harden public MCP request handling

.github/workflows/ci.yml

@@ -25,7 +25,7 @@ jobs:
           go-version-file: go.mod
       - uses: golangci/golangci-lint-action@v9
         with:
-          version: v2.12.2
+          version: v2.14.0
 
   dockerfile:
     runs-on: ubuntu-latest

.golangci.yml

@@ -23,6 +23,7 @@ linters:
 
     # Allow partial initialization of structs
     - exhaustruct
+    - exhaustruct_v5
 
     # Allow "globals"; this linter is not currently configurable and fails even unexported package-level declarations
     - gochecknoglobals

build/containers/deployment/release.Dockerfile

@@ -1,6 +1,6 @@
 # syntax=docker/dockerfile:1.7
 
-ARG GO_VERSION=1.26.4
+ARG GO_VERSION=1.27.1
 FROM golang:${GO_VERSION} AS builder
 
 WORKDIR /src

go.mod

@@ -1,31 +1,33 @@
 module github.com/olcf/s3m-cli
 
-go 1.26.4
+go 1.27.1
 
 require (
-	github.com/jedib0t/go-pretty/v6 v6.8.0
-	github.com/modelcontextprotocol/go-sdk v1.6.1
-	github.com/olcf/s3m-apis v0.0.0-00010101000000-000000000000
-	github.com/urfave/cli/v3 v3.9.0
-	golang.org/x/term v0.44.0
-	google.golang.org/grpc v1.81.1
-	google.golang.org/protobuf v1.36.11
+	github.com/jedib0t/go-pretty/v6 v6.8.3
+	github.com/modelcontextprotocol/go-sdk v1.8.0
+	github.com/olcf/s3m-apis v0.4.0
+	github.com/urfave/cli/v3 v3.13.0
+	golang.org/x/term v0.46.0
+	google.golang.org/grpc v1.84.0
+	google.golang.org/protobuf v1.36.12
 )
 
 require (
 	github.com/clipperhouse/uax29/v2 v2.7.0 // indirect
 	github.com/google/jsonschema-go v0.4.3 // indirect
-	github.com/grpc-ecosystem/grpc-gateway/v2 v2.29.0 // indirect
-	github.com/mattn/go-runewidth v0.0.24 // indirect
+	github.com/grpc-ecosystem/grpc-gateway/v2 v2.31.0 // indirect
+	github.com/mattn/go-runewidth v0.0.30 // indirect
 	github.com/segmentio/asm v1.2.1 // indirect
 	github.com/segmentio/encoding v0.5.4 // indirect
 	github.com/yosida95/uritemplate/v3 v3.0.2 // indirect
-	golang.org/x/net v0.55.0 // indirect
-	golang.org/x/oauth2 v0.36.0 // indirect
-	golang.org/x/sys v0.46.0 // indirect
-	golang.org/x/text v0.38.0 // indirect
-	google.golang.org/genproto/googleapis/api v0.0.0-20260608224507-4308a22a1bab // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20260608224507-4308a22a1bab // indirect
+	golang.org/x/net v0.59.0 // indirect
+	golang.org/x/oauth2 v0.37.0 // indirect
+	golang.org/x/sync v0.23.0 // indirect
+	golang.org/x/sys v0.48.0 // indirect
+	golang.org/x/text v0.42.0 // indirect
+	golang.org/x/time v0.16.0 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20260921155816-b14227669459 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20260921155816-b14227669459 // indirect
 )
 
