Use actual disk files instead of creating input files on the fly, as this makes it easier to run commands on the same data outside the test and simplifies the test fn definition.

test-data/Kexample.+008+31967.key

@@ -0,0 +1 @@
+example.	IN	DNSKEY	257 3 8 AwEAAaYL5iwWI6UgSQVcDZmH7DrhQU/P6cOfi4wXYDzHypsfZ1D8znPwoAqhj54kTBVqgZDHw8QEnMcS3TWxvHBvncRTIXhCLx0BNK5/6mcTSK2IDbxl0j4vkcQrOxc77tyExuFfuXouuKVtE7rggOJiX6ga5LJW2if6Jxe/Rh8+aJv7 ;{id = 31967 (ksk), size = 1024b}

test-data/Kexample.+008+31967.private

@@ -0,0 +1,10 @@
+Private-key-format: v1.2
+Algorithm: 8 (RSASHA256)
+Modulus: pgvmLBYjpSBJBVwNmYfsOuFBT8/pw5+LjBdgPMfKmx9nUPzOc/CgCqGPniRMFWqBkMfDxAScxxLdNbG8cG+dxFMheEIvHQE0rn/qZxNIrYgNvGXSPi+RxCs7Fzvu3ITG4V+5ei64pW0TuuCA4mJfqBrkslbaJ/onF79GHz5om/s=
+PublicExponent: AQAB
+PrivateExponent: InZhxVCrAUCcJzKd1/mv++B4j7oVSHa6nc7UOIk28c8owFRX/RQ6AzrY9feOmvtJ/OSZKvvSFjdCFjzXYXapBZqnqrXM0QJ3LA09u2OQNylc1PYj+QtrEhUbKBO9ujgfWw+JAg7eDxuoxfeDmsdQMa2Jx22mk2eJvTIvkLeTtME=
+Prime1: 0zxbxvJdeJJn0q7guFpAj6gN8o9JLkDfDEGuY0eWKcCvBTAwT+SZWH3T3e316TS/PCUDvUCmbgJHVFwP8PUCKw==
+Prime2: yTv/9Ysj5khXOy7KRhXcPyAwaHp+XtpfCd8msXjmthZI9Z45kvDX6iDOgADoIJQsoUCy8IOKiqd93wYpN091cQ==
+Exponent1: aZPde05gEYd7hP4LK5lQc3zXm8iqFwgtc37QnqaFE1FPKRSw0P2891HMtzvckTbf7jvB5rGNfaZ96FgrT4/mCQ==
+Exponent2: Q7x6kABh+SXolvdNBwJcvLLtGH4DA5Kl4wDGWX7Eyg3+SQ8VeiyvwROB7vxfJng5/Z11nhfpDnsKl4PPY9rPQQ==
+Coefficient: TDG5Jgi0fbqUUkRhugX6VaWGllzt9pew5U3YnlCoNm2lT3s5jiYyaLwHWMmuYRJTAxU6/UheyGg1CL36fUh42w==

test-data/Kexample.+008+38353.key

@@ -0,0 +1 @@
+example.	IN	DNSKEY	256 3 8 AwEAAbsD4Tcz8hl2Rldov4CrfYpK3ORIh/giSGDlZaDTZR4gpGxGvMBwu2jzQ3m0iX3PvqPoaybC4tznjlJi8g/qsCRHhOkqWmjtmOYOJXEuUTb+4tPBkiboJM5QchxTfKxkYbJ2AD+VAUX1S6h/0DI0ZCGx1H90QTBE2ymRgHBwUfBt ;{id = 38353 (zsk), size = 1024b}

