C# AS4 sending and listening messages

@Microlent

Hello! I have gone through with your requirement and understand that you need a C# prototype implementing AS4 messaging that securely sends an XML payload, signs it with your private certificate, encrypts it using the recipient’s public certificate, and later receives and processes an asynchronous response. I can develop a Windows-compatible C# implementation that constructs and sends the AS4 message (SOAP + WS-Security), signs the payload with your internal private key certificate, and encrypts it using the external public certificate. The solution will also include a listener endpoint hosted on your VPS to receive the async message, where the system will decrypt the message using your private key and verify the sender’s signature with their public key. The implementation will include secure certificate handling, XML processing, error handling, and logging, ensuring reliability and compliance with AS4 messaging standards. The code will be clean, modular, and suitable for integration into your larger system. At delivery, you will receive the complete source code, documentation, and a working demo, showing successful send and receive operations with signing, encryption, decryption, and signature verification. Best regards, Jasmin

@ZohaibRoy

⭐⭐⭐⭐⭐ Create AS4 XML Prototype for Secure Message Transmission ❇️ Hi My Friend, I hope you're doing well. I've reviewed your project requirements and see you're looking for an AS4 XML prototype. You don't need to look any further; Zohaib is here to help you! My team has successfully completed 50+ similar projects for secure message transmission. I will create the prototype to send XML strings securely, using the required certificates for signing and encryption. ➡️ Why Me? I can easily create your AS4 XML prototype as I have 5 years of experience in secure communications, specializing in XML messaging, encryption, and decryption. My expertise includes working with certificates, API integration, and data transmission. Additionally, I have a strong grip on other relevant technologies, ensuring a complete and secure solution for your project. ➡️ Let's have a quick chat to discuss your project in detail and let me show you samples of my previous work. Looking forward to discussing this with you in chat. ➡️ Skills & Experience: ✅ XML Messaging ✅ AS4 Protocol ✅ Data Encryption ✅ API Integration ✅ Certificate Management ✅ Secure Communication ✅ Windows Development ✅ Error Handling ✅ Debugging ✅ Source Code Development ✅ Remote Collaboration ✅ Security Best Practices Waiting for your response! Best Regards, Zohaib

@a4logic

Hello, With a deep understanding and extensive experience in C# programming, I am well-equipped to tackle the intricate task of sending and receiving messages through AS4 protocol. As a testament to my capabilities, I have developed numerous robust applications that operate on the Windows platform. From data encryption and decryption to ensuring secure communication channels, I will meticulously incorporate all the necessary functionalities your project demands. Having successfully handled similar projects before, I am aware of the threats and challenges that lurk when it comes to data transmission and cybersecurity. With this profound understanding, I assure you 100% reliability and security with zero loopholes in my code. To demonstrate this, I am willing to subject my program to rigorous attacks from your team to further root out any potential vulnerabilities. Moreover, with my team's focus on excellent customer service, we work side by side with our clients throughout the project, considering their valuable input at every stage. This collaborative approach combined with my dedication towards delivering high-quality products, makes me the ideal fit for not just this project, but potentially other work as well. Thanks!

@einnovention

With our extensive experience in .NET, C# programming, and API development, Einnovention is the perfect fit for this project. We have a proven track record of delivering high-quality, scalable, and secure solutions - skills that are crucial for AS4 message sending and listening. Having completed 248 projects successfully on Freelancer, we are well-versed in handling complex code integrations as well. What sets us apart is not just our technical expertise but also our commitment to your satisfaction. We offer unlimited revisions until you're fully satisfied with the output and provide free support even after the delivery to ensure complete reliability. Additionally, we are known for transparent communication and adhering to clear milestones for every project. Moreover, given that this project holds a high degree of importance for you, I assure you that our team will put their heart and soul into it! We are confident in our skills and know what it takes to build robust software that can withstand all kinds of penetrations tests without any loopholes. By choosing Einnovention, you'll not only get your required work done but will also initiate a strategic partnership aimed at successfully accomplishing not just this project but potentially many more in the future.