 replace github.com/olcf/s3m-apis => ./internal/pkg/s3m-apis

go.sum

@@ -1,13 +1,5 @@
-github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
-github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/clipperhouse/uax29/v2 v2.7.0 h1:+gs4oBZ2gPfVrKPthwbMzWZDaAFPGYK72F0NJv2v7Vk=
 github.com/clipperhouse/uax29/v2 v2.7.0/go.mod h1:EFJ2TJMRUaplDxHKj1qAEhCtQPW2tJSwu5BF98AuoVM=
-github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
-github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/go-logr/logr v1.4.3 h1:CjnDlHq8ikf6E492q6eKboGOC0T8CDaOvkHCIg8idEI=
-github.com/go-logr/logr v1.4.3/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
-github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
-github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
 github.com/golang-jwt/jwt/v5 v5.3.1 h1:kYf81DTWFe7t+1VvL7eS+jKFVWaUnK9cB1qbwn63YCY=
 github.com/golang-jwt/jwt/v5 v5.3.1/go.mod h1:fxCRLWMO43lRc8nhHWY6LGqRcf+1gQWArsqaEUEa5bE=
 github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
@@ -16,61 +8,49 @@ github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
 github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
 github.com/google/jsonschema-go v0.4.3 h1:/DBOLZTfDow7pe2GmaJNhltueGTtDKICi8V8p+DQPd0=
 github.com/google/jsonschema-go v0.4.3/go.mod h1:r5quNTdLOYEz95Ru18zA0ydNbBuYoo9tgaYcxEYhJVE=
-github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
-github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
-github.com/grpc-ecosystem/grpc-gateway/v2 v2.29.0 h1:5VipnvEpbqr2gA2VbM+nYVbkIF28c5ZQfqCBQ5g2xfk=
-github.com/grpc-ecosystem/grpc-gateway/v2 v2.29.0/go.mod h1:Hyl3n6Twe1hvtd9XUXDec4pTvgMSEixRuQKPTMH2bNs=
-github.com/jedib0t/go-pretty/v6 v6.8.0 h1:fQOTjATVQl5RhssBro6ZuHANFybCkmJ7FjYPo4b7sEY=
-github.com/jedib0t/go-pretty/v6 v6.8.0/go.mod h1:YwC5CE4fJ1HFUDeivSV1r//AmANFHyqczZk+U6BDALU=
-github.com/mattn/go-runewidth v0.0.24 h1:cpokDiIn0MGnhdHwuWnJBITySJ20QyNGnY2kR/ay2DU=
-github.com/mattn/go-runewidth v0.0.24/go.mod h1:XBkDxAl56ILZc9knddidhrOlY5R/pDhgLpndooCuJAs=
-github.com/modelcontextprotocol/go-sdk v1.6.1 h1:0zOSupjKUxPKSocPT1Wtago+mUHU2/uZ4xSOY0FGReU=
-github.com/modelcontextprotocol/go-sdk v1.6.1/go.mod h1:kzm3kzFL1/+AziGOE0nUs3gvPoNxMCvkxokMkuFapXQ=
-github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
-github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/grpc-ecosystem/grpc-gateway/v2 v2.31.0 h1:Bd7KaOxzULLxtZ/K5s1aLbWhR0+5RToO65TXHsf3bqQ=
