curl/curl
Oct 2024 – Oct 2025
13 Months active
Languages Used
CPythonYAMLCMakeMarkdownShellMakefileNone
Technical Skills
C programmingCI/CDContinuous IntegrationHTTPPythonPython Testing
Stefan Eissing
PROFILE
Stefan Eissing
Stefan Eissing engineered core networking, TLS, and protocol features for the curl/curl repository, focusing on robust, cross-platform secure data transfer. Over 13 months, he delivered deep improvements to QUIC, HTTP/2/3, and multi-interface workflows, modernizing socket handling and session management using C and Python. His work unified TLS/SSL APIs, enhanced asynchronous event-driven models, and strengthened test infrastructure for CI/CD. By refactoring authentication and connection metadata, Stefan improved reliability and maintainability across backends like OpenSSL and GnuTLS. He addressed edge-case failures, optimized performance, and expanded observability, resulting in safer, faster, and more predictable network operations for diverse deployment environments.
Overall Statistics
Feature vs Bugs
44%Features
Repository Contributions
342Total
Bugs
128
Commits
342
Features
101
Lines of code
75,617
Activity Months13
Your Network
178 people
Work History
October 2025
46 Commits • 10 Features
Oct 1, 2025October 2025 (2025-10) monthly summary for curl/curl: Focused on stabilizing QUIC/TLS, enhancing IO paths, and expanding platform-friendly features. Delivered core fixes across QUIC/TLS core stability and resource management; improved VQuIC IO performance and reliability; added SSL connection reuse to boost throughput for repeated connections; strengthened HTTP/2 handling with validated push headers and cleanup on failure; and extended DOH policy alignment by inheriting new custom SSL flags. Collectively, these efforts improved reliability on high-latency networks, reduced teardown leaks, and lowered latency for secure connections, supporting broader adoption and maintainability.
46 Commits • 10 Features
Oct 1, 2025October 2025 (2025-10) monthly summary for curl/curl: Focused on stabilizing QUIC/TLS, enhancing IO paths, and expanding platform-friendly features. Delivered core fixes across QUIC/TLS core stability and resource management; improved VQuIC IO performance and reliability; added SSL connection reuse to boost throughput for repeated connections; strengthened HTTP/2 handling with validated push headers and cleanup on failure; and extended DOH policy alignment by inheriting new custom SSL flags. Collectively, these efforts improved reliability on high-latency networks, reduced teardown leaks, and lowered latency for secure connections, supporting broader adoption and maintainability.
October 2025
September 2025
34 Commits • 5 Features
Sep 1, 2025September 2025 performance summary for curl/curl. The team delivered core feature enhancements to multi-interface workflows, strengthened websocket reliability, and improved TLS/QUIC stability across multiple backends, while advancing safety, testing, and backend readiness. The work reduced latency and failure modes in high-load networking scenarios and broadened platform compatibility, reinforcing curl's role in production-grade deployments.
September 2025
34 Commits • 5 Features
Sep 1, 2025September 2025 performance summary for curl/curl. The team delivered core feature enhancements to multi-interface workflows, strengthened websocket reliability, and improved TLS/QUIC stability across multiple backends, while advancing safety, testing, and backend readiness. The work reduced latency and failure modes in high-load networking scenarios and broadened platform compatibility, reinforcing curl's role in production-grade deployments.
August 2025
30 Commits • 7 Features
Aug 1, 2025August 2025 (curl/curl) - Delivered significant networking core modernization, TLS/HTTP improvements, DNS resolver enhancements, and comprehensive build/test fixes. The work emphasizes business value through faster, more reliable connections, better observability, and improved memory usage, enabling safer deployments and easier maintenance.
30 Commits • 7 Features
Aug 1, 2025August 2025 (curl/curl) - Delivered significant networking core modernization, TLS/HTTP improvements, DNS resolver enhancements, and comprehensive build/test fixes. The work emphasizes business value through faster, more reliable connections, better observability, and improved memory usage, enabling safer deployments and easier maintenance.
August 2025
July 2025
35 Commits • 13 Features
Jul 1, 2025July 2025 performance and stability milestone for curl/curl: delivered targeted features, addressed core stability issues, and strengthened protocol support across QUIC/HTTP3, TLS, and networking stacks. Key enhancements include diagnostic visibility through Scorecard flame graphs and docs, a new long option for curl (--out-null), QUIC TLS pointer reporting (CURLINFO_TLS_SSL_PTR), updated WebSocket read callback support with an enhanced example, and HTTP/3 handshake reporting aligned with TCP behavior. Multiple quality and reliability fixes improved correctness, robustness, and test coverage, underpinning safer, faster, and more predictable network transfers.
July 2025
35 Commits • 13 Features
Jul 1, 2025July 2025 performance and stability milestone for curl/curl: delivered targeted features, addressed core stability issues, and strengthened protocol support across QUIC/HTTP3, TLS, and networking stacks. Key enhancements include diagnostic visibility through Scorecard flame graphs and docs, a new long option for curl (--out-null), QUIC TLS pointer reporting (CURLINFO_TLS_SSL_PTR), updated WebSocket read callback support with an enhanced example, and HTTP/3 handshake reporting aligned with TCP behavior. Multiple quality and reliability fixes improved correctness, robustness, and test coverage, underpinning safer, faster, and more predictable network transfers.
