feat(OIDC): add back channel logout (#8837)

# Which Problems Are Solved

Currently ZITADEL supports RP-initiated logout for clients. Back-channel
logout ensures that user sessions are terminated across all connected
applications, even if the user closes their browser or loses
connectivity providing a more secure alternative for certain use cases.

# How the Problems Are Solved

If the feature is activated and the client used for the authentication
has a back_channel_logout_uri configured, a
`session_logout.back_channel` will be registered. Once a user terminates
their session, a (notification) handler will send a SET (form POST) to
the registered uri containing a logout_token (with the user's ID and
session ID).

- A new feature "back_channel_logout" is added on system and instance
level
- A `back_channel_logout_uri` can be managed on OIDC applications
- Added a `session_logout` aggregate to register and inform about sent
`back_channel` notifications
- Added a `SecurityEventToken` channel and `Form`message type in the
notification handlers
- Added `TriggeredAtOrigin` fields to `HumanSignedOut` and
`TerminateSession` events for notification handling
- Exported various functions and types in the `oidc` package to be able
to reuse for token signing in the back_channel notifier.
- To prevent that current existing session termination events will be
handled, a setup step is added to set the `current_states` for the
`projections.notifications_back_channel_logout` to the current position

- [x] requires https://github.com/zitadel/oidc/pull/671

# Additional Changes

- Updated all OTEL dependencies to v1.29.0, since OIDC already updated
some of them to that version.
- Single Session Termination feature is correctly checked (fixed feature
mapping)

# Additional Context

- closes https://github.com/zitadel/zitadel/issues/8467
- TODO:
  - Documentation
  - UI to be done: https://github.com/zitadel/zitadel/issues/8469

---------

Co-authored-by: Hidde Wieringa <hidde@hiddewieringa.nl>
This commit is contained in:
Livio Spring
2024-10-31 15:57:17 +01:00
committed by GitHub
parent 9cf67f30b8
commit 041af26917
87 changed files with 1778 additions and 280 deletions