test-data/Kexample.+008+38353.private

@@ -0,0 +1,10 @@
+Private-key-format: v1.2
+Algorithm: 8 (RSASHA256)
+Modulus: uwPhNzPyGXZGV2i/gKt9ikrc5EiH+CJIYOVloNNlHiCkbEa8wHC7aPNDebSJfc++o+hrJsLi3OeOUmLyD+qwJEeE6SpaaO2Y5g4lcS5RNv7i08GSJugkzlByHFN8rGRhsnYAP5UBRfVLqH/QMjRkIbHUf3RBMETbKZGAcHBR8G0=
+PublicExponent: AQAB
+PrivateExponent: rUCY4nVDMgd6fvvRfbhhoz5biTkQjfXkq6+ZCPcOVGzVJmIZ9wX4+O90cUmpnl5ZNKvaqJwfY5s5JGX57njzF/FHBK1h8KIRIAFUyuuJFZfKC7IlvE6Jty6BZC3M+IG3NVRtnOKlv4mm2AHcEY6/a6gzkYWE6o05LTBJCd1xhFk=
+Prime1: 89TrECdSSWCCIOvdbSfb/fEiYKNQViOqpKtte+DDyhbtLVhuDJ1QpiQIG2ia+Bc69S/u/tdIxGldu+yozCT6Kw==
+Prime2: xFkZbpPOZWdt4CrTqq3gAUZHIXXW/89pRqDmfIcphFNKvuYZVH/prJla6xiNBzgWRnMOMJcc+61DjRhHOMrrxw==
+Exponent1: rdSDaFbAITO+Ub4Vc/ZQre+09HQ5l8+Bnjfgq8oHixFhMUyz2CZnEqrpZLDkmi3liFsN5XyRkgUUIB+OD0vlVQ==
+Exponent2: eJLSeEIR69mA8ri59MUDmyTCB30qwzpmRrYF9BC4YQcZDnOUuHw4TgJ6f4Y7DGTX4PlEjHgvlynGIr329pw9/w==
+Coefficient: 5Q/xDoWngb0ahc3wFT42DIM2/E8SLRqkBZ/j0C2BKRi73g7OMXRWpDKf2z45WePP5p/SoTlYYHhRZmNngOoXlA==

test-data/example

@@ -0,0 +1,29 @@
+; Extracted from https://datatracker.ietf.org/doc/html/rfc4035#appendix-A
+; Keys have been replaced by newer algorithm 8 instead of older algorithm 5
+; which we do not support, and to match key pairs stored alongside this file.
+example.        3600    IN      SOA     ns1.example. bugs.x.w.example. 1081539377 3600 300 3600000 3600
+example.        3600    IN      NS      ns2.example.
+example.        3600    IN      NS      ns1.example.
+example.        3600    IN      MX      1 xx.example.
+example.        3600    IN      DNSKEY  257 3 8 AwEAAaYL5iwWI6UgSQVcDZmH7DrhQU/P6cOfi4wXYDzHypsfZ1D8znPwoAqhj54kTBVqgZDHw8QEnMcS3TWxvHBvncRTIXhCLx0BNK5/6mcTSK2IDbxl0j4vkcQrOxc77tyExuFfuXouuKVtE7rggOJiX6ga5LJW2if6Jxe/Rh8+aJv7 ;{id = 31967 (ksk), size = 1024b}
+example.        3600    IN      DNSKEY  256 3 8 AwEAAbsD4Tcz8hl2Rldov4CrfYpK3ORIh/giSGDlZaDTZR4gpGxGvMBwu2jzQ3m0iX3PvqPoaybC4tznjlJi8g/qsCRHhOkqWmjtmOYOJXEuUTb+4tPBkiboJM5QchxTfKxkYbJ2AD+VAUX1S6h/0DI0ZCGx1H90QTBE2ymRgHBwUfBt ;{id = 38353 (zsk), size = 1024b}
+a.example.      3600    IN      NS      ns2.a.example.
+a.example.      3600    IN      NS      ns1.a.example.
+a.example.      3600    IN      DS      57855 5 1 b6dcd485719adca18e5f3d48a2331627fdd3636b
+ns1.a.example.  3600    IN      A       192.0.2.5
+ns2.a.example.  3600    IN      A       192.0.2.6
+ai.example.     3600    IN      A       192.0.2.9
+ai.example.     3600    IN      HINFO   "KLH-10" "ITS"
+ai.example.     3600    IN      AAAA    2001:db8::f00:baa9
+b.example.      3600    IN      NS      ns1.b.example.
+b.example.      3600    IN      NS      ns2.b.example.
+ns1.b.example.  3600    IN      A       192.0.2.7
+ns2.b.example.  3600    IN      A       192.0.2.8
+ns1.example.    3600    IN      A       192.0.2.1
+ns2.example.    3600    IN      A       192.0.2.2
+*.w.example.    3600    IN      MX      1 ai.example.
+x.w.example.    3600    IN      MX      1 xx.example.
+x.y.w.example.  3600    IN      MX      1 xx.example.
+xx.example.     3600    IN      A       192.0.2.10
+xx.example.     3600    IN      HINFO   "KLH-10" "TOPS-20"
+xx.example.     3600    IN      AAAA    2001:db8::f00:baaa