June 2025
35 Commits • 6 Features
Jun 1, 2025June 2025 (curl/curl) — Focused on stabilizing TLS/network paths, delivering API cleanups, and hardening CI across OpenSSL variants. The month combined critical bug fixes with strategic refactors that lay groundwork for backend-agnostic TLS, improved transfer management, and more robust test infrastructure.
35 Commits • 6 Features
Jun 1, 2025June 2025 (curl/curl) — Focused on stabilizing TLS/network paths, delivering API cleanups, and hardening CI across OpenSSL variants. The month combined critical bug fixes with strategic refactors that lay groundwork for backend-agnostic TLS, improved transfer management, and more robust test infrastructure.
June 2025
May 2025
30 Commits • 10 Features
May 1, 2025May 2025 monthly summary for curl/curl focused on delivering architectural improvements, reliability, and testability that enable faster, safer releases and stronger surface for TLS and multi-protocol usage.
May 2025
30 Commits • 10 Features
May 1, 2025May 2025 monthly summary for curl/curl focused on delivering architectural improvements, reliability, and testability that enable faster, safer releases and stronger surface for TLS and multi-protocol usage.
April 2025
34 Commits • 11 Features
Apr 1, 2025April 2025 (curl/curl) monthly performance summary: Delivered key features across asynchronous resolver enhancements, QUIC/OpenSSL integration, and comprehensive connection meta data handling, while stabilizing core transports and improving resource management. Targeted bug fixes across HTTP/2, TLS/QUIC, and testing infrastructure reduced edge-case failures and improved reliability. The outcomes contributed to stronger network performance, better cross-protocol state management, and maintainability improvements, aligning with business goals for robust, scalable connectivity.
34 Commits • 11 Features
Apr 1, 2025April 2025 (curl/curl) monthly performance summary: Delivered key features across asynchronous resolver enhancements, QUIC/OpenSSL integration, and comprehensive connection meta data handling, while stabilizing core transports and improving resource management. Targeted bug fixes across HTTP/2, TLS/QUIC, and testing infrastructure reduced edge-case failures and improved reliability. The outcomes contributed to stronger network performance, better cross-protocol state management, and maintainability improvements, aligning with business goals for robust, scalable connectivity.
April 2025
March 2025
29 Commits • 11 Features
Mar 1, 2025March 2025 monthly summary for curl/curl: Delivered stability, security, and performance improvements across HTTP/2, QUIC, and TLS backends, with substantial memory safety and test-quality gains. Highlights include resets and error detection in HTTP/2, streamlined transfer state via mid identifiers, and safer resource management across SSH stacks, alongside backend-specific correctness fixes and expanded test/build hygiene.
March 2025
29 Commits • 11 Features
Mar 1, 2025March 2025 monthly summary for curl/curl: Delivered stability, security, and performance improvements across HTTP/2, QUIC, and TLS backends, with substantial memory safety and test-quality gains. Highlights include resets and error detection in HTTP/2, streamlined transfer state via mid identifiers, and safer resource management across SSH stacks, alongside backend-specific correctness fixes and expanded test/build hygiene.
February 2025
24 Commits • 12 Features
Feb 1, 2025February 2025 performance summary for curl/curl: Delivered security and performance enhancements across TLS, QUIC, and session management, while stabilizing upgrades and improving maintainability. Implemented WolfSSL TLS early data support and centralized early data logic in vtls, enabling faster resume and reduced handshake latency. Brought TLSv1.3 early data support to the OpenSSL/quictls backend, expanding modern TLS deployment options. Extended SSL session cache with an exportable flag to improve cache portability and debugging. Completed a major multi-interface refactor to an event-based model, improving responsiveness and scalability across transports. These changes, combined with targeted bug fixes for TLS upgrades across POP3/IMAP/SMTP and HTTP/3 quic interactions, significantly enhance reliability and performance, delivering tangible business value through faster secure connections and more predictable behavior.
24 Commits • 12 Features
Feb 1, 2025February 2025 performance summary for curl/curl: Delivered security and performance enhancements across TLS, QUIC, and session management, while stabilizing upgrades and improving maintainability. Implemented WolfSSL TLS early data support and centralized early data logic in vtls, enabling faster resume and reduced handshake latency. Brought TLSv1.3 early data support to the OpenSSL/quictls backend, expanding modern TLS deployment options. Extended SSL session cache with an exportable flag to improve cache portability and debugging. Completed a major multi-interface refactor to an event-based model, improving responsiveness and scalability across transports. These changes, combined with targeted bug fixes for TLS upgrades across POP3/IMAP/SMTP and HTTP/3 quic interactions, significantly enhance reliability and performance, delivering tangible business value through faster secure connections and more predictable behavior.