68
go.sum
View File

@@ -80,8 +80,8 @@ github.com/beorn7/perks v1.0.0/go.mod h1:KWe93zE9D1o94FZ5RNwFwVgaQK1VOXiVxmqh+Ce
github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
github.com/bgentry/speakeasy v0.1.0/go.mod h1:+zsyZBPWlz7T6j88CTgSN5bM796AkVf0kBD4zp0CCIs=
github.com/bmatcuk/doublestar/v4 v4.6.1 h1:FH9SifrbvJhnlQpztAx++wlkk70QBf0iBWDwNy7PA4I=
github.com/bmatcuk/doublestar/v4 v4.6.1/go.mod h1:xBQ8jztBU6kakFMg+8WGxn0c6z1fTSPVIjEY1Wr7jzc=
github.com/bmatcuk/doublestar/v4 v4.7.1 h1:fdDeAqgT47acgwd9bd9HxJRDmc9UAmPpc+2m0CXv75Q=
github.com/bmatcuk/doublestar/v4 v4.7.1/go.mod h1:xBQ8jztBU6kakFMg+8WGxn0c6z1fTSPVIjEY1Wr7jzc=
github.com/boombuler/barcode v1.0.1-0.20190219062509-6c824513bacc/go.mod h1:paBWMcWSl3LHKBqUq+rly7CNSldXjb2rDl3JlRe0mD8=
github.com/boombuler/barcode v1.0.2 h1:79yrbttoZrLGkL/oOI8hBrUKucwOL0oOjUgEguGMcJ4=
github.com/boombuler/barcode v1.0.2/go.mod h1:paBWMcWSl3LHKBqUq+rly7CNSldXjb2rDl3JlRe0mD8=
@@ -354,8 +354,8 @@ github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0/go.mod h1:8NvIoxWQoOIhqOTXgf
github.com/grpc-ecosystem/grpc-gateway v1.9.5/go.mod h1:vNeuVxBJEsws4ogUvrchl83t/GYV9WGTSLVdBhOQFDY=
github.com/grpc-ecosystem/grpc-gateway v1.16.0 h1:gmcG1KaJ57LophUzW0Hy8NmPhnMZb4M0+kPpLofRdBo=
github.com/grpc-ecosystem/grpc-gateway v1.16.0/go.mod h1:BDjrQk3hbvj6Nolgz8mAMFbcEtjT1g+wF4CSlocrBnw=
github.com/grpc-ecosystem/grpc-gateway/v2 v2.20.0 h1:bkypFPDjIYGfCYD5mRBvpqxfYX1YCS1PXdKYWi8FsN0=
github.com/grpc-ecosystem/grpc-gateway/v2 v2.20.0/go.mod h1:P+Lt/0by1T8bfcF3z737NnSbmxQAppXMRziHUxPOC8k=
github.com/grpc-ecosystem/grpc-gateway/v2 v2.22.0 h1:asbCHRVmodnJTuQ3qamDwqVOIjwqUPTYmYuemVOx+Ys=
github.com/grpc-ecosystem/grpc-gateway/v2 v2.22.0/go.mod h1:ggCgvZ2r7uOoQjOyu2Y1NhHmEPPzzuhWgcza5M1Ji1I=
github.com/h2non/filetype v1.1.1/go.mod h1:319b3zT68BvV+WRj7cwy856M2ehB3HqNOt6sy1HndBY=
github.com/h2non/filetype v1.1.3 h1:FKkx9QbD7HR/zjK1Ia5XiBsq9zdLi5Kf3zGyFTAFkGg=
github.com/h2non/filetype v1.1.3/go.mod h1:319b3zT68BvV+WRj7cwy856M2ehB3HqNOt6sy1HndBY=
@@ -628,8 +628,8 @@ github.com/rogpeppe/go-internal v1.8.0/go.mod h1:WmiCO8CzOY8rg0OYDC4/i/2WRWAB6po
github.com/rogpeppe/go-internal v1.12.0 h1:exVL4IDcn6na9z1rAb56Vxr+CgyK3nn3O+epU5NdKM8=
github.com/rogpeppe/go-internal v1.12.0/go.mod h1:E+RYuTGaKKdloAfM02xzb0FW3Paa99yedzYV+kq4uf4=
github.com/rs/cors v1.7.0/go.mod h1:gFx+x8UowdsKA9AchylcLynDq+nNFfI8FkUZdN/jGCU=
github.com/rs/cors v1.11.0 h1:0B9GE/r9Bc2UxRMMtymBkHTenPkHDv0CW4Y98GBY+po=
github.com/rs/cors v1.11.0/go.mod h1:XyqrcTp5zjWr1wsJ8PIRZssZ8b/WMcMf71DJnit4EMU=
github.com/rs/cors v1.11.1 h1:eU3gRzXLRK57F5rKMGMZURNdIG4EoAmX8k94r9wXWHA=
github.com/rs/cors v1.11.1/go.mod h1:XyqrcTp5zjWr1wsJ8PIRZssZ8b/WMcMf71DJnit4EMU=
github.com/rs/xid v1.5.0 h1:mKX4bl4iPYJtEIxp6CYiUuLQ/8DYMoz0PUdtGgMFRVc=
github.com/rs/xid v1.5.0/go.mod h1:trrq9SKmegXys3aeAKXMUTdJsYXVwGY3RLcfgqegfbg=
github.com/russellhaering/goxmldsig v1.4.0 h1:8UcDh/xGyQiyrW+Fq5t8f+l2DLB1+zlhYzkPUJ7Qhys=
