diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3bdad9ba8f..c63b2fadd2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixes
 * crash when opening submodule ([#2895](https://github.com/gitui-org/gitui/issues/2895))
 * when staging the last file in a directory, the first item after the directory is no longer skipped [[@Tillerino](https://github.com/Tillerino)] ([#2748](https://github.com/gitui-org/gitui/issues/2748))
+* support SSH commit signing through ssh-agent and external signer programs ([#2188](https://github.com/gitui-org/gitui/issues/2188))
 
 ## [0.28.1] - 2026-03-21
 
diff --git a/Cargo.lock b/Cargo.lock
index 1534622d6a..eec949a4c7 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -17,41 +17,6 @@ version = "2.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "512761e0bb2578dd7380c6baaa0f4ce03e84f95e960231d1dec8bf4d7d6e2627"
 
-[[package]]
-name = "aead"
-version = "0.5.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d122413f284cf2d62fb1b7db97e02edb8cda96d769b16e443a4f6195e35662b0"
-dependencies = [
- "crypto-common",
- "generic-array",
-]
-
-[[package]]
-name = "aes"
-version = "0.8.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b169f7a6d4742236a0a00c541b845991d0ac43e546831af1249753ab4c3aa3a0"
-dependencies = [
- "cfg-if",
- "cipher",
- "cpufeatures",
-]
-
-[[package]]
-name = "aes-gcm"
-version = "0.10.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "831010a0f742e1209b3bcea8fab6a8e149051ba6099432c8cb2cc117dec3ead1"
-dependencies = [
- "aead",
- "aes",
- "cipher",
- "ctr",
- "ghash",
- "subtle",
-]
-
 [[package]]
 name = "aho-corasick"
 version = "1.1.3"
@@ -152,7 +117,6 @@ version = "0.28.1"
 dependencies = [
  "bitflags 2.10.0",
  "crossbeam-channel",
- "dirs",
  "easy-cast",
  "env_logger",
  "fuzzy-matcher",
@@ -168,7 +132,6 @@ dependencies = [
  "scopetime",
  "serde",
  "serial_test",
- "ssh-key",
  "tempfile",
  "thiserror 2.0.18",
  "unicode-truncate",
@@ -205,35 +168,12 @@ dependencies = [
  "windows-link",
 ]
 
-[[package]]
-name = "base16ct"
-version = "0.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4c7f02d4ea65f2c1853089ffd8d2787bdbc63de2f0d29dedbcf8ccdfa0ccd4cf"
-
 [[package]]
 name = "base64"
 version = "0.22.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "72b3254f16251a8381aa12e40e3c4d2f0199f8c6508fbecb9d91f575e0fbb8c6"
 
-[[package]]
-name = "base64ct"
-version = "1.6.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8c3c1a368f70d6cf7302d78f8f7093da241fb8e8807c05cc9e51a125895a6d5b"
-
-[[package]]
-name = "bcrypt-pbkdf"
-version = "0.10.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6aeac2e1fe888769f34f05ac343bbef98b14d1ffb292ab69d4608b3abc86f2a2"
-dependencies = [
- "blowfish",
- "pbkdf2",
- "sha2",
-]
-
 [[package]]
 name = "bincode"
 version = "1.3.3"
@@ -297,25 +237,6 @@ dependencies = [
  "generic-array",
 ]
 
-[[package]]
-name = "block-padding"
-version = "0.3.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a8894febbff9f758034a5b8e12d87918f56dfc64a8e1fe757d65e29041538d93"
-dependencies = [
- "generic-array",
-]
-
-[[package]]
-name = "blowfish"
-version = "0.9.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e412e2cd0f2b2d93e02543ceae7917b3c70331573df19ee046bcbc35e45e87d7"
-dependencies = [
- "byteorder",
- "cipher",
-]
-
 [[package]]
 name = "bstr"
 version = "1.12.0"
@@ -380,15 +301,6 @@ dependencies = [
  "rustversion",
 ]
 
-[[package]]
-name = "cbc"
-version = "0.1.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "26b52a9543ae338f279b96b0b9fed9c8093744685043739079ce85cd58f289a6"
-dependencies = [
- "cipher",
-]
-
 [[package]]
 name = "cc"
 version = "1.2.7"
@@ -412,17 +324,6 @@ version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "613afe47fcd5fac7ccf1db93babcb082c5994d996f20b8b159f2ad1658eb5724"
 
-[[package]]
-name = "chacha20"
-version = "0.9.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c3613f74bd2eac03dad61bd53dbe620703d4371614fe0bc3b9f04dd36fe4e818"
-dependencies = [
- "cfg-if",
- "cipher",
- "cpufeatures",
-]
-
 [[package]]
 name = "chrono"
 version = "0.4.44"
@@ -434,16 +335,6 @@ dependencies = [
  "windows-link",
 ]
 