@brayanstiven5

Hi, there, I possess extensive experience in security, .NET, API development, and C# programming, making me well-equipped for the C# AS4 project. With a proven track record in handling similar tasks, I am confident in delivering exceptional results. ✅ Utilizing my expertise, I will create a robust prototype that securely sends XML strings via AS4, incorporating the necessary encryption and signature verification processes. ✅ Once the message is sent, I will set up the system to listen for asynchronous messages, ensuring successful decryption and verification using the provided certificates. ✅ Employing stringent security measures, I will rigorously test the program to guarantee its reliability and bug-free performance on the Windows platform. ✅ After integration and thorough testing, I will ensure that the program meets all specified requirements and is fully functional, ready for deployment. ✅ Throughout the project, I will prioritize security, accuracy, and efficiency to ensure a seamless end-to-end communication process. I look forward to working with you. Best Regards, Brayan

@juanjosec63

Hello, I’m excited about the opportunity to develop the AS4 messaging prototype for securely sending and receiving XML messages. With strong experience in C#/.NET, XML messaging protocols, and secure certificate-based encryption and signing, I can implement a Windows-compatible solution that signs messages with your private key, encrypts them with the recipient’s public key, and handles asynchronous message reception and verification. I’ll ensure the prototype follows secure AS4 messaging practices, including signature validation, proper decryption flow, and reliable handling of delayed callbacks on your VPS environment. You can expect clean source code, clear documentation for integration into your larger system, and a stable implementation ready for your security testing and verification process. Best regards, Juan.

@GameOfWords

Hi, I'll build a secure C# AS4 prototype for Windows that sends XML payloads signed with your internal private key certificate and encrypted with the external public key, implements an async listener on your VPS URL to receive, verify, and decrypt incoming AS4 messages, and delivers clean, well-structured source code ready for integration into your larger system—built to be secure, reliable, and bug-free against adversarial testing.

@SamirBanna

Hello, I’m a Senior Software Engineer with extensive experience in Python automation and web scraping & C# WindowFormApp and WFP. I’ve carefully reviewed your requirements and I can deliver a reliable, production-ready solution — not a quick workaround. ✅ Clean and maintainable code ✅ Clear communication ✅ On-time delivery I’d be happy to discuss your project details and propose the best technical approach. Best regards, Samir

@devbaloni1983

Hi, ***** .Net expert***** I have more than 15 years of experience in the development As I am an expert, I can build it according to your requirements. Because I have a lot of experience in these fields, I can build your project as soon as possible. I offer excellent software quality work and provide the best support for your project. If you give me this job, I will do my best to finish your job by your timeline. If you want to see my past works, I can show you my past works right now. Ready to discuss this with you about the task now. Thank you for the reading.

@hien223234

✅Hi, Client. I am a senior Python/C# developer✅ I have successfully completed several projects similar like yours. I am interested in your project. I would like to work for you in the long term. Please send a message to discuss this project. I look forward to hearing from you. My main goal is to gain my client's satisfaction by completing a job with 100% accuracy I am a senior Python/C# developer with over 10 years of rich experience in C#/C/C++/QT/Java/Python/tesseract OCR/OpenCV/ML Programming, API integration/Database management. So, I can complete it within your timeline. Best regards! From Hien ...

@maxscender

I can help you build a secure, fully functional AS4 messaging prototype in C#. The solution will handle signing, encryption, and message validation using standard X509 certificates, ensuring interoperability with your partner’s AS4 implementation. I’ll structure it around reliable .NET cryptography libraries to avoid dependency pitfalls and memory leaks common in custom XML-signing code. I’ll also implement strict certificate chain validation and canonicalization to prevent signature mismatch and replay attacks—issues that often emerge in AS4 pilots. The code will be clean, auditable, and ready for direct integration into your larger system.

@arbu1499

Hello Ken, I understand you need a Windows-compatible prototype that sends XML via AS4, signing the message with your internal private key and encrypting it with the external public key, then later listening for the async response, decrypting it with your private key, and verifying their signature. I have experience working with secure message exchange, certificate-based signing/encryption, and API integrations, and can build a reliable prototype that sends the message, handles the delayed callback, and ensures proper verification and decryption. I will deliver clean, secure source code that can be integrated into your larger system and tested against your security checks. I’d also be happy to discuss the architecture and libraries suitable for AS4 implementation before starting. Looking forward for your positive response in the chatbox. Best Regards, Arbaz Ali

@mkh559a5a1fd66e9

With over 14 years of experience as a Full Stack Developer primarily specializing in C# programming, software security and architecture design, I am more than capable to deliver the solution you require for your AS4 messaging prototype. My excellent track record in developing robust applications that integrate with external systems and employ cryptographic technologies is testament to my proficiency in building and securing applications. In addition to being highly skilled with C# and .NET, I also possess comprehensive knowledge of encryption practices which will enable me to successfully sign your XML messages yet conduct regular checks to ensure complete security, thereby minimizing any potential loopholes. Moreover, since your product will be integrated into a larger system, my experience with CI/CD pipelines would ensure ease of deployment for future updates. Your project aligned with my skill set, as indicated by my exposure working on advanced processing of PDFs and similar domains. Rest assured, I will deploy my every ounce of expertise in safeguarding your data integrity and ensuring 100% successful message transfer. Given the nature of the task, I am entirely comfortable welcoming your team's rigorous challenge & confident that my delivered program will earn their approval. In short, I am thrilled at the prospect of contributing to your project and demonstrating the depth of my abilities in C# programming and security protocols.

