ios - 如何在 Swift 3 中使用带有指数和模数的 RSA 来加密密码？

Question

如何在 Swift 3 中使用带有指数和模数的 RSA 来加密密码？

我有一个指数和一个模数(字符串形式)，那么如何使用这些值来加密我的密码？

"modulus" : "AI8W0a1hVzDphH0J8Q2tz64Y4UWNNqdUdck3RJrl3V8RYSaxW1lwBos77LNsXU13OcOpgB\/TfeefRBl0J2Dv\/8IwmBZC1M5ZGUfcq0JuogggRWro72WLCuIDPUGH9fO8D\/klAdVDFjVz6LnkWvCoX5WGE1OSygKqAPBO\/BWIRt4l",
"exponent" : "AQAB"

我找到了一些框架，但我没有任何 pem 文件可提供。

Answer 1

我找到了解决方案。

1. 获取 openssl

pod 'OpenSSL-Universal'

Basee64 辅助类

NSData+TheBase64.h:

#import <Foundation/Foundation.h>

void *NewBase64Decode(const char *inputBuffer, size_t length, size_t *outputLength);
char *NewBase64Encode(const void *inputBuffer, size_t length, bool separateLines, size_t *outputLength);

@interface NSData (TheBase64)

+ (NSData *)dataFromBase64String:(NSString *)aString;
- (NSString *)base64EncodedString;

@end

NSData+TheBase64.m:

#import "NSData+TheBase64.h"

//
// Mapping from 6 bit pattern to ASCII character.
//
static unsigned char kBase64EncodeLookup[65] =
    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

//
// Definition for "masked-out" areas of the base64DecodeLookup mapping
//
#define xx 65

//
// Mapping from ASCII character to 6 bit pattern.
//
static unsigned char kBase64DecodeLookup[256] =
{
    xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, 
    xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, 
    xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, 62, xx, xx, xx, 63, 
    52, 53, 54, 55, 56, 57, 58, 59, 60, 61, xx, xx, xx, xx, xx, xx, 
    xx,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 
    15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, xx, xx, xx, xx, xx, 
    xx, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 
    41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, xx, xx, xx, xx, xx, 
    xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, 
    xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, 
    xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, 
    xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, 
    xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, 
    xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, 
    xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, 
    xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, 
};

//
// Fundamental sizes of the binary and base64 encode/decode units in bytes
//
#define BINARY_UNIT_SIZE 3
#define BASE64_UNIT_SIZE 4

//
// NewBase64Decode
//
// Decodes the base64 ASCII string in the inputBuffer to a newly malloced
// output buffer.
//
//  inputBuffer - the source ASCII string for the decode
//  length - the length of the string or -1 (to specify strlen should be used)
//  outputLength - if not-NULL, on output will contain the decoded length
//
// returns the decoded buffer. Must be free'd by caller. Length is given by
//  outputLength.
//
void *NewBase64Decode(
    const char *inputBuffer,
    size_t length,
    size_t *outputLength)
{
    if (length == -1)
    {
        length = strlen(inputBuffer);
    }

    size_t outputBufferSize =
        ((length+BASE64_UNIT_SIZE-1) / BASE64_UNIT_SIZE) * BINARY_UNIT_SIZE;
    unsigned char *outputBuffer = (unsigned char *)malloc(outputBufferSize);

    size_t i = 0;
    size_t j = 0;
    while (i < length)
    {
        //
        // Accumulate 4 valid characters (ignore everything else)
        //
        unsigned char accumulated[BASE64_UNIT_SIZE];
        size_t accumulateIndex = 0;
        while (i < length)
        {
            unsigned char decode = kBase64DecodeLookup[inputBuffer[i++]];
            if (decode != xx)
            {
                accumulated[accumulateIndex] = decode;
                accumulateIndex++;

                if (accumulateIndex == BASE64_UNIT_SIZE)
                {
                    break;
                }
            }
        }

        //
        // Store the 6 bits from each of the 4 characters as 3 bytes
        //
        // (Uses improved bounds checking suggested by Alexandre Colucci)
        //
        if(accumulateIndex >= 2)  
            outputBuffer[j] = (accumulated[0] << 2) | (accumulated[1] >> 4);  
        if(accumulateIndex >= 3)  
            outputBuffer[j + 1] = (accumulated[1] << 4) | (accumulated[2] >> 2);  
        if(accumulateIndex >= 4)  
            outputBuffer[j + 2] = (accumulated[2] << 6) | accumulated[3];
        j += accumulateIndex - 1;
    }

    if (outputLength)
    {
        *outputLength = j;
    }
    return outputBuffer;
}

