Usage

git clone --recursive https://github.com/tobefuturer/app2dylib.gitcd app2dylib && make./app2dylib

./app2dylib /tmp/AlipayWallet -o /tmp/libAlipayApp.dylib

#import <UIKit/UIKit.h>#import <dlfcn.h>#import <mach/mach.h>#import <mach-o/loader.h>#import <mach-o/dyld.h>int main(int argc, char * argv[]) {    NSString * dylibName = @"libAlipayApp";    NSString * path = [[NSBundle mainBundle] pathForResource:dylibName ofType:@"dylib"];    if (dlopen(path.UTF8String, RTLD_NOW) == NULL){        NSLog(@"dlopen failed ，error %s", dlerror());        return 0;    };        uint32_t dylib_count = _dyld_image_count();    uint64_t slide = 0;    for (int i = 0; i < dylib_count; i ++) {        const char * name = _dyld_get_image_name(i);        if ([[NSString stringWithUTF8String:name] isEqualToString:path]) {            slide = _dyld_get_image_vmaddr_slide(i);        }    }    assert(slide != 0);            Class c = NSClassFromString(@"aluSecurity");    NSString * plain = @"alipay";    NSString * pubkey = @"MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDZ6i9VNEGEaZaYE7XffA9XRj15cp/ZKhHYY43EEva8LIhCWi29EREaF4JjZVMwFpUAfrL+9gpA7NMQmaMRHbrz1KHe2Ho4HpUhEac8M9zUbNvaDKSlhx0lq/15TQP+57oQbfJ9oKKd+he4Yd6jpBI3UtGmwJyN/T1S0DQ0aXR8OQIDAQAB";    NSString * cipher = [c performSelector:NSSelectorFromString(@"rsaEncryptText:pubKey:") withObject:plain withObject:pubkey];    NSLog(@"ciphertext： %@", cipher);        typedef int (*BASE64_ENCODE_FUNC_TYPE) (char * output, int * output_size , char * input, int input_length);        /** get function pointer*/    BASE64_ENCODE_FUNC_TYPE base64_encode = (BASE64_ENCODE_FUNC_TYPE)(slide + 0xa798e4);    char output[1000] = {0};    int length = 1000;    char * input = "alipay";    base64_encode(output, & length,  input, (int)strlen(input));    NSLog(@"base64 length: %d , %s", length,  output);    }