@Alesha1018

Hello, hope you are doing well, Working with XML is a forte of mine, and I specialize in crafting robust C# programs. I completely understand the dynamics of your project, and I know how to send and receive messages via AS4 as per your requirements. Over the years, I've tackled numerous encryption and decryption challenges, this has honed my ability to work with private and public keys adeptly. I bring experience from similar projects where I’ve ensured data security and maintained high performance even when dealing with large XML strings. Also, my attentiveness to details ensures that all aspects including verifying signatures are properly addressed. Being process-oriented, I also value a bug-free program with no loopholes. Lastly, I truly appreciate clear communication and can adapt well to meet the goals of clients. Just like you, I believe in stress-free collaboration so I assure you a smooth working experience where you'll remain updated at every step. Let's not forget, my work isn't just done until it works seamlessly on your machine; this aligns with your need for complete delivery before payment. All these reasons combined make me the best fit for not only completing this project successfully but also for any other similar tasks you may Téléchargementenue in the future.

@billybryan98

Hello, I’m an experienced C# developer focused on secure message exchange and API integration for Windows environments. I’ve built and shipped prototype-grade AS4-like workflows using .NET, XML handling, and certificate-based signing/encryption, ensuring end-to-end integrity between systems. I can design a compact, test-first prototype that signs an XML payload with your internal private key, encrypts it with the external public key, and sends it to the destination URL, then listens on your VPS-enabled endpoint for an asynchronous reply and verifies/decrypts it with your keys. Based on similar work, I implement robust error handling, logging, and a clean separation of concerns so you can drop this into a larger system later. I’ll provide a Windows-friendly, well-documented source package you can integrate with, along with a straightforward build and test plan. I can handle the work based on my expertise and past experiences and guarantee a reliable, secure delivery. Best regards, Billy Bryan

@KanzahAfaqAhmad

Hi There, I understand that you need a prototype to send XML strings via AS4, complete with secure signing and encryption using certificates. I can deliver an effective solution that meets your specifications. I am Kanzah Afaq, with over 7 years of experience in XML, .NET, C# Programming, Software Architecture, Security, and API Development. My expertise aligns perfectly with your project requirements, ensuring reliable and secure communication between systems. Here are my portfolio links for your review: https://www.freelancer.com/u/KanzahAfaqAhmad I am committed to producing high-quality, bug-free code that gains your trust, with a transparent approach to the submission of the source code upon completion. I look forward to discussing further how I can bring this project to fruition. Thank you, Regards, Kanzah Afaq

@antonk52

✅✅✅Hold on!! Looking for a Developer Who Gets Results? Hire Me, Relax, and Watch Your Project Turn Into Success✅✅✅ As a seasoned developer with a vast skill set, I'm well-versed in the world of .NET and C# programming, making me an ideal fit for your project. Not only am I experienced in handling XML, but I've also worked on complex protocols like AS4 that require encryption, signature verification, and data exchange. This expertise will undoubtedly come in handy when creating your prototype to ensure secure communication of your XML string with the necessary encryptions and verifications. Not limiting myself to just delivering source code, I understand the added complexity involved with integrating into larger systems. Additionally, given that you will need to test and attack my program for comprehensiveness I assure you that it will be absolutely secure and bug-free. Consider this proposition not just as a demo but as a solid foundation for future collaboration should there be a need for additional work post-Bidding stage. Let's have a chat so I can demonstrate even more how I align with the demands of your project!

@piralihaider

Hi, i am interested with working with u in this project. I already ceated application that create message in columbia dain feature. waiting for your kind reply

@anirudhat

I've built AS4-compliant messaging systems in C# using .NET and have deep experience with X.509 certificate handling, including PKCS#12 private key signing, public key encryption via WS-Security headers, and SOAP envelope construction that AS4 requires. For your project, I'll implement the sending component using an HttpClient-based AS4 sender that signs your outgoing XML payload with your internal private key and encrypts it with the recipient's public certificate, then build a lightweight Kestrel-based HTTPS listener on your VPS to receive the async response, verify their signature against their public key, and decrypt with your private key. I've reviewed your certificate links and understand the exact handshake flow. My code will be clean, modular C# targeting Windows, designed for easy integration into your larger system, and I'm ready to start immediately.