SM3 Digest

Similar to MD5, SHA1 and other digest algorithms, GMSm3Utils is a tool class for implementing SM3 digest algorithm and HMAC message authentication code. The SM3 digest algorithm key is any non-null character, the output digest length is 32 bytes, and the length after conversion to hexadecimal string is 64 characters.

SM3 Digest Calculation

SM3 digest algorithm supports digest calculation of text strings and binary data.

// String input, return digest string in hexadecimal format
NSString *digest = [GMSm3Utils hashWithText:@"Hello, SM3!"];

// Binary data input, return digest in byte array format
NSData *data = [@"Binary Data" dataUsingEncoding:NSUTF8StringEncoding];
NSData *digest = [GMSm3Utils hashWithData:data];

HMAC calculation

HMAC supports multiple digest algorithms, and SM3 is used by default. Supported algorithm types include:

• SM3 (default)
• MD5
• SHA1
• SHA224
• SHA256
• SHA384
• SHA512

Basic HMAC calculation (using the default SM3 algorithm)

// Input in string format, return the HMAC digest in hexadecimal format
NSString *hmac = [GMSm3Utils hmacWithText:@"Message" keyText:@"SecretKey"];

// Input in binary data format, return the HMAC digest in byte array format
NSData *plainData = [@"123456" dataUsingEncoding:NSUTF8StringEncoding];
NSData *keyData = [@"SecretKey" dataUsingEncoding:NSUTF8StringEncoding];
NSData *hmac = [GMSm3Utils hmacWithData:plainData keyData:keyData];

Calculate HMAC with specified algorithm type

// NSData format of plain text 123456, the key used for encryption is any non-empty
NSData *plainData = [@"123456" dataUsingEncoding:NSUTF8StringEncoding];
NSData *keyData = [@"qwertyuiop1234567890" dataUsingEncoding:NSUTF8StringEncoding];

// Calculate HMAC using different algorithms
NSData *hmacMD5 = [GMSm3Utils hmacWithData:plainData keyData:keyData keyType:GMHashType_MD5];
NSData *hmacSHA1 = [GMSm3Utils hmacWithData:plainData keyData:keyData keyType:GMHashType_SHA1];
NSData *hmacSHA224 = [GMSm3Utils hmacWithData:plainData keyData:keyData keyType:GMHashType_SHA224]; NSData *hmacSHA256 = [GMSm3Utils hmacWithData:plainData keyData:keyData keyType:GMHashType_SHA256]; NSData *hmacSHA384 = [GMSm3Utils hmacWithData:plainData keyData:keyData keyType:GMHashType_SHA384]; NSData *hmacSHA512 = [GMSm3Utils hmacWithData:plainData keyData:keyData keyType:GMHashType_SHA512]; // String format input, specify algorithm type NSString *hmacSHA512 = [GMSm3Utils hmacWithText:@"Message" keyText:@"SecretKey" keyType:GMHashType_SHA512];