//
// NewBase64Encode
//
// Encodes the arbitrary data in the inputBuffer as base64 into a newly malloced
// output buffer.
//
//  inputBuffer - the source data for the encode
//  length - the length of the input in bytes
//  separateLines - if zero, no CR/LF characters will be added. Otherwise
//      a CR/LF pair will be added every 64 encoded chars.
//  outputLength - if not-NULL, on output will contain the encoded length
//      (not including terminating 0 char)
//
// returns the encoded buffer. Must be free'd by caller. Length is given by
//  outputLength.
//
char *NewBase64Encode(
    const void *buffer,
    size_t length,
    bool separateLines,
    size_t *outputLength) {
    const unsigned char *inputBuffer = (const unsigned char *)buffer;

    #define MAX_NUM_PADDING_CHARS 2
    #define OUTPUT_LINE_LENGTH 64
    #define INPUT_LINE_LENGTH ((OUTPUT_LINE_LENGTH / BASE64_UNIT_SIZE) * BINARY_UNIT_SIZE)
    #define CR_LF_SIZE 2

    //
    // Byte accurate calculation of final buffer size
    //
    size_t outputBufferSize =
            ((length / BINARY_UNIT_SIZE)
                + ((length % BINARY_UNIT_SIZE) ? 1 : 0))
                    * BASE64_UNIT_SIZE;
    if (separateLines) {
        outputBufferSize +=
            (outputBufferSize / OUTPUT_LINE_LENGTH) * CR_LF_SIZE;
    }

    //
    // Include space for a terminating zero
    //
    outputBufferSize += 1;

    //
    // Allocate the output buffer
    //
    char *outputBuffer = (char *)malloc(outputBufferSize);
    if (!outputBuffer) {
        return NULL;
    }

    size_t i = 0;
    size_t j = 0;
    const size_t lineLength = separateLines ? INPUT_LINE_LENGTH : length;
    size_t lineEnd = lineLength;

    while (true) {
        if (lineEnd > length) {
            lineEnd = length;
        }

        for (; i + BINARY_UNIT_SIZE - 1 < lineEnd; i += BINARY_UNIT_SIZE) {
            //
            // Inner loop: turn 48 bytes into 64 base64 characters
            //
            outputBuffer[j++] = kBase64EncodeLookup[(inputBuffer[i] & 0xFC) >> 2];
            outputBuffer[j++] = kBase64EncodeLookup[((inputBuffer[i] & 0x03) << 4)
                | ((inputBuffer[i + 1] & 0xF0) >> 4)];
            outputBuffer[j++] = kBase64EncodeLookup[((inputBuffer[i + 1] & 0x0F) << 2)
                | ((inputBuffer[i + 2] & 0xC0) >> 6)];
            outputBuffer[j++] = kBase64EncodeLookup[inputBuffer[i + 2] & 0x3F];
        }

        if (lineEnd == length) {
            break;
        }

        //
        // Add the newline
        //
        outputBuffer[j++] = '\r';
        outputBuffer[j++] = '\n';
        lineEnd += lineLength;
    }

    if (i + 1 < length) {
        //
        // Handle the single '=' case
        //
        outputBuffer[j++] = kBase64EncodeLookup[(inputBuffer[i] & 0xFC) >> 2];
        outputBuffer[j++] = kBase64EncodeLookup[((inputBuffer[i] & 0x03) << 4)
            | ((inputBuffer[i + 1] & 0xF0) >> 4)];
        outputBuffer[j++] = kBase64EncodeLookup[(inputBuffer[i + 1] & 0x0F) << 2];
        outputBuffer[j++] = '=';
    } else if (i < length) {
        //
        // Handle the double '=' case
        //
        outputBuffer[j++] = kBase64EncodeLookup[(inputBuffer[i] & 0xFC) >> 2];
        outputBuffer[j++] = kBase64EncodeLookup[(inputBuffer[i] & 0x03) << 4];
        outputBuffer[j++] = '=';
        outputBuffer[j++] = '=';
    }
    outputBuffer[j] = 0;

    //
    // Set the output length and return the buffer
    //
    if (outputLength) {
        *outputLength = j;
    }
    return outputBuffer;
}

@implementation NSData (TheBase64)

//
// dataFromBase64String:
//
// Creates an NSData object containing the base64 decoded representation of
// the base64 string 'aString'
//
// Parameters:
//    aString - the base64 string to decode
//
// returns the autoreleased NSData representation of the base64 string
//
+ (NSData *)dataFromBase64String:(NSString *)aString {
    NSData *data = [aString dataUsingEncoding:NSASCIIStringEncoding];
    size_t outputLength;
    void *outputBuffer = NewBase64Decode([data bytes], [data length], &outputLength);
    NSData *result = [NSData dataWithBytes:outputBuffer length:outputLength];
    free(outputBuffer);
    return result;
}