+github.com/grpc-ecosystem/grpc-gateway/v2 v2.31.0/go.mod h1:nN7ts3dFXKtCZWc//yfkpcQNKJABg16/uDVAZpLDalo=
+github.com/jedib0t/go-pretty/v6 v6.8.3 h1:yVSk5aemoYHCvcrtqyXklwqcgHQIQzmy/oUzFlmffSQ=
+github.com/jedib0t/go-pretty/v6 v6.8.3/go.mod h1:YwC5CE4fJ1HFUDeivSV1r//AmANFHyqczZk+U6BDALU=
+github.com/mattn/go-runewidth v0.0.30 h1:+KUuiDA4fF0R1p5FeueHefjDm+GIM+kWfFnDjybOPgk=
+github.com/mattn/go-runewidth v0.0.30/go.mod h1:3qAiGCV4Koz/yuveO58qUefmUTRm8r0IGEXZ9jeHp/8=
+github.com/modelcontextprotocol/go-sdk v1.8.0 h1:KIvahhYqwtbeniWVPs3TcXEA7b8jEtwfBpOTAI+Urx4=
+github.com/modelcontextprotocol/go-sdk v1.8.0/go.mod h1:dL7u98E/zjJTGzEq+j30jQ8K2k1mb6LeAH4inEcSGts=
 github.com/segmentio/asm v1.2.1 h1:DTNbBqs57ioxAD4PrArqftgypG4/qNpXoJx8TVXxPR0=
 github.com/segmentio/asm v1.2.1/go.mod h1:BqMnlJP91P8d+4ibuonYZw9mfnzI9HfxselHZr5aAcs=
 github.com/segmentio/encoding v0.5.4 h1:OW1VRern8Nw6ITAtwSZ7Idrl3MXCFwXHPgqESYfvNt0=
 github.com/segmentio/encoding v0.5.4/go.mod h1:HS1ZKa3kSN32ZHVZ7ZLPLXWvOVIiZtyJnO1gPH1sKt0=
-github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
-github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
-github.com/urfave/cli/v3 v3.9.0 h1:AV9lIiPv3ukYnxunaCUsHnEozptYmDN2F0+yWqLMn/c=
-github.com/urfave/cli/v3 v3.9.0/go.mod h1:ysVLtOEmg2tOy6PknnYVhDoouyC/6N42TMeoMzskhso=
+github.com/stretchr/testify v1.12.1 h1:EuwCh5fleGS7H32xRwO3wRGT7DxrDhLAT6FF8MpWDWE=
+github.com/stretchr/testify v1.12.1/go.mod h1:MDEgiDPPsNp5cuIrHPPCyornHKgEVbtFUmoNlxoYthg=
+github.com/urfave/cli/v3 v3.13.0 h1:Dr6jqMfIyyFsRVn7Nz5mqLsMY+ZMpfh3a0aMs+umPVY=
+github.com/urfave/cli/v3 v3.13.0/go.mod h1:vXn6HxPNccJSzQr2QvwVncOKrgYGIHU0HY5h8B2nQj4=
 github.com/yosida95/uritemplate/v3 v3.0.2 h1:Ed3Oyj9yrmi9087+NczuL5BwkIc4wvTb5zIM+UJPGz4=
 github.com/yosida95/uritemplate/v3 v3.0.2/go.mod h1:ILOh0sOhIJR3+L/8afwt/kE++YT040gmv5BQTMR2HP4=
-go.opentelemetry.io/auto/sdk v1.2.1 h1:jXsnJ4Lmnqd11kwkBV2LgLoFMZKizbCi5fNZ/ipaZ64=
-go.opentelemetry.io/auto/sdk v1.2.1/go.mod h1:KRTj+aOaElaLi+wW1kO/DZRXwkF4C5xPbEe3ZiIhN7Y=
-go.opentelemetry.io/otel v1.43.0 h1:mYIM03dnh5zfN7HautFE4ieIig9amkNANT+xcVxAj9I=
-go.opentelemetry.io/otel v1.43.0/go.mod h1:JuG+u74mvjvcm8vj8pI5XiHy1zDeoCS2LB1spIq7Ay0=
-go.opentelemetry.io/otel/metric v1.43.0 h1:d7638QeInOnuwOONPp4JAOGfbCEpYb+K6DVWvdxGzgM=
-go.opentelemetry.io/otel/metric v1.43.0/go.mod h1:RDnPtIxvqlgO8GRW18W6Z/4P462ldprJtfxHxyKd2PY=