-[[package]]
-name = "cipher"
-version = "0.4.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "773f3b9af64447d2ce9850330c473515014aa235e6a783b02db81ff39e4a3dad"
-dependencies = [
- "crypto-common",
- "inout",
-]
-
 [[package]]
 name = "clap"
 version = "4.5.57"
@@ -510,12 +401,6 @@ dependencies = [
  "windows-sys 0.59.0",
 ]
 
-[[package]]
-name = "const-oid"
-version = "0.9.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c2459377285ad874054d797f3ccebf984978aa39129f6eafde5cdc8315b612f8"
-
 [[package]]
 name = "convert_case"
 version = "0.10.0"
@@ -628,18 +513,6 @@ dependencies = [
  "winapi",
 ]
 
-[[package]]
-name = "crypto-bigint"
-version = "0.5.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0dc92fb57ca44df6db8059111ab3af99a63d5d0f8375d9972e319a379c6bab76"
-dependencies = [
- "generic-array",
- "rand_core",
- "subtle",
- "zeroize",
-]
-
 [[package]]
 name = "crypto-common"
 version = "0.1.6"
@@ -660,41 +533,6 @@ dependencies = [
  "phf",
 ]
 
-[[package]]
-name = "ctr"
-version = "0.9.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0369ee1ad671834580515889b80f2ea915f23b8be8d0daa4bbaf2ac5c7590835"
-dependencies = [
- "cipher",
-]
-
-[[package]]
-name = "curve25519-dalek"
-version = "4.1.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "97fb8b7c4503de7d6ae7b42ab72a5a59857b4c937ec27a3d4539dba95b5ab2be"
-dependencies = [
- "cfg-if",
- "cpufeatures",
- "curve25519-dalek-derive",
- "digest",
- "fiat-crypto",
- "rustc_version",
- "subtle",
-]
-
-[[package]]
-name = "curve25519-dalek-derive"
-version = "0.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f46882e17999c6cc590af592290432be3bce0428cb0d5f8b6715e4dc7b383eb3"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn 2.0.117",
-]
-
 [[package]]
 name = "darling"
 version = "0.20.10"
@@ -750,16 +588,6 @@ version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5729f5117e208430e437df2f4843f5e5952997175992d1414f94c57d61e270b4"
 
-[[package]]
-name = "der"
-version = "0.7.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f55bf8e7b65898637379c1b74eb1551107c8294ed26d855ceb9fd1a09cfc9bc0"
-dependencies = [
- "const-oid",
- "zeroize",
-]
-
 [[package]]
 name = "deranged"
 version = "0.5.8"
@@ -804,9 +632,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9ed9a281f7bc9b7576e61468ba615a66a5c8cfdff42420a70aa82701a3b1e292"
 dependencies = [
  "block-buffer",
- "const-oid",
  "crypto-common",
- "subtle",
 ]
 
 [[package]]
@@ -862,66 +688,12 @@ version = "0.5.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "23f40539c229fc2e4674bdecdf24bfcc2cb83631ca911c78a035fa9f2381c32b"
 
-[[package]]
-name = "ecdsa"
-version = "0.16.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ee27f32b5c5292967d2d4a9d7f1e0b0aed2c15daded5a60300e4abb9d8020bca"
-dependencies = [
- "der",
- "digest",
- "elliptic-curve",
- "rfc6979",
- "signature",
- "spki",
-]
-
-[[package]]
-name = "ed25519"
-version = "2.2.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "115531babc129696a58c64a4fef0a8bf9e9698629fb97e9e40767d235cfbcd53"
-dependencies = [
- "signature",
-]
-
-[[package]]
-name = "ed25519-dalek"
-version = "2.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4a3daa8e81a3963a60642bcc1f90a670680bd4a77535faa384e9d1c79d620871"
-dependencies = [
- "curve25519-dalek",
- "ed25519",
- "sha2",
- "subtle",
-]
-
 [[package]]
 name = "either"
 version = "1.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "60b1af1c220855b6ceac025d3f6ecdd2b7c4894bfe9cd9bda4fbb4bc7c0d4cf0"
 
-[[package]]
-name = "elliptic-curve"
-version = "0.13.8"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b5e6043086bf7973472e0c7dff2142ea0b680d30e18d9cc40f267efbf222bd47"
-dependencies = [
- "base16ct",
- "crypto-bigint",
- "digest",
- "ff",
- "generic-array",
- "group",
- "pkcs8",
- "rand_core",
- "sec1",
- "subtle",
- "zeroize",
-]
-
 [[package]]
 name = "encode_unicode"
 version = "1.0.0"
@@ -1028,22 +800,6 @@ version = "2.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "37909eebbb50d72f9059c3b6d82c0463f2ff062c9e95845c43a6c9c0355411be"
 