February 2025
January 2025
22 Commits • 5 Features
Jan 1, 2025January 2025: TLS/SSL feature enhancements, HTTP/2 compliance fixes, protocol handling improvements, reliability fixes, and CI/test improvements. Delivered TLS session import/export support, early data handling, and updated session cache dimensions; fixed HTTP/2 TE header handling and data_pending checks; clarified protocol semantics and moved redirect handling to the protocol layer; stabilized WebSocket message sending and cleaned up connection filters; improved CI/test pipelines with colored pytest output, direct httpd/apache2 testing, and removal of the repeat parameter.
January 2025
22 Commits • 5 Features
Jan 1, 2025January 2025: TLS/SSL feature enhancements, HTTP/2 compliance fixes, protocol handling improvements, reliability fixes, and CI/test improvements. Delivered TLS session import/export support, early data handling, and updated session cache dimensions; fixed HTTP/2 TE header handling and data_pending checks; clarified protocol semantics and moved redirect handling to the protocol layer; stabilized WebSocket message sending and cleaned up connection filters; improved CI/test pipelines with colored pytest output, direct httpd/apache2 testing, and removal of the repeat parameter.
December 2024
7 Commits • 4 Features
Dec 1, 2024December 2024: Delivered key features, reliability improvements, and build hygiene for curl/curl, driving latency reduction, security, and multi-process reliability. Highlights include 0-RTT data support for QUIC over GnuTLS enabling faster HTTP/3 handshakes; a redesigned TLS session ticket caching mechanism with per-TLS-version structure and a put/take/return access pattern; connection limit aware shutdown handling to improve retries for pending transfers; and macOS build hygiene to reduce noisy warnings. Core bug fixes addressed data integrity and transfer reliability: fix for small-read stalls in the Base64 MIME encoder and MBedTLS send retry on blocked writes. The combined work enhances performance, security posture, and reliability across platforms.
7 Commits • 4 Features
Dec 1, 2024December 2024: Delivered key features, reliability improvements, and build hygiene for curl/curl, driving latency reduction, security, and multi-process reliability. Highlights include 0-RTT data support for QUIC over GnuTLS enabling faster HTTP/3 handshakes; a redesigned TLS session ticket caching mechanism with per-TLS-version structure and a put/take/return access pattern; connection limit aware shutdown handling to improve retries for pending transfers; and macOS build hygiene to reduce noisy warnings. Core bug fixes addressed data integrity and transfer reliability: fix for small-read stalls in the Base64 MIME encoder and MBedTLS send retry on blocked writes. The combined work enhances performance, security posture, and reliability across platforms.
December 2024
November 2024
6 Commits • 4 Features
Nov 1, 2024November 2024 highlights for curl/curl: delivered cross-TLS compatibility features, reinforced crypto initialization reliability, expanded observability and metrics, and strengthened testing. Focused on business value: smoother mixed TLS deployments, more robust security initialization, clearer transfer visibility, and improved error messaging across TLS stacks.
November 2024
6 Commits • 4 Features
Nov 1, 2024November 2024 highlights for curl/curl: delivered cross-TLS compatibility features, reinforced crypto initialization reliability, expanded observability and metrics, and strengthened testing. Focused on business value: smoother mixed TLS deployments, more robust security initialization, clearer transfer visibility, and improved error messaging across TLS stacks.
October 2024
10 Commits • 3 Features
Oct 1, 2024Monthly summary for curl/curl - 2024-10. Key accomplishments include delivering cross-backend TLS session caching and robustness improvements across wolfSSL, BearSSL, mbedTLS, and Schannel with QUIC session caching, plus a Schannel close-handling fix; expanding the testing framework to cover multi-backend SSL and CI improvements; and optimizing VQUIC performance with larger buffers and streamlined packet reception. Major bug fixes across the TLS/QUIC stack include Schannel recv handling fix for close-notify and an ngtcp2 recv loop fix, along with reliability improvements for multissl test runs. These changes enhance interoperability, reliability, and performance of TLS/QUIC paths, enabling faster secure deployments and reduced operational risk.
10 Commits • 3 Features
Oct 1, 2024Monthly summary for curl/curl - 2024-10. Key accomplishments include delivering cross-backend TLS session caching and robustness improvements across wolfSSL, BearSSL, mbedTLS, and Schannel with QUIC session caching, plus a Schannel close-handling fix; expanding the testing framework to cover multi-backend SSL and CI improvements; and optimizing VQUIC performance with larger buffers and streamlined packet reception. Major bug fixes across the TLS/QUIC stack include Schannel recv handling fix for close-notify and an ngtcp2 recv loop fix, along with reliability improvements for multissl test runs. These changes enhance interoperability, reliability, and performance of TLS/QUIC paths, enabling faster secure deployments and reduced operational risk.
October 2024
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Quality Metrics
Correctness92.8%
Maintainability85.8%
Architecture87.0%
Performance85.8%
AI Usage24.8%
Skills & Technologies
Programming Languages
CCMakeM4MakefileMarkdownNonePerlPythonShellXML
Technical Skills
ALPNAPI DevelopmentAPI designAPI developmentAPI testingAPI usageAsynchronous programmingAuthentication ProtocolsBug FixingBug fixingBuild SystemBuild System ConfigurationBuild configurationCC Programming
Repositories Contributed To
Overview of all repositories you've contributed to across your timeline