-go.opentelemetry.io/otel/sdk v1.43.0 h1:pi5mE86i5rTeLXqoF/hhiBtUNcrAGHLKQdhg4h4V9Dg=
-go.opentelemetry.io/otel/sdk v1.43.0/go.mod h1:P+IkVU3iWukmiit/Yf9AWvpyRDlUeBaRg6Y+C58QHzg=
-go.opentelemetry.io/otel/sdk/metric v1.43.0 h1:S88dyqXjJkuBNLeMcVPRFXpRw2fuwdvfCGLEo89fDkw=
-go.opentelemetry.io/otel/sdk/metric v1.43.0/go.mod h1:C/RJtwSEJ5hzTiUz5pXF1kILHStzb9zFlIEe85bhj6A=
-go.opentelemetry.io/otel/trace v1.43.0 h1:BkNrHpup+4k4w+ZZ86CZoHHEkohws8AY+WTX09nk+3A=
-go.opentelemetry.io/otel/trace v1.43.0/go.mod h1:/QJhyVBUUswCphDVxq+8mld+AvhXZLhe+8WVFxiFff0=
-golang.org/x/net v0.55.0 h1:bcvxaJn3e1U6InsFWt1JUq1aSjnRxLzT2rtD2KfkDF8=
-golang.org/x/net v0.55.0/go.mod h1:L5U2KuzuOe1lY7Z+aWVIKK6qEeJXnXV9yzGA+WCHJww=
-golang.org/x/oauth2 v0.36.0 h1:peZ/1z27fi9hUOFCAZaHyrpWG5lwe0RJEEEeH0ThlIs=
-golang.org/x/oauth2 v0.36.0/go.mod h1:YDBUJMTkDnJS+A4BP4eZBjCqtokkg1hODuPjwiGPO7Q=
-golang.org/x/sys v0.46.0 h1:noSf2Fq6F8DBgS+LysIkx7rIExoNHJsxOAtPp4rthXw=
-golang.org/x/sys v0.46.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
-golang.org/x/term v0.44.0 h1:0rLvDRCtNj0gZkyIXhCyOb2OAzEhLVqc4B+hrsBhrmc=
-golang.org/x/term v0.44.0/go.mod h1:7ze4MdzUzLXpSAoFP1H0bOI9aXDqveSvatT5vKcFh2Y=
-golang.org/x/text v0.38.0 h1:sXmwo9DwP3OK9EZ7PqAdaooSGozfl/3a6/xJcbzPRhE=
-golang.org/x/text v0.38.0/go.mod h1:YXZt3QhHUKYT53r2lLKFIVi6Ao1jdzrTR/KQ09qyxF4=
-golang.org/x/tools v0.45.0 h1:18qN3FAooORvApf5XjCXgsuayZOEtXf6JK18I3+ONa8=
-golang.org/x/tools v0.45.0/go.mod h1:LuUGqqaXcXMEFEruIVJVm5mgDD8vww/z/SR1gQ4uE/0=
+go.yaml.in/yaml/v3 v3.0.5 h1:N6y/pJk8buWs9NY5ERU2HSMfm+IuD/OtfdAnq6kESPw=
+go.yaml.in/yaml/v3 v3.0.5/go.mod h1:HVTZu1O7/Vkt2N+BFy8Zza+lnLsABggaTM2ZpNIGuKg=
+golang.org/x/net v0.59.0 h1:5zfYln+w5XCxwrnMMJPufRgNoXEaGxl0wo5GqPXyues=
+golang.org/x/net v0.59.0/go.mod h1:2DA/G1UfVbCpQPeWTmMPGY7Cs2PkBkwu743bVX5PIVg=
+golang.org/x/oauth2 v0.37.0 h1:JUlcxA8oAtauLfiH8FX2/FkAWHAdi0QtGCGc+hofE98=
+golang.org/x/oauth2 v0.37.0/go.mod h1:IxwZNxUULJmpBFf9K/9NTMSIfZZuvuTy1gGxhigP/58=
+golang.org/x/sync v0.23.0 h1:KameEIfc1IkluZyXWLn39Wd4tURc6GbCiISGiZm2bQk=
+golang.org/x/sync v0.23.0/go.mod h1:sUUOizhqBxiL6pEWpqNLUiaJn1ShEbZ6BBqskPbjZm0=
+golang.org/x/sys v0.48.0 h1:bbX/i/6MgT9BVLM9RT1thmxL04yeTAhbEz4SyadbXoo=
+golang.org/x/sys v0.48.0/go.mod h1:hNLxWAXmnKAxqDtdwIYC4bM9oQPEecfsnNMuSxOs3og=
+golang.org/x/term v0.46.0 h1:3+OXuTbaKDgwk8jTi3aSLHRlmWqHEUDUtxnbFigO4YE=
+golang.org/x/term v0.46.0/go.mod h1:+K02xbkittuwc0Am4abfA3Fc+XRGXkvBXNO88NCXPoc=