@@ -723,8 +723,8 @@ github.com/zenazn/goji v1.0.1 h1:4lbD8Mx2h7IvloP7r2C0D6ltZP6Ufip8Hn0wmSK5LR8=
github.com/zenazn/goji v1.0.1/go.mod h1:7S9M489iMyHBNxwZnk9/EHS098H4/F6TATF2mIxtB1Q=
github.com/zitadel/logging v0.6.1 h1:Vyzk1rl9Kq9RCevcpX6ujUaTYFX43aa4LkvV1TvUk+Y=
github.com/zitadel/logging v0.6.1/go.mod h1:Y4CyAXHpl3Mig6JOszcV5Rqqsojj+3n7y2F591Mp/ow=
github.com/zitadel/oidc/v3 v3.28.1 h1:PsbFm5CzEMQq9HBXUNJ8yvnWmtVYxpwV5Cinj7TTsHo=
github.com/zitadel/oidc/v3 v3.28.1/go.mod h1:WmDFu3dZ9YNKrIoZkmxjGG8QyUR4PbbhsVVSY+rpojM=
github.com/zitadel/oidc/v3 v3.32.0 h1:Mw0EPZRC6h+OXAuT0Uk2BZIjJQNHLqUpaJCm6c3IByc=
github.com/zitadel/oidc/v3 v3.32.0/go.mod h1:DyE/XClysRK/ozFaZSqlYamKVnTh4l6Ln25ihSNI03w=
github.com/zitadel/passwap v0.6.0 h1:m9F3epFC0VkBXu25rihSLGyHvWiNlCzU5kk8RoI+SXQ=
github.com/zitadel/passwap v0.6.0/go.mod h1:kqAiJ4I4eZvm3Y6oAk6hlEqlZZOkjMHraGXF90GG7LI=
github.com/zitadel/saml v0.2.0 h1:vv7r+Xz43eAPCb+fImMaospD+TWRZQDkb78AbSJRcL4=
@@ -742,24 +742,24 @@ go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.5
go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.53.0/go.mod h1:azvtTADFQJA8mX80jIH/akaE7h+dbm/sVuaHqN13w74=
go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.53.0 h1:4K4tsIXefpVJtvA/8srF4V4y0akAoPHkIslgAkjixJA=
go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.53.0/go.mod h1:jjdQuTGVsXV4vSs+CJ2qYDeDPf9yIJV23qlIzBm73Vg=
go.opentelemetry.io/otel v1.28.0 h1:/SqNcYk+idO0CxKEUOtKQClMK/MimZihKYMruSMViUo=
go.opentelemetry.io/otel v1.28.0/go.mod h1:q68ijF8Fc8CnMHKyzqL6akLO46ePnjkgfIMIjUIX9z4=
go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.28.0 h1:3Q/xZUyC1BBkualc9ROb4G8qkH90LXEIICcs5zv1OYY=
go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.28.0/go.mod h1:s75jGIWA9OfCMzF0xr+ZgfrB5FEbbV7UuYo32ahUiFI=
go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.28.0 h1:R3X6ZXmNPRR8ul6i3WgFURCHzaXjHdm0karRG/+dj3s=
go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.28.0/go.mod h1:QWFXnDavXWwMx2EEcZsf3yxgEKAqsxQ+Syjp+seyInw=
go.opentelemetry.io/otel v1.29.0 h1:PdomN/Al4q/lN6iBJEN3AwPvUiHPMlt93c8bqTG5Llw=
go.opentelemetry.io/otel v1.29.0/go.mod h1:N/WtXPs1CNCUEx+Agz5uouwCba+i+bJGFicT8SR4NP8=
go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.29.0 h1:dIIDULZJpgdiHz5tXrTgKIMLkus6jEFa7x5SOKcyR7E=
go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.29.0/go.mod h1:jlRVBe7+Z1wyxFSUs48L6OBQZ5JwH2Hg/Vbl+t9rAgI=
go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.29.0 h1:nSiV3s7wiCam610XcLbYOmMfJxB9gO4uK3Xgv5gmTgg=
go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.29.0/go.mod h1:hKn/e/Nmd19/x1gvIHwtOwVWM+VhuITSWip3JUDghj0=
go.opentelemetry.io/otel/exporters/prometheus v0.50.0 h1:2Ewsda6hejmbhGFyUvWZjUThC98Cf8Zy6g0zkIimOng=
go.opentelemetry.io/otel/exporters/prometheus v0.50.0/go.mod h1:pMm5PkUo5YwbLiuEf7t2xg4wbP0/eSJrMxIMxKosynY=
go.opentelemetry.io/otel/exporters/stdout/stdouttrace v1.28.0 h1:EVSnY9JbEEW92bEkIYOVMw4q1WJxIAGoFTrtYOzWuRQ=
