在iOS/Objective-C Ruby/Rails中匹配Base64編碼的HMAC-SHA1字符串

Question

我知道有很多關於將NSData轉換爲NSString，NSData轉換爲Base64編碼字符串，生成HMAC等的帖子，但似乎沒有回覆在iOS和Rails中生成匹配的Base64編碼的HMAC-SHA1字符串。

使用下面的代碼，簽名不匹配。

iOS的代碼：

NSString *secret = @"xxx"; 
NSString *data = @"http://someurl?someparams"; 
const char *cKey = [secret cStringUsingEncoding:NSASCIIStringEncoding]; 
const char *cData = [data cStringUsingEncoding:NSASCIIStringEncoding]; 
unsigned char cHMAC[CC_SHA1_DIGEST_LENGTH]; 
CCHmac(kCCHmacAlgSHA1, cKey, strlen(cKey), cData, strlen(cData), cHMAC); 
NSData *HMAC = [[NSData alloc] initWithBytes:cHMAC length:sizeof(cHMAC)]; 
NSString *signature = [HMAC base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength]; 

Rails代碼：

secret = "xxx"; 
data = "http://someurl?someparams"; 
hmac = OpenSSL::HMAC.hexdigest(OpenSSL::Digest::Digest.new('sha1'), secret.encode("ASCII"), data.encode("ASCII")) 
signature = Base64.encode64(hmac) 
puts "HMAC#{hmac}" 
puts "Signature #{signature}" 

iOS的輸出：

HMAC <05651433 c9a3d449 5816ded7 80bef87f dc903e4a> 
Signature BWUUM8mj1ElYFt7XgL74f9yQPko= 

導軌輸出：

HMAC 05651433c9a3d4495816ded780bef87fdc903e4a 
Signature MDU2NTE0MzNjOWEzZDQ0OTU4MTZkZWQ3ODBiZWY4N2ZkYzkwM2U0YQ== 

使用下面的代碼我可以讓它們匹配。但感覺哈克（在IOS側Rails中使用的描述和字符串替換的和chomp）：

iOS的代碼：

NSString *secret = @"xxx"; 
NSString *data = @"http://someurl?someparams"; 
const char *cKey = [secret cStringUsingEncoding:NSASCIIStringEncoding]; 
const char *cData = [data cStringUsingEncoding:NSASCIIStringEncoding]; 
unsigned char cHMAC[CC_SHA1_DIGEST_LENGTH]; 
CCHmac(kCCHmacAlgSHA1, cKey, strlen(cKey), cData, strlen(cData), cHMAC); 
NSData *HMAC = [[NSData alloc] initWithBytes:cHMAC length:sizeof(cHMAC)]; 
NSString *HMACStr = [[HMAC description] stringByReplacingOccurrencesOfString:@"<" withString:@""]; 
HMACStr = [HMACStr stringByReplacingOccurrencesOfString:@">" withString:@""]; 
HMACStr = [HMACStr stringByReplacingOccurrencesOfString:@" " withString:@""]; 
HMAC = [HMACStr dataUsingEncoding:NSASCIIStringEncoding]; 
NSString *signature = [HMAC base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength]; 
NSLog(@"HMAC %@", [HMAC description]); 
NSLog(@"Signature %@", signature); 

Rails代碼：

secret = "xxx" 
data = "http://someurl?someparams" 
hmac = OpenSSL::HMAC.hexdigest(OpenSSL::Digest::Digest.new('sha1'), secret.encode("ASCII"), data.encode("ASCII")) 
signature = Base64.encode64(hmac).chomp 
puts "HMAC#{hmac}" 
puts "Signature #{signature}" 

iOS的輸出：

HMAC <30353635 31343333 63396133 64343439 35383136 64656437 38306265 66383766 64633930 33653461> 
Signature MDU2NTE0MzNjOWEzZDQ0OTU4MTZkZWQ3ODBiZWY4N2ZkYzkwM2U0YQ== 

導軌輸出：

HMAC 05651433c9a3d4495816ded780bef87fdc903e4a 
Signature MDU2NTE0MzNjOWEzZDQ0OTU4MTZkZWQ3ODBiZWY4N2ZkYzkwM2U0YQ== 

如何在不使用黑客的情況下生成匹配的簽名？

Answer 1

我不熟悉Rails的，但在我看來，

hmac = OpenSSL::HMAC.hexdigest(OpenSSL::Digest::Digest.new('sha1'), secret.encode("ASCII"), data.encode("ASCII")) 

計算摘要作爲十六進制字符串，而

unsigned char cHMAC[CC_SHA1_DIGEST_LENGTH]; 
CCHmac(kCCHmacAlgSHA1, cKey, strlen(cKey), cData, strlen(cData), cHMAC); 
NSData *HMAC = [[NSData alloc] initWithBytes:cHMAC length:sizeof(cHMAC)]; 

計算摘要作爲NSData對象，這僅僅是 任意字節序列的包裝。

你或許應該改變Rails代碼計算摘要作爲 字節序列以及（可能使用digest代替hexdigest？），而不是一個十六進制字符串