-[[package]]
-name = "ff"
-version = "0.13.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ded41244b729663b1e574f1b4fb731469f69f79c17667b5d776b16cda0479449"
-dependencies = [
- "rand_core",
- "subtle",
-]
-
-[[package]]
-name = "fiat-crypto"
-version = "0.2.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "28dea519a9695b9977216879a3ebfddf92f1c08c05d984f8996aecd6ecdc811d"
-
 [[package]]
 name = "filedescriptor"
 version = "0.8.3"
@@ -1186,7 +942,6 @@ checksum = "85649ca51fd72272d7821adaf274ad91c288277713d9c18820d8499a7ff69e9a"
 dependencies = [
  "typenum",
  "version_check",
- "zeroize",
 ]
 
 [[package]]
@@ -1235,16 +990,6 @@ dependencies = [
  "regex",
 ]
 
-[[package]]
-name = "ghash"
-version = "0.5.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f0d8a4362ccb29cb0b265253fb0a2728f592895ee6854fd9bc13f2ffda266ff1"
-dependencies = [
- "opaque-debug",
- "polyval",
-]
-
 [[package]]
 name = "gimli"
 version = "0.32.3"
@@ -2120,17 +1865,6 @@ dependencies = [
  "gix-validate",
 ]
 
-[[package]]
-name = "group"
-version = "0.13.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f0f9ef7462f7c099f518d754361858f86d8a07af53ba9af0fe635bbccb151a63"
-dependencies = [
- "ff",
- "rand_core",
- "subtle",
-]
-
 [[package]]
 name = "hash32"
 version = "0.3.1"
@@ -2188,15 +1922,6 @@ version = "0.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7f24254aa9a54b5c858eaee2f5bccdb46aaf0e486a595ed5fd8f86ba55232a70"
 
-[[package]]
-name = "hmac"
-version = "0.12.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6c49c37c09c17a53d937dfbb742eb3a961d65a994e6bcdcf37e7399d0cc8ab5e"
-dependencies = [
- "digest",
-]
-
 [[package]]
 name = "iana-time-zone"
 version = "0.1.61"
@@ -2418,16 +2143,6 @@ dependencies = [
  "libc",
 ]
 
-[[package]]
-name = "inout"
-version = "0.1.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a0c10553d664a4d0bcff9f4215d0aac67a639cc68ef660840afe309b807bc9f5"
-dependencies = [
- "block-padding",
- "generic-array",
-]
-
 [[package]]
 name = "insta"
 version = "1.44.3"
@@ -2588,9 +2303,6 @@ name = "lazy_static"
 version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
-dependencies = [
- "spin",
-]
 
 [[package]]
 name = "leb128fmt"
@@ -2618,12 +2330,6 @@ dependencies = [
  "pkg-config",
 ]
 
-[[package]]
-name = "libm"
-version = "0.2.11"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8355be11b20d696c8f18f6cc018c4e372165b1fa8126cef092399c9951984ffa"
-
 [[package]]
 name = "libredox"
 version = "0.1.3"
@@ -2864,23 +2570,6 @@ dependencies = [
  "winapi",
 ]
 
-[[package]]
-name = "num-bigint-dig"
-version = "0.8.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dc84195820f291c7697304f3cbdadd1cb7199c0efc917ff5eafd71225c136151"
-dependencies = [
- "byteorder",
- "lazy_static",
- "libm",
- "num-integer",
- "num-iter",
- "num-traits",
- "rand",
- "smallvec",
- "zeroize",
-]
-
 [[package]]
 name = "num-conv"
 version = "0.2.0"
@@ -2898,26 +2587,6 @@ dependencies = [
  "syn 2.0.117",
 ]
 
-[[package]]
-name = "num-integer"
-version = "0.1.46"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7969661fd2958a5cb096e56c8e1ad0444ac2bbcd0061bd28660485a44879858f"
-dependencies = [
- "num-traits",
-]
-
-[[package]]
-name = "num-iter"
-version = "0.1.45"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1429034a0490724d0075ebb2bc9e875d6503c3cf69e235a8941aa757d83ef5bf"
-dependencies = [
- "autocfg",
- "num-integer",
- "num-traits",
-]
-
 [[package]]
 name = "num-traits"
 version = "0.2.19"
@@ -2925,7 +2594,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "071dfc062690e90b734c0b2273ce72ad0ffa95f0c74596bc250dcfd960262841"
 dependencies = [
  "autocfg",
- "libm",
 ]
 
 [[package]]
@@ -2980,12 +2648,6 @@ dependencies = [
  "pkg-config",
 ]
 
-[[package]]
-name = "opaque-debug"
-version = "0.3.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c08d65885ee38876c4f86fa503fb49d7b507c2b62552df7c70b2fce627e06381"
-
 [[package]]
 name = "openssl-probe"
 version = "0.1.5"
@@ -3029,44 +2691,6 @@ dependencies = [
  "num-traits",
 ]
 