//
// base64EncodedString
//
// Creates an NSString object that contains the base 64 encoding of the
// receiver's data. Lines are broken at 64 characters long.
//
// returns an autoreleased NSString being the base 64 representation of the
//  receiver.
//
- (NSString *)base64EncodedString {
    size_t outputLength;
    char *outputBuffer =
        NewBase64Encode([self bytes], [self length], true, &outputLength);

    NSString *result =
        [[NSString alloc] initWithBytes:outputBuffer length:outputLength encoding:NSASCIIStringEncoding];
    free(outputBuffer);
    return result;
}

@end

加密

PublicKeyRSA.h:

#import <Foundation/Foundation.h>
#import <OpenSSL/rsa.h>
#import "NSData+TheBase64.h"

@interface PublicKeyRSA : NSObject
//+ (RSA * __nullable)rsaFromExponent:(NSString * __nonnull)exponent modulus:(NSString * __nonnull)modulus;
//+ (NSString * __nullable)cleanString:(NSString * __nonnull)input;
+ (NSString * __nullable)encrypt:(NSString * __nonnull)string exponentB64:(NSString * __nonnull)exponentB64 modulusB64:(NSString * __nonnull)modulusB64;
@end

PublicKeyRSA.m:

#import "PublicKeyRSA.h"

@implementation PublicKeyRSA

+ (RSA *)rsaFromExponent:(NSString *)exponent modulus:(NSString *)modulus {
    RSA *rsa_pub = RSA_new();

    const char *N = [modulus UTF8String];
    const char *E = [exponent UTF8String];

    if (!BN_hex2bn(&rsa_pub->n, N))
    {
        // TODO
    }
    printf("N: %s\n", N);
    printf("n: %s\n", BN_bn2dec(rsa_pub->n));

    if (!BN_hex2bn(&rsa_pub->e, E))
    {
        // TODO
    }
    printf("E: %s\n", E);
    printf("e: %s\n", BN_bn2dec(rsa_pub->e));

    return rsa_pub;
}

+ (NSString *)cleanString:(NSString *)input {
    NSString *output = input;
    output = [output stringByReplacingOccurrencesOfString:@"<" withString:@""];
    output = [output stringByReplacingOccurrencesOfString:@">" withString:@""];
    output = [output stringByReplacingOccurrencesOfString:@" " withString:@""];
    return output;
}

+ (NSString *)encrypt:(NSString *)string exponentB64:(NSString *)exponentB64 modulusB64:(NSString *)modulusB64 {

    // 1. decode base64
    NSData *exponent = [NSData dataFromBase64String:exponentB64];
    NSData *modulus = [NSData dataFromBase64String:modulusB64];

    NSString *exponentHex = [self cleanString:[exponent description]];
    NSString *modulusHex = [self cleanString:[modulus description]];

    // 2. create RSA public key
    RSA *rsa_pub = [self rsaFromExponent:exponentHex modulus:modulusHex];

    // 3. encode base 64
    NSData *data = [string dataUsingEncoding: NSASCIIStringEncoding];
    NSString *b64String = [data base64EncodedString];

    // 4. encrypt
    const unsigned char *from = (const unsigned char *)[b64String cStringUsingEncoding: NSASCIIStringEncoding];
    int flen = strlen((const char *)from);
    unsigned char *to = (unsigned char *) malloc(RSA_size(rsa_pub));
    int padding = RSA_PKCS1_PADDING;
    int result = RSA_public_encrypt(flen, from, to, rsa_pub, padding);
    if (-1 == result) {
        return nil;
    }
//        NSLog(@"from: %s", from); // echo VEVTVA==
//        NSLog(@"to: %s", to); // echo something strange with characters like: ~™Ÿû—...
    // 5. encode base 64
    NSData *cipherData = [NSData dataWithBytes:(const void *)to length:result];
    NSString *cipherDataB64 = [cipherData base64EncodedString];
    NSLog(@"user encrypted b64: %@", cipherDataB64); // now echo the expected value
    return  cipherDataB64;
}

@end

4.创建桥接头文件 Bridging-Header 并导入 <OpenSSL/rsa.h> 、 "PublicKeyRSA.h" 和 "NSData+TheBase64.h"

尝试一下

PublicKeyRSA.encrypt(string, exponentB64: exponent, modulusB64: modulus)