainText.length + AES_BLOCK_SIZE);
    EVP_EncryptUpdate(ctx, outbuf, &len, plainText.bytes, (int)plainText.length);
    cipherText = [NSData dataWithBytes:outbuf length:len];
    free(outbuf);
    
    // 获取tag
    outbuf = malloc(tagLength);
    EVP_EncryptFinal_ex(ctx, outbuf, &outlen);
    tag = [NSData dataWithBytes:outbuf length:outlen];
    free(outbuf);
    
    // 释放EVP_CIPHER_CTX
    EVP_CIPHER_CTX_free(ctx);
    
    // 返回加密结果和tag
    NSMutableData *resultData = [NSMutableData dataWithData:cipherText];
    [resultData appendData:tag];
    return resultData;
}

// AES-GCM解密
+ (NSData *)AESGCMDecryptWithKey:(NSData *)key iv:(NSData *)iv aad:(NSData *)aad cipherText:(NSData *)cipherText tagLength:(NSUInteger)tagLength {
    EVP_CIPHER_CTX *ctx;
    int len, outlen;
    unsigned char *outbuf;
    NSData *tag = nil;
    NSData *plainText = nil;
    
    // 初始化EVP_CIPHER_CTX
    ctx = EVP_CIPHER_CTX_new();
    EVP_DecryptInit_ex(ctx, EVP_aes_256_gcm(), NULL, NULL, NULL);
    
    // 设置key和iv
    EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_SET_IVLEN, (int)iv.length, NULL);
    EVP_DecryptInit_ex(ctx, NULL, NULL, key.bytes, iv.bytes);
    
    // 设置aad
    EVP_DecryptUpdate(ctx, NULL, &len, aad.bytes, (int)aad.length);
    
    // 解密密文
    outbuf = malloc(cipherText.length);
    EVP_DecryptUpdate(ctx, outbuf, &len, cipherText.bytes, (int)cipherText.length - tagLength);
    plainText = [NSData dataWithBytes:outbuf length:len];
    free(outbuf);
    
    // 获取tag
    tag = [cipherText subdataWithRange:NSMakeRange(cipherText.length - tagLength, tagLength)];
    EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_SET_TAG, (int)tag.length, (void *)tag.bytes);
    
    // 验证tag
    if (EVP_DecryptFinal_ex(ctx, NULL, &outlen) <= 0) {
        return nil; // tag验证失败
    }
    
    // 释放EVP_CIPHER_CTX
    EVP_CIPHER_CTX_free(ctx);
    
    // 返回解密结果
    return plainText;
}

4. 实现ECB加密解密：

// ECB加密
+ (NSData *)ECBEncryptWithKey:(NSData *)key plainText:(NSData *)plainText {
    EVP_CIPHER_CTX *ctx;
    int len;
    unsigned char *outbuf;
    NSData *cipherText = nil;
    
    // 初始化EVP_CIPHER_CTX
    ctx = EVP_CIPHER_CTX_new();
    EVP_EncryptInit_ex(ctx, EVP_aes_256_ecb(), NULL, key.bytes, NULL);
    
    // 加密明文
    outbuf = malloc(plainText.length + AES_BLOCK_SIZE);
    EVP_EncryptUpdate(ctx, outbuf, &len, plainText.bytes, (int)plainText.length);
    cipherText = [NSData dataWithBytes:outbuf length:len];
    free(outbuf);
    
    // 释放EVP_CIPHER_CTX
    EVP_CIPHER_CTX_free(ctx);
    
    // 返回加密结果
    return cipherText;
}

// ECB解密
+ (NSData *)ECBDecryptWithKey:(NSData *)key cipherText:(NSData *)cipherText {
    EVP_CIPHER_CTX *ctx;
    int len;
    unsigned char *outbuf;
    NSData *plainText = nil;
    
    // 初始化EVP_CIPHER_CTX
    ctx = EVP_CIPHER_CTX_new();
    EVP_DecryptInit_ex(ctx, EVP_aes_256_ecb(), NULL, key.bytes, NULL);
    
    // 解密密文
    outbuf = malloc(cipherText.length);
    EVP_DecryptUpdate(ctx, outbuf, &len, cipherText.bytes, (int)cipherText.length);
    plainText = [NSData dataWithBytes:outbuf length:len];
    free(outbuf);
    
    // 释放EVP_CIPHER_CTX
    EVP_CIPHER_CTX_free(ctx);
    
    // 返回解密结果
    return plainText;
}

以上就是使用OpenSSL实现AES-GCM和ECB加密解密的步骤，需要注意的是，在iOS13及以上版本中，Apple已经将OpenSSL库废弃，推荐使用自带的CryptoKit框架实现加密解密。