-[[package]]
-name = "p256"
-version = "0.13.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c9863ad85fa8f4460f9c48cb909d38a0d689dba1f6f6988a5e3e0d31071bcd4b"
-dependencies = [
- "ecdsa",
- "elliptic-curve",
- "primeorder",
- "sha2",
-]
-
-[[package]]
-name = "p384"
-version = "0.13.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "70786f51bcc69f6a4c0360e063a4cac5419ef7c5cd5b3c99ad70f3be5ba79209"
-dependencies = [
- "ecdsa",
- "elliptic-curve",
- "primeorder",
- "sha2",
-]
-
-[[package]]
-name = "p521"
-version = "0.13.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0fc9e2161f1f215afdfce23677034ae137bbd45016a880c2eb3ba8eb95f085b2"
-dependencies = [
- "base16ct",
- "ecdsa",
- "elliptic-curve",
- "primeorder",
- "rand_core",
- "sha2",
-]
-
 [[package]]
 name = "parking_lot"
 version = "0.12.5"
@@ -3090,24 +2714,6 @@ dependencies = [
  "windows-link",
 ]
 
-[[package]]
-name = "pbkdf2"
-version = "0.12.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f8ed6a7761f76e3b9f92dfb0a60a6a6477c61024b775147ff0973a02653abaf2"
-dependencies = [
- "digest",
-]
-
-[[package]]
-name = "pem-rfc7468"
-version = "0.7.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "88b39c9bfcfc231068454382784bb460aae594343fb030d46e9f50a645418412"
-dependencies = [
- "base64ct",
-]
-
 [[package]]
 name = "percent-encoding"
 version = "2.3.1"
@@ -3221,27 +2827,6 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"
 
-[[package]]
-name = "pkcs1"
-version = "0.7.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c8ffb9f10fa047879315e6625af03c164b16962a5368d724ed16323b68ace47f"
-dependencies = [
- "der",
- "pkcs8",
- "spki",
-]
-
-[[package]]
-name = "pkcs8"
-version = "0.10.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f950b2377845cebe5cf8b5165cb3cc1a5e0fa5cfa3e1f7f55707d8fd82e0a7b7"
-dependencies = [
- "der",
- "spki",
-]
-
 [[package]]
 name = "pkg-config"
 version = "0.3.31"
@@ -3261,29 +2846,6 @@ dependencies = [
  "time",
 ]
 
-[[package]]
-name = "poly1305"
-version = "0.8.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8159bd90725d2df49889a078b54f4f79e87f1f8a8444194cdca81d38f5393abf"
-dependencies = [
- "cpufeatures",
- "opaque-debug",
- "universal-hash",
-]
-
-[[package]]
-name = "polyval"
-version = "0.6.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9d1fe60d06143b2430aa532c94cfe9e29783047f06c0d7fd359a9a51b729fa25"
-dependencies = [
- "cfg-if",
- "cpufeatures",
- "opaque-debug",
- "universal-hash",
-]
-
 [[package]]
 name = "portable-atomic"
 version = "1.10.0"
@@ -3305,15 +2867,6 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "439ee305def115ba05938db6eb1644ff94165c5ab5e9420d1c1bcedbba909391"
 
-[[package]]
-name = "ppv-lite86"
-version = "0.2.20"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "77957b295656769bb8ad2b6a6b09d897d94f05c41b069aede1fcdaa675eaea04"
-dependencies = [
- "zerocopy",
-]
-
 [[package]]
 name = "pretty_assertions"
 version = "1.4.1"
@@ -3334,15 +2887,6 @@ dependencies = [
  "syn 2.0.117",
 ]
 
-[[package]]
-name = "primeorder"
-version = "0.13.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "353e1ca18966c16d9deb1c69278edbc5f194139612772bd9537af60ac231e1e6"
-dependencies = [
- "elliptic-curve",
-]
-
 [[package]]
 name = "proc-macro2"
 version = "1.0.94"
@@ -3397,17 +2941,6 @@ version = "0.8.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404"
 dependencies = [
- "rand_chacha",
- "rand_core",
-]
-
-[[package]]
-name = "rand_chacha"
-version = "0.3.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e6c10a63a0fa32252be49d21e7709d4d4baf8d231c2dbce1eaa8141b9b127d88"
-dependencies = [
- "ppv-lite86",
  "rand_core",
 ]
 
@@ -3416,9 +2949,6 @@ name = "rand_core"
 version = "0.6.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ec0be4795e2f6a28069bec0b5ff3e2ac9bafc99e6a9a7dc3547996c5c816922c"
-dependencies = [
- "getrandom 0.2.15",
-]
 
 [[package]]
 name = "ratatui"
@@ -3591,16 +3121,6 @@ version = "0.8.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2b15c43186be67a4fd63bee50d0303afffcef381492ebe2c5d87f324e1b8815c"
 
-[[package]]
-name = "rfc6979"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f8dd2a808d456c4a54e300a23e9f5a67e122c3024119acbfd73e3bf664491cb2"
-dependencies = [
- "hmac",
- "subtle",
-]
-
 [[package]]
 name = "ron"
 version = "0.12.0"
@@ -3615,27 +3135,6 @@ dependencies = [
  "unicode-ident",
 ]
 
