yourkarma/JWT

//
//  JWTCryptoSecurity+Extraction.m
//  JWT
//
//  Created by Dmitry on 7/31/18.
//  Copyright © 2018 JWTIO. All rights reserved.
//

#import "JWTCryptoSecurity+Extraction.h"
@implementation JWTCryptoSecurityComponent
- (instancetype)initWithContent:(NSString *)content type:(NSString *)type {
    if (type == nil || content == nil) {
        return nil;
    }
    if (self = [super init]) {
        self.content = content;
        self.type = type;
    }
    return self;
}
@end

@interface JWTCryptoSecurityComponents ()
@property (copy, nonatomic, readwrite) NSArray <JWTCryptoSecurityComponent *>*components;
@end

@implementation JWTCryptoSecurityComponents
+ (NSString *)Certificate { return NSStringFromSelector(_cmd).uppercaseString; }
+ (NSString *)PrivateKey { return @"Private".uppercaseString; }
+ (NSString *)PublicKey { return @"Public".uppercaseString; }
+ (NSString *)Key { return NSStringFromSelector(_cmd).uppercaseString; }
+ (NSArray *)components:(NSArray *)components ofType:(NSString *)type {
    return [components filteredArrayUsingPredicate:[NSPredicate predicateWithFormat:@"type contains %@", type]];
}

- (instancetype)initWithComponents:(NSArray *)components {
    if (self = [self init]) {
        self.components = components;
    }
    return self;
}

- (NSArray *)componentsOfType:(NSString *)type {
    return [self.class components:self.components ofType:type];
}
@end

@interface JWTCryptoSecurityComponents (Extraction)
+ (NSString *)determineTypeByPemHeaderType:(NSString *)headerType;
+ (NSRegularExpression *)pemEntryRegularExpression;
+ (JWTCryptoSecurityComponent *)componentFromTextResult:(NSTextCheckingResult *)textResult inContent:(NSString *)content;
+ (instancetype)parsedComponentsInContent:(NSString *)content;
@end

@implementation JWTCryptoSecurityComponents (Extraction)
+ (NSString *)determineTypeByPemHeaderType:(NSString *)headerType {
    __auto_type validateBlock = ^(NSString *headerType, NSString *string) {
        return [headerType rangeOfString:string options:NSCaseInsensitiveSearch].location != NSNotFound;
    };
    if (validateBlock(headerType, @"CERTIFICATE")) {
        return self.Certificate;
    }
    if (validateBlock(headerType, @"PUBLIC")) {
        return self.PublicKey;
    }
    if (validateBlock(headerType, @"PRIVATE")) {
        return self.PrivateKey;
    }
    if (validateBlock(headerType, @"KEY")) {
        return self.Key;
    }
    return nil;
}

+ (NSRegularExpression *)pemEntryRegularExpression {
    __auto_type expression = [[NSRegularExpression alloc] initWithPattern:@"-----BEGIN(?<Begin>[\\w\\s]+)-----(?<Content>.+?)-----END(?<End>[\\w\\s]+)-----" options:NSRegularExpressionDotMatchesLineSeparators error:nil];
    return expression;
}
+ (JWTCryptoSecurityComponent *)componentFromTextResult:(NSTextCheckingResult *)textResult inContent:(NSString *)content {
    if (textResult.numberOfRanges > 2) {
        __auto_type beginRange = [textResult rangeAtIndex:1];
        __auto_type contentRange = [textResult rangeAtIndex:2];
        // cleanup string.
        __auto_type beginString = [content substringWithRange:beginRange];
        __auto_type contentString = [content substringWithRange:contentRange];
        __auto_type resultType = [beginString stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];//[self determineTypeByPemHeaderType:beginString]; // we need full string to parse attributes "Private/Public" "EC/RSA" "KEY/CERTIFICATE" etc.
        __auto_type resultContent = [contentString stringByReplacingOccurrencesOfString:@"\n" withString:@""];
        return [[JWTCryptoSecurityComponent alloc] initWithContent:resultContent type:resultType];
    }
    else {
        return nil;
    }
}
+ (instancetype)parsedComponentsInContent:(NSString *)content {
    __auto_type expression = [self pemEntryRegularExpression];
    __auto_type results = [expression matchesInString:content options:0 range:NSMakeRange(0, content.length)];
    __auto_type components = (NSArray <JWTCryptoSecurityComponent *>*)@[];
    for (NSTextCheckingResult *result in results) {
        id object = [self componentFromTextResult:result inContent:content];
        components = [components arrayByAddingObject:object];
    }
    return [[self alloc] initWithComponents:components];
}
@end

@implementation JWTCryptoSecurity (Extraction)
+ (JWTCryptoSecurityComponents *)componentsFromFile:(NSURL *)url {
    NSError *error = nil;
    __auto_type content = [NSString stringWithContentsOfURL:url encoding:NSUTF8StringEncoding error:&error];
    return [self componentsFromFileContent:content];
}
+ (JWTCryptoSecurityComponents *)componentsFromFileContent:(NSString *)content {
    return [JWTCryptoSecurityComponents parsedComponentsInContent:content];
}
@end