go.opentelemetry.io/otel/exporters/stdout/stdouttrace v1.28.0/go.mod h1:Ea1N1QQryNXpCD0I1fdLibBAIpQuBkznMmkdKrapk1Y=
go.opentelemetry.io/otel/metric v1.28.0 h1:f0HGvSl1KRAU1DLgLGFjrwVyismPlnuU6JD6bOeuA5Q=
go.opentelemetry.io/otel/metric v1.28.0/go.mod h1:Fb1eVBFZmLVTMb6PPohq3TO9IIhUisDsbJoL/+uQW4s=
go.opentelemetry.io/otel/sdk v1.28.0 h1:b9d7hIry8yZsgtbmM0DKyPWMMUMlK9NEKuIG4aBqWyE=
go.opentelemetry.io/otel/sdk v1.28.0/go.mod h1:oYj7ClPUA7Iw3m+r7GeEjz0qckQRJK2B8zjcZEfu7Pg=
go.opentelemetry.io/otel/sdk/metric v1.28.0 h1:OkuaKgKrgAbYrrY0t92c+cC+2F6hsFNnCQArXCKlg08=
go.opentelemetry.io/otel/sdk/metric v1.28.0/go.mod h1:cWPjykihLAPvXKi4iZc1dpER3Jdq2Z0YLse3moQUCpg=
go.opentelemetry.io/otel/trace v1.28.0 h1:GhQ9cUuQGmNDd5BTCP2dAvv75RdMxEfTmYejp+lkx9g=
go.opentelemetry.io/otel/trace v1.28.0/go.mod h1:jPyXzNPg6da9+38HEwElrQiHlVMTnVfM3/yv2OlIHaI=
go.opentelemetry.io/otel/exporters/stdout/stdouttrace v1.29.0 h1:X3ZjNp36/WlkSYx0ul2jw4PtbNEDDeLskw3VPsrpYM0=
go.opentelemetry.io/otel/exporters/stdout/stdouttrace v1.29.0/go.mod h1:2uL/xnOXh0CHOBFCWXz5u1A4GXLiW+0IQIzVbeOEQ0U=
go.opentelemetry.io/otel/metric v1.29.0 h1:vPf/HFWTNkPu1aYeIsc98l4ktOQaL6LeSoeV2g+8YLc=
go.opentelemetry.io/otel/metric v1.29.0/go.mod h1:auu/QWieFVWx+DmQOUMgj0F8LHWdgalxXqvp7BII/W8=
go.opentelemetry.io/otel/sdk v1.29.0 h1:vkqKjk7gwhS8VaWb0POZKmIEDimRCMsopNYnriHyryo=
go.opentelemetry.io/otel/sdk v1.29.0/go.mod h1:pM8Dx5WKnvxLCb+8lG1PRNIDxu9g9b9g59Qr7hfAAok=
go.opentelemetry.io/otel/sdk/metric v1.29.0 h1:K2CfmJohnRgvZ9UAj2/FhIf/okdWcNdBwe1m8xFXiSY=
go.opentelemetry.io/otel/sdk/metric v1.29.0/go.mod h1:6zZLdCl2fkauYoZIOn/soQIDSWFmNSRcICarHfuhNJQ=
go.opentelemetry.io/otel/trace v1.29.0 h1:J/8ZNK4XgR7a21DZUAsbF8pZ5Jcw1VhACmnYt39JTi4=
go.opentelemetry.io/otel/trace v1.29.0/go.mod h1:eHl3w0sp3paPkYstJOmAimxhiFXPg+MMTlEh3nsQgWQ=
go.opentelemetry.io/proto/otlp v1.3.1 h1:TrMUixzpM0yuc/znrFTP9MMRh8trP93mkCiDVeXrui0=
go.opentelemetry.io/proto/otlp v1.3.1/go.mod h1:0X1WI4de4ZsLrrJNLAQbFeLCm3T7yBkR0XqQ7niQU+8=
go.uber.org/atomic v1.3.2/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
@@ -857,13 +857,13 @@ golang.org/x/net v0.7.0/go.mod h1:2Tu9+aMcznHK/AK1HMvgo6xiTLG5rD5rZLDS+rp2Bjs=
golang.org/x/net v0.10.0/go.mod h1:0qNGK6F8kojg2nk9dLZ2mShWaEBan6FAoqfSigmmuDg=
golang.org/x/net v0.21.0/go.mod h1:bIjVDfnllIU7BJ2DNgfnXvpSvtn8VRwhlsaeUTyUS44=
golang.org/x/net v0.22.0/go.mod h1:JKghWKKOSdJwpW2GEx0Ja7fmaKnMsbu+MWVZTokSYmg=
golang.org/x/net v0.26.0 h1:soB7SVo0PWrY4vPW/+ay0jKDNScG2X9wFeYlXIvJsOQ=
golang.org/x/net v0.26.0/go.mod h1:5YKkiSynbBIh3p6iOc/vibscux0x38BZDkn8sCUPxHE=
golang.org/x/net v0.28.0 h1:a9JDOJc5GMUJ0+UDqmLT86WiEy7iWyIhz8gz8E4e5hE=
golang.org/x/net v0.28.0/go.mod h1:yqtgsTWOOnlGLG9GFRrK3++bGOUEkNBoHZc8MEDWPNg=
golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
golang.org/x/oauth2 v0.0.0-20200107190931-bf48bf16ab8d/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
golang.org/x/oauth2 v0.22.0 h1:BzDx2FehcG7jJwgWLELCdmLuxk2i+x9UDpSiss2u0ZA=