-[[package]]
-name = "rsa"
-version = "0.9.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "47c75d7c5c6b673e58bf54d8544a9f432e3a925b0e80f7cd3602ab5c50c55519"
-dependencies = [
- "const-oid",
- "digest",
- "num-bigint-dig",
- "num-integer",
- "num-traits",
- "pkcs1",
- "pkcs8",
- "rand_core",
- "sha2",
- "signature",
- "spki",
- "subtle",
- "zeroize",
-]
-
 [[package]]
 name = "rustc-demangle"
 version = "0.1.24"
@@ -3726,20 +3225,6 @@ version = "3.0.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "584e070911c7017da6cb2eb0788d09f43d789029b5877d3e5ecc8acf86ceee21"
 
-[[package]]
-name = "sec1"
-version = "0.7.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d3e97a565f76233a6003f9f5c54be1d9c5bdfa3eccfb189469f11ec4901c47dc"
-dependencies = [
- "base16ct",
- "der",
- "generic-array",
- "pkcs8",
- "subtle",
- "zeroize",
-]
-
 [[package]]
 name = "semver"
 version = "1.0.24"
@@ -3903,16 +3388,6 @@ dependencies = [
  "libc",
 ]
 
-[[package]]
-name = "signature"
-version = "2.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "77549399552de45a898a580c1b41d445bf730df867cc44e6c0233bbc4b8329de"
-dependencies = [
- "digest",
- "rand_core",
-]
-
 [[package]]
 name = "similar"
 version = "2.7.0"
@@ -3950,73 +3425,6 @@ version = "1.15.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "67b1b7a3b5fe4f1376887184045fcf45c69e92af734b7aaddc05fb777b6fbd03"
 
-[[package]]
-name = "spin"
-version = "0.9.8"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6980e8d7511241f8acf4aebddbb1ff938df5eebe98691418c4468d0b72a96a67"
-
-[[package]]
-name = "spki"
-version = "0.7.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d91ed6c858b01f942cd56b37a94b3e0a1798290327d1236e4d9cf4eaca44d29d"
-dependencies = [
- "base64ct",
- "der",
-]
-
-[[package]]
-name = "ssh-cipher"
-version = "0.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "caac132742f0d33c3af65bfcde7f6aa8f62f0e991d80db99149eb9d44708784f"
-dependencies = [
- "aes",
- "aes-gcm",
- "cbc",
- "chacha20",
- "cipher",
- "ctr",
- "poly1305",
- "ssh-encoding",
- "subtle",
-]
-
-[[package]]
-name = "ssh-encoding"
-version = "0.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eb9242b9ef4108a78e8cd1a2c98e193ef372437f8c22be363075233321dd4a15"
-dependencies = [
- "base64ct",
- "pem-rfc7468",
- "sha2",
-]
-
-[[package]]
-name = "ssh-key"
-version = "0.6.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3b86f5297f0f04d08cabaa0f6bff7cb6aec4d9c3b49d87990d63da9d9156a8c3"
-dependencies = [
- "bcrypt-pbkdf",
- "ed25519-dalek",
- "num-bigint-dig",
- "p256",
- "p384",
- "p521",
- "rand_core",
- "rsa",
- "sec1",
- "sha2",
- "signature",
- "ssh-cipher",
- "ssh-encoding",
- "subtle",
- "zeroize",
-]
-
 [[package]]
 name = "stable_deref_trait"
 version = "1.2.0"
@@ -4076,12 +3484,6 @@ dependencies = [
  "syn 2.0.117",
 ]
 
-[[package]]
-name = "subtle"
-version = "2.6.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "13c2bddecc57b384dee18652358fb23172facb8a2c51ccc10d74c157bdea3292"
-
 [[package]]
 name = "syn"
 version = "1.0.109"
@@ -4440,16 +3842,6 @@ version = "0.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ebc1c04c71510c7f702b52b7c350734c9ff1295c464a03335b00bb84fc54f853"
 
-[[package]]
-name = "universal-hash"
-version = "0.5.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fc1de2c688dc15305988b563c3854064043356019f97a4b46276fe734c4f07ea"
-dependencies = [
- "crypto-common",
- "subtle",
-]
-
 [[package]]
 name = "url"
 version = "2.5.4"
@@ -5126,27 +4518,6 @@ dependencies = [
  "synstructure",
 ]
 
-[[package]]
-name = "zerocopy"
-version = "0.7.35"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1b9b4fd18abc82b8136838da5d50bae7bdea537c574d8dc1a34ed098d6c166f0"
-dependencies = [
- "byteorder",
- "zerocopy-derive",
-]
-
-[[package]]
-name = "zerocopy-derive"
-version = "0.7.35"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fa4f8080344d4671fb4e831a13ad1e68092748387dfc4f55e356242fae12ce3e"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn 2.0.117",
-]
-
 [[package]]
 name = "zerofrom"
 version = "0.1.5"
@@ -5168,12 +4539,6 @@ dependencies = [
  "synstructure",
 ]
 
