diff --git a/context.go b/context.go index d211098b..bea95cca 100644 --- a/context.go +++ b/context.go @@ -766,7 +766,7 @@ func (c *Context) ClientIP() string { if trusted && c.engine.ForwardedByClientIP && c.engine.RemoteIPHeaders != nil { for _, headerName := range c.engine.RemoteIPHeaders { - ip, valid := validateHeader(c.requestHeader(headerName)) + ip, valid := c.engine.validateHeader(c.requestHeader(headerName)) if valid { return ip } @@ -775,6 +775,17 @@ func (c *Context) ClientIP() string { return remoteIP.String() } +func (e *Engine) isTrustedProxy(ip net.IP) bool { + if e.trustedCIDRs != nil { + for _, cidr := range e.trustedCIDRs { + if cidr.Contains(ip) { + return true + } + } + } + return false +} + // RemoteIP parses the IP from Request.RemoteAddr, normalizes and returns the IP (without the port). // It also checks if the remoteIP is a trusted proxy or not. // In order to perform this validation, it will see if the IP is contained within at least one of the CIDR blocks @@ -789,35 +800,25 @@ func (c *Context) RemoteIP() (net.IP, bool) { return nil, false } - if c.engine.trustedCIDRs != nil { - for _, cidr := range c.engine.trustedCIDRs { - if cidr.Contains(remoteIP) { - return remoteIP, true - } - } - } - - return remoteIP, false + return remoteIP, c.engine.isTrustedProxy(remoteIP) } -func validateHeader(header string) (clientIP string, valid bool) { +func (e *Engine) validateHeader(header string) (clientIP string, valid bool) { if header == "" { return "", false } items := strings.Split(header, ",") - for i, ipStr := range items { - ipStr = strings.TrimSpace(ipStr) + for i := len(items) - 1; i >= 0; i-- { + ipStr := strings.TrimSpace(items[i]) ip := net.ParseIP(ipStr) if ip == nil { return "", false } - // We need to return the first IP in the list, but, - // we should not early return since we need to validate that - // the rest of the header is syntactically valid - if i == 0 { - clientIP = ipStr - valid = true + // X-Forwarded-For is appended by proxy + // Check IPs in reverse order and stop when find untrusted proxy + if (i == 0) || (!e.isTrustedProxy(ip)) { + return ipStr, true } } return diff --git a/context_test.go b/context_test.go index 07a35f52..e9fe88f9 100644 --- a/context_test.go +++ b/context_test.go @@ -1419,7 +1419,7 @@ func TestContextClientIP(t *testing.T) { // Only trust RemoteAddr _ = c.engine.SetTrustedProxies([]string{"40.40.40.40"}) - assert.Equal(t, "20.20.20.20", c.ClientIP()) + assert.Equal(t, "30.30.30.30", c.ClientIP()) // All steps are trusted _ = c.engine.SetTrustedProxies([]string{"40.40.40.40", "30.30.30.30", "20.20.20.20"}) diff --git a/go.mod b/go.mod index c03439a0..c25eecf9 100644 --- a/go.mod +++ b/go.mod @@ -5,7 +5,7 @@ go 1.13 require ( github.com/gin-contrib/sse v0.1.0 github.com/go-playground/validator/v10 v10.9.0 - github.com/goccy/go-json v0.7.9 + github.com/goccy/go-json v0.7.10 github.com/json-iterator/go v1.1.12 github.com/mattn/go-isatty v0.0.14 github.com/stretchr/testify v1.7.0 diff --git a/go.sum b/go.sum index 7bf71f9f..51497a0b 100644 --- a/go.sum +++ b/go.sum @@ -12,8 +12,8 @@ github.com/go-playground/universal-translator v0.18.0 h1:82dyy6p4OuJq4/CByFNOn/j github.com/go-playground/universal-translator v0.18.0/go.mod h1:UvRDBj+xPUEGrFYl+lu/H90nyDXpg0fqeB/AQUGNTVA= github.com/go-playground/validator/v10 v10.9.0 h1:NgTtmN58D0m8+UuxtYmGztBJB7VnPgjj221I1QHci2A= github.com/go-playground/validator/v10 v10.9.0/go.mod h1:74x4gJWsvQexRdW8Pn3dXSGrTK4nAUsbPlLADvpJkos= -github.com/goccy/go-json v0.7.9 h1:mSp3uo1tr6MXQTYopSNhHTUnJhd2zQ4Yk+HdJZP+ZRY= -github.com/goccy/go-json v0.7.9/go.mod h1:6MelG93GURQebXPDq3khkgXZkazVtN9CRI+MGFi0w8I= +github.com/goccy/go-json v0.7.10 h1:ulhbuNe1JqE68nMRXXTJRrUu0uhouf0VevLINxQq4Ec= +github.com/goccy/go-json v0.7.10/go.mod h1:6MelG93GURQebXPDq3khkgXZkazVtN9CRI+MGFi0w8I= github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk= github.com/google/go-cmp v0.5.5 h1:Khx7svrCpmxxtHBq5j2mp/xVjsi8hQMfNLvJFAlrGgU= github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=