golang.org/x/oauth2 v0.22.0/go.mod h1:XYTD2NtWslqkgxebSiOHnXEap4TF09sJSc7H1sXbhtI=
golang.org/x/oauth2 v0.23.0 h1:PbgcYx2W7i4LvjJWEbf0ngHV6qJYr86PkAV3bXdLEbs=
golang.org/x/oauth2 v0.23.0/go.mod h1:XYTD2NtWslqkgxebSiOHnXEap4TF09sJSc7H1sXbhtI=
golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
@@ -934,8 +934,8 @@ golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
golang.org/x/text v0.7.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
golang.org/x/text v0.9.0/go.mod h1:e1OnstbJyHTd6l/uOt8jFFHp6TRDWZR/bV3emEE/zU8=
golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
golang.org/x/text v0.18.0 h1:XvMDiNzPAl0jr17s6W9lcaIhGUfUORdGCNsuLmPG224=
golang.org/x/text v0.18.0/go.mod h1:BuEKDfySbSR4drPmRPG/7iBdf8hvFMuRexcpahXilzY=
golang.org/x/text v0.19.0 h1:kTxAhCbGbxhK0IwgSKiMO5awPoDQ0RpfiVYBfK860YM=
golang.org/x/text v0.19.0/go.mod h1:BuEKDfySbSR4drPmRPG/7iBdf8hvFMuRexcpahXilzY=
golang.org/x/time v0.0.0-20180412165947-fbb02b2291d2/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
golang.org/x/time v0.0.0-20191024005414-555d28b269f0/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
golang.org/x/time v0.5.0 h1:o7cqy6amK/52YcAKIPlM3a+Fpj35zvRj2TP+e1xFSfk=
@@ -983,10 +983,10 @@ google.golang.org/genproto v0.0.0-20200526211855-cb27e3aa2013/go.mod h1:NbSheEEY
google.golang.org/genproto v0.0.0-20210126160654-44e461bb6506/go.mod h1:FWY/as6DDZQgahTzZj3fqbO1CbirC29ZNUFHwi0/+no=
google.golang.org/genproto v0.0.0-20240624140628-dc46fd24d27d h1:PksQg4dV6Sem3/HkBX+Ltq8T0ke0PKIRBNBatoDTVls=
google.golang.org/genproto v0.0.0-20240624140628-dc46fd24d27d/go.mod h1:s7iA721uChleev562UJO2OYB0PPT9CMFjV+Ce7VJH5M=
google.golang.org/genproto/googleapis/api v0.0.0-20240701130421-f6361c86f094 h1:0+ozOGcrp+Y8Aq8TLNN2Aliibms5LEzsq99ZZmAGYm0=
google.golang.org/genproto/googleapis/api v0.0.0-20240701130421-f6361c86f094/go.mod h1:fJ/e3If/Q67Mj99hin0hMhiNyCRmt6BQ2aWIJshUSJw=
google.golang.org/genproto/googleapis/rpc v0.0.0-20240701130421-f6361c86f094 h1:BwIjyKYGsK9dMCBOorzRri8MQwmi7mT9rGHsCEinZkA=
google.golang.org/genproto/googleapis/rpc v0.0.0-20240701130421-f6361c86f094/go.mod h1:Ue6ibwXGpU+dqIcODieyLOcgj7z8+IcskoNIgZxtrFY=
google.golang.org/genproto/googleapis/api v0.0.0-20240822170219-fc7c04adadcd h1:BBOTEWLuuEGQy9n1y9MhVJ9Qt0BDu21X8qZs71/uPZo=
google.golang.org/genproto/googleapis/api v0.0.0-20240822170219-fc7c04adadcd/go.mod h1:fO8wJzT2zbQbAjbIoos1285VfEIYKDDY+Dt+WpTkh6g=
google.golang.org/genproto/googleapis/rpc v0.0.0-20240822170219-fc7c04adadcd h1:6TEm2ZxXoQmFWFlt1vNxvVOa1Q0dXFQD1m/rYjXmS0E=
google.golang.org/genproto/googleapis/rpc v0.0.0-20240822170219-fc7c04adadcd/go.mod h1:UqMtugtsSgubUsoxbuAoiCXvqvErP7Gf0so0mK9tHxU=
google.golang.org/grpc v1.17.0/go.mod h1:6QZJwpn2B+Zp71q/5VxRsJ6NXXVCE5NRUHRo+f3cWCs=
google.golang.org/grpc v1.19.0/go.mod h1:mqu4LbDTu4XGKhr4mRzUsmM4RtVoemTSY81AxZiDr8c=
google.golang.org/grpc v1.20.0/go.mod h1:chYK+tFQF0nDUGJgXMSgLCQk3phJEuONr2DCgLDdAQM=