-[[package]]
-name = "zeroize"
-version = "1.8.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b97154e67e32c85465826e8bcc1c59429aaaf107c1e4a9e53c8d8ccd5eff88d0"
-
 [[package]]
 name = "zerovec"
 version = "0.10.4"
diff --git a/asyncgit/Cargo.toml b/asyncgit/Cargo.toml
index 5e77498ae3..adc0ae3bd1 100644
--- a/asyncgit/Cargo.toml
+++ b/asyncgit/Cargo.toml
@@ -14,7 +14,6 @@ keywords = ["git"]
 [dependencies]
 bitflags = "2"
 crossbeam-channel = "0.5"
-dirs = "6.0"
 easy-cast = "0.5"
 fuzzy-matcher = "0.3"
 git2 = "0.20"
@@ -34,7 +33,7 @@ rayon = "1.11"
 rayon-core = "1.13"
 scopetime = { path = "../scopetime", version = "0.1" }
 serde = { version = "1.0", features = ["derive"] }
-ssh-key = { version = "0.6.7", features = ["crypto", "encryption"] }
+tempfile = "3"
 thiserror = "2.0"
 unicode-truncate = "2.0"
 url = "2.5"
@@ -44,7 +43,6 @@ env_logger = "0.11"
 invalidstring = { path = "../invalidstring", version = "0.1" }
 pretty_assertions = "1.4"
 serial_test = "3.3"
-tempfile = "3"
 
 [features]
 default = ["trace-libgit"]
diff --git a/asyncgit/src/sync/sign.rs b/asyncgit/src/sync/sign.rs
index da5079f72c..bab124bb58 100644
--- a/asyncgit/src/sync/sign.rs
+++ b/asyncgit/src/sync/sign.rs
@@ -1,7 +1,6 @@
 //! Sign commit data.
 
-use ssh_key::{HashAlg, LineEnding, PrivateKey};
-use std::path::PathBuf;
+use tempfile::NamedTempFile;
 
 /// Error type for [`SignBuilder`], used to create [`Sign`]'s
 #[derive(thiserror::Error, Debug)]
@@ -72,11 +71,11 @@ pub trait Sign {
 
 	/// only available in `#[cfg(test)]` helping to diagnose issues
 	#[cfg(test)]
-	fn program(&self) -> &String;
+	fn program(&self) -> String;
 
 	/// only available in `#[cfg(test)]` helping to diagnose issues
 	#[cfg(test)]
-	fn signing_key(&self) -> &String;
+	fn signing_key(&self) -> String;
 }
 
 /// A builder to facilitate the creation of a signing method ([`Sign`]) by examining the git configuration.
@@ -156,35 +155,91 @@ impl SignBuilder {
 				String::from("x509"),
 			)),
 			"ssh" => {
-				let ssh_signer = config
+				let program = config
+					.get_string("gpg.ssh.program")
+					.unwrap_or_else(|_| "ssh-keygen".to_string());
+
+				let signing_key = config
 					.get_string("user.signingKey")
-					.ok()
-					.and_then(|key_path| {
-						key_path.strip_prefix('~').map_or_else(
-							|| Some(PathBuf::from(&key_path)),
-							|ssh_key_path| {
-								dirs::home_dir().map(|home| {
-									home.join(
-										ssh_key_path
-											.strip_prefix('/')
-											.unwrap_or(ssh_key_path),
-									)
-								})
-							},
+					.map_err(|err| {
+						SignBuilderError::SSHSigningKey(
+							err.to_string(),
+						)
+					})?;
+
+				let (
+					signing_key_path,
+					use_agent,
+					public_key_temp_file,
+				) = {
+					let signing_key = signing_key
+						.strip_prefix("key::")
+						.unwrap_or(&signing_key);
+					if Self::looks_like_ssh_public_key(signing_key) {
+						let temp_file =
+							Self::write_signing_key_to_temp_file(
+								signing_key,
+							)?;
+						(
+							temp_file.path().display().to_string(),
+							true,
+							Some(temp_file),
 						)
-					})
-					.ok_or_else(|| {
-						SignBuilderError::SSHSigningKey(String::from(
-							"ssh key setting absent",
-						))
-					})
-					.and_then(SSHSign::new)?;
-				let signer: Box<dyn Sign> = Box::new(ssh_signer);
-				Ok(signer)
+					} else {
+						(
+							signing_key.to_string(),
+							Self::path_contains_ssh_public_key(
+								signing_key,
+							),
+							None,
+						)
+					}
+				};
+
+				Ok(Box::new(SSHSign {
+					program,
+					signing_key_path,
+					use_agent,
+					public_key_temp_file,
+				}))
 			}
 			_ => Err(SignBuilderError::InvalidFormat(format)),
 		}
 	}
+
+	fn write_signing_key_to_temp_file(
+		signing_key: &str,
+	) -> Result<NamedTempFile, SignBuilderError> {
+		use std::io::Write;
+
+		let mut temp_file = NamedTempFile::new().map_err(|err| {
+			SignBuilderError::SSHSigningKey(err.to_string())
+		})?;
+		writeln!(temp_file, "{signing_key}").map_err(|err| {
+			SignBuilderError::SSHSigningKey(err.to_string())
+		})?;
+		Ok(temp_file)
+	}
+
+	fn looks_like_ssh_public_key(signing_key: &str) -> bool {
+		let key_type = signing_key
+			.split_ascii_whitespace()
+			.next()
+			.unwrap_or_default();
+
+		key_type.starts_with("ssh-")
+			|| key_type.starts_with("ecdsa-sha2-")
+			|| key_type.starts_with("sk-ssh-")
+			|| key_type.starts_with("sk-ecdsa-")
+	}
+
+	fn path_contains_ssh_public_key(signing_key_path: &str) -> bool {
+		std::fs::read_to_string(signing_key_path).ok().is_some_and(
+			|contents| {
+				Self::looks_like_ssh_public_key(contents.trim())
+			},
+		)
+	}
 }
 