+golang.org/x/text v0.42.0 h1:JbOZXgfeCPU9gacVtYliJqOhD+zhrEqK4LfdpmlUZqI=
+golang.org/x/text v0.42.0/go.mod h1:ojzP1Z+2QtioaF8DTtO8K5q7JWVVYwZKenzujK0Zd0E=
+golang.org/x/time v0.16.0 h1:vMb6ptszcQMkcwiRTAuNNU50gom6++Q/6gY2hDM6VDE=
+golang.org/x/time v0.16.0/go.mod h1:rVKOqvZeKvrDKTQiAHJ7wmwP0RzleSphoEA9RcdLA0s=
+golang.org/x/tools v0.50.0 h1:c2ifzfcuY7L90lZ2aKd8S4K2NpASF08SZx9ZuJkHmSU=
+golang.org/x/tools v0.50.0/go.mod h1:7ulVMw3831Mwi5EZD6RomGyffr4VFjuNYXf2BbCEAV0=
 gonum.org/v1/gonum v0.17.0 h1:VbpOemQlsSMrYmn7T2OUvQ4dqxQXU+ouZFQsZOx50z4=
 gonum.org/v1/gonum v0.17.0/go.mod h1:El3tOrEuMpv2UdMrbNlKEh9vd86bmQ6vqIcDwxEOc1E=
-google.golang.org/genproto/googleapis/api v0.0.0-20260608224507-4308a22a1bab h1:Foefixyu0l973HSYkX8Etw/fPxAmKRhyMGwuqXFiVI0=
-google.golang.org/genproto/googleapis/api v0.0.0-20260608224507-4308a22a1bab/go.mod h1:KdNqO+rCIWgFumrNBSEDlDNrkrQnpkax7Tv1WxNY8V4=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20260608224507-4308a22a1bab h1:cY0oV1VnAqvaim8VsR8ZyEKAudzbRJMRGwD3W/L7yOw=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20260608224507-4308a22a1bab/go.mod h1:4Hqkh8ycfw05ld/3BWL7rJOSfebL2Q+DVDeRgYgxUU8=
-google.golang.org/grpc v1.81.1 h1:VnnIIZ88UzOOKLukQi+ImGz8O1Wdp8nAGGnvOfEIWQQ=
-google.golang.org/grpc v1.81.1/go.mod h1:xGH9GfzOyMTGIOXBJmXt+BX/V0kcdQbdcuwQ/zNw42I=
-google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
-google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
-gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
-gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+google.golang.org/genproto/googleapis/api v0.0.0-20260921155816-b14227669459 h1:GS9OIt/j7c8bvBjYNgnKQysVfmV7e4jM0H8ZK95G4t8=
+google.golang.org/genproto/googleapis/api v0.0.0-20260921155816-b14227669459/go.mod h1:PX5/4vemwVoXtwEcRDWwcR1/r0qrosfx3qoVADMwnVE=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20260921155816-b14227669459 h1:b0xCahf3FK2m2Cv0p4vTozGPWncCvLfwV86UNg8xWU8=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20260921155816-b14227669459/go.mod h1:OaIUM3+LpYcK2GXM4FTmhWoIq371Owdr+Cc7/BsYHHc=
+google.golang.org/grpc v1.84.0 h1:soMyaPJ8pAak5PIQ0DGBUir0XRo2fRoMqhNWMLlLxO0=
+google.golang.org/grpc v1.84.0/go.mod h1:ljCht0DrxQrXBDRTZp52Qxh3Ffk8CdYm2sj4O2QN2C0=
+google.golang.org/protobuf v1.36.12 h1:pJOKDDOyeXErUroCihFAd5LQuwXBSpVnKGrj5o/fwxc=
+google.golang.org/protobuf v1.36.12/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=

