objective-c - What do these build errors mean & how can I better debug in situations like this? XCode, PayPal SDK

Question

I need to understand what this means & how I go about resolving it in future.

I have been following this guide & followed it exactly,

https://cms.paypal.com/cms_content/US/en_US/files/developer/PP_MPL_Developer_Guide_and_Reference_iPhone.pdf

I have added the following files to my solution from the PayPal SDK

![PayPal SDK][1]

..had an image of the files in my solution, not allowed to post image, i don't have more than 10 points

I have imported PayPal.h & PayPalAdvancedPayment.h into one of my classes, the sample code supplied by paypal is on page 30 of that guide.

I added it made sure there was no obvious errors and then built the solution. My solution has been building and running fine until I imported these two files.

PayPal.h & PayPalAdvancedPayment.h

![XCode build errors][2]

..had an image of the debug errors in XCode

The full debug message dump is below.

Undefined symbols for architecture armv7:
"_SecPolicyCreateBasicX509", referenced from:
  +[Encryption encryptWithPublicKey:] in libPayPalMPL.a(Encryption.o)
"_SecTrustCreateWithCertificates", referenced from:
  +[Encryption encryptWithPublicKey:] in libPayPalMPL.a(Encryption.o)
"_inflateEnd", referenced from:
  -[GZipper obfm_initWithGzippedData:] in libPayPalMPL.a(GZipper.o)
  +[GZipper obfm_gzipInflate:] in libPayPalMPL.a(GZipper.o)
  -[GZipper obfm_zlibInflate] in libPayPalMPL.a(GZipper.o)
"_deflateInit_", referenced from:
  -[GZipper obfm_zlibDeflate] in libPayPalMPL.a(GZipper.o)
"_inflate", referenced from:
  -[GZipper obfm_initWithGzippedData:] in libPayPalMPL.a(GZipper.o)
  +[GZipper obfm_gzipInflate:] in libPayPalMPL.a(GZipper.o)
  -[GZipper obfm_zlibInflate] in libPayPalMPL.a(GZipper.o)
"_deflateEnd", referenced from:
  -[GZipper obfm_zlibDeflate] in libPayPalMPL.a(GZipper.o)
  +[GZipper obfm_gzipDeflate:] in libPayPalMPL.a(GZipper.o)
"_inflateInit_", referenced from:
  -[GZipper obfm_zlibInflate] in libPayPalMPL.a(GZipper.o)
"_SecTrustCopyPublicKey", referenced from:
  +[Encryption encryptWithPublicKey:] in libPayPalMPL.a(Encryption.o)
"_SecKeyGetBlockSize", referenced from:
  +[Encryption encryptWithPublicKey:] in libPayPalMPL.a(Encryption.o)
"_inflateInit2_", referenced from:
  -[GZipper obfm_initWithGzippedData:] in libPayPalMPL.a(GZipper.o)
  +[GZipper obfm_gzipInflate:] in libPayPalMPL.a(GZipper.o)
"_SecCertificateCreateWithData", referenced from:
  +[Encryption encryptWithPublicKey:] in libPayPalMPL.a(Encryption.o)
"_SecKeyEncrypt", referenced from:
  +[Encryption encryptWithPublicKey:] in libPayPalMPL.a(Encryption.o)
"_SecTrustEvaluate", referenced from:
  -[AdaptivePaymentsSOAP11BindingOperation   connection:didReceiveAuthenticationChallenge:] in libPayPalMPL.a(AdaptivePayments.o)
  +[Encryption encryptWithPublicKey:] in libPayPalMPL.a(Encryption.o)
  -[GMAdapterSOAP11BindingOperation connection:didReceiveAuthenticationChallenge:] in    libPayPalMPL.a(GMAdapter.o)
"_deflate", referenced from:
  -[GZipper obfm_zlibDeflate] in libPayPalMPL.a(GZipper.o)
  +[GZipper obfm_gzipDeflate:] in libPayPalMPL.a(GZipper.o)
"_deflateInit2_", referenced from:
  +[GZipper obfm_gzipDeflate:] in libPayPalMPL.a(GZipper.o)
ld: symbol(s) not found for architecture armv7
clang: error: linker command failed with exit code 1 (use -v to see invocation)

What is the problem? How do I identify what the problem is so that I can solve this in future myself?

I am normally a Visual Studio C#.NET developer, still learning to get the hang of XCode & Objective-C

Answer 1

It appears you need to add the Security framework to your project. In Xcode, select your target then select the Summary tab. Scroll down to the Linked Frameworks and Libraries section. Click on the + symbol at the bottom of the section and select Security.framework.