 /// Sign commit data using `OpenPGP`
@@ -193,16 +248,6 @@ pub struct GPGSign {
 	signing_key: String,
 }
 
-impl GPGSign {
-	/// Create new [`GPGSign`] using given program and signing key.
-	pub fn new(program: &str, signing_key: &str) -> Self {
-		Self {
-			program: program.to_string(),
-			signing_key: signing_key.to_string(),
-		}
-	}
-}
-
 impl Sign for GPGSign {
 	fn sign(
 		&self,
@@ -261,55 +306,23 @@ impl Sign for GPGSign {
 	}
 
 	#[cfg(test)]
-	fn program(&self) -> &String {
-		&self.program
+	fn program(&self) -> String {
+		self.program.clone()
 	}
 
 	#[cfg(test)]
-	fn signing_key(&self) -> &String {
-		&self.signing_key
+	fn signing_key(&self) -> String {
+		self.signing_key.clone()
 	}
 }
 
-/// Sign commit data using `SSHDiskKeySign`
+/// Sign commit data using `ssh-keygen` or a git-compatible SSH signer.
 pub struct SSHSign {
-	#[cfg(test)]
 	program: String,
-	#[cfg(test)]
-	key_path: String,
-	secret_key: PrivateKey,
-}
-
-impl SSHSign {
-	/// Create new `SSHDiskKeySign` for sign.
-	pub fn new(mut key: PathBuf) -> Result<Self, SignBuilderError> {
-		key.set_extension("");
-		if key.is_file() {
-			#[cfg(test)]
-			let key_path = format!("{}", &key.display());
-			std::fs::read(key)
-				.ok()
-				.and_then(|bytes| {
-					PrivateKey::from_openssh(bytes).ok()
-				})
-				.map(|secret_key| Self {
-					#[cfg(test)]
-					program: "ssh".to_string(),
-					#[cfg(test)]
-					key_path,
-					secret_key,
-				})
-				.ok_or_else(|| {
-					SignBuilderError::SSHSigningKey(String::from(
-						"Fail to read the private key for sign.",
-					))
-				})
-		} else {
-			Err(SignBuilderError::SSHSigningKey(
-				String::from("Currently, we only support a pair of ssh key in disk."),
-			))
-		}
-	}
+	signing_key_path: String,
+	use_agent: bool,
+	// Keep inline public-key temp files alive until the signer process reads them.
+	public_key_temp_file: Option<NamedTempFile>,
 }
 
 impl Sign for SSHSign {
@@ -317,23 +330,72 @@ impl Sign for SSHSign {
 		&self,
 		commit: &[u8],
 	) -> Result<(String, Option<String>), SignError> {
-		let sig = self
-			.secret_key
-			.sign("git", HashAlg::Sha256, commit)
-			.map_err(|err| SignError::Spawn(err.to_string()))?
-			.to_pem(LineEnding::LF)
-			.map_err(|err| SignError::Spawn(err.to_string()))?;
-		Ok((sig, None))
+		use std::io::Write;
+		use std::process::{Command, Stdio};
+
+		let _keep_public_key_file_alive =
+			self.public_key_temp_file.as_ref();
+
+		let mut cmd = Command::new(&self.program);
+		cmd.stdin(Stdio::piped())
+			.stdout(Stdio::piped())
+			.stderr(Stdio::piped())
+			.arg("-Y")
+			.arg("sign")
+			.arg("-n")
+			.arg("git")
+			.arg("-f")
+			.arg(&self.signing_key_path);
+
+		if self.use_agent {
+			cmd.arg("-U");
+		}
+
+		log::trace!("signing command: {cmd:?}");
+
+		let mut child = cmd
+			.spawn()
+			.map_err(|e| SignError::Spawn(e.to_string()))?;
+
+		let mut stdin = child.stdin.take().ok_or(SignError::Stdin)?;
+
+		stdin
+			.write_all(commit)
+			.map_err(|e| SignError::WriteBuffer(e.to_string()))?;
+		drop(stdin);
+
+		let output = child
+			.wait_with_output()
+			.map_err(|e| SignError::Output(e.to_string()))?;
+
+		if !output.status.success() {
+			let error_msg = std::str::from_utf8(&output.stderr)
+				.unwrap_or("[error could not be read from stderr]");
+			if error_msg.contains("passphrase") {
+				return Err(SignError::Shellout(String::from(
+					"Currently, we only support unencrypted pairs of ssh keys in disk or ssh-agents",
+				)));
+			}
+			return Err(SignError::Shellout(format!(
+				"failed to sign data, program '{}' exited non-zero: {}",
+				&self.program, error_msg
+			)));
+		}
+
+		let signed_commit = std::str::from_utf8(&output.stdout)
+			.map_err(|e| SignError::Shellout(e.to_string()))?;
+
+		Ok((signed_commit.to_string(), None))
 	}
 