internal/auth/introspect.go

@@ -8,6 +8,7 @@ import (
 	"time"
 
 	tmspb "github.com/olcf/s3m-apis/tms/v1"
+	"google.golang.org/grpc"
 
 	grpcclient "github.com/olcf/s3m-cli/internal/grpc"
 	"github.com/olcf/s3m-cli/internal/util"
@@ -21,29 +22,41 @@ type IntrospectionResult struct {
 func IntrospectToken(
 	ctx context.Context, target, token string, connectTimeout, callTimeout time.Duration, debug bool,
 ) IntrospectionResult {
-	res := IntrospectionResult{
-		Record: TokenRecord{
-			Token: token,
-		},
-	}
-
 	conn, err := grpcclient.DialAndWait(ctx, target, token, connectTimeout, debug)
 	if err != nil {
-		res.Err = fmt.Errorf("dial token control: %w", err)
-		return res
+		return IntrospectionResult{
+			Record: TokenRecord{Token: token},
+			Err:    fmt.Errorf("dial token control: %w", err),
+		}
 	}
 
+	res := IntrospectTokenWithConn(ctx, conn, token, callTimeout)
+
 	defer func() {
 		if closeErr := conn.Close(); closeErr != nil && res.Err == nil {
 			res.Err = fmt.Errorf("close connection: %w", closeErr)
 		}
 	}()
 
+	return res
+}
+
+func IntrospectTokenWithConn(
+	ctx context.Context, conn grpc.ClientConnInterface, token string, callTimeout time.Duration,
+) IntrospectionResult {
+	res := IntrospectionResult{
+		Record: TokenRecord{
+			Token: token,
+		},
+	}
+
 	client := tmspb.NewTokenControlClient(conn)
 
 	callCtx, cancel := context.WithTimeout(ctx, callTimeout)
 	defer cancel()
 
+	callCtx = grpcclient.ContextWithAuthToken(callCtx, token)
+
 	resp, err := client.IntrospectAuthToken(callCtx, &tmspb.IntrospectAuthTokenRequest{
 		GrpcPermissions: true,
 	})

internal/cmd/servercmd/helpers.go

@@ -175,7 +175,14 @@ func wrapWithAuthTokenExtraction(handler http.Handler) http.Handler {
 			return
 		}
 
-		token := grpcclient.TokenFromAuthorizationHeader(r.Header.Get("Authorization"))
+		authorization := r.Header.Get("Authorization")
+		if len(authorization) > maxAuthorizationHeaderBytes {
+			http.Error(w, "Authorization header too large", http.StatusRequestHeaderFieldsTooLarge)
+
+			return
+		}
+
+		token := grpcclient.TokenFromAuthorizationHeader(authorization)
 
 		logAuthTokenExtraction(r, token)
 
@@ -191,6 +198,8 @@ func wrapWithAuthTokenExtraction(handler http.Handler) http.Handler {
 	})
 }
 
+const maxAuthorizationHeaderBytes = 16 << 10
+
 func registerStatelessOpenAPIHandlers(
 	mux *http.ServeMux,
 	routes []toolset.HTTPRouteSpec,

internal/cmd/servercmd/helpers_test.go

@@ -146,6 +146,23 @@ func TestWrapWithAuthTokenExtractionMissingHeader(t *testing.T) {
 	}
 }
 
+func TestWrapWithAuthTokenExtractionRejectsOversizedHeader(t *testing.T) {
+	inner := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		t.Fatal("inner handler should not be called")
+	})
+
+	handler := wrapWithAuthTokenExtraction(inner)
+	req := httptest.NewRequest(http.MethodPost, "/", nil)
+	req.Header.Set("Authorization", strings.Repeat("x", maxAuthorizationHeaderBytes+1))
+
+	rr := httptest.NewRecorder()
+	handler.ServeHTTP(rr, req)
+
+	if rr.Code != http.StatusRequestHeaderFieldsTooLarge {
+		t.Fatalf("expected status 431, got %d", rr.Code)
+	}
+}
+
 func TestWrapWithAuthTokenExtractionOptionsPassthrough(t *testing.T) {
 	called := false