96v8TrK7

1#import <Foundation/NSString.h>
2#import <CommonCrypto/CommonHMAC.h>
3#import <CommonCrypto/CommonDigest.h>
4
5@interface NSString (NSStringAdditions)
6
7+ (NSString *) base64StringFromData:(NSData *)data length:(int)length;
8- (NSString *) base64StringWithHMACSHA1Digest:(NSString *)secretKey;
9
10@end
11
12-------------------------------------------
13
14#import "NSStringAdditions.h"
15
16static char base64EncodingTable[64] = {
17  'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
18  'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
19  'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
20  'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'
21};
22
23@implementation NSString (NSStringAdditions)
24
25- (NSString *) base64StringWithHMACSHA1Digest:(NSString *)secretKey {
26  unsigned char digest[CC_SHA1_DIGEST_LENGTH];
27  char *keyCharPtr = strdup([secretKey UTF8String]);
28  char *dataCharPtr = strdup([self UTF8String]);
29
30  CCHmacContext hctx;
31  CCHmacInit(&hctx, kCCHmacAlgSHA1, keyCharPtr, strlen(keyCharPtr));
32  CCHmacUpdate(&hctx, dataCharPtr, strlen(dataCharPtr));
33  CCHmacFinal(&hctx, digest);
34  NSData *encryptedStringData = [NSData dataWithBytes:digest length:CC_SHA1_DIGEST_LENGTH];
35
36  free(keyCharPtr);
37  free(dataCharPtr);
38
39  return [NSString base64StringFromData:encryptedStringData length:[encryptedStringData length]];
40}
41
42+ (NSString *) base64StringFromData: (NSData *)data length: (int)length {
43  unsigned long ixtext, lentext;
44  long ctremaining;
45  unsigned char input[3], output[4];
46  short i, charsonline = 0, ctcopy;
47  const unsigned char *raw;
48  NSMutableString *result;
49
50  lentext = [data length]; 
51  if (lentext < 1)
52    return @"";
53  result = [NSMutableString stringWithCapacity: lentext];
54  raw = [data bytes];
55  ixtext = 0; 
56
57  while (true) {
58    ctremaining = lentext - ixtext;
59    if (ctremaining <= 0) 
60       break;        
61    for (i = 0; i < 3; i++) { 
62       unsigned long ix = ixtext + i;
63       if (ix < lentext)
64          input[i] = raw[ix];
65       else
66          input[i] = 0;
67    }
68    output[0] = (input[0] & 0xFC) >> 2;
69    output[1] = ((input[0] & 0x03) << 4) | ((input[1] & 0xF0) >> 4);
70    output[2] = ((input[1] & 0x0F) << 2) | ((input[2] & 0xC0) >> 6);
71    output[3] = input[2] & 0x3F;
72    ctcopy = 4;
73
74    switch (ctremaining) {
75      case 1: 
76         ctcopy = 2; 
77         break;
78      case 2: 
79         ctcopy = 3; 
80         break;
81    }
82
83    for (i = 0; i < ctcopy; i++)
84       [result appendString: [NSString stringWithFormat: @"%c", base64EncodingTable[output[i]]]];
85
86    for (i = ctcopy; i < 4; i++)
87       [result appendString: @"="];
88
89    ixtext += 3;
90    charsonline += 4;
91
92    if ((length > 0) && (charsonline >= length))
93      charsonline = 0;
94
95    return result;
96 }
97
98 @end