 	#[cfg(test)]
-	fn program(&self) -> &String {
-		&self.program
+	fn program(&self) -> String {
+		self.program.clone()
 	}
 
 	#[cfg(test)]
-	fn signing_key(&self) -> &String {
-		&self.key_path
+	fn signing_key(&self) -> String {
+		self.signing_key_path.clone()
 	}
 }
 
@@ -423,19 +485,101 @@ mod tests {
 
 	#[test]
 	fn test_ssh_program_configs() -> Result<()> {
+		let (_tmp_dir, repo) = repo_init_empty()?;
+		let temp_file = tempfile::NamedTempFile::new()
+			.expect("failed to create temp file");
+
+		{
+			let mut config = repo.config()?;
+			config.set_str("gpg.format", "ssh")?;
+			config.set_str(
+				"user.signingKey",
+				temp_file.path().to_str().unwrap(),
+			)?;
+		}
+
+		let sign =
+			SignBuilder::from_gitconfig(&repo, &repo.config()?)?;
+
+		assert_eq!("ssh-keygen", sign.program());
+		assert_eq!(
+			temp_file.path().to_str().unwrap(),
+			sign.signing_key()
+		);
+
+		Ok(())
+	}
+
+	#[test]
+	fn test_ssh_keyliteral_config() -> Result<()> {
+		use std::path::PathBuf;
+
+		let (_tmp_dir, repo) = repo_init_empty()?;
+
+		{
+			let mut config = repo.config()?;
+			config.set_str("gpg.format", "ssh")?;
+			config
+				.set_str("user.signingKey", "ssh-ed25519 test-key")?;
+		}
+
+		let sign =
+			SignBuilder::from_gitconfig(&repo, &repo.config()?)?;
+
+		assert_eq!("ssh-keygen", sign.program());
+		assert!(PathBuf::from(sign.signing_key()).is_file());
+
+		Ok(())
+	}
+
+	#[test]
+	fn test_ssh_keyliteral_with_key_prefix_config() -> Result<()> {
+		use std::path::PathBuf;
+
 		let (_tmp_dir, repo) = repo_init_empty()?;
 
 		{
 			let mut config = repo.config()?;
-			config.set_str("gpg.program", "ssh")?;
-			config.set_str("user.signingKey", "/tmp/key.pub")?;
+			config.set_str("gpg.format", "ssh")?;
+			config.set_str(
+				"user.signingKey",
+				"key::ssh-ed25519 test-key",
+			)?;
+		}
+
+		let sign =
+			SignBuilder::from_gitconfig(&repo, &repo.config()?)?;
+
+		assert_eq!("ssh-keygen", sign.program());
+		assert!(PathBuf::from(sign.signing_key()).is_file());
+
+		Ok(())
+	}
+
+	#[test]
+	fn test_ssh_external_bin_config() -> Result<()> {
+		let (_tmp_dir, repo) = repo_init_empty()?;
+		let temp_file = tempfile::NamedTempFile::new()
+			.expect("failed to create temp file");
+
+		{
+			let mut config = repo.config()?;
+			config.set_str("gpg.format", "ssh")?;
+			config.set_str("gpg.ssh.program", "/opt/ssh/signer")?;
+			config.set_str(
+				"user.signingKey",
+				temp_file.path().to_str().unwrap(),
+			)?;
 		}
 
 		let sign =
 			SignBuilder::from_gitconfig(&repo, &repo.config()?)?;
 
-		assert_eq!("ssh", sign.program());
-		assert_eq!("/tmp/key.pub", sign.signing_key());
+		assert_eq!("/opt/ssh/signer", sign.program());
+		assert_eq!(
+			temp_file.path().to_str().unwrap(),
+			sign.signing_key()
+		);
 
